bit run report run: well: cp-ex1 rig: xdec/zj70 size ... run report.pdf · customer: knoc fergana...

BIT RUN REPORT

DEPTH OUT: 309 m MW: 11.25 PPG TFA: 1.13 in2 DRILLED: 297 m PV/YP: - FLOW: 1000 GPM TOTAL HRS: - hr DP: 800-1850 PSI ON BTM. HRS: 71.50 hr Bit HHP: 473.4 TOTAL ROP: m/hr HSI: 0.91 Satisfactory EFFECTIVE ROP: 4.15 m/hr IF: 1644 Lbs. WOB: RPM: D.H.M. RPM: Torque: Total Revolutions:

5-16 tonne 60-110 RPM

- RPM 1.8-2.7 Kftlbs

429 KRevs

NOZ.VEL:

SURVEY:

283 ft/seg

DEPTH:

Run:

Customer:

1 KNOC Ferhana Operating Company

Well: CP-Ex1 RIG: XDEC/ZJ70

BIT:

Y11

SERIAL:

NN2381

SIZE (Inches): 26"

TOP VIEW SIDE VIEW

IADC DULL GRADING

INNER ROWS

OUT ER ROWS

DULL CHARACT.

LOCAT ION BRNG. /SEALS

GAUGE 1/16"

OTHER CHARACT.

REASON PULLED

2 2 WT A 4 In CT PR

Rig grade: 2-2-NO-A-2-1-NO-PR Re-runnable: NO DRILLED OUT SHOE: NO Repairable: NO

RUN INFORMATION: MUD: HYDRAULICS:

DEPTH IN: 12 m TYPE: WBM NOZZ: 3*20/32, CJ 1*16/32

BHA: 26" RC Bit/9"Bit sub w/float/DC 9"/S. Stb 26"/DC 9"/S. Stb 26"/X-O/DC 8"/Jar 8"/DC 8"/X-O/HWDP 5,5"/DP 5,5"

ANG. IN: 0 AZIM IN: 0

ANG. OUT: 2.8º AZIM. OUT: 174.4º

DLS:

12 m 309 m

COMMENTS The objective for new Y11 was to drill 26" vertical section from 12m till section TD at 508m. Currently the bit drilled 297m through layers of claystones, sandstones and gravels in the interval from 12m till MD 309m accumulating av. ROP of 4.15m/h. At the depth of MD 117m was pulled to surface to check dull condition of the bit, where neither damage to cutting structure nor balling issue was observed. Y11C was run back in hole to continue drilling. In the interval of 297-309m, ROP significantly dropped down to 1-2m/h, where decision was made to POOH to surface and change the bit. On surface Y11 was graded as 2-2-NO-A-2-1-NO-PR, whereas bit engineer graded it as 2-2 - W T-A-4 - I- CT-PR. Cutting structures has exhibited normal wear and slight chipping, which should be due to vibrations. Major wear observed was bearing failure as Y11C (IADC 115) which is non-seal roller bearing milled tooth bit with aggressive cutting structure. Under normal drilling conditions service life for unsealed bearing is 500KRevs , where subject bit was rotated 429KRevs. Analysis of the run revealed that 1-1 cutting structure is well suited for subject formation as no significant wear on the cutting structure was observed and possible reason of low ROP was insufficient WOB. Low ROP resulted in long drilling time , which made Y11C not suitable for this application due to short bearing life. The W OB during the run was limited due to deviation problems. Subject bit can neither be re-run nor repared , due to bearing falure . Further usage of this bit may result in lost cone. Thus for future runs NOV Downhole recommends using milled tooth bit with IADC of 115 which has sealed roller bearing (bearing life over 1,000 KRevs) with pack holed BHA assembly to avoid hole deviation and higher WOB in the range of 22--25 t to achieve higher ROP.

LITHOLOGIES Sandstone 20% , Claystone 80%

DATE: 27-Feb-12 Bit Engineer:

Rig Manager: Drilling Supervisor:

BIT RUN REPORT Run: 1 Customer: KNOC Ferhana Operating Company Well: CP-Ex1 RIG: XDEC/ZJ70

BIT: Y11 SERIAL: NN2381 SIZE (Inches): 26"

- Y11C has not reached section TD due to low penetration rate

- Possible reason of Low ROP was insufficient WOB

RESULTS &

RECOMMENDATIONS

- Bearing failed due to longer drilling time than planned and short bearing life, where bearing life for unsealed roller bearing bits is 500KRevs under normal drilling conditions - Cutting structure has exhibited normal wear and slight chipping possible due to downhole vibrations - Cutting structure is well suited for subject application as no damage to cutting structure was observed after the run. - Use of Milled Tooth bit with 1-1 cutting structure for 26" hole size drilling in Chustpap field - Use of Roller Cone bits with sealed roller bearing to have extended bearing life - Drilling with higher WOB in the range of 22-25t to achieve higher ROP

- Use of packed hole BHA assembly to avoid deviation problems

DATE: 27-Feb-12

Bit Engineer: Rig Manager:

Drilling Supervisor:

BIT RUN REPORT RUN: CUSTOMER: BIT TYPE:

1 KNOC Fergana Operating Company T41

WELL NAME: CP-Ex1 SERIAL NUMBER: D151374

RIG: XDEC6/ZJ70 SIZE(Inches): 26”

Bit Engineer: Rig Manager: Drilling Supervisor:

DATE: _2 – Mar – 2012_

TOTAL REVs: 400 KRevs ANG. IN: 2.8 AZIM IN: 174.7

IADC DULL GRADING

INNER ROWS

OUTTER ROWS

DULL. CHARACT.

LOCATION BRNG / SEALS

GAUGE 1/16”

OTHER CHARACT.

REASON PULLED

1

1

WT

A

E

In

NO

TD

RIG GRADE: 1 – 1 – NO – A – F – 1 – NO – TD RE-RUNNABLE: YES

DRILLED OUT SHOE:

NO

REPAIRABLE:

NO

RUN INFORMATION MUD INFORMATION HYDRAULICS

DEPTH IN: 309 Meters TYPE: WBM NOZZ: 3x22/32, 18/32 CJ DEPTH OUT: 508 Meters MW: 9.8 PPG TFA: 1.362 Sq. In. DRILLED: 199 Meters PV/YP: 12/21 Cp/Pa FLOW: 1100 GPM TOTAL HRS: - Hrs DP: 1900-2010 PSI ON BTM HOURS: 71 Hrs BIT HHP: 376 TOTAL ROP: - m/hr HSI: 0.71 Satisfactory EFFECTIVE ROP: 2.8 m/hr IF: 1434 Lbs WOB: 6-18 Tons NOZ.VEL: 259 Ft/seg RPM: 90-115 RPM D.H.M. RPM: - RPM TORQUE: 1.6-2.4 Kft x Lbs SURVEY: DEPTH:

309 Meters

BHA: 26” RC Bit / Sub / 2 x 9” DC / 26” S. Stab / 1 x 9” DC / 26” S. Stab / x-o / 9 x 8” DC / 8” JAR / 9 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP;

ANG. OUT: 1.5 508 Meters AZIM OUT: 38

DLS:

LITHOLOGIES: Claystones‐80%, Sandstone – 20% with Gravel stringers






DATE: _2 – Mar – 2012_

COMMENTS

The objective for T41 was to finish drilling 26” vertical section from the depth 309m till TD at 508m. The bit drilled 199m of formation through layers of clay stone and sandstone with thin stringers of gravel accumulating av.ROP of 2.8m/hr. Totally T41 was rotated for 400Krevs. There was no issue with hole cleaning observed. Possible reasons for low ROP are insufficient WOB, downhole vibrations that cause inefficient drilling and 4-1 cutting structure of T41 was not aggressive enough for a given formation. After reaching section TD the bit was pulled out to surface and graded as 1 – 1 – NO – A – F – 1 – NO – TD, whereas bit engineer graded it as 1 – 1 – WT – A – E – I – NO – TD. The visual inspection of the subject bit revealed no major damage on the bit. Cutting structure of T41 exhibited normal wear and came out to surface with still effective bearings, though, normally, drilling under continues vibrations significantly reduce bearing life of roller cone bits. Subject T41 is still in good condition and can be considered for re-run. Considering all the above mentioned facts, NOV Downhole recommends using Milled Tooth bits of IADC 1- 1-5 in the similar application, with apply of sufficient WOB (20-25t), which will help to achieved higher ROP, and packed hole BHA assembly to avoid hole deviation. In order to create a room for further improvement drilling of 26” hole in similar application, NOV Downhole would like to recommend usage of its’ shock tools which dampens axial vibrations (bouncing) of drilling string and thus prolong the life of BHA components and improve drilling efficiency.






DATE: _2 – Mar – 2012_

RESULTS &

CONCLUSION

RECOMMEN- DATION

Subject T41 has accomplished set objectives

Possible reasons of Low ROP were insufficient WOB, downhole vibrations and less aggressive

cutting structure Cutting structure has exhibited normal wear T41 was rotated for 400Krevs and came out to surface with effective bearing, although it was used

under continues downhole vibrations

T41 came out to surface in good condition and can be considered for re-run Use of Milled Tooth bit with 1‐1 cutting structure for 26” hole size drilling in Chust‐pap field Use of Roller Cone bits with sealed roller bearing to extended bearing life Drill with higher WOB in the range 20‐25t to improve ROP Use of packed hole BHA assembly to avoid hole deviation Use NOV Downhole shock tools to dampen axial vibrations (bouncing) thus prolong life of BHA

components and improve drilling efficiency Note: Information about the NOV Downhole Shock tools can be provided upon request.

BIT RUN REPORT

RUN: 2 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: T13 SERIAL NUMBER: D150175 SIZE(Inches): 17 1/2”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS

DULL. CHARACT. LOCATION BRNG /

SEALS GAUGE

1/16” OTHER

CHARACT. REASON PULLED

1 1 WT A E In NO BHA

RIG GRADE: 1 – 1 – NO – A – E – I – NO – PR RE-RUNNABLE: YES

DRILLED OUT SHOE: YES REPAIRABLE: NO


DEPTH IN: 508 Meters TYPE: WBM NOZZ: 3x20/32, 18/32 CJ DEPTH OUT: 830 Meters MW: 10.20 PPG TFA: 1.18 Sq. In. DRILLED: 322 Meters PV/YP: 14/21 Cp/Pa FLOW: 900 GPM TOTAL HRS: - Hrs DP: 1300-2100 PSI ON BTM HOURS: 73.25 Hrs BIT HHP: 292 TOTAL ROP: - m/hr HSI: 1.22 Good EFFECTIVE ROP: 4.4 m/hr IF: 1,170 Lbs WOB: 10-16 Tonne NOZ.VEL: 247 Ft/seg RPM: 90-110 RPM D.H.M. RPM: - RPM TORQUE: 1.8-3.1 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 496 KRevs ANG. IN: 1.5° 508 Meters AZIM IN: 38° BHA 1: 17 1/2” RC Bit / Sub / 1 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / x-o / 9 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP; BHA 2: 17 ½” RC Bit / Junk Basket / x-o / Sub / 2 x 9” DC / 17 ½” S. Stab / 1 x 9” DC / 17 ½” S. Stab. / 1 x 9” DC / x-o / MWD / 1 x 8” NMDC / 13 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP;

ANG. OUT: 0.7° 830 Meters AZIM OUT: N/A DLS:

LITHOLOGIES: Claystones-90%, Siltstone – 10% with little 2-4 mm Gravel stringers

BIT RUN REPORT


Bit Engineer:

COMMENTS

17 ½” T13 is a milled tooth bits (IADC 1-3-5) designed for soft formations with low compressive strength and high drillability. It was run twice in CP-Ex1 well. The objective for the first run was to drill out the casing shoe and continue drilling 17 ½” vertical section (depending on ROP) with Rotary BHA (BHA 1) assembly. T13 drilled 322 meters of formation (Interval of 508 – 830 meters) through layers of Claystone and Siltstone with rare Gravel stringers of 2-4 mm size. Overall no issues with hole cleaning were observed, except 5-6t overpulls at the of 646meters, due to wellbore instability which was cured after increase of Mud Weight. Continues downhole vibrations were observed while drilling given interval, where trial of various drilling parameters did not result changes in performance. Possibly, the cutting structure of T13 did not match formation that was drilled. On the subject run the bit was rotated for 459,273 revolutions and at 830 meters depth was pulled to surface due to undesirable ROP, where the decision was made to replace Milled Tooth bit with PDC. T13 achieved av. ROP of 4.4 m/hr. On surface T13 was dull graded as 1–1–WT–A–E–I –NO–BHA, where the bit engineer’s grading was the same. The cutting structure exhibited no significant wear and the bit came out to surface with effective bearings. The bit was in re-run condition and could be considered for another run if there was a need for it. At the depth of 1942mm subject T13 was run again to clean out the junk in the hole possibly left from previously run T43C bit. T13 was RIH with rotary BHA (BHA 2 with Junk basket) assembly, which was pulled to surface at 1948m to change BHA and replace milled tooth bit to PDC. Bit drilled 6 meters in the interval of 1942-1948m through layers of Claystone, Sandstone and minor stringers of Conglomerate accumulating av. ROP of 0.86 m/hr. In the subject run the bit was rotated for 36,367 revolutions. Drilling parameters used were as follows: WOB – 8-20t; RPM – 50-100; Flow Rate – 845 gpm; Rotary Torque – 3-5 kft x Lbs, SPP-3000 PSI & Mud Weight 10.41 PPG. The TFA used was 1.18 sq. inch (nozzle conf: 1 x 18CJ + 3 x 20/32),

BIT RUN REPORT


Bit Engineer:

COMMENTS CONTINUE

RESULTS & CONCLUSION RECOMMEN- DATION

T13 was used twice on CP-Ex1 well

T13 accomplished all set objectives After both runs the bit came out in re-run condition

T13 is recommended to consider for using in the upcoming wells for drilling soft formation and drill out / clean out runs.

where HSI achieved was 1.03. On surface the T13 was graded as 1-1-WT-A-E-I-NO-PR, whereas the bit engineer graded it as 1-1-WT-A-E-I-NO-BHA. The cutting exhibited no wear and the bit came out to surface with effective bearings. 1.2 kg of small metal pieces and 6 middle metal pieces were retrieved from junk basket. Considering above mentioned facts, T13 accomplished all set objectives and in two run was rotated for 495,640 revolutions. It is still in re-run condition. NOV Downhole recommends considering particular bit type for upcoming wells as multi-purpose option. Option for drilling soft formations and drill out / clean out runs.

BIT RUN REPORT


Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 2 BT N/G E In CT/WT PR

RIG GRADE: RE-RUNNABLE: YES

DRILLED OUT SHOE: NO REPAIRABLE: NO


DEPTH IN: 1531 Meters TYPE: WBM NOZZ: 3x20/32, 18/32 CJ DEPTH OUT: 1573 Meters MW: 10.20 PPG TFA: 1.18 Sq. In. DRILLED: 42 Meters PV/YP: 14/21 Cp/Pa FLOW: 835 GPM TOTAL HRS: - Hrs DP: 2300 PSI ON BTM HOURS: 35 Hrs BIT HHP: 232 TOTAL ROP: - m/hr HSI: 0.96 Good EFFECTIVE ROP: 1.2 m/hr IF: 1,170 Lbs WOB: 16-22 Tons NOZ.VEL: 247 Ft/seg RPM: 90-120 RPM D.H.M. RPM: - RPM TORQUE: 3-4 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 300.4 KRevs ANG. IN: 1.5° 1531 Meters AZIM IN: 155,8 17 ½” RC Bit / Sub / 2 x 9” DC / 17 ½” S. Stab / 1 x 9” DC / 17 ½” S. Stab. / 1 x 9” DC / x-o / MWD / 1 x 8” NMDC / 7 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP;

ANG. OUT: 1.8° 1573 Meters AZIM OUT: 166,1 DLS:

LITHOLOGIES: Claystones-55%, Sandstone – 20% andGravel - 25%

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS


The objective for new 17.5" T13 was to ream approximately 19 meters of undergauge hole section (because of previous TFR519S-A3 was pulled out to surface from the depth of 1531m with significant gauge wear) and then continue drilling 17 ½” vertical section (depending on ROP).

During RIH tight spots (4-5t) were observed at the depth of 1520m. Probably undergauge hole section started from this depth. At the beginning of reaming WOB has not increased more than 4t to avoid a possible of sidetracking. After 4m of reaming, WOB increased to 7-8t. At the depth of 1526m axial vibrations (bit bouncing) were observed. WOB has increased to 10-12t to stop vibrations. TQ increased significantly up to 20 klb*ft and TDS stopped rotation because of TQ limitation has sated on 15 klb*ft. Have reached the bottom (1531, 69m) after several tries. TQ spikes up to 20 klb*ft were observed again and were fluctuating from 0-20 klb*ft. There was a possible that lost cutters of previous PDC bitwere on the bottom affects TQ spikes. Decreased FR from 54 to 46 l/s to reduce fluctuating of those cutters and push them into the hole wall. After finishing the reaming of under gauge hole section, start drilling. At the beginning of drilling axial vibrations were observed several times, possible reasons for this were formationwhich containedGravel reached 25%.

T13 drilled 42 meters of formation (Interval of 1531 – 1573 meters) through layers of Claystone, Sandstone and Gravel,with average ROP of 1.2m/hrs. Continues downhole vibrations were observed while drilling given interval, where trial of various drilling parameters did not result changes in performance. Due to the cutting structure of T13 wasnot suitable for this kind of formation. Inasmuch as 17 ½” T13 is a milled tooth bits (IADC 1-3-5) designed for soft formations with low compressive strength and high drillability. On the subject run the bit was rotated for 300,426 revolutions and at 1573 meters depth was pulled to surface due to low ROP.

On the surface T13 was dull graded as 1-2-BT-N/G-E-I-CT/WT-PR. The major dull characteristic for the cutting structure was broken and chipped teeth on the nose and gauge of the bit which indicates on axial vibration. The wear pattern was not similar on each cone. Cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations.

T13 accomplished all set objectives After reaming undergauge hole section and drilling through hard formation such as gravel the bit

came out in re-run condition


BIT RUN REPORT

RUN: 2 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: T41C SERIAL NUMBER: D151034 SIZE(Inches): 17 1/2”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 2 BT N/G E 1/8 WT/CT/OC/TR PR

RIG GRADE: RE-RUNNABLE: NO



DEPTH IN: 1573 Meters TYPE: WBM NOZZ: 3x20/32, 18/32 CJ DEPTH OUT: 1600 Meters MW: 10.32 PPG TFA: 1.17 Sq. In. DRILLED: 27 Meters PV/YP: 14/21 Cp/Pa FLOW: 856 GPM TOTAL HRS: - Hrs DP: 2600-2900 PSI ON BTM HOURS: 33,75 Hrs BIT HHP: 255 TOTAL ROP: - m/hr HSI: 1.04 Good EFFECTIVE ROP: 0,8 m/hr IF: 1071 Lbs WOB: 16-22 Tons NOZ.VEL: 235 Ft/sec RPM: 90-120 RPM D.H.M. RPM: - RPM TORQUE: 3,5 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 403 KRevs ANG. IN: 1.8° 1573 Meters AZIM IN: 166,1 BHA 1: 17 ½” RC Bit / Junk Basket / x-o / Sub / 2 x 9” DC / 17 ½” S. Stab / 1 x 9” DC / 17 ½” S. Stab. / 1 x 9” DC / x-o / MWD / 1 x 8” NMDC / 7 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP; BHA 2: 17 1/2” RC Bit / Sub / 2 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / x-o / MWD / 1 x 8” NMDC / 7 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP;

ANG. OUT: 1.5° 1580 Meters AZIM OUT: 177,1 DLS:

LITHOLOGIES: Claystones, Sandstone, Gravel, Conglomerate

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS


T41Cbit was run twice in CP-Ex1 well. The objective for the first run was to clean out the junk in the hole possibly left from previously run T13 bit. T41C was RIH with rotary BHA (BHA 1 with Junk basket), which was pulled to surface at 1600m to change BHA and replace insert bit to PDC. Bit drilled 27 meters in the interval of 1573-1600m through layers of Claystone, Sandstone, Gravel and Conglomerate accumulating av. ROP of 0.8 m/hr. In the subject run the bit was rotated for 192,350 revolutions. On surface the T41C was graded as 1-1-WT-A-E-I-TR-PR. The cutting exhibited no wear and the bit came out to surface with effective bearings. At the depth of 1818m subject bit was run againwith rotary BHA (BHA 2) to continue drilling, due to formation changefrom medium to hard (conglomerate-25%), during drilling with previous TFR619S-A3 which came to surface 3/16” undergauge. On the subject run T41C drilled 20 meters of formation (Interval of 1818 – 1838 meters) through layers of Claystone,Sandstone andConglomerate 25-30%, where continuesaxial vibrations were observed. Multiple attempts to vary the drilling parameters were unsuccessful.WOB was limited (not more than 18t) due to weight below jar was 24t. The decision was made to change to less aggressive insert bit (IADC 435) and add 6 joints of DC to BHA. On the subject run the bit was rotated for 403,000 revolutions and at 1838 meters depth was pulled to surface due to low ROP. On surface T41C was dull graded as 1-2-BT-N/G-E-1/8-WT/CT/OC/TR-PR. The major dull characteristic for the cutting structure was broken and chipped teeth on the nose and gauge of the bit which indicates on axial vibration. The wear pattern was not similar on each cone. Cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. T41C has not accomplished all set objectives due to low ROP and came out to surface in non re-run condition. Since17 ½” T41C is an insert bit (IADC 4-1-5) designed for soft formations with low compressive strength and high drillability, NOV DOWNHOLE recommends to consider T41C for using in the upcoming wells for drilling soft formation and drill out / clean out runs.

Drilling with more WOB in the range 22-26t during drilling hard formation such as conglomerate to improve ROP;

Assembling BHA with enough DC to have a possible apply more WOB.


T41C was used twice on CP-Ex1 well

T41Cwas not accomplished all set objectives

Reasons for low ROP are: Insufficient WOB due to not enough DC in BHA;

Downhole vibrations that cause inefficient drilling;

Formation has changed;content of conglomerate has reached 30%;

T41C came out to surface 1/8” undergauge, thus cannot be considered for re-run

BIT RUN REPORT


Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


3 5 BT M/G E/F/E 1/8 JD/CT HR

RIG GRADE: - RE-RUNNABLE: NO



DEPTH IN: 1838 Meters TYPE: WBM NOZZ: 1x18; 1x20; 2x22 DEPTH OUT: 1942 Meters MW: 9.8 PPG TFA: 1.36 Sq. In. DRILLED: 104 Meters PV/YP: 12/21 Cp/Pa FLOW: 835-856 GPM TOTAL HRS: - Hrs DP: 2800-2900 PSI ON BTM HOURS: 110 Hrs BIT HHP: 182-196 TOTAL ROP: - m/hr HSI: 0.76-0,82 Good EFFECTIVE ROP: 1.63 m/hr IF: 872-916 Lbs WOB: 7-24 Tonne NOZ.VEL: 206-212 Ft/sec RPM: 70-120 RPM D.H.M. RPM: - RPM TORQUE: 2-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 734741 Revs ANG. IN: 2.5° 1838 Meters AZIM IN: 170.2 BHA:17 1/2” RC Bit / F/S w/float / 1 x 9” DC /1 x 9” DC/ 17 1/2” S. Stab / 1 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / x-o / MWD /8" NMDC /13 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP.

ANG. OUT: 1.3° 1942 Meters AZIM OUT: 158°

LITHOLOGIES: Claystones-75%, Sandstone–20%,conglomerate-5%.

BIT RUN REPORT


Bit Engineer:

COMMENTS

The objective for the above bit was to drill the vertical section from the depth 1838m.Totally this bit drilled 104 meters of formation through layers of Claystone and Sandstone andconglomerates with average ROP 1.03 m/h. Overall there were no issue with hole cleaning were observed. T43C is an insert bit (IADC 4-3-5) designed for soft formations with low compressive strength and high drillability. Possible reasons oflow ROP were vibrations which affectdrilling efficiencyand aggressive cutting structure for drilling of such formations. In the interval 1929-1938m torque spikes up to 10 kft/lb and vibrations were observed. When the bit reached the depth of 1938m continues torque spikes and vibrations were observed till the depth of 1942m. The bit was rotated in the hole for 734,741 revs. Normally while rotating the bit in hole for extensive period of time under continues vibrations the service life of bearings significantly reduces. Thus it wasimportant to pull the drill string out to surface and check the condition of the bit. On the surface the bit was graded as: 3-5-BT-M/G – E/F/E – 1/8 - JD/CT - HR. The visual inspection of the bit revealed that the cutting structure mainly exhibited chipping and broken in the middle and gauge rows and bit came outto surface 1/8” undergauge. Normally, chipped and broken inserts occur due to impacts caused either severe continues vibrations or junk in the hole. It seems like that both of above mentioned scenarios can be fit to our case. Drilling with T43C on the subject well was performed almost under continues vibrations and the amount of junk retrieved (1.2 kg of small metal pieces and 6 middle metal pieces) from the junk basket on the following run with T13 bit justifies possibility of junk damage. The reason why the bit came out to surface 1/8” undergauge, can be lateral vibration. If you refer to dull pictures of the bit you may see thatthe shirttail on one cone was worn more than the other two.

BIT RUN REPORT


Bit Engineer:

COMMENTS CONTINUE


T43С has not accomplished set objectives T43С showed good performance in terms of bearing reliability Cutting structure of T43 has suffered from impact damage caused by vibrations and junk in

the hole T43С came out to surface 1/8” undergauge due to lateral vibrations T43С is not in re-run condition

Use of NOV Downhole’s large diameter roller cone bits of Titan™ series with IADC 515 or 535 for drilling similar formation

Use of NOV DOWNHOLE shock tools to reduce ratio of the axial vibrations while drilling which will extend the service life of BHA components and improve the drilling efficiency.

Note: The information about NOV DOWNHOLE shock tools can be provided upon request.

This shows the bit was not drilling about its centerline, but orbiting off center - one shirttail was contacting the formation more than the other two. Usually, this causes bearings failure on that cone if the bit is run long enough. Basically, on the subject run one of the cones of the bit failed. Considering above mentioned facts and observations, subject 17 ½” T43 has showed good performance in terms of bearing reliability. Though, in order to improve ROP in drilling similar applications, the use of NOV Downhole’s large diameter roller cone bits of Titan™ series with IADC 515 or 535 can be considered as better option. For further performance enhancement in 17 ½” hole size drilling, we also would like to recommend use of NOV DOWNHOLE shock tools to reduce ratio of the axial vibrations while drilling, which will extend the service life of BHA components and improve the drilling efficiency.

BIT RUN REPORT

RUN: 2 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: TFR519S-A3 SERIAL NUMBER: E153093 SIZE(Inches): 17 1/2”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


3 8 WT S/G X 4 7/8 BT/CT PR

RIG GRADE: 5 – 8 – WT – G/S – X – 4 7/8 – BT/LT/HC – PR RE-RUNNABLE: NO



DEPTH IN: 830 Meters TYPE: WBM NOZZ: 5 x 16/32 DEPTH OUT: 1531 Meters MW: 10.42 PPG TFA: 0.982 Sq. In. DRILLED: 701 Meters PV/YP: 20/19 Cp/Pa FLOW: 850 GPM TOTAL HRS: - Hrs DP: 2450-3000 PSI ON BTM HOURS: 152.75 Hrs BIT HHP: 357 TOTAL ROP: - m/hr HSI: 1.48 Good EFFECTIVE ROP: 4.6 m/hr IF: 1,270 Lbs WOB: 2-9 Tonne NOZ.VEL: 278 Ft/seg RPM: 30-80 RPM D.H.M. RPM: 145-

155 RPM

TORQUE: 3.6-4.5 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: 0.7° 508 Meters AZIM IN: - BHA 1: 17 1/2” PDC Bit / x-o / DHM / x-o / Sub / 1 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / 17 1/2” S. Stab / 1 x 9” DC / x-o / MWD x-o / 1 x 8” NMDC / 9 x 8” DC / x-o / 15 x 5 ½” HWDP / 5 ½” DP;

ANG. OUT: 1.5° 1460 Meters AZIM OUT: 155.8° DLS:

LITHOLOGIES: Claystones-80%, Siltstone – 15% and Sandstone -5%

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS


TFR519S-A6 has not accomplished set objectives, but showed impressive performance. TFR519S-A6 is capable to achieve ROP 10-15m/h in the similar applications if recommended

drilling parameters are applied TFR519S-A6 came out to surface 4 7/8” undergauge and cannot be considered for re-run Excessive gauge wear was possibly caused by hard formation (2- 4 mm size gravel & 20-25% of

conglomerates) and downhole vibrations.

NOV Downhole recommends:

Consider running TFR519S-A6 type PDCs for vertical applications with soft formations Closely watch cuttings on the shakers and react immediately to any formation change, in order to

able to save the bit from damage in hard formations

The objective for a new TFR519S-A6 was drill 17 ½” section from the depth of 830 m till section TD at 3000m. The subject bit drilled 701 m in the interval of 830 – 1531 m in 152.75 hrs through layers of Claystone, Sandstone, and Siltstones with minor layers of gravel of 2-4 mm size and towards the end of the run 20-25% of conglomerates. PDC in the average achieved ROP of 4.59m/h. In the subject well the bit was ran twice, where the reason for the first pull out (at the depth of 1461 m) was due to hours on motor (Dull grade: 1-1-WT-A-X-I-CT-DMF) and the second one was ( at the depth of 1531m) due to low penetration rate. Approximately, till the depth of 1517 m TFR519S showed good performance, where the ROP ranged between 4 – 7 m/hr., though it could drill even faster with apply of more WOB. The WOB was controlled due to torque limit on downhole motor. In the interval of 1517 – 1531 m the ROP suddenly dropped down to 1 – 2 m /hr and top drive stalling was observed. Thus after reaching the depth of 1531 m the decision was made to pull out to surface. On surface the bit was graded as 3 – 8 – WT – G/S – X – 4 7/8 – BT/CT – PR. The cutting structure and the bit body exhibited sever wear (refer to dull pictures). The bit came out 4 7/8 inch undergauge. In the inner raw of the cutting structure has suffered less compare to outer raw though the traces of chipped and broken cutter could be seen. The very possible reason for such kind of wear can be hard interbedded formations (2- 4 mm size gravel & 20-25% of conglomerates) and downhole vibrations. TFR519S-A6 is 5 blades and 19 mm cutters aggressive steel body bit which is not suitable for drilling in hard formations. Due to its’ aggressive nature while drilling through hard formations the cutting structure eventually gets damaged, which affects the stability of the bit and causes downhole vibrations. TFR519S-A6 is hardfaced steel body bit and when it loses gauge cutters the blades get exposed to wellbore and under continues contact (friction) with the wellbore, we witness such kind excessive wear on the bit body. Considering above mentioned facts, TFR519S-A6 has showed good performance though was pulled out to surface in non rerun condition. NOV Downhole recommends to consider running particular type PDC in the upper intervals of 17 ½” section of Chust-Pap field, where the formation does not contain gravels and conglomerates. It is also strongly recommended closely watch cuttings on the shakers while drilling with PDC bits that are fitted with 19mm cutters and react immediately to any formation change in order to be able to save the bit from damage in hard formation.

BIT RUN REPORT


IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 3 BT S/G X 3 CT/WT PR

RIG GRADE: 3-5-BT-T/S/G-X-3/16-CT/LT/WT-PR RE-RUNNABLE: YES



DEPTH IN: 1600 Meters TYPE: WBM NOZZ: 9x12/32 DEPTH OUT: 1818 Meters MW: 9.8 PPG TFA: 0.99 Sq. In. DRILLED: 218 Meters PV/YP: 12/21 Cp/Pa FLOW: 856 GPM TOTAL HRS: - Hrs DP: 2850-

2950 PSI

ON BTM HOURS: 69 Hrs BIT HHP: TOTAL ROP: - m/hr HSI: Good EFFECTIVE ROP: 7.41 m/hr IF: Lbs WOB: 3-14 Tonne NOZ.VEL: Ft/seg RPM: 110-120 RPM D.H.M. RPM: - RPM TORQUE: 4-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - Revs ANG. IN: 1.5°

1600 Meters AZIM IN: 177.1

BHA:17 1/2" PDC/ F/S w/float/ 1 x 9” DC /17 1/2" S.Stab/1 x 9” DC / 17 1/2" S.Stab/ 1 x 9” DC / x-o / MWD /8" NMDC /7 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 15 x 5 ½” HWDP.

ANG. OUT: 2.7° 1818 Meters AZIM OUT: 170.

5°

LITHOLOGIES: Claystones, Sandstone , Siltstone,Conglomerate.

BIT RUN REPORT


BIT RUN REPORT


COMMENTS

The objective for a new TFR619S-A3 was drill 17 ½” vertical section from the depth 1600m till planned section TD at 3000m. The subject PDC after drilling 218 m of formation through layers of mainly Claystones interbedded with stringers of sandstone and siltstone and 25% of conglomerate layers toward the end of the run. The average ROP achieved for the run was 3.16m/h. The HSI was within the recommended range above 1. On CP-Ex1 well the TFR619S-A3 was run twice. On the first run the PDC showed very good ROP in the range 4 – 7 m/r drilling through relatively soft layers of claystone interbedded with stringers of sandstone and siltstone. The bit had capabilities to perform at higher penetration if more WOB (10-15t) would have been applied during the run, but due to hole deviation problems it was not done. There were no issues with hole condition were observed. At the depth of 1809 m the decision was made to pull the string out to surface due to MWD failure. On surface the bit was graded as 1-1-WT-A-X-I-NO-DTF. The visual inspection of the bit revealed that the cutting structure has exhibited normal wear and was in re-run condition. Thus after replacing MWD the decision was run back in hole with the same TFR619S-A3 bit. On the second run, while RIH operation in the interval of 920-1010m periodical WOB spikes were observed in the range of 5-7 t, due to tight holes, which obliged drilling team to ream through this interval. The formation was changed. The presence of conglomerate in the formation increased up to 25%, which was the main reason for significant ROP reduction. Several attempts on changing of drilling parameters to enhance the penetration rate were unsuccessful. Thus at the depth of 1818m the decision was made to pull the string out to check the bit and BHA components. On the surface the bit was graded as 1-3-BT-S/G-X-3-CT/WT-PR. The visual inspection of the bit revealed that the cutting structure exhibited sever impact damage mainly at the shoulder and gauge. It had numerous cutters broken and chipped. The hardfacing on the gauge pad of blades 1, 4 and 6 was missing as well. Looking at the wear pattern of the bit we can assume that such wear occurred due to repeated impacts which caused PDC cutters to chip and break. This also could cause small cracks in the hardfacing that grow at the contact of the hardfacing and the bit body metal. The repeated impacts are most likely from the bit whirl caused by low depth of cut. This is usually can be seen on long runs in hard rocks, such as cemented conglomerates. Considering, the ROP was low the bit was rotated in the hole for extended period of time (20.5hrs), which resulted such kind of severe wear of cutting structure. Taking into account all the above made comments and observations, the TFR619S-A3 has failed to achieve set objectives due to geological factors. Because of the exploratory nature of CP-Ex1 well, nobody expected to meet such high percentage (25%) of hard conglomerates in the drilled interval. Currently, PDC is non re-run condition and cannot be considered for further use.

BIT RUN REPORT


COMMENTS CONTINUE


TFR619S-A3 has not accomplished set objectives, due to geological factors. TFR619S-A3 is capable to achieve ROP 10-15m/h in the similar applications if

recommended drilling parameters are applied TFR619S-A3 came out to surface 3/16” undergauge TFR619S-A3 exhibited severe damage on cutting structure and had hardfacing on the gauge

pad of blades 1, 4 & 6 missing due to repeated impacts caused by bit whirl (lateral vibrations)


Consider running TFR619S-A3 type PDCs for vertical applications with soft formations Closely watch cuttings on the shakers and react immediately to any formation change, in

order to able to save the bit from damage in hard formations

NOV Downhole recommends the use of particular type PDC bits in the upper intervals of 17 ½” section of Chust-Pap field, where the formation does not contain any gravels and conglomerates. It is also strongly recommended to watch closely the cuttings on the shakers while drilling with PDC bits that are fitted with 19mm cutters and react immediately to any formation change in order to be able to save the bit from damage in hard formation.

BIT RUN REPORT

RUN: 2 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: TFR619S-A6 SERIAL NUMBER: E148736 SIZE(Inches): 17 ½ ”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 2 BT A X In CT/HC/BU TD




DEPTH IN: 2451 Meters TYPE: WBM NOZZ: 1x15/32; 2x16/32; 3x18/32 DEPTH OUT: 2945 Meters MW: 10.5 PPG TFA: 1.31 Sq. In. DRILLED: 494 Meters PV/YP: 28/23 Cp/lb/100sf FLOW: 750-840 GPM TOTAL HRS: - Hrs DP: 2700-3000 PSI ON BTM HOURS: 254.15 Hrs BIT HHP: 139-195 TOTAL ROP: - m/hr HSI: 0.58-0.81 Satisfactory EFFECTIVE ROP: 1.94 m/hr IF: 746-936 Lbs WOB: 4-11 Tons NOZ.VEL: 184-206 Ft/sec RPM: 120-140 RPM D.H.M. RPM: - RPM TORQUE: 5-9 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: 2.68 2468 Meters AZIM IN: 156 BHA:17 1/2" PDC / Floatsubw/float / 3x9" DC / 17 1/2" S.Stab / 1x9" DC/ x-o/ MWD / 1x 8"NMDC / 6x8" DC / 1x8" Jar / 2x8" DC / x-o / 15x5 ½” HWDP / 5 ½” DP;

ANG. OUT: 2.78 2931 Meters AZIM OUT: 168 DLS:

LITHOLOGIES: Claystone, siltstone, sandstone.

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS


The objective for new TFR619S-A6 was to drill remaining part of 17 ½” vertical section from the depth of 2451m till section TD. Totally the bit drilled 494 meters of formation in the interval 2451 – 2945 meters through interbedded layers of Claystone, Siltstone andSandstone, accumulating av. ROP of 1.94m/hr. The subject bit was twice pulled to surface, while drilling above mentioned interval. In the first run the bit drilled 230 meters of formation with av. ROP of 3 m/hr in the interval of 1948 – 2681 meters. The reason for pull out was an accident due to wash out 8” DC part of BHA lost in hole. In the beginning of the run the ROP was ranging 5-6m/hr with WOB applied 9-10 tones, which gradually decreased down to 2 m/hr as drilling proceeded. The causes of such reduction in penetration rate possibly were poor bit cleaning and inability to apply 10-15t of WOB (due to hole deviation problem). On surface the bit was graded as 1-1-BT-N/S-X-I-CT/HC/BU-LIH. The cutting structure exhibited broken cutters with slight chipping, heat checking. The bit was in good re-run condition thus was run back in hole to continue drilling. In the second run TFR619S-A6 drilled 264 meters of formation in the interval of 2681 – 2945 meters (section TD), through interbedded layers of Claystone, Siltstone and Sandstone accumulating average ROP of 1.58m/hrs. Continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. Problems with hole deviation continued. On surface the bit was graded as 1-2-BT-A-X-I-CT/HC/BU-TD. The major dull characteristic for the cutting structure was broken and chipped cutters on the nose, shoulder and gaugeof the bit and heat checking. The wear pattern was not similar on each blade. This kind of wear normally occurs due to lateral vibration while reaming or drilling operations. Heat checking on worn cutters and broken /chipped cutters at the gauge of every blade is indication of torsional vibration. Two broken cutters on the inner raw of cutting structure are indication of axial vibration. Heat checking is indicationof insufficient bit cleaning. The bit also came out to surface balled up. Considering above made observations we can conclude that cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. The possible causes of bit balling can be insufficient bit cleaning (due to large TFA and low HSI). The TFR619S-A6 has aggressive cutting structure (6 blades 19mm) fitted with NOV Downhole’sRaptor™ cutters that are designed for maximized abrasion resistant and heat tolerant. Overall the TFR619S-A6 came out to surface in re-run condition and had capabilities to continue drilling with higher ROP if not the obstacles (poor bit cleaning andinsufficient WOB due to hole deviation problems) limiting its’ performance. For future projects NOV Downhole recommends to consider TFR619S-A6 as one of good options for drilling 17 ½” section with similar application. Good ROP and Durability (longer service life) performance can be achieved if the recommended drilling parameters (WOB in the range of 10-15t and HSI above 1) are applied.

Subject TFR619S-A6 hasaccomplished set objectives; Reasons for low ROP are:

Insufficient, restricted WOB due to inclination problem; Downhole vibrations that cause inefficient drilling; Insufficient bit cleaning (due to large TFA and low HSI);

TFR619S-A6 came out to surface in a good, re-run condition.

Apply of recommended drilling parameters may improve av. ROP and extend service life of the bit. RPM when encountering conglomerate or other hard formations should below 100 to maximize

cutters life and ensure full formation penetration; Drilling with more WOB in the range 10-15t during drilling hard formation to improve ROP; Hard formations require high WOB and low RPM to allow bits to penetrate and shear the formation; Apply HSI above 1 to allow clean and cool cutters of the bit.

BIT RUN REPORT

RUN: 2 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: TFF716S-A2 SERIAL NUMBER: E144235 SIZE(Inches): 17 1/2”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 3 BT S/G X In CT/WT/BU PR




DEPTH IN: 1948 Meters TYPE: WBM NOZZ: 3x15/32; 4x16/32 DEPTH OUT: 2451 Meters MW: 10.4-10.7 PPG TFA: 1.303 Sq. In. DRILLED: 503 Meters PV/YP: 30/18 Cp/lb/100sf FLOW: 794 GPM TOTAL HRS: - Hrs DP: 2900-3350 PSI ON BTM HOURS: 232.2 Hrs BIT HHP: 165-169 TOTAL ROP: - m/hr HSI: 0.68-0.7 Satisfactory EFFECTIVE ROP: 2.17 m/hr IF: 833-857 Lbs WOB: 7-15 Tons NOZ.VEL: 196 Ft/sec RPM: 90-140 RPM D.H.M. RPM: - RPM TORQUE: 3-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: 1.2 1948 Meters AZIM IN: 157 BHA:17 1/2" PDCBit / Floatsubw/float / 2x9" DC / 17 1/2" S.Stab / 1x9" DC / 17 1/2" S.Stab / 1x9" DC / x-o / MWD / 1x 8"NMDC / 7x8" DC / 1x8" Jar / 2x8" DC / x-o / 15x5 ½” HWDP / 5 ½” DP;

ANG. OUT: 2.68 2451 Meters AZIM OUT: 156 DLS:

LITHOLOGIES: Claystone, sandstone, siltstone, conglomerate.

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS

The objective for new TFF716S-A2 was to drill remaining part of 17 ½” vertical section from the depth of 1948m till section TD. Totally the bit drilled 503 meters of formation in the interval 1948 – 2451 meters through interbedded layers of Claystone, Sandstone, Siltstone and Conglomerates accumulating av. ROP of 2.17m/hr. The subject bit was twice pulled to surface, while drilling above mentioned interval. In the first run the bit drilled 202 meters of formation with av. ROP of 2.95 m/hr in the interval of 1948 – 2150 meters. The reason for pull out was rig maintenance. In the beginning of the run the ROP was ranging 5-6m/hr with WOB applied 7 tones, which gradually decreased down to 2 m/hr as drilling proceeded. The causes of such reduction in penetration rate possibly were poor bit cleaning (from the depth of 1978 meters SPP increased up 3200 PSI, probably due to nozzle plugging or balling), hard formations (up 20% of conglomerates layers) and inability to apply 15-20t of WOB (due to hole deviation problem). On surface the bit was graded as 1-1-WT-A-X-I-CT-RIG. The cutting structure mainly exhibited normal wear with slight chipping. The bit was in good re-run condition thus was run back in hole to continue drilling. In the second run TFF716S-A2 drilled 301 meters of formation in the interval of 2150 – 2451meters through interbedded layers of Claystone, Sandstone, Siltstone and Conglomerates accumulating average ROP of 1.84m/hrs. The reason for pull out was low penetration rate. While RIH to continue drilling, several tight hole intervals (2122 – 2151 meters) were observed, which were reamed. Back reaming was also performed while drilling interval 2167 – 2170 m where formation contained 10-20% of Conglomerates. Continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. Problems with hole deviation continued. Towards the end of the run drilling mud losses were also observed. On surface the bit was graded as 1-3-BT-S/G-X-I-CT/WT/BU-PR. The major dull characteristic for the cutting structure was broken and chipped cutters on the gauge and shoulder of the bit. The wear pattern was not similar on each blade. This kind of wear normally occurs due to lateral vibration while reaming or drilling operations. Broken and chipped cutters at the gauge of every blade are indication of torsional vibration. Two chipped cutters on the inner raw of cutting structure are indication of axial vibration. The bit also came out to surface slightly balled up. Considering above made observations we can conclude that cutting structure of the bit suffered mainly from impact damage possibly caused by combination of downhole vibrations while reaming and drilling operations. The possible causes of bit balling can be insufficient bit cleaning (due to large TFA and low HSI) and hole problems (due to losses occurred towards the end of the run). Another observation that requires recognition is the durability of cutting structure on TFF716S-A2 while drilling through interbedded layers of Claystone, Sandstone and Siltstone with 3-20% layers of hard conglomerate. The TFF716S-A2 has medium set cutting structure (7 blades 16mm) fitted with NOV Downhole’s latest DuraForce™ cutters that are designed for maximized impact toughness. Overall the TFF716S-A2 came out to surface in re-run condition and had capabilities to continue drilling with higher ROP if not the obstacles (Insufficient WOB due to hole deviation problems) limiting its’ performance. For future projects NOV Downhole recommends to consider particular PDC type as one of the good options for drilling 17 ½” section with similar application. Good ROP and Durability (longer service life) performance can be achieved if the recommended drilling parameters (WOB in the range of 15-20t and HSI above 1) are applied.

BIT RUN REPORT


Bit Engineer:


Subject TFF716S-A2 has notaccomplished set objectives;

Reasons for low ROP are:

Insufficient, restricted WOB due to inclination problem;

Downhole vibrations that cause inefficient drilling; High RPM does not allow the cutting structure to penetrate the formation sufficiently, this may lead to vibration;

Formation change; especially content of conglomerate has reached 20%;

TFF716S-A2came out to surface in not bad condition and can be considered for re-run.

Apply of recommended drilling parameters may improve av. ROP and extend service life of the bit. RPM when encountering conglomerate or other hard formations should below 100 to maximize

cutters life and ensure full formation penetration; Drilling with more WOB in the range 15-20t during drilling hard formation such as conglomerate to

improve ROP; Hard formations require high WOB and low RPM to allow bits to penetrate and share the formation. Use of packed hole BHA assembly to avoid hole deviation.

BIT RUN REPORT

RUN: 3 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: DSR616M-A28 SERIAL NUMBER: A155138 SIZE(Inches): 12 1/4”

IADC DULL GRADING

NNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 2 BT G X 1/16 CT/HC HP

RIG GRADE: - RE-RUNNABLE: YES



DEPTH IN: 2949 Meters TYPE: WBM NOZZ: 1x18; 5x15 DEPTH OUT: 3608 Meters MW: 10.9 PPG TFA: 1.112 Sq. In. DRILLED: 659.44 Meters PV/YP: 26/25.0 Cp/Pa FLOW: 689-726 GPM TOTAL HRS: - Hrs DP: 3000-

3720 PSI

ON BTM HOURS:

186.55 Hrs BIT HHP: 149

TOTAL ROP: - m/hr HSI: 1.27 Good EFFECTIVE ROP:

6.31 m/hr IF: 743 Lbs

WOB: 3-10 Tonne NOZ.VEL: 199 Ft/seg RPM: 50 RPM D.H.M. RPM: 100-111 RPM TORQUE: 5-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - Revs ANG. IN: 2.4°

2971 Meters AZIM IN: 164° BHA1:PDC Bit 12 1/4", DHM,Float sub w/float,12 1/4" S.Stab,MWD,8"NMDC,12 1/4" S.Stab,8" DCx9,8" Jar,8" DCx2,X/O,X/O,HWDPx18. BHA2:PDC Bit 12 1/4", DHM,Float sub w/float,12 1/4" S.Stab,MWD,8"NMDC,8" DCx9,8" Jar,8" DCx2,X/O,X/O,HWDPx18,DPx192 BHA3:PDC Bit 12 1/4", DHM (adjustable 1°),Float sub w/float,12 1/4" S.Stab,MWD,8"NMDC,8" DCx9,8" Jar,8" DCx2,X/O,HWDPx18,DPx192

ANG. OUT: 0.92° 3542

Meters AZIM OUT: 83.1°

LITHOLOGIES: Claystones, Sandstone, Siltstone.

BIT RUN REPORT


BIT RUN REPORT


The objective for new DSR616M-A28 was to continue drilling of 12 ¼ section till TD. Totally the bit drilled 659.44 meters of formation in the interval 2949 –3608 meters through interbedded layers of Claystone, Sandstone, Siltstone. Accumulating av. ROP was 3.48m/hr. The subject bit was triply run. Forward and backward reaming operations were performed while drilling above mentioned interval, total amount of which was 41.1 hours. In the first run the bit drilled 535.88 meters of formation with sliding and rotating mode, av. ROP was 3.43 m/hr in the interval of 2949 – 3484.88 meters.Continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. Problems with hole deviation continued. Towards the end of the drillingafter wiper trip several tight spots (up to 10-12t) and TQ spikes (up to 12-13kft*lb)were observed in the interval of 3355m - 3402m, which were reamed. Decision was made increase MW from 10.7 to 11ppg. The bitcould not reach the bottom (3404m) due to TQ spikes. Resume drilling after TQ stabilization. And at the depth 3484,88m ROP dropped to 0.79 m/h, due to DHM failure. Decision was made POOH to change DHM. On the surface the bit was graded as: 1-2-BT-G-X-I-CT/HC-DTF. The major dull characteristic for the cutting structure was broken and chipped cutters with heat checking on the gauge of the bit. The reason for broken gauge cutters is excessive reaming. The total reaming time for this run was 12.5 hours.The bit was in good re-run condition thus was run back in hole to continue drilling. In the second run DSR616M-A28 drilled 123.56 meters of formation in the interval 3484.88-3608 meters. Accumulating average ROP was 4.02 m/hrs. While RIHintervals oftight spots 4-5 t and torque spikes 5-10 kft*lb were observed, which were reamed. At the depth 3516 meters attempt to take survey but no success, MWD failed.

COMMENTS

BIT RUN REPORT


RESULTS &CONCLUSION

RECOMMENDATION

DSR616M-A28 was used triply on CP-Ex1 well; DSR616M-A28 has not accomplished set objectives; After three runs the bit came out in non- rerun condition; Inasmuch as hole problems, there were performed reaming operations (41.1 hours in total) which

caused of damage gauge cutters of the bit.

For future projects NOV Downhole recommends to consider particular PDC type as one of the good options for drilling 12 ¼” section with similar application.

Use milled tooth bit instead of PDC bit for reaming, to avoidpremature wear of cutting structure of PDC bit.

At the depth 3608m decision was made POOH due to MWD failure. During POOHtorque spikes up to 4-15kft*lb were observedin the interval 3573m to 3551m, hard reaming of this interval was performed. On surface the bit was graded as: 1-2-BT-G-X-I-CT/HC-DTF.The total reaming time for this run was 12.45 hours, overall bit condition was good and it was run back in the hole to continue drilling.

Duringthird RIH permanent torque spikes up to 4-15 kft*/lb and tight spots up to 5-8 t were observedin the interval 3392-3559m. After 3559 meters the bit could not reach the bottom (3608m) due to TQ spikes and tight spots.Decision was made POOH to replace PDC with milled tooth bit and perform reaming due to hole problems. On the surface the bit was graded as: 1-2-BT-G-X-1/16-CT/HC-HP.The total reaming time for this run was 16.15 hours.The bit came out 1/16 inchundergauge and cannot be consider for further run.

BIT RUN REPORT


IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


2 4 BT S/G X I CT BHA




DEPTH IN: 3608.9 Meters TYPE: WBM NOZZ: 1x18; 5x15 DEPTH OUT: 3714 Meters MW: 11.42 PPG TFA: 1.112 Sq. In. DRILLED: 105.1 Meters PV/YP: 36/37.0 Cp/Pa FLOW: 700-704 GPM TOTAL HRS: - Hrs DP: 3300-3400 PSI ON BTM HOURS:

42 Hrs BIT HHP: 170

TOTAL ROP: - m/hr HSI: 1.45 Good EFFECTIVE ROP:

3.49 m/hr IF: 834 Lbs

WOB: 3-8 Tonne NOZ.VEL: 202 Ft/seg RPM: 90-130 RPM D.H.M. RPM: - RPM TORQUE: 5-10 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - Revs ANG. IN: 0.97°

3608.9 Meters AZIM IN: 123° BHA1:PDC Bit 12 1/4", DHM,Float sub w/float,12 1/8" S.Stab,MWD,8"NMDC,8" DCx9,8" Jar,8" DCx2,X/O,HWDPx18. BHA2:PDC Bit 12 1/4",Float sub w/float,MWD,8"NMDC,12 1/8" S.Stab,,8" DCx9,8" Jar,8" DCx2,X/O,HWDPx12,DPx192

ANG. OUT: 2.6° 3705

Meters AZIM OUT: 146°

LITHOLOGIES: Claystones, Sandstone, Siltstone.

BIT RUN REPORT


BIT RUN REPORT


The objective for new DSR616M-A28 was to continue drilling of 12 ¼ section till TD. Totally above mentioned bit drilled 105.1 meters of formation in the interval 3608.9 –3714 meters through interbedded layers of Claystone, Sandstone, Siltstone. Accumulating av. ROP was 2.79m/hr. The subject bit was run twice.Reaming operations were performed while drilling above mentioned interval, total amount of which was 16.45 hours. First time the bit was RIH with DHM (BHA1).RIH was with reaming. The bit reached the bottom but could not drill due to DHM failure (there was no pressure drop). Decision was made POOH to check DHM. On the surface the bit was graded as: 1-1-CT-S/G-X-I-NO-BHA. The major dull characteristic for the cutting structure was chipped cutters on the gaugeand shoulder of the bit. The reason for chipped gauge / shoulder cutters is excessive reaming. The total reaming time for this run was 6.15 hours.The bit was in good re-run condition thus was run back in hole to continue drilling. Second time DSR616M-A28 was RIH with rotary BHA (BHA2). In the second run the bit drilled 105.1 meters of formation in the interval 3608.9.-3714 meters. Accumulating average ROP was 2.79 m/hrs. Several intervals of tight spots (4-5t) and TQ spikes (5-15 kft*lb) were observed and reamed while drilling above mentioned interval. From the depth 3707m ROP was decreasing 1.9 m/h, 1.2 m/h, 0,8 m/h and WOB restricted (max. 7t) due to hole deviation problems(2.6°). It was made a decision to POOH and RIH with DHM (with bent housing 1°). During POOH TQ spikes up to 15kft*lb were observed in the interval 3714 - 3585m, this interval was reamed. On the surface the bit was graded as: 2-4-BT-S/G-X-I-CT-BHA.The major dull characteristic for the cutting structure was broken and chipped cutters on the shoulder / gauge of the bit. Total reaming time for this run was 10.30 hours. The bit was run twice, the first run had some broken shoulder/gauge cutters, but was otherwise in excellent condition so was re-run. The reason for broken shoulder/ gauge cutters is excessive reaming. Thus, those broken cutters were the start of the damage on the 2nd run. Whenthe bit has a broken cutter, the cutters next to it, and also the next cutter in the spiral order have to take more loads, and therefore break more easily than normal.

COMMENTS

RESULTS &CONCLUSION

RECOMMENDATION

DSR616M-A28 was used twice on CP-Ex1 well; DSR616M-A28 did not accomplished set objectives; After two runs the bit came out in non-rerun condition; The main reason for damaged cutting structure is excessive reaming. When the bit has a broken

cutter, the cutters next to it, and also the next cutter in the spiral order have to take more load, and therefore break more easily than normal.


Consider particular PDC type as one of the good options for drilling 12 ¼” section with similar application.

For reaming operations use milled tooth bit instead of PDC bit, to avoidpremature wear of cutting structure of PDC bit.

BIT RUN REPORT

RUN: 1 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: S13G SERIAL NUMBER: D157922 SIZE(Inches): 12 1/4”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 1 A NO E I NO BHA




DEPTH IN: 3608 Meters TYPE: WBM NOZZ: 1x20; 2x22 DEPTH OUT: 3608 Meters MW: 11.33 PPG TFA: 1.05 Sq. In. DRILLED: - Meters PV/YP: 32/30 Cp/Pa FLOW: 648-777 GPM TOTAL HRS: - Hrs

DP: 2600-3200

PSI

ON BTM HOURS: - Hrs BIT HHP: 150 TOTAL ROP: - m/hr HSI: 1.28 Good EFFECTIVE ROP: - m/hr IF: 751 Lbs WOB: 0-2 Tonne NOZ.VEL: 198 Ft/sec RPM: 50-60 RPM D.H.M. RPM: - RPM TORQUE: 4-12 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: 55575 Revs ANG. IN:

- Meters AZIM IN:

BHA:12 1/4” RC Bit / Bit sub w/float / 9 x 8” DC / 8” JAR / 2 x 8” DC / x-o / 18 x 5” HWDP.

ANG. OUT: - Meters AZIM OUT:

LITHOLOGIES:

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS

The objective for the above bit was to ream the vertical section from the depth 3493m to 3608. Totally this

bit reamed 116 meters of drilled interval by previous PDC DSR616M-A28. Previous PDC bit could not

ream above mentioned interval, due to hole condition was not stable (regular TQ spikes up to 15kft*lb

were observed) and it could not pass through this interval. Decision was made to change PDC bit to

Milled tooth bit to perform reaming operations.S13G has reamed above mentioned interval successfully.

Following which it was pulled to surface. On the surface the bit was graded as: 1-1-NO-A-E-I-NO-BHA.

RESULTS &CONCLUSION

RECOMMENDATION

S13G is recommended to consider for using in the upcoming wells for drilling soft formation and drill

out / clean out runs.

S13G has accomplished set objectives S13G showed good performance. S13G came out to surface in good condition and can be considered for rerun.

RUN: 1 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR713D

BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:A158501

RIG:XDEC6/ZJ70

SIZE(Inches): 12 1/4”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 1 CT G X I BT BHA




DEP. IN:3716.35 DEP.OUT: 4032 DRILLED: 315.65 TOTAL HRS: - ON BTM HOURS: 218.95 TOTAL ROP: - EFFECTIVE ROP: 2.37 WOB:2-12 RPM: 30 D.H.M. RPM: 100-101 TORQUE:3-15 TOTAL REVs:1787457

Meters Meters Meters Hrs Hrs m/hr m/hr Tone RPM RPM Kft/Lbs Revs

TYPE: WBM NOZZ:5x14/32, 2x16/32 TFA:1.15Sq. In. FLOW:652-664GPM DP:3400-3750PSI BIT HHP: 143 HSI:1.21Poor IF:186Lbs NOZ.VEL:122Ft/sec

MW: 11.92 PPG

PV/YP: 37/39 Cp/Pa

SURVEY: DEPTH: ANG.IN: 2.64° 3716 Meters AZIM IN: 145.62°

BHA: 12 1/4” PDC Bit / Mud motor (adjustable1°)/Float sub w/float / 12 1/4" S.Stab/ MWD / 8"NMDC / 9 x 8” DC / 1 x 8” Jar /2 x 8” DC /X/O /18 x 5” HWDP/;

ANG.OUT: 2.29° 4013 Meters AZIMOUT: 63.5º DLS:

LITHOLOGIES: Claystone, Siltstone, Sandstone.



RIG:XDEC6/ZJ70


Bit Engineer:



RIG:XDEC6/ZJ70


Bit Engineer:

COMMENTS

Inasmuch as two 12 ¼” DSR616 were in non-rerun conditions due hole problems, new DSR713D was RIH while new ordered bit will arrive to the Wellsite.The objective for new DSR713D was to drill remaining part of 12 ¼” vertical section from the depth 3716m till arriving of new DSF616D-I2. Totally thebit drilled 315.65 meters of formation in the interval 3716.35–4032 mwith rotating and sliding mode, through interbedded layers of Claystone, Siltstone, Sandstone.Where accumulating av. ROP of 1.42 m/hr. Performed reaming while drilling above mentioned interval whereTQ spikes up to15 kft/lb were observed.Continues drill of tests was performed to identify best drilling parameters, where increase of ROP with increase of WOB was observed. At the depth 4032m it was attempt to take survey. Withoutsuccess. Probably the battery of the MWD wasdischarged. Decision was made POOH to change DHM, MWD. On the surface the bit was graded as: 1-1-CT-G-X-I-BT-BHA. The major dull characteristic for the cutting structure was slight chipped and broken cutters on the gauge of the bit. The reason for chipped gauge cutters is excessive reaming.Total reaming time of this interval was 9 hours. The reason for low ROP is the cutting structure of DSR713D which is not aggressive. DSR713D has 7 blades with 13mm cutters, which requires more WOB to increase ROP in compare with more aggressive DRS616. There was no possible to apply 12-15t of WOB due to hole deviation problems and TQ limitation of DHM. Overall the bit is in good condition and can be consider as rerun.

RESULTS &CONCLUSION

Subject DSR713D has accomplished set objectives; The reason for low ROP is the cutting structure of DSR713D which is not aggressive. DSR713D has 7

blades with 13mm cutters; DSR713D came out to surface in good condition and can be considered for re-run.

RECOMMENDATION

DSR713D is recommended to consider for using in the upcoming wells for drilling hard formations. Drilling with more WOB in the range 12-15t to improve ROP;

BIT RUN REPORT

RUN: 2 CUSTOMER: KNOC Fergana Operating Company WELL NAME: CP-Ex1 RIG: XDEC6/ZJ70 BIT TYPE: DSF616D-I2 SERIAL NUMBER: A158722 SIZE(Inches): 12 1/4”

Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 2 BT S/G X In CT/WT/BU TD

RIG GRADE: 1 – 2 – BT – S/G – X – I – CT/WT/HC/BU – PR RE-RUNNABLE: YES



DEPTH IN: 4032 Meters TYPE: WBM NOZZ: 5x12’; 2x16’; 2x15’ DEPTH OUT: 5010 Meters MW: 14.33 PPG TFA: 1.29 Sq. In. DRILLED: 978 Meters PV/YP: 40/46 Cp/Pa FLOW: 630 GPM TOTAL HRS: - Hrs DP: 3800 PSI ON BTM HOURS: 546.75 Hrs BIT HHP: 40 TOTAL ROP: - m/hr HSI: 0.34 VERY LOW EFFECTIVE ROP: 1.78 m/hr IF: 358 Lbs WOB: 6-10 Tonne NOZ.VEL: 110 Ft/sec RPM: 50 RPM D.H.M. RPM: 85 RPM TORQUE: 5-9 Kft x Lbs SURVEY: DEPTH: TOTAL REVs: - KRevs ANG. IN: 2.1° 4003 Meters AZIM IN: 62.9° BHA 1: 12 ¼” PDC Bit / DHM (1° bent) / Float sub / 1 x 12 3/16” Stab. / MWD / 1 x 8” NMDC / 9 x 8” DC / 1 x 8” JAR / 2 x 8” DC / x-o / 18 x 5” HWDP / 5” DP; BHA 2: 12 ¼” PDC / DHM (1° bent) / Float sub / 1 x 8” Short DC / 12 3/16” Stab. / MWD / 1 x 8” NMDC / 7 x 8” DC / 1 x 8” JAR / 2x 8” DC / x-o / 12x5” HWDP / 5” x DP”

ANG. OUT: 0.75° 5008 Meters AZIM OUT: 143.1° DLS:

LITHOLOGIES: Claystones-75%, Siltstone – 23% and Sandstone -2%

BIT RUN REPORT


Bit Engineer:

BIT RUN REPORT


Bit Engineer:

COMMENTS


DSF616D-I2 has accomplished set objective;

PDC showed slow but stable performance through hard formations; Cutting structure mainly exhibited chipped and broken cutters on the shoulder and gauge of the bit;

PDC came to surface balled up;

HSI achieved for subject run was very low; PDC remained in re-run condition.

DSF616D-I2 is recommend for upcoming wells with similar applications;

Reduction of TFA is recommended to improve the HSI, which will lead to higher ROP and better bit and hole cleaning.

The objective for new DSF616D-I2 was to finish the remaining part of 12 ¼” section from the depth of 4032m till TD. The bit has showed slow but stable performance. It has accomplished set objective drilling through hard layers of Claystone, Sandstone and Siltstone. Overall, bit achieved av. ROP of 1.78m/h in the interval 4032-5010m. While drilling subject interval the PDC was pulled to surface once (at the depth of 4507 m), due to hours on MWD /DHM, IBOP leakage and hole problems. HSI of 0.34 achieved for the run was way below the recommended range of 2-7. Thus it reflected on ROP, hole and bit cleaning which resulted in long reaming intervals. At the TD the bit was pulled to surface and graded as 1-2-BT-S/G-X-I – CT/WT/HC/ BU-TD. The visual inspection of the bit on surface revealed that the cutting structure has mainly suffered from broken and chipped cutters on the shoulder and gauge. Broken/Chipped cutters on PDC bits usually occur due to impact caused by downhole vibrations. Considering the amount of reaming performed while drilling probably the vibrations occurred were lateral. Beside the mentioned wear the cutting structure exhibited normal wear and came to surface balled up. Bit balling is another justification of poor hydraulics applied while drilling subject section. NOV Downhole recommends reduction and adjustment of drilling parameters to preserve the cutting structure of PDC bits while reaming operations. We also recommend considering particular PDC design for upcoming wells with similar application. Subject DSF616D-I2 remained in re-run condition and can be considered for further use.

RUN: 4 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR616M-J1


RIG:XDEC6/ZJ70


Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


4 2 WT N/T X I BT/CT/HC DMF




DEP. IN:5016 DEP.OUT:5630.15 DRILLED:614.15 TOTAL HRS: - ON BTM HOURS: 701.25 TOTAL ROP: - EFFECTIVE ROP: 1.82 WOB:2-10 RPM:30-60 D.H.M. RPM:110-127 TORQUE:4-7 TOTAL REVs: -


TYPE: WBM NOZZ: 6x16/32 TFA:1.2Sq. In. FLOW:410-502GPM DP:3800-3850PSI BIT HHP: 81 HSI:1.43Good IF:588Lbs NOZ.VEL:137Ft/sec

MW: 16.6 PPG

PV/YP: 37/54.2 Cp/Pa

SURVEY: DEPTH: ANG.IN: 0.75° 5030 Meters AZIM IN: 143.1°

BHA1: 8 1/2” PDC Bit / Mud motor /Float sub w/float / X/O/6 1/4" MWD/6 1/4" NMDC/8 3/8" S.Stab/ 18 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC /X/O /12 x 5” HWDP/;

ANG.OUT: 4.55° 5551 Meters AZIMOUT: 154º

DLS:

LITHOLOGIES: Claystone, Siltstone, Sandstone (very hard, dense and compacted), Limestone, Anhydrite,conglomerate



RIG:XDEC6/ZJ70


Bit Engineer:

BHA 4: 8 1/2” PDC Bit / Mud motor / Float sub w/float / X/O/ 6 1/4" MWD/6 1/4" NMDC/8 3/8" S.Stab / 17 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC / X/O / 12 x 5” HWDP/;

BHA2: 8 1/2” PDC Bit / Mud motor / Float sub w/float / X/O/6 1/4" pony DC/8 3/8" S.Stab/ 6 1/4" MWD/6 1/4" NMDC/18 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC / X/O / 12 x 5” HWDP/;

BHA3: 8 1/2” PDC Bit / Mud motor / Float sub w/float / X/O/ 6 1/4" MWD/6 1/4" NMDC/8 3/8" S.Stab / 1x6 1/4" DC/8 3/8" S.Stab /16 x 6 1/4" DC / 1 x 6 1/4" Jar /2 x 6 1/4" DC / X/O / 12 x 5” HWDP/;



RIG:XDEC6/ZJ70


Bit Engineer:



RIG:XDEC6/ZJ70


Bit Engineer:

COMMENTS

The objective for new DSR616M-J1 was to finish the remaining part of 8 ½” section from the depth of 5016m till TD.Totally thebit drilled 614.15 meters of formation in the interval5016–5630.15 m, through interbedded layers of Claystone, Siltstone, Sandstone (conglomeratic compacted sandstone mainly with quartzite),Anhydrite, Limestone, accumulating av. ROP of 0.82m/hr. The subject bit was four times pulled to surface, while drilling above mentioned interval. In the first run the bit drilled 215.45 meters of formation in the interval of 5016 – 5231.45 meters with av. ROP 1.2 m/hr. At the depth 5167m attempt to take survey but no success, MWD failed, probablybattery of the MWD was discharged. At the depth 5180 m the SPP dropped to 3400 psi. Increased FR to 31 L/sec. SPP go up to 3800 psi. ROP dropped to 0.57 m/h. Check the differential pressure off bottom and on bottom, SPP is the same. Probably DHM was failed. At the depth of 5231.45 it was made a decision to POOH to change DHM and MWD. On the surface the bit was graded as:1-1-WT-A-X-I-NO-BHA. The total reaming time for thisinterval was 2 hours. The bit was in good condition thus was run back in hole to continue drilling. In the second run the bit drilled 218.55 meters of formation with sliding and rotating mode, av. ROP was 1.08 m/hr in the interval of 5231.45 – 5450 meters. WOB was restricted (max. 7 t), due to inclination.Attempt to take survey at 5407m - no success, MWD signal was lost. At the depth of 5450DHM was failed. Decision was made POOH to change DHM and MWD. On the surface the bit was graded as:1-1-WT-A-X-I-NO-DMF. The total reaming time for this interval was 3.45 hours. The bit was in good re-run condition thus was run back in hole to continue drilling. In the third run the bit drilled 57.9 meters of formation, av. ROP was 0.69 m/hr in the interval of 5450 – 5507.9 meters. The bit had capabilities to perform at higher penetration if more WOB (10-15t) would have been applied during the run, but due to hole deviation problems it was not done.At the depth 5507 m the SPP dropped from 3800 to 3550 psi and ROP decreased to 0.4m/h. Off bottom and on bottom pressure was the same. Probably DHM failed. Decision was made POOH. On the surface the bit was graded as:1-1-CT-T/S-X-I-WT-DTF. The major dull characteristic for the cutting structure were chipped cutters on taper and shoulder of the bit. The total reaming time for this interval was 0.45 hours. Totally the bit was in good condition thus was run back in hole to continue drilling. In the fourth run the bit drilled 122.25 meters of formation, av. ROP was 0.88 m/hr in the interval of 5507.9 – 5630.15 meters.At the depth of 5550m the ROP dropped to 0.61 m/h, due to lithology changed to 50% of sandstone (conglomeratic compacted mainly with quartzite), 20 % claystone and 30 % siltstone. At the depth of 5552m formation changed to conglomerate 30%, sandstone 50% (conglomeratic compacted mainly with quartzite), claystone10%, siltstone 10% and ROP dropped more (to 0.46 m/h).From the depth of 5558 m continue drilling of hard conglomeratic compacted sandstone mainly with quartzite 70%-80%.At the depth of 5630.15m the TQ suddenly increased to 9 Kft/lb, SPP dropped from 3850 to 3770 psi with. ROP dropped to 0. Differentialpressure checked, off bottom and on bottom pressure is the same.DHM failed. Decision was made POOH. On the surface the bit was graded as:4-2-WT-N/T-X-I-BT/CT/HC-DMF. The major dull characteristic for the cutting structure was excessivewear, broken and chipped cuttersmainly at the nose and taper. Looking at the wear pattern of the bit we can assume that such wear occurred due to drilling abrasion formations such as conglomeratic sandstone with quartzite. Considering, the ROP was low the bit was rotated in the hole for extended period of time, which resulted such kind of severe wear of cutting structure. Currently, PDC is in non-rerun condition and cannot be considered for further use.



RIG:XDEC6/ZJ70


Bit Engineer:

RESULTS &CONCLUSION

- DSR616M-J1 has not accomplished set objectives, but showed impressive performance; - Reasons for low ROP are:

Insufficient, restricted WOB due to inclination problem; Formation changes, especially conglomeratic compacted sandstone with quartzite content 70%-80% and conglomerate 20%;

- DSR616M-J1 came out to surface in non-rerun condition and cannot be considered for further run.

RECOMMENDATION

- Apply of recommended drilling parameters may improve average ROP and extend service life of the bit; - Hard formations require high WOB and low RPM to allow bits to penetrate and shear the formation; - Drilling with more WOB in the range 15-20t during drilling hard formation, such as conglomeratic compacted

sandstone with quartzite content and conglomerate to improve ROP.

RUN: 2 CUSTOMER:KNOC Fergana Operating Company. BIT TYPE:DSR613M-D5


RIG:XDEC6/ZJ70


Bit Engineer:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE 1/16” OTHER CHARACT.

REASON PULLED

1 2 BT G X I CT/WT/BU/PN HP




DEP. IN:5630 DEP.OUT: 5796 DRILLED: 166 TOTAL HRS: - ON BTM HOURS: 86 TOTAL ROP: - EFFECTIVE ROP:2.36 WOB: 2-7 RPM: 50 D.H.M. RPM:114-126 TORQUE:4-7 TOTAL REVs: -


TYPE: WBM NOZZ:3x12/32;2x18/32;1x16/32 TFA:1.03Sq. In FLOW:425-470GPM DP:3560-3840PSI BIT HHP: 90 HSI:1.58Good IF:603Lbs NOZ.VEL:147Ft/sec

MW: 16.9 PPG


SURVEY: DEPTH: ANG.IN: Meters AZIM IN:

BHA1: 8 1/2” PDC Bit / Mud motor /Float sub/ X/O/1 x 6 1/4" DC/ 8 3/8" S.Stab /17 x 6 1/4" DC /1 x 6 1/4" Jar/2 x 6 1/4" DC /X/O /12 x 5” HWDP/;

ANG.OUT: Meters AZIMOUT: DLS:

LITHOLOGIES: Claystone, Siltstone, Sandstone,Limestone, Anhydrite



RIG:XDEC6/ZJ70


Bit Engineer:

BHA2: 8 1/2” PDC Bit / Mud motor / Float sub/ X/O/ 8 3/8" S.Stab /1 x 6 1/4" DC/ 8 7/16" S.Stab /17 x 6 1/4" DC /1 x 6 1/4" Jar/2 x 6 1/4" DC / X/O / 12 x 5” HWDP/;



RIG:XDEC6/ZJ70


Bit Engineer:



RIG:XDEC6/ZJ70


Bit Engineer:

COMMENTS

New 8 1/2” PDC bit DSR613M-D5 was run in the hole at the depth 5630m. The objective for this bit was to drill remaining part of 8 1/2” section.Totally thebit drilled 166 meters of formation in the interval5630–5796 m, through interbedded layers of Claystone, Siltstone, Sandstone,Anhydrite, Limestone, with average ROP 1.93m/hr. The subject bit was two times pulled to surface, while drilling above mentioned interval. In the first run the bit drilled 116.58 meters of formation, av. ROP was 2.12 m/hr in the interval of 5630 – 5746.58 meters. At the depth of 5746.58 it was made a decision to POOH due to core point. On the surface the bit was graded as:1-1-BT-G-X-I-CT/WT-CP.The major dull characteristic for the cutting structure was slight breakingof the cutters on the bit`s gauge. The total reaming time for this run was 3.45 hours.Overall the bit was in good re-run condition, thus was run back in hole to continue drilling. Inasmuch as coring assembly could not reach TD due to unstable hole condition, decision was RIH withDSR613M-D5. In the second run the bit drilled 49.42 meters of formation, av. ROP was 1.75 m/hr in the interval of 5746.58 – 5796 meters.Drill string was stuck in the hole at the depth of 5796 m. After release the drill string, it was made decision to POOH due to hole problems. On the surface the bit was graded as: 1-2-BT-G-X-I-CT/WT/BU/PN-HP.The major dull characteristic for the cutting structure was some broken cutters on the gauge of the bit. Also the bit came out to surface with bulled up and plugged nozzles by rubber from DHM. Since the bit was run twice, in the first run had some broken gauge cutters, but was otherwise in excellent condition so was re-run. The reason for broken gauge cutters is excessive reaming. The total reaming time for this run was 24 hours. Thus, those broken cutters were the start of the damage on the 2nd run. When the bit has a broken cutter, the cutters next to it, and also the next cutter in the spiral order have to take more loads, and therefore break more easily than normal. Currently, PDC is in re-run condition and can be considered for further use.

RESULTS &CONCLUSION

- DSR613M-D5has not accomplished set objectives due to hole problems; - DSR613M-D5 was used two times on CP-Ex1well; - DSR613M-D5 has showed good performance in both intervals; - After two intervals DSR613M-D5 came out to surface in re-run condition;

RECOMMENDATION

NOV Downhole recommends: - For reaming operations use milled tooth bit instead of PDC bit, to avoidpremature wear of cutting structure

of PDC bit. - Consider particular PDC type as one of the good options for drilling 8 ½” section with similar application.

RUN: 2 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:R30AMP

BIT RUN REPORT WELL NAME:CP-Ex1 SERIAL NUMBER:D158421

RIG:XDEC6/ZJ70

SIZE(Inhes):8 1/2”

DATE: _28 – October – 2012_Bit Engineer: Rig Manager: Drilling Supervisor:

IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


1 1 BT N E I JD/ER/WT LOG




DEP. IN: DEP.OUT: DRILLED: TOTAL HRS: ON BTM HOURS: TOTAL ROP: EFFECTIVE ROP: WOB: RPM: D.H.M. RPM: TORQUE: TOTAL REVs:

5013 Meters Meters Meters Hrs Hrs m/hr m/hr Tone RPM RPM Kft*Lbs Revs

TYPE: WBM NOZZ:3x20/32 TFA:0.93Sq. In. FLOW:401GPM DP:3800PSI BIT HHP:58 HSI:1.03Good IF:414Lbs NOZ.VEL:140Ft/seg

5016 3 - 7.8 - 0.77 2-12 50 110 4-6 76752

MW: 14.3 PPG


BHA 1: 8 1/2" Bit/ Mud motor/ Float sub/X-Over/6 1/4"MWD/ 6 1/4"NMDC/8 3/8" S.Stab/ 18 x 6 1/4"DC / 1 x 6 1/4"Jar /2 x 6 1/4"DC / X/O / 12 x 5” HWDP/;

ANG.IN: Meters AZIM IN: ANG.OUT: Meters AZIMOUT:

LITHOLOGIES: Claystone, Siltstone



RIG:XDEC6/ZJ70





RIG:XDEC6/ZJ70



Comments

Results & Conclusion

Recommendations

R30AMP bit was run twice in CP-Ex1 well. R30AMPis an insert bit (IADC 5-3-7) designed for soft to medium formations with high compressive strength. The objective for the first run was to clean out the junk in the hole possibly left from previous run S21G bit and continue drilling from the depth 5013 m depending on ROP. Totally this bit drilled 3 meters of formation through layers of Claystone and Siltstone with average ROP 0.54 m/h. At the depth 5016 it was made a decision to POOH to replace Insert bit with PDC. In the subject run the bit was rotated for76752 revolutions. The reason for low ROP was limited WOB (not more than 12t) due to weight below jar was 18t. Whereas Weight On Bit Range by bit specification is 9-27t. On the surface the bit was graded as:1-1-BT-N-E-I-JD/ER/WT-BHA.The visual inspection of the bit revealed that the cutting structure of the bit was in good condition except one broken insert. And on the cones were observed junk damaged traces which occurred due junk in the hole left by previous milled tooth bit. Second time R30AMP RIH to ream the vertical section from the depth 5579 to 5805 m, logging tools could not reach TD due to hole condition was not stable (regular TQ spikes up to 15 kft*lb, tight spots and overpulls up to 10 t). Totally this bit reamed 226 meters for 20.15 hours. Overall R30AMP came out to surface in rerun condition and had capabilities to continue drilling with higher ROP if not the obstacle (Insufficient WOB) limiting its’ performance.

R30AMP has accomplished the mainset objective (clean out the junk in the hole); Reason for low ROP isinsufficient WOB due to not enough DC; R30AMP came out to surface in good condition and can be considered for re-run;

R30AMPis recommended to consider for using in the upcoming wells for drilling soft formation

and drill out / clean out runs; Drilling with more WOB in the range 18-20t to improve ROP;

RUN: 1 CUSTOMER:KNOC Fergana Operating Company BIT TYPE:S21G


RIG:XDEC6/ZJ70


IADC DULL GRADING

INNER ROWS

OUTTER ROWS


SEALS GAUGE

1/16” OTHER


4 1 BT N/M F I JD BHA


DRILLED OUT SHOE: YES REPAIRABLE: NO


DEP. IN: DEP.OUT: DRILLED: TOTAL HRS: ON BTM HOURS: TOTAL ROP: EFFECTIVE ROP: WOB: RPM: D.H.M. RPM: TORQUE: TOTAL REVs:

5010 Meters Meters Meters Hrs Hrs m/hr m/hr Tone RPM RPM Kft*Lbs Revs

TYPE: WBM NOZZ:3x20/32 TFA:0.93Sq. In. FLOW:542GPM DP:3830PSI BIT HHP: 147 HSI:2.59Good IF:770Lbs NOZ.VEL:189Ft/seg

5013 3 - 5 - 0.6 8-10 60-70 - 5-7 55230

MW: 14.58 PPG


BHA: 8 1/2" Milled tooth bit /Bit /Float Sub/ 18x6 1/4" DC / 1 x 6 1/4"Jar / 2x6 1/4" DC/ 1 x 6.5”X/O/ 15 x 5” HWDP/;

ANG.IN: Meters AZIM IN: ANG.OUT: Meters AZIMOUT:


LITHOLOGIES: Claystone, Siltstone



RIG:XDEC6/ZJ70





RIG:XDEC6/ZJ70


Comments

Results & Conclusion

Recommendations


S21Gis a milled tooth bit (IADC 217) designed for medium to medium-hard formations with high compressive strength. The objective for newS21Gwas to drill out cement and continue drilling 8½ section (depending on ROP). From the depth 4940m the subject bitdrilled out cement, cement plug, top float collar, bottom float collar and float shoe. And bit drilled 3 meters of a new formation in the interval of 5010-5013 meters, through interbedded layers of claystone 90% and siltstone10%. Accumulating av. ROP of 0.6 m/hr. In the subject run the bit was rotated for 55230 revolutions. Axial vibrations and Torque spikes up to 15 Kft/lb were observed while drilling above mentioned interval.Axial vibrations usually occur during drilling hard formations with roller cone bits. It was not possible to prevent axial vibrations by increasing WOB due to not enough DC in BHA. At the depth 5013 meters decision was madePOOH due to undesirable ROP.The reason for low ROP was limited WOB (not more than 10t). Whereas WOBrange by bit specification is 5-20t.On the surface the bit was graded as:4-1-BT-N/M-F-I-JD-BHA. The major dull characteristic for the cutting structure was broken and chipped teeth on nose and middle row of the bit which indicates on axial vibrations. Considering that the wear pattern was not similar on each cone, we make conclusion thatcutting structure of the bit suffered mainly from shock actions, possibly caused by combination of downhole vibrations. S21G is in non-rerun condition and cannot be considered for further use.

S21G has accomplished set objectives; Cutting structure of S21Ghas suffered from shock actionscaused by combination of downhole

vibration; S21Gis in non-re-run conditionand cannot be considered for further use.

S21G is recommended to consider for using in the upcoming wells for drilling soft formation

and drill out / clean out runs.

bit run report run: well: cp-ex1 rig: xdec/zj70 size ... run report.pdf · customer: knoc fergana...

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