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    Avoid Lost CirculationRaise or lower the drill string slowly.

    Ream any tight section;

    Don't not spud.

    Begin rotation and then start the pump at a low rate and gradually increase the rate.

    Operate the pump at the lowest rate that will assure adequate cooling of the bit and removal of cuttings.

    If seepage losses occur while drilling, condition the mud before the losses become severe.

    Prevent bit and stabilizer balling

    Do not drill soft formations so fast as to overload the hole.

    Make frequent measurements of mud properties and treat and maintain the drilling fluid

    minimum weight (hydrostatic head and solids content)

    minimum viscosity (pressure in the annulus while circulating)

    minimum filtration (filter cake restriction of the annulus)

    Keep gel strength down

    In other word keep the surge pressure's under control

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    LUBEANDBLEEDMETHOD.Basicallyestablishthefollowing:

    SafetyFactor(SF)

    Recommend50psi

    PressureIncrement(PI)

    HPofmudlubricatedperstep

    Recommend50psi

    LubeIncrement(LI)

    MudvolumeequivalenttoPI

    Thenfollowthisprocedure:

    1.SelectSF,PIandcalculateLI

    2.NoteCP,thenpumpLI(basedonSF)

    3.BleedgasuntilCPreachesCPnotedinStep2(ThisestablisheshydrostaticSF)

    4.NoteCP,thenpumpLI(basedonPI)

    5.BleedgasuntilCPreachesCPnotedinStep4minusPI

    6.Repeatsteps4and5untilwellisdeadorCPreacheswellborelimits(MAASP)

    WAITANDWEIGHTMETHODW&W method only has the advantage of less pressure at the shoe if the volume of the string is less than the

    volume of the open hole from the kick zone to the shoe.

    That means that kill weight mud is out of the string into the annulus (and starts to have an effect on BHP)

    before the kick is circulated into the casing shoe.

    If you have a shallow shoe and a long open hole section, W&W could be a better method.

    dispersedandnondispersedmudsExamplesofdispersedandnondispersedmudsareLignosulphonatemudsandPolymermudsrespectively.

    Typicallythetwotypesofwatebasemudaredistingushedbyafundamentaldifferenceintheirrheologyandfiltrationcontrol

    where:

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    Dispersedmuds PV>YPandideallyYP=MWnumericallyspeaking.Theviscosityandfiltercakesubstratearebothfrom

    prehydratedbentonite&/orreactive(smectitic)formationclays.

    Nondispersedmuds YP>PVwheretheviscosityandfiltercakesubstrateshouldbothbefrompolymersonly.

    Themovementbetweenthetwoextremesisknownas"flipping"

    HoweveryouwilloftenseeslightlyorheavilydispersedpolymermudasdescriptivenamesespeciallyforHP/HTwellswhereitis

    difficulttocontrolthegelationandflocculationofclays&/orreactivedrilledsolids

    Pros&cons.

    Thesupremebutenvironmentally unacceptabledispersant chromiumlignosulphonate meansincorporationofreactivedrilled

    solidsandhencetheirdilution(mainlywithfreshmud)tocontrolincreasingviscosityandhencealargerwastemudvolumefor

    ultimatedisposal....whereaspolymersmostlyencapsulatedrilledsolids,stoptheirdispersionandfacilitatetheirremovalby

    solidscontrolequipmentwhichinturnmeanslessdilutionisrequired.

    AdditionallythereisanissuethatarelativelyhigherpH(9.5 10)isneededforlignosulphonatemudstofunctionOPTIMALLY

    andthe

    hydroxyl

    alkalinity

    in

    turn

    will

    promote

    reactive

    shale

    hydration...

    whereas

    polymers

    themselves

    do

    not

    require

    such

    pH

    adjustments...

    Ofcourseeverythinginlifeisusuallyacompromisebetweenvariousobjectivesandthelignosulphonatesystemcanbetailored

    accordingly.....

    BITBALLING.

    TomyunderstandingisifyouhaveaconsistantorsignificantdropinROPcoupledwithreducedtorqueisbasicalysomewhat

    relatedtoBit'sbeingballedup.

    Toconfirmthiscondition,onewillpickofbottom&pumpathighrateswithrotation,gobackdown&seeifanyprogressis

    made.

    ButthenagainbeingindrillingfluidsthefirstinstanceofballingtheywouldrefertotheMUD.Yesifyouhavepoorinhibition,

    lubricityetc

    Ihavefoundinrecentsituations,keepingtheviscositylow,nohigherthan32seconds,usingadetergentinconjunctionwithKCL

    oraKCLreplacementtendstoworkwell.

    Bitchoiceisimportanttoo.ThehighertheviscositytheslowertheROPtendstobe.

    Wecandoquiteabittominimizeclayhydrationanddispersion.

    1.

    Manage

    ROP,

    TFA

    of

    bit,

    and

    pump

    rates

    to

    keep

    the

    bore

    clean.

    2.ManagethefluidtomaximizecuttingsremovalandperhapslimitECD.

    3.Createawallcakeorphysicalbarrierbetweenthefluidandformation.

    4.Createamembraneorosmoticbarriertolimitthetransferofwatertocuttingsorformation.

    5.Limitthewateractivityor'willingness'ofthewatertointeractwithclays.

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    6.Limittheactivityorreactivityoftheformationandpreventthedispersionofcuttingsthemselves.

    7.Provideafluidthatcoatsthedrillsteeltopreventadhesion.

    Ihavehadgoodresultsinpumpinga"NutPlug"orgroundwalnuthullspilldowntothebit,whichjustsandblaststhebit.The

    hullshavenoeffectonthemudpropertiesandjustgoovertheshaker

    CausticPillasacureforballing/ seven25kgsacksofcausticweremixedinto15bblmud,andpumped.Wesloweddisplacement

    asthepillwentthroughthebit,meanwhilerotatingfast,andgentlytaggingbottom.sucharemedyhassafetyimplications,not

    onlywhen

    mixing

    the

    pill,

    but

    also

    when

    it

    comes

    back

    over

    the

    shakers.

    So

    everyone

    needs

    to

    be

    kept

    in

    the

    loop

    about

    what's

    happening.

    orbitballing,shouldbemakeabrinewith(kcl&Nacl),withhighph(caustic),pumpintheholebehindBHA.withhighrpm

    andup&downstring.cleanthebit.

    .

    Forcv

    Youmaywanttomentionyouhaveagoodworkethic,you'reusedtoworkinglonghoursinthefield,you'refamiliarwithdrilling

    operations,youworkwellunderpressure,you'rewillingtoworkwhenevertheyneedyou,you'reflexible,youhavecompetent

    computerskills,you'regoodatmath,youknowyourwayaroundacalculator,youareabletobuildstrongandlasting

    relationshipsintheworkplace.........

    Goodunderstandingofdrillingrigequipmentanddownholetools.Astrongcommitmenttosafeworkpracticesand

    anabilitytokeepdetailedsafetyrecordsAbleandwillingtotravelasrequiredStrongorganizationandtime

    managementskills

    Work

    in

    ateam

    atmosphere

    where

    the

    drilling

    engineer

    is

    an

    integral

    part

    of

    the

    group

    rather

    thananindividualentit

    HPHT Fingerprinting Tests for Reservoir hole section

    Section 1 Summary

    Section 2 Tool Details

    Section 3 Programme

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    Section 4 Constraints

    Section 5 Procedure: Clean Out Trip

    Section 6 Procedure: Subsequent Operations

    Section 7 Reporting

    Section 8 Key Uses of Data

    Section 9 Performance Indicators

    1. Summary

    This programme will be performed to establish the operating limits and wellbore characteristics within which the reservoir holesection of this HPHT well will be drilled. These limits will be established by measurements from a downhole PWD sub and also

    from surface tests and measurements.

    Mud weight profile in the well (barite sag characteristics). On bottom mud hydrostatic. Effective circulating density at the casing shoe and during drilling. Swab and surge pressures applied to the formations whilst tripping.In addition a stripping drill, dummy flow check and well shut in will be made in order to get a good understanding of the wellbore

    characteristics.

    The purpose of taking these measurements is as follows:

    To ensure that sufficient hydrostatic overbalance is maintained on the wellbore during all drilling operations. To indicate the amount of barite sag, and optimise the management of it. To ensure that the ECD remains below the fracture gradient of the weakest formation. To monitor the ECD whilst drilling as a possible indicator of poor hole cleaning. To fingerprint the wellbore response under static conditions so that deviations from normal wellbore behaviour can beidentified easily. To validate hydraulic models.The running of the PWD tool and the data gathering exercises are planned to assist in the management of the drilling in the

    reservoir section. At all times well control and wellbore integrity will be of higher priority than any of the data gathering planned.

    2. Tool Details

    The PWD tool is an MWD sub and will be run in the BHA on at least the first drilling assembly run in the reservoir hole section.

    The measurements of the pressure in the annulus are recorded continuously however only whilst circulating is data transmitted

    real time. Data measurements whilst the pumps are off or if the flow rate is below a threshold cannot be transmitted grealtime h but are downloaded once the tool is pulled out of the hole.It is important that the internal clock for the tool is synchronised with the mud loggers and rig floor recording equipment as that

    will make correlation of downhole with surface events much simpler, particularly for the data that is stored and downloaded at

    surface.

    Table 1 PWD data transmission

    Test Real Time Downloaded

    Gradients tripping in/out X

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    FIT X

    Static mud weights X

    ECD at slow circulating rates X (below threshold)

    ECD at drilling flow rates X

    Tripping swab / surge X

    Transmission / storage rate PWD data depends upon the other tools in the MWD string. However this is typically 80 seconds per

    data point for pumped data and 10 seconds per data point for stored data. This is sufficient for the purpose of monitoring the

    parameters whilst drilling ahead.

    All depth monitoring systems shall be calibrated and consistent with each other. Also periodically during drilling ops and tripping

    both the MWD supervisor and Mud Logging supervisor shall check their depths against the drillers.

    For the first trip in and out of the hole, the depth gline h should be on to record depth of the PWD whilst RIH. This is to checkthe hydrostatic column for barite sag and also to provide data on swab / surge whilst tripping. If barite sag is not seen, the depth

    line may be left off on trips after this but the PWD data on trips should still be presented against time.

    Data should be recorded from surface to surface in order that all of the trip data pertaining to swab / surge and sag is captured.

    3. Programme

    This procedure is written on the basis of the following general programme.

    Trip in hole (intermediate mud weight in hole), with slick assembly + PWD. Undertake fingerprinting tests. Test numbers 1 to 7. Drill out shoe. Drill 15 ft of new formation. Conduct FIT. POOH with slick assembly. Download PWD data. RIH with drilling assy. Drill ahead.

    4. Constraints

    It is important that the tests are made with drilling mud weight, therefore they are conducted after displacing the hole to drilling

    mud. However this imposes particular constraints upon the procedures which are outlined below.

    All the specific tests shall be undertaken with the bit inside casing unless the use of motors / turbines dictate otherwise. The tests should not commence unless the mud is in condition and gas free. The running / pumping speed limits are based upon worst case reservoir pressure and expected formation strength at thecasing shoe with a 100 psi safety margin. This is to ensure that the test procedures are maintained within the pore pressure /

    fracture gradient window. The maximum allowable pump rate for the purpose of the tests is the upper threshold limit on the tool.

    The following table outlines the limits which have been applied to the test procedures where either swab, surge or circulatingpressures are imposed upon the formation.

    Table 2: Limits for Test Procedures

    Activity Potential effect Base Case Safety Margin

    Pull out Swab Worst case reservoir pressure + 100 psi

    Run in Surge FIT expectations - 100 psi

    Pump out Swab/Surge Worst case res press / FIT +/- 100 psi

    Circulate ECD FIT expectations - 100 psi

    Subsequently if the formation leaks off lower than the FIT expected, the tests may have to be repeated following discussionwith Base.

    At no time should the ECD be allowed to exceed the FIT expected.

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    If at any time during the tests the well gives any kick indications the well should be closed in and kick procedures instigated.

    5. Procedure: Clean Out Trip

    Run the PWD tool in the slick drillout string BHA, as indicated in the drilling programme. BHA summaries should include

    numbers and spacing of any in-string devices that may affect the ECD.

    Whilst performing the stripping drill, record the surface stripping parameters so that when downloading the PWD pressure datacan be evaluated against the stripping drill.

    Whilst displacing to drilling mud weight monitor and record the PWD data for the duration of the displacement.

    The tests will be made with conditioned drilling mud weight.

    Record carefully the measured depth and the true vertical depth of the PWD sensor. Where pump rates or tripping rates are

    changed between tests, sufficient time should be allowed for the mud system to stabilise.

    Test Number 1: Static Mud Weight Test

    Purpose of Test

    The purpose of this test is to measure the actual hydrostatic pressure of the mud downhole. The data will be downloaded when the

    PWD tool is back at surface and correlated to the temperature corrected mud weight at surface. Prior to the tests ensure that the

    flow line temperature has stabilised, this will ensure that the temperature profile of the drilling mud in the hole is similar to that

    expected under gnormal h drilling conditions.ProcedureBit in casing just above float collar.

    Temperature corrected mud weight taken immediately prior to finishing circulating.

    Pumps off.

    No pipe rotation.

    Monitor for 5 minutes.

    Test Number 2: Slow Circulating Rates

    Purpose of Test

    The purpose of this test is to measure system pressure losses at kill circulation rates as per standard well control procedures.

    Additional downhole PWD data will be collated in order to measure the ECD at the slow circulating rates.

    ProcedureAs per standard SCR procedures. As the pump rate will be to slow to initiate real time transmission the data should be

    downloaded at surface on the first trip out.

    SPM SPM SPM

    Pump 1 20 30 40

    Pump 2 20 30 40

    Pump 3 20 30 40

    Test Number 3: Open Choke Circulation fsPurpose of Test

    The purpose of the test is to ascertain the ECD imposed at the bottom of the well whilst circulating via an open choke at typical

    circulating rates.

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    Procedure

    Flow Rate Rotation Time

    Pump 1 350 gpm 0 5 mins

    Test Number 4: Dummy Flow Check

    Purpose of Test

    To indicate the typical well response when a flow check is made on a benign well.

    ProcedurePerform a flow check on the well from drilling flowrate. Continue the flowcheck until the trip tank stabilises (allow up to 30

    minutes).

    Test Number 5: Trapped Pressure Test

    Purpose of Test

    To confirm the typical magnitude of trapped pressure when performing a well shut in. The results of this test do not change well

    control procedures. The existence of pressure when the well is shut in should always be regarded as a live situation. However the

    magnitude of the shut in pressure may exclude trapped pressure if it is greater than that experienced in this test.

    Procedure

    Perform a well shut in after shutting down the pumps from drilling flow rate, using the standard shut in. Note time taken to close

    the well in from the shutting down of the mud pumps and the amount of gtrapped h pressure (if any).

    Test Number 6: Drilling Flow Rate Tests

    Purpose of Test

    The purpose of the test is to measure the actual ECD for given sets of flow rate and rotation.

    Procedure

    Flow Rate Rotary Speeds Time per

    (gpm) 0 rpm 60 rpm 120 rpm test, mins.

    250 x x x 5 (not real time)

    300 x x x 5

    350 x x x 5

    400 x x x 5

    Note: x denotes where a test is required.

    Note: Lower flow rate for PWD tool may be 300 gpm.

    Note: If PWD pressure has not stabilised after 5 minutes, continue with test.

    Note: The ECD from the PWD sub should be continually monitored and the actual ECD not allowed to exceed the expected FIT

    value. Record both surface and PWD data.

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    Test Number 7: Tripping Swab / Surge Tests

    Purpose of Test Ascertain the swab pressures are for any given pulling speed. Ascertain the swab pressures are for any combination of likely pulling / pumping combinations. It is important to recognisethat pumping out of the hole can still impart swab pressures if the tripping speed is too high relative to the ECD created by the

    pump rate. Ascertain the surge pressures are for any given running speed.

    Procedure

    Operation Stands Trip Speed Pump Rate

    POOH 1 60 sec/std 0

    RIH 1 60 sec/std 0POOH 1 60 sec/std 0

    RIH 1 60 sec/std 0

    POOH 1 60 sec/std 0

    RIH 1 60 sec/std 0

    POOH 1 120 sec/std 0

    RIH 1 120 sec/std 0

    POOH 1 120 sec/std 0RIH 1 120 sec/std 0

    POOH 1 120 sec/std 0

    RIH 1 120 sec/std 0

    Pump Out 1 60 sec/std 300 gpm

    Pump Out 1 60 sec/std 300 gpm

    Pump Out 1 60 sec/std 300 gpm

    * Allow 2~3 min between each activity with pipe static (assuming pipe is in casing) for pressure effects in the well to dissipate.

    Completion of tests, continue as per programme.

    6. Reporting

    The following reports should be emailed or faxed to Base Operations at appropriate time. It is important that all graphs and

    reported data is annotated sufficiently to allow that data to be evaluated. Other pertinent data should be reported at the discretion

    of the Snr TP.

    6.1 On Clean Out Trip

    Stripping Drill Graph of PWD pressure vs time during the stripping drill, annotate with pertinent stripping data. Summary of additional pressures exerted on the formation whilst stripping in the hole.Tripping in/out Graph of PWD pressures as trip in/out of the hole annotated with depth at regular intervals. List of mud gradient for every 500 ft interval. List of temperature for every 500 ft interval.FIT Graph of PWD pressure vs time, annotated with depth of measurement TVD, depth of shoe TVD, mud weight in the hole. Graph of surface pressure vs time.Static Mud Weight Test Graph of PWD pressure vs time, annotated with depth of measurement TVD, surface mud weight corrected for temperature,temperature of flow line prior to stopping circulation.

    Slow Circulating Rates

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    Graph of PWD pressure vs time, annotated with depth of measurement TVD, surface mud weight, circulating rates. System pressure losses at SCR fs.Drilling Flow Rate Tests Graph of PWD pressure vs time, annotated with depth of measurement TVD, surface mud weight, circulating rates, rotaryspeeds. Table/graph of the ECD at the flow rate/RPM combinations.Dummy Flow Check

    Plot of trip tank level vs time.

    Trapped Pressure Test Trapped pressure value (if any) and shut in time. Volume bled back when opened well.Tripping Swab / Surge Tests (Casing not drilled out) Graph of PWD Pressure vs Time, annotated with tripping speeds, mud weight in the hole, depths of measurement (TVD). Table to swab/surge equivalent mud weights for each combination. Plot of the data for POOH/RIH of trip speed vs equivalent mud weight. Plot of the data for pumping out of pump rate vs equivalent mud weight.6.2 Subsequent Drilling Operations (if PWD run in BHA)

    Tripping (Downloaded from tool when at surface) Graph of PWD pressure as trip in/out of the hole annotated with depth at regular intervals. If no depth line is attached depthapproximations should be obtained from mud loggers. List of mud gradient for every 500 ft interval. List of temperature for every 500 ft interval. Report the PWD static mud weight prior to commencing circulating after tripping in. Mud Logging data.Drilling/Circulating Report ECD on daily drilling reports with depth of ECD measurement and mud flow rate. Report ECD after any changes e.g. Flow rate, mud weight, mud parameters etc. These will be seen on the daily time basedlogs which should be annotated. Graph of PWD data vs time from any circulation fs e.g. after trips, well kills, pills, hole cleaning circulation fs. Mud Logging data.7. Key Uses of Data

    It is important to understand how the data will impact the operation of the well, this is listed in the table below.

    The data will be discussed and evaluated at Base and at the rig.

    Data Use Result

    Tripping Data To monitor and manage the amount of barite sag. To calculate the effect of barite sag on the hydrostatic at top

    reservoir to ensure that the well cannot become underbalanced due to barite sag alone.

    To recommend a gtrip in h circulating plan that allows the barite sag to be circulated out of the hole without exceeding thepore/frac limits of the well.Static Mud Weight To ensure an overbalance on worst case reservoir pore pressure.

    To validate the temperature corrected mud weight measurement at surface. Adjust mud weight as necessary.

    FIT (If PWD fitted in drilling BHA) To confirm actual pressure applied to formation during FIT. Adjust upper limited for ECD

    etc. based upon actual pressure applied during FIT.

    Data Use Result

    Drill Flow Rate Tests To ensure that the ECD does not exceed the FIT. Recommend a maximum flow rate/pipe rotation

    combination allowable to ensure borehole integrity.

    Dummy Flow Check Understand normal well behaviour. Produce a gstandard h flowcheck curve for the rig floor.Trapped Pressure Test Understand normal well behaviour. To have an early indicator if a shut in well is not behaving gnormally h.Tripping Swab / Surge Tests To confirm the pressures applied to the formation during these activities. Recommend a maximum

    tripping speed and to recommend a suitable pulling / pumping combination.

    All To validate model. More effective use of hydraulic models to assist the wellbore management.

    8. Performance Indicators

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    No kicks due to management of mud hydrostatic (static and dynamic). No losses due to management of mud hydrostatic (static and dynamic). Management of sag without inducing wellbore problems. To undertake the tests without fracturing the formation or underbalancing the wellbore. PWD mean time between failures.

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