well prognosis

7/30/2019 Well Prognosis

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WELL PROGNOSIS

PLANNING & MONITORING OF A DRILLING WELL

Nababrot GogoiDy. Suptdg. GeologistGeology & Reservoir Dept

INDUSTRY-ACADEMIA WORKSHOP

On

Upstream Petroleum Technology30th May-1st June,2011


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EXPLN & DEV

E&P CYCLE


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Rig-up & Installationof all Rig

Equipments,

Infrastructure

Drilling Flow Chart

Spudding Drilling & Casing ofConductor hole

(17.1/2)

Drilling & Casing ofIntermediate hole;

Intermediate OHLogging (12.1/4)

Drilling of Oilstring/Production hole;

Convetional Coring

(8.1/2)

Open Hole Logging(Resistivity, Density-neutron,Sonic, MDT, Open Hole DST,

SWC)

Well Completion(Casing setting,

Cementation)

Cased HoleLogging

(CBL_VDL_USIT)

Initial tests,Perforation, Unloadingby NPU / CTU /Gaslifts


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Released Locations

LOCATIONS

Exploratory DevelopmentAppraisal

Generally first well on a

new structure/ new fault

closure to probe HC

prospects in different

geological formations.

Wells drilled on a

discovered structure for

ascertaining reservoir

limit, OWC/GWC, HC vol

Wells drilled for

production purpose

from a known reservoir

and limited up

production potential as

per FDP.


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WHY WE DRILL A

WELL?


6/35BOTTOMHOLE BEHAVIOUR


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WELL PROGNOSIS (DDDP / GTO)

Depth Data & Drilling Policy

GEOLOGICAL INFORMATIONS (STRUCTURE, PROSPECT, SUBSURFACE POSITION, POSSIBLE

FORMATION TOPS)

CASING POLICIES (SIZE, SETTING DEPTH, TYPE, CEMENTATION)

MUD POLICIES (PARAMETERS, COMPOSITIONS etc.)

DEVIATIONS {PROPOSED PLAN (BUILD-UP/HOLDING/DROPPING)}

INFORMATION OF POREPRESSURE / FOMATION PRESSURE FROM NEIGHBOURING WELLS

EXPECTED SUBSURFACE DRILLING COMPLICATIONS (LOSS ZONE, STUCK PIPE , TIGHT SPOTS)

SAMPLE COLLECTIONS , GAS LOGGING, CONVENTIONAL CORING

WIRELINE SERVICES

WELL COMPLETION AND PRODUCTION TESTING


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Geological Information

BASEMAP

SURFACE LOCATION MAP

DISTANCE & BEARINGS W.R.TO NEIGHBOURING WELLS/STRUCTUERES

-STRUCTURAL CONFIGURATION

-CLOSURE (4 WAY/ FAULT)

-PROSPECT AREA

-FLUID MARGINS

STRUCTURAL MAP

ISOPAY MAP


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Geological Information

-PROSPECT LEVEL

-UPDIP/DOWNDIP W.R.TO NEIGHBOURING WELLS

-PRESSURE-PRODUCTION BEHAVIOUR OF NEIGHBOURING WELLS

-LITHOCOLUMN INDICATING EXPECTED FORMATION TOPS (BASED ON

SEISMIC DATA & NEIGHBOURING WELLS)

GEOLOGICAL SECTION LITHOLOGY FORMATION

Barail

Kopili

Narpuh

Lakadong + Therria

Tipam+Surma

Alluvium+ Dhekiajuli

Langpar

Prang

Basement

Namsang

Girujan


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CASING POLICY

CASING IS LOWERED & SET TO :

PROTECT & MAINTAIN THE HOLE

FACILITATE FLOW OF OIL/GAS FOR LONG PERIODS OF TIME


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FACTORS TO CONSIDER FOR CASING DESIGN:

Total depth of well

Pore pressure, fracture gradients, geothermal gradient

Presence of shallow gas pockets / Boulder, Pebble bed

Critical zones

Depth of potential prospect zones

Time limits on open hole drilling

Casing program compatibility with existing wellhead systems

Casing program compatibility with planned completion programme on

production wells

Casing availability: size, grade and weight

Economics drilling time, casing lowering time, cost of materials & other

equipments

Casing Policy


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WELL PROFILE

J-BendVertical Well

Horizontal Well

S-Bend Well


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TD: < 4000 m TD: > 4000 m

17.1/2

(13.3/8)

12.1/4(9.5/8)

8.1/2(5.1/2)

17.1/2(13.3/8)

26(20)

12.1/4(9.5/8)

8.1/2(5.1/2)

17.1/2(13.3/8)

12.1/4(9.5/8)

8.1/2(5.1/2)

26

(20)

36(30)

TD: > 5000 m

CASING DESIGN: VERTICAL & DEVIATED WELLS

Alluvium/ Namsang

Girujan

Barail/Kopili

Lk+Th/Langpar

Girujan

All/Nam

Lk+Th/Langpar/

Basement


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17.1/2

(13.3/8)

12.1/4

(9.5/8)

8.1/2 (7Liiner)

6

(4.1/2 SlottedLIiner

CASING POLICY

Alluvium/ Namsang

Girujan

Prospect

1000-1500 m

400 m

HORIZONTAL WELL


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DRILLING FLUID

Drilling Fluid Policy


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DRILLING FLUID

ITS A SYSTEM TO PROVIDE A SUITABLE MEDIUM FOR CARRYING OUT EFFECTIVE

AND EFFICIENT DRILLING OPERATIONS AND TO IMPART BOREHOLE STABILITY

PROTECT HOLE FROM COLLAPSE

CUTTINGS REMOVAL FROM THE BIT TO THE SURFACE

CONTROL FORMATION PRESSURE

COOLING AND LUBRICATION

AID IN FORMATION EVALUATION

FUNCTIONS OF DRILLING FLUID:


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HOLD CUTTINGS AND WEIGHT MATERIALS IN SUSPENSIONS, WHEN

CIRCUALTION STOPPED

SUPPORTING A PART OF THE WEIGHT OF DRILL PIPE AND CASING ( i.e. BOUYANCY)

IN TRANSMITTING HYDRAULIC HORSEPOWER TO THE BIT

ACTING AS MEDIUM FOR WIRELINE LOGGING

ENSURING MAXIMUM INFORMATION ABOUT THE FORMATIONS PENETRATED

ACTING AS A MEDIUM FOR HORIZONTAL DRILLING SIGNAL IN PULSES

DRILLING FLUID

FUNCTIONS OF DRILLING FLUID:


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DRILLING FLUID

TYPES OF DRILLING FLUID

OIL BASE WATER BASE

PNEUMATICS

Weight, Temperature, Funnel viscosity, Plastic viscosity, Yield point, Gel

strengths, Water losses, Filter cake, Sand content, Solids content, Oil content,

Calcium content, Salinity

PROPERTIES OF DRILLING FLUID

OIL BASE MUD (OBM): Oil the continuous phase with other chemicals

WATER BASE MUD (WBM): Water the continuous phase with Bentonite

PNEUMATICS: Used predominantly air or gas as the circulating medium


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DEVIATION

DEVIATION POLICY


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DEVIATION

AVERAGE ANGLE METHOD

RADIUS OF CURVATURE METHOD

MINIMUM CURVATURE METHOD

TANGENTIAL METHOD

BALANCED TANGENTIAL METHOD

DEVIATION CALIBRATION METHODS

CRITERIA FOR DEVIATED WELLS

LOGISTICS, LAND ACQUISITION, CLUSTER PLINTH

DEVIATION METHODS SS READING, MWD READING


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LOSS CIRCULATION, PIPE STUCK AND OTHER EVENTS

WELLBORE STABILITY & FLUID LOSS/KICK

PORE PRESSURE ANALYSIS

STUCK PIPE EVENTS/ DRILLING EVENTS


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GEO TECHNICAL ORDER

GTO (Geo Technical Order)

GEOLOGICAL DATA

PORE PRESSURE

PREDICTION

FORMATIONS

DEPTHS vs DAYS

WELLHEAD DATA

CASING SEAT

MUD DATA etc.

Its a glimps:


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SAMPLE COLLECTION, GAS LOGGING, CONVENTIONAL CORING

LITHOLOGICAL DESCRIPTION:

COLOUR, HARDNESS, FRAMEWORK GRAIN IDENTIFICATION, MATRIX, GRAIN

SIZE, SORTING, ANGULARITY

HYDROCARBON INDICATION:

GAS DETECTION: GAS CHART INTERPETATION (ZERO GAS, BACKGROUND GAS,

TRIP GAS, GAS SHOWS, CONNECTION GAS, RECYCLE GAS

OIL SHOWS: ODOR, STAIN, BLEEDING, COLOUR (Dark brown to Pale),

FLUORESCENCE (Dark brown, Golden yellow, Light yellow, Bluish)

RECORDING OF GAS READING & GAS CHROMATOGRAPHY

PREPARE & MAINTAIN FLUSH SAMPLE LOGS/ CUTTINGS LOGS/ MASTER LOGS

CORRELATE WITH NEIGHBOURING WELLS


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ITS A PICTORIAL PRESENTATION OF DIRECT OBSRVATIONS OF LITHOLOGY FLUSHED OUT FROM BOTTOM

HOLE & ITS FLUORESCENCE ALONG WITH GAS READING, ROP, HYDRULICS, DRILLING EVENTS W.R.TO DEPTH

FLUSH SAMPLE LOG

THE FIRST

INFORMATION OF

SUBSURFACE

GEOLOGY

Typical Flush Sample/Cuttings Log/ Master Log


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FLUSH SAMPLE LOG

MASTER LOG

DRILLING DYNAMIC LOG

COMPOSITE LOG

GEOPREMIUM SOFTWARE

ROP, GAS READING, BIT INFORMATIONS, LITHOLOGICAL DESCRIPTION,

FLUORESCENCE etc. ONLINE MONITORING OF DRILLING, GEOLOGICAL &

MUD PARAMETERS IN MLU


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WIRELINE LOGS

WIRELINE LOGS

OPEN HOLE CASED HOLE

Resistivity Logs

Density-Porosity Logs

GR, GR Spectrometry

Sonic Tools

Vertical Seismic Profiling (VSP)

Dipmeter, Inclinometer (Strike, Dip)

Borehole Imaging Tool (XRMI / FMI)

Caliper

Wireline Testing & Sampling (MDT/

RDT)

Neutron Tools

NMR /MRIL

Tool Pusher Logging

GR-CCL

GR-NEUTRON-CCL

VSP

CBL-VDL

USIT / CAST-V

TTP / HSC

BP, RP, TTBP

RMT / RST

WFL

PLT

RECOMMENDING CORING


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RECOMMENDING CORING

RESPONSIBILITY

SideWall Core

Petrology & Mineralogical study,

Sedimentological Study (Grain size, Shape,

Sorting), Petrographic Study (Thin Section,

XRD, SEM), Biostratigraphic Study

(Palaoentology, Playnology), Rock

Mechanics, Geochemistry, ReservoirCharacteristics (porosity, Permeability, oil

saturation, Oil content, Water content)

Conventional Core

By Wireline (CST) During Drilling

Permeability (Vertical, Lateral), CapillaryStudy, Sedimentary Structures, Environment

of Deposition including all studies as in

SWC/CST

ELAN Interpretation


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SWC, PerforationPerforation:Fluid uncertain:

3893.0

3900.03901.0

3919.0

3920.5

3941.0

Why we needCBL-VDL-USIT logs?

PERFORATIONS:

Selection of

Perforation Range Gun type, Perforation

Density SPF), Phasing,

Total Depth Of

Penetration

Open Hole Composite

ELAN Interpretation

CBL_VDL


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GEOLOGISTS RESPONSIBILTY

EXAMINATION OF DRILLCUTTINGS IN HAND SPECIMEN & UNDER

MICROSCOPE FOR IDENTIFICATION & DESCRIPTION OF LITHOLOGY

IDENTIFICCATION OF HC BEARING ZONES BY EXAMINING SAMPLES UNDER

FLUOROSCOPE FOR FLUORESCENCE ( YELLOW, YELLOWISH WHITE etc.

INDICATE OIL / BLUISH WHITE INDICATE GAS / NO FLURORESCENCE

INDICATE WATER ) CORRELATION & SECTION PREPARATION


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GEOLOGISTS RESPONSIBILTY

OIL STRING CASING POLICY (SHOE, FLOAT COLLAR, SHORT JOINTS, CENTRALISER,

SCRATCHERS)

OIL STRING CEMENTATION POLICY (OVERGAUGE, TRUE GAUGE, UNDERGAUGE,

VOLUME OF CEMENT REQUIRED, CEMENT TOP etc.)

INITIAL TESTING POLICY (ZONE TO BE TESTED, PRODUCTION STRING, PACKER, GLVs

etc.)

BULLET PERFORATION NOTIFICATION (BPN)- DETAILS ON PERFORATIONS GUN TYPE,

SPF, CHARGES etc.


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GEOLOGICAL CROSS SECTION


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GEOLOGICAL CORRELATION


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CONCLUSIONSPerforation:

GEOLOGISTS PLAYS PIVOTAL ROLE DURING

DRILLING OF A WELL, FROM SPUDDING TILL INITIAL

TESTING / RIG DOWN.

ALL MAJOR DECISIONS ARE TAKEN BY G&R DEPT.

DRILLING OPERATION ACTIVITIES ARE AN INTEGRATED

TEAM EFFORT INCLUDING G&R, DRILLING, CHEMICAL,

PRDUCTION DEPTS


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Perforation:

THANK YOU

Sunset in Libya

@ nababrot gogoi

well prognosis

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