8/13/2019 Coring and Logging on M-64 Well

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Edisi 11. November 2013Ruang Pustaka

Coring and Logging Witnessingi M-64 Well,Meruap FieldArtikel oleh HQrlina RachmanI - 6 May 2013ime: 28 AprilThe trip purpo$e is to witness coring acquisition and wireline logging activities in M-64 well as part oftraining program.The witnessed job was done for 8,5 inch hole section.

1. COREACQUSITIONM-64 well has acquired cores for several reservoir units. The coringacquisition in M-64 well is planning for four interval (see Table 1 .).However the actual acquisition is only recovered three core intervals(see Table 2.).

1

Coring lnterval(ft-TVDss)BarrelLength(Ft)

Comments,Special Activities2040-2060 20 20 Air Benakat(Semi Unconsolidated)

2 2160-2180 20 20 Air Benakat(5emi Unconsolidated)3 2575-2595 20 20 Air Benakat(Semi Unconsolidated)4 2655-267s 20 2A Air Benakat(Semi Unconsolidated)

Total 80 ft. wl 20ftbarrelTable 1. M-64 Coring plan

And the actual coring acquisition is only recovered for 3 (three)intervals (see Table 2.).

Table 2. M-64 Actual coring acquisitionThe first coring interval was using a Full Closure System as core

catcher. This core catcher system usually runs in the soft formation(loose sand reservoir). lt will act as the primary mechanism toprevent"soft"formation cores exiting the inner barrel prematurely.

Unfortunately, the first interval is a hard formation. The tool got stuckafter penetrate 5.75 ft depth.The next coring interval was running by using a Conventional system.And it was worked in the next three intervals run.Coring point decision is also a critical factor in this core acquisitionactivity. The wellsite geologist should be very careful in looking at thewell correlation.The well correlation was done by using mud log fromsurrounding/offset wells since there was no LWD in this well. ThisM-64 well is using M-17 and M-16 data as offset wells for correlation.The monitoring of real time total gas is very crucial since high totalgas is usually related to hydrocarbon reservoir.The core bit was using MCP 552 type (see Picture 1.). And the corebarrel was using Ultra Stable, heavy d uty 7 1/8" x 4" x 20 ft core barrel.The core barrel consists oftwo parts: the inner barrel and the outerbarrel. This 20 ft core barrel run will help reduce risk of compressiondamage in softer sand. And the 4"core diameter (large diameter)will help the core stronger, less prone to pack-off and minimizeopportunity for structural damage and invasion.The drilling parameters while coring acquisition. such as: WOB,RPM, pump rate (GPM), torque and standpipe pressure, are veryimportant. These are valuable indicators of coring performance. lt isrecommended to have WOB 2 to 4 Klbs, RPM 50-80 and flow rate GPM60-90 (sandstone) to 100-150 (claylshale) until at least 3 ft is cored.When coring is established, the parameters could be increased tomaximum rate of parameters: WOB 20 Klbs, RPM i 00 and 200 GPM.After the core was acquired and laid down, it has several steps tohandle:a. The core is removed from the inner barrel.b. Cut the core into several short pieces (3 ft each) and put mark on

the each core tube (see Picture 3).c. The wellsite geologist will take a small chip sample from each topface for subsequent detailed description.d. Close the core tube with good quality steel tape and put the resinfluid into the tube. This fluid is to protect core from fluids or anyother materials that may come in contact with the core in order topreserve the core (see Picture 4).e. Finally put the core tubes into the wood boxes and transportedinto the Lab (see Picture 5).

CoreRun # Coring lnterval(ft-TVDss) Total toCore (Ft) Comments

1 2247-2252.75 5.7528.75olo recovery. Toolgot stucked due to hardformation (run SoftPro fullclosuresystem)

2 2348-2363.2 15.2 760lo recovery withconventional system.3 2762 0 00,6 recovery. Suspecteddue to failed toolj 2860-2880.7 20.7 100.3olo recovery withconventional system

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Picture '1 . Crire Bit MCP 552 Type

Picture 2. Core Barrel Assembly

Huang Pustaka 6,disi 11. November 2013

Picture 4. Putting resin f.luid into the core tube process

Picture 5. Paeking the core tubes into the wood boxes

Picture 6" Core examples frorn Well M-642. WIRELINE LOGGN${GSeveral logging tools were run in the well M-54 by wireline cable, theywere: PEX-All ADI FMl, CMll, ECs, XPT and CST. Allthese loEginEtools were run in 8.5 inch hole diarneter and divicled into 5 runs.) Run 1 : PEX-AIT combined with ADT) Run 2: FtVll) Run 3 :CMR conrbined with ECSF Run 4: XPT)> Run5:CST

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8/13/2019 Coring and Logging on M-64 Well

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1 Edisi 11. November 2013Ruang Pustaka2,1 PEX-AITPEX-AIT was run with ADT combination. The PEX-AIT measures astandard open hole log curves, such as: GR (gamma ray), Resistivity,Neutron and Density curves of the borehole (see Picture 6). Fromthis measurement we can determi{e the reservoir quality andreservoir content by Petrophysict (Formation Evaluation) analysis andcalculation.2.2 ADT, CMR and ECSThe ADT and CMR-ECS tools were not run in the same time.This isbecause the CMR tool contents a magnetic resource which couldinterfere the ADT tool reading. But the data results of ADT, CMR andECS will be combined together to give a better determination of all oilbearings interval within the formation (see Picture 7).ADT (Dlelectric Scanner) is a direct measurement of water saturation(Sw) or fluid content of reservoir, water salinity and water-filledporosity within the invaded zone. This measurement is independentfrom resistivity.CMR (Combinable Magnetic Resonance) tool basically determine allpermeable intervals. lt provides high resolution answer on reservoirpermeability and porosity (hydrocarbon pore volume). lt also couldidentify hydrocarbons in low contrast and low resistivity pay zonesalso thin pay zones.ECS (Elemental Capture Spectroscopy Sonde) measures primarymineralogy elements in the formation, such as: silicon (5i), iron (Fe),calcium (Ca), sulfur (S), titanium (Ti), gadolinlum (Gd), chlorine (Cl),barium (Ba) and hydrogen (H).The purpose of this measurement is tointegrate with petrophysical analysis.

,* *"3fl"lor[-J?"ltv bv ci*R vtith probahlePicture 7. ADT-CMR-ECS data analysis for reservoir quality analysis

2.3 FMI (Fullbore Formation Micro lmager)The FMI is a very useful tool to analyze the sedimentary and structuralimage of reservoir. The sedimentary images such as: beddingsu rfaces, lamination, cross bedding, erosional surfaces, bioturbationetc, could be used to interpret the depositional environment of theformation. The structural images such as: structural dip, fractures,folds, faults, could be used to interpret the structural event within theformation.2.4 XPT (Pressure Xpress Tool)XPT tool provides high quality reservoir pressure and mobilitymeasurements. This pressure profile and mobility measurements canidentify virgin or depleted reservoir zone in a wider mobility rangeand fluid content identification from pressure gradients calculation.2.5 CST (Cores Sample Taker)CST sometimes called as SWC (Side Wall Cores). CST tool cancollect up to 90 sidewall cores in one trip. ln this case, M-64 wellwas using 30 numbers of bullets in the CST gun (see Picture B).This CST gun is accurately depth positioned by using Gamma Ray(GR) or Spontaneous (SP) logs. From this sidewall cores, manyreservoir data information acquired, such as: lithology identification,porosity measurement, permeability estimation and hydrocarbonidentification.

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Picture 6. PEX-AIT and ADT Log curves result Picture B. CSTTool with 30 bullets