1. IMPLEMENTATION OF PWLS MNEMONICS IN FINDER UNDER EPINET by OIL AND NATURAL GAS CORPORATION LTD.

2.   Log Data Management is an integral part of EPINET.   Original Logs are managed in LogDB in original format.   Edited and spliced logs (Composite Logs) are managed in Finder.   Web Based data delivery from both LogDB as well as Finder. LOG DATA MANAGEMENT IN EPINET

3. LOG TAPES TRANSCRIPTION (dlisu) ORIGINAL LOG MANAGEMENT (LOGDB) COMPOSTE LOG MANAGEMENT (FINDER) FLOW CHART OF LOG DATA MANAGEMENT IN EPINET ATTRIBUTE INFORMATION ONLINE / NEARLINE STORAGE WEB BASED DATA DELIVERY COMPOSITE LOG* GENERATION (GEOFRAME) * Composite Log: Spliced Log

4. DATA DELIVERY   Original Logs from LogDB (Petrophysical applications).   Composite Logs from Finder (Geological, Geophysical & Petrophysical applications).   Web based data delivery to authorized users.

5. Deep resistivity (if different type of tools are run in different intervals: LLD/ AT90 /RLA5/GRD) or 3/6 resistivities (if same type of tool is run in all the intervals: LLD, LLS, MSFL / ILD, ILM, LL3 / GRD, SGRD, FRXO / AT 90, AT 60, AT30, AT20, AT10, RXOZ / RLA5, RLA4, RLA3, RLA2, RLA1, RXOZ) Density (RHOB / RHOZ) Neutron Porosity (NPHI) Sonic (DT / DTCO / DTL / DTLN / DTLF) Gamma Ray (GR / SGR / GKUT) CURVES WHICH ARE SPLICED AND LOADED INTO FINDER

6. Self Potential (SP) Resistivity (LLD, LLS, MSFL / ILD, ILM, LL3 / GRD, SGRD, FRXO / AT 90, AT 60, AT30, AT20, AT10, RXOZ / RLA5, RLA4, RLA3, RLA2, RLA1, RXOZ) Density (RHOB / RHOZ) along with DRHO & PE Neutron Porosity (NPHI) Sonic (DT / DTCO, DTSM, VPVS / DTL / DTLN, DTLF) Gamma Ray (GR / SGR / GKUT) Spectral Gamma Ray (SGR, CGR, THOR, URAN, POTA/ HSGR, HCGR, HTHO, HURA, HFK) CURVES WHICH ARE LOADED INTO FINDER RUNWISE

7. CHALLENGES FACED Two different types of tools are used in different intervals. DLL-MSFL-GR (deep resistivity: LLD) recorded in the top interval AIT-MCFL-NGS (deep resistivity: AT90) recorded in bottom interval Proliferation in the number of curve mnemonics A large number of LWD curve mnemonics have further compounded the problem

8. SOLUTION TO THE PROBLEM PWLS (Practical Well Log Standards) Geology SIG of Energistics

9. LOG TAPES TRANSCRIPTION (dlisu) ORIGINAL LOG MANAGEMENT (LOGDB) COMPOSTE LOG MANAGEMENT PWLS STANDARDIZED (FINDER) ATTRIBUTE INFORMATION ONLINE / NEARLINE STORAGE WEB BASED DATA DELIVERY COMPOSITE LOG* GENERATION (GEOFRAME) * Composite Log: Spliced Log FLOW CHART OF LOG DATA MANAGEMENT IN EPINET

10. PWLS Joined (1 of 3): Change Results Company (and Code) Curve Mnemonic Curve Description Business Value Curve Class POSC 1000 AC Acoustic Slowness HIGHAcoustic_Slowness POSC 1000 AC_SHEAR Shear Slowness HIGHShear_Slowness POSC 1000 AC_SHR_CAL Calibrated Shear Acoustic Slowness HIGHShear_Slowness POSC 1000 AC_SHR_BP Geophysical Shear Acoustic Slowness HIGHShear_Slowness POSC 1000 AC_COMP Compressional Slowness HIGH POSC 1000 AC_CMP_CAL Calibrated Compressional Acoustic Slowness HIGH Compressional_Slow ness POSC 1000 AC_CMP_GP Geophysical Compressional Acoustic Slowness HIGH Compressional_Slow ness POSC 1000 AC_STONE Stoneley Slowness HIGHStoneley_Slowness POSC 1000 AC_IMP Acoustic Impedance HIGHAcoustic_Impedance REMOVED

11. PWLS Joined (2 of 3) Company (and Code) Curve Mnemonic Curve Description Business Value Curve Class POSC 1000 BIT_SIZE Bit Size HIGH Nom_Borehole_Siz e POSC 1000 CALICaliperHIGHCaliper DENDensityHIGHBulk_Density DEN_GP Calibrated Geophysical Density HIGHBulk_Density POSC 1000 GR Gamma Ray HIGHGamma_Ray POSC 1000 NEU Neutron Porosity HIGHNeutron_Porosity POSC 1000 PR Poisson Ratio HIGHPoisson_Ratio POSC 1000 TIM_DEP Time Depth HIGHTime POSC 1000 VP_VS Compressional to Shear Acoustic Velocity Ratio HIGH Compressional_Sh ear_Velocity_Ratio

12. PWLS Joined (3 of 3): Change Results Company (and Code) Curve Mnemonic Curve Description Business Value Curve Class POSC 1000 KPotassiumHIGHPotassium_Concentration GRKT Potassium Plus Thorium HIGH Gamma_Ray_Minus_Uraniu m POSC 1000 THThoriumHIGHThorium_Concentration UUraniumHIGHUranium_Concentration PEF Photoelectric Factor HIGHPhotoelectric_Factor POSC 1000 SP Spontaneous Potential HIGHSpontaneous_Potential POSC 1000 RES_DEP Deep Resistivity HIGHDeep_Resistivity POSC 1000 RES_MED Medium Resistivity HIGHMedium_Resistivity POSC 1000 RES_SHA Shallow Resistivity HIGHShallow_Resistivity POSC 1000 RES_MIC Micro Resistivity HIGHMicro_Resistivity POSC 1000 RT Formation Resistivity HIGHFormation_Resistivity POSC 1000 RXO Flushed Zone Resistivity HIGHFlushed_Zone_Resistivity

13.   A project to implement PWLS mnemonics was initiated in Mumbai region of ONGC.   It has already been implemented in Bassein field.   For remaining wells being implemented.   After implementation in MR it may be implemented in other regions of ONGC. THE PROJECT

14. KEY BENEFITS Simplified curve mnemonics. User friendliness. True representation of a curve if different types of tools are run in a well.

15. KEY BENEFITS For example: For deep resistivity before PWLS implementation: LLD ILD GRD AT 90 RLA5 ……… After PWLS implementation RES_DEP