SPE 141023

Heavy Duty Wireline Fishing Operations in a HP/HT Sour Gas Well – A Case Study Gustioro, SPE, Idi Yusuf A, SPE, Syahriza Ghany R., SPE, P.T. Medco E&P Indonesia John Vincent, Weatherford International Ltd.

Copyright 2011, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Middle East Oil and Gas Show and Conference held in Manama, Bahrain, 25–28 September 2011. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright.

Abstract HP/HT gas wells, especially those in South Sumatra, Indonesia, present many challenges to exploitation operations due to a 408°F bottomhole temperature, a 10,500psi bottom hole pressure at some 11,000ft, and sour gas components of 34% CO2 and 100 – 200ppm H2S. During the final stages of the completion of one such well, after setting the production packer a wireline run was made with .108” slick line to recover the plug body from the seating nipple at 11.406ft. While pulling out and with the plug at 6000ft. the well became live without warning, blowing the tool string up the hole and, to contain the well, the drilling BOPs were closed shearing the landing joint which in turn closed the sub surface safety valve. Subsequently the well was successfully completed and prepared for wireline fishing operations. The wireline fishing operation went on for several days using .108” wire, during which 45 runs were made with the recovery of only approximately 550ft of wire and so it was decided to call in heavy duty wireline fishing (HDWF) expertise to review the situation and make recommendations as to how to proceed. This resulted in a commitment being made to mobilize personnel and equipment from Aberdeen and the Middle East to carry out the required operations. In the meantime a total of 11 further runs were made in the well using coiled tubing which resulted in recovery of the upper part of the tool string and some additional wire. Fishing operations were recommenced using 7/32” Supa 75 braided cable with two two/man crews providing 24 hour operation and a project leader located at the clients office to provide for direct liaison. After a total of 17 runs over 6 days of continuous operation, the fish was completely recovered and the well made ready for production. In this paper the authors will review the situation that was faced, the remedial work done to complete the well, the early fishing operations and the subsequent input of HDWF expertise. They will conclude with a detailed account of the successful HDWF operation – an excellent example of how careful planning, experienced personnel, dedicated project management and a collaborative relationship between the client and service company can lead to a successful outcome.

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Introduction There is a gas field located in south Sumatra which has estimated gross reserves of 271 Bscf however its’ exploitation and development is made extremely difficult by the bottomhole conditions and the nature of the gas:

• Bottomhole Temperature - 408°F • Bottomhole Pressure – 10,550psi. • H2S content – 100 to 200 ppm. • CO2 content – 34%.

These conditions require the use of special materials and techniques in order to allow development of the field in order to try to avoid HSE incidents. A development well in this field was drilled in late 2009 and was planned to be completed with 4-1/2” 18.9lbs/ft. 15% chrome tubing (See Fig. 1). However following the setting of the 9-5/8” production packer, the PR-6 plug was being retrieved from the DB-6 landing nipple using .108” slick line when, at a depth of some 6000ft. the well started to come in. At 3700ft. the well overcame the tool string and it was blown up the hole and in order to contain the well the drilling shear rams were closed on the landing joint, which in turn terminated the downhole safety valve control line, closing the valve. Approximately 3000ft. of slick line were recovered from the crown block leaving a fish in the hole consisting of some 1300ft of .108” slick line, the 1-7/8” tool string with PRS pulling tool (See Fig. 2) and the 3.312 DB-6 lock and plug body. Subsequently, after several unsuccessful attempts to bull head the well to kill it, the wellhead was frozen with dry ice, the sheared landing joint was retrieved, during which process several fingers were lost from the screwdriver recovery tool (See Fig. 3), and the Christmas tree was installed. During the process slick line was observed in the ice plug at surface however the exact location of the line and fish relative to the wellhead and the downhole safety valve (DHSV) was difficult to determine – well pressure was observed at surface indicating that the DHSV was not fully sealing perhaps due to it having slammed shut under extremely high pressure. The DHSV was subsequently operated by way of the repaired control line and gave every indication of functionality. Initial Fishing Operations The first attempts to fish the equipment left in the well started on Jan 23rd 2010 using similar .108” slick line equipment. The first few runs with a wireline grab encountered the fish at or close to the tubing hanger and over the first 12 such runs a total of 236ft of wire were retrieved in small pieces. On the 13th run the fish was not tagged until 1560ft, well below the DHSV but a further 228ft. of wire was recovered. The next 18 runs in the well with an assortment of fishing tools failed to recover any more of the fish which continued to move down the hole at each attempt, eventually reaching a depth of 11,126ft where the next 6 runs retrieved further lengths of wire line totaling an additional 88ft. A further 7 runs were made during which the fish was chased down to 11,273ft., but no additional recovery was achieved and so, recognizing that some additional expertise would be needed in order to resolve the problem, it was decided on Jan 30th to contact a heavy duty wireline fishing service company to assess the situation and to make recommendations as to how to proceed. In the meantime, whilst waiting on this assessment, it was decided to terminate the wireline fishing operation, rig down and then mobilize a coiled tubing (CT) unit and fishing equipment to continue operations. On Feb. 4th CT was run in the well but wellhead pressure climbed to an unacceptable level for the CT equipment on location so it was pulled out and measures taken to reduce wellhead pressure. There followed a total of 11 additional CT runs with various fishing, jetting and pulling tools, impression blocks and magnets all to little avail except that the upper part of the wireline tool string fish was recovered leaving a broken knuckle joint looking up. During this process a 2-1/8” Bowen spiral grapple was lost in the well, further complicating the situation. CT fishing operations were finally terminated on Feb. 22nd and operations were suspended while waiting on the arrival of HDWF equipment and personnel and the decisions as to what operation should follow. HDWF review of situation The HDWF region team leader in Aberdeen, Scotland made an initial review of the situation and submitted a detailed proposal to supply surface and downhole equipment from their operations in Aberdeen & Qatar. For this operation the use of 5/16” OD Dyform cable in conjunction with a high load toolstring which can deliver impacts of up to 120,00lbs at maximum setting (See Fig. 4) was considered preferable. However due to the well conditions suitable cable material was not available and so a 7/32” Dyform Supa 75 cable was proposed which if used at 60% of maximum bearing load provides a safe line pull of 3900lbs. It is important here to note that any wireline fishing job should be performed with a fishing line that is an order of magnitude stronger than the line being fished. The applicable operational data was:

• Wire weight per 1000ft – 111lbs. • Tool string weight at surface – 350lbs. • MBL of wire 6500lbs. • Safe pull at 60% of MBL – 900lbs. • Wire weight on depth – 1265lbs. • Jar setting available- approx. 2285lbs.

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• Impact available – 40-80,000lbs. The tooling recommended consisted of a selection of the following:

• Wireline finder/grab/spear equipment. • Wire brush assemblies. • High power magnets. • Alligator grabs. • A comprehensive selection of heavy duty pulling tools for the full range of fishing necks anticipated. • Heavy duty releasable overshots in the event that fishing necks were found to be worn or damaged.

The proposal was accepted and the equipment was mobilised by air freight, the fishing specialists were dispatched from Aberdeen and, due to the logistical problems involved and considering the volatility of the well conditions, the HDWF region team leader traveled from the UK to provide a focal point in the clients’ office for operational and technical support. The objectives were to recover the following items:

• The balance of the .108” slick line left in the well – this amount was not accurately known. • 1-7/8” toolstring complete with PRS pulling tool and with the broken bottom half of a knuckle joint looking up. • 3.312” OD DB6-HP lock. • 2-1/8” Bowen spiral grapple perhaps in pieces. • Broken fingers from the female screwdriver used to retrieve the sheared landing joint.

The limiting factors for success in the operation would come down to:

• The line pull available from the 7/32” Supa 75 braided cable with which the mobilized wireline unit was equipped. • The well pressure and the capabilities available to kill/suppress the pressure in the well. • The HP/HT conditions. • The position and nature of debris left in the well – a major unknown after all the fishing operations that had been

performed. • The amount of wire that might still be wrapped around the fish.

Heavy Duty Wireline Fishing Operations A pre-job meeting was held with all personnel involved prior to commencing operations to discuss communications, roles and responsibilities, to review the proposed operation and HSE considerations and finally a tool box talk to familiarize all participants with the equipment. The surface BOP installation used was as shown in Fig. 5. Before each run in the well the BOPs were tested to 10Kpsi and the rope socket pull tested to a minimum of 4250lbs while wellhead pressures, accurate pick up weights and depth recordings were made during each run. Once the equipment had been mobilised to the site, heavy duty wireline fishing operations commenced on Feb. 24th with specialists working in the field on a 24 hour continuous basis and the region team leader liaising with the customer on each step of the process. The following sequence of events ensued:

• First of all, in order better to assess the situation, a run was made with a lead impression block to identify the top of the fish at 11,250ft. A good clean impression was obtained of the top of the broken knuckle joint. (See Fig. 6)

• Ran in with a JU pulling tool, latched the fish at 11,250ft and after attempts to work it up the hole the fish was manipulated down to 11,271ft and then pulled out of the hole (POOH). Additional weight was evident but this fell off at 1100ft and nothing was recovered.

• Reran the JU pulling tool and tried to latch the fish at the point where weight loss was noted in the previous run but without success. POOH

• A heavy duty dual shear pulling tool was then run and latched onto the fish at 11,258ft with a weight gain of 140lbs being noted. POOH and recovered the remaining tool string and PRS running tool. The PRS tool had one full finger and one finger tip missing from the latch collet and the remaining fingers bent out of shape. (See Fig. 7)

• On run #5 a high temperature magnet was run in the well and metal swarf recovered from 11,274ft. (See Fig. 8). • Reran the magnet and recovered more metal swarf and an 11” section of .108 wire. • Deployed a ball impression block (BIB) and obtained an impression of the fish at 11,274ft – slickline marks were

observed around the circumference, on the face and the sides of the BIB. (See Fig. 9) • A 2.50” alligator grab was then run in to tag the fish at 11,274ft, jarred down to 11,281ft and POOH with an initial

overpull of 500lbs to recover 2ft of slickline. • The next run was made with a 2.70” combination wire finder grab/spear, they were worked onto the fish at 11,281ft and

POOH with a 550lbs overpull. Weight loss was noted at 1295 ft but a ball of wire equal to some 40ft was recovered. • The same tool was run again and this time a further ball of some 50ft of wire was recovered.

4 SPE 141023

• The same tool was run again and recovered small pieces of wire and chrome tubing shavings – all 3 legs of the grab gave positive indications of having been inside the neck of the 3.312” plug.

• A check shear run was then made with the PRS pulling tool with the latching collet removed. The plug was tagged at 11,371ft and jarred down before POOH where the tool was found to be fully sheared.

• The PRS tool was run and attempts made to latch the plug but despite 33 jars down no latching was obtained and so POOH again. The PRS was not sheared and visual marks of wire on the core of the tool were observed.

• Ran a wireline/grab/spear combination to enter the plug body, jar down and then POOH. Positive indications were noted that the spear had entered the plug body a total of 23” - marks and tearing on the outer edges of the legs of the grab were observed and the spear tip was flattened.

• Ran the PRS pulling tool, located the plug at 11,369ft jarred down, applied overpull to confirm latching and jarred up 30 times before coming free. POOH with additional weight but found a 1” section of slick line in the latching collet fingers which had prevented latching. (See Fig. 10)

• Reran the PRS tool and located the plug at 11,369ft, worked into the plug body and obtained overpull indicating possible latching. Jarred up 7 times and came free with120lbs additional weight. POOH and recovered the plug body with all the V packing missing, lost screwdriver fingers jammed across the packing mandrel, the nose cone of the plug full of debris (See Fig. 11), multiple pieces of wire, a total of 12” of pieces of the lost 2-1/8”grapple (See Fig. 12), the lost finger and finger tip from the collet on the PRS left in the hole after run #4, a garter spring, grub screw and the knuckle joint housing.

• This seemed to represent the totality of the fish but an additional run was made to 11,665ft to confirm that the tubing was clear of debris and the well was handed back to production operations on March.

The 17 wireline runs which were made were carried out in a total of 7days with the results of each run being evaluated by the region team leader and fishing specialists and the next run being agreed with the client in every instance. Conclusions This operation was successfully concluded in part due to the fishing expertise brought to bear on the problem but also due to the seamless integration of the client knowledge of the well and the in-office HDWF region team leader. As each run was concluded the next one was discussed and agreed with the client and so the whole operation was greatly accelerated, no time was lost in decision making and as a result the operation was performed very efficiently. This operation was a classic example of the value of experience when it comes to fishing, when fishing situations arise in drilling operations it is standard practice to call in a fishing expert and the appropriate tools, the same should probably apply to wireline fishing operations but seldom is the expertise mobilized before the situation is exacerbated. Wireline fishing is an art in itself but not one that routine wireline operations personnel have much chance to acquire, as a result they are often “thrown in the deep end” with the all too common result that, despite the best will in the world being brought to bear, the situation is made worse. In this instance a total of 45 wireline runs and 11 CT runs only served to compound the problem, but just 17 runs made by heavy duty wireline fishing expertise, backed up by extremely responsive client company collaboration, fixed the problem. It can be concluded that HDWF services should be the first, not a last, resort. Acknowledgements The authors would like to thank Medco E & P Indonesia and Weatherford International Ltd. for permission to publish this paper and for their encouragement to do so. List of Illustrations Fig. 1 Well completion diagram. Fig. 2 Fish left in the well. Fig. 3 Screwdriver recovery tool showing lost fingers. Fig. 4 High load tool string. Fig. 5 Surface BOP arrangement for fishing operations. Fig. 6 Lead impression block from Run #1. Fig. 7 PRS pulling tool with damaged and missing fingers. Fig. 8 Material recovered with magnet – runs Fig. 9 BIB with slick line impressions. Fig. 10 PRS pulling tool with Slick line in latch fingers. Fig. 11 Nose cone of DB plug filled with debris. Fig. 12 Grapple parts recovered on final run.

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Fig. 1.

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Fig. 2.

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Fig. 3. Fig. 4.

Operational example with 5/16" Dy form Operational example with 7/32" Dy formUtilising a Petroline Premium 2 11/16" High Load Toolstring Utilising a Petroline Premium 2 1/2" High Load ToolstringDepth 11,400 ft Depth 11,400 ftWire Weight/1000ft - 7/32" 232 lbs Wire Weight/1000ft - 7/32" 111 lbsToolstring weight at surface 550 lbs Toolstring weight at surface 350 lbsMBL of wire 19000 lbs MBL of wire 6500 lbs

Safe Pull at 60% 11400 lbs Safe Pull at 60% 3900 lbsWire Weight on depth 2645 lbs Wire Weight on depth 1265 lbsToolstring Weight 550 lbs Toolstring Weight 350 lbs

Combined T/S & Wire Wt on depth 3195 lbs Combined T/S & Wire Wt on depth 1615 lbsJar Setting Available - approx 8205 lbs Jar Setting Available - approx 2285 lbs

Approximate Impact Available 120 - 150,000 lbs Approximate Impact Available 40 - 80,000 lbs

Diameter Recommended Flow Tube Diameter

Approximate Weight Recommended Minimum Pulley Diameter

Minimum Breaking Load (MBL)

Inches Inches lbs/1000ft Inches lbf5/16" STD 17,550

5/16" HS 19,000*STD: Standard Dyform Construction*HS: Higher breaking load has been achieved by increasing the tensile strength of individual wires.

H2S & CO2Corrosive Elements Chloride, Brine etc H2S, CO2 and Chloride

Galvanised Very Poor Good Extremely Poor

Diameter Recommended Flow Tube Diameter

Approximate Weight Recommended Minimum Pulley Diameter

Minimum Breaking Load (MBL)

Inches Inches lbs/1000ft Inches lbf

*STD: Standard Dyform Construction*HS: Higher breaking load has been achieved by increasing the tensile strength of individual wires.

H2S & CO2Corrosive Elements Chloride, Brine etc H2S, CO2 and Chloride

Supa 75 Excellent all conditions Excellent Very Good

0.228" 111 14

HDWF - 7/32" Supa 75 Dyform Fishing Cable Corrosion Properties

7/32" 6,500

202320.330"

HDWF - 5/16" Galvanised Dyform Fishing Cable Construction

HDWF - 5/16" Galvanised Dyform Fishing Cable Corrosion Properties

Fig. 5.

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1 Grease Injection Head 10k 65 Weatherford ME

Grease Head 6 1/2" Otis x/over Weatherford HDWF

Lubricator 6 1/2" Otis 8.00 3.00" 10k 275 MEDCO

Lubricator 6 1/2" Otis 8.00 3.00" 10k 275 MEDCO

Lubricator 6 1/2" Otis 8.00 3.00" 10k 275 MEDCO

Lubricator 8 3/8" Otis 8.00 4.00" 10k 410 MEDCO

8 3/8" Otis QU to 4 1/16" Flange 1.50 75 MEDCO2 4 1/16" Flange to 8 7/8" Otis Pin 1.50 4.06" 10k 100 Weatherford HDWF

8 7/8" Triple BOP 5.00 5.125" 10k 1500 Weatherford ME2 x 7/32", 1 x Shear & Seal8 7/8" Otis Box to 4 1/16" Flange 1.50 4.06" 10k 100 Weatherford HDWF

Lubricator Spool 4 1/16" 19.00 4.06" 10k 1000 MEDCO

3 4 1/116" ELMAR Dual BOP (Dressed Blind) 5.54 4.06" 10k 1250 MEDCO4 1/16" Shaffer Annular BOP 2.33 4.06" 10k Weatherford APAC

4 4 1/16" Shaffer Shear Seal c/w Boosters 1.66 4.06" 10k Weatherford APAC4 1/16" Shaffer Blind Ram 1.66 4.06" 10k Weatherford APAC

5 4 1/16" Manual Valve 2.16 4.06" 10k Weatherford APAC4 1/16" Hydraulic Valve 2.16 4.06" 10k Weatherford APAC

6 4 1/16" Manual Valve 2.16 4.06" 10k Weatherford APAC4 1/16" X-Mas Tree 4.06" 10k MEDCO

7 Total Internal PCE Length above hyd v/v 73.85 ftTotal external height above tree 104.00 ft

Total weight8 5600 KG

High estimate

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MEDCO E&P7/32" Weatherford HDWF Rig Up

Item Description Length (feet)

ID (inches) MWP (kpsi) Weight(Kgs) Supplier

Additional Info Elevation

Lubricator slings 20 ft x 6.5t SWL eachTotal rig up height is 104 ft w ith lubricator slings..

This excludes tree height.

This is only a suggested rig up schematic, This drawing could change once HDWF Tech is on site.

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Fig. 6. Fig.7. Fig. 8. Fig. 9.

Fig. 10.

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Fig. 11. Fig. 12.

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