Ron Cherry, Maged Fam and Emiliano López Magnetic Resonance Imaging Logging, development and evolution as a fundamental evaluation tool in the reservoir management Ron Cherry, Maged Fam and Emiliano López

Geological & Reservoir Overview Formation Evaluation Problems High uncertainty in reservoir evaluation using conventional Log Analysis, due to: Multilayer reservoirs made up of an average of 20 stacked layers, about 5 mt. each. Low formation water salinity Several water/oil and gas/light oil contacts randomly distributed throughout a rock column of 1000 mts. (average 1500 to 2500 mts.) Complex lithology (shaly and tuffaceous sand reservoirs) Different hydrocarbon types

Core Porosity vs Permeability Permeability (md) Core measurements on samples from about 60 wells, 800 samples from San Jorge Basin Porosity (%) Permeability (md)

Grain Density Vs Core Porosity Matrix Density Distribution in so called “Sandstone” from San Jorge Basin Grain Density Vs Core Porosity Core Porosity (%) Grain Density (G/c3)

MRI Core Porosity vs. Core Porosity San Jorge Basin MRI Core Porosity (%) Core Porosity (%) Core Porosity Vs MRI Core Porosity

Geometric Mean T2 Cutoff vs. Depth Geometric Mean T2 Cutoff (ms) Depth (m) Geometric Mean T2 Cutoff Vs. Depth The high degree of variation in the T2 cutoff range may cause some inconsistencies in the final Interpretation. Thus the SBVI method is a better technique for determining BVI.

Spectral Bulk Volume Irreductible SBVI SBVI Coef. 0.0XXX

Core Permeability and MRI Permeability Models Vs Depth Core Permeability and MRI Permeability Models (md) Depth (m) Core Permeability and MRI Permeability Models Vs Depth N.B.: MRI Permeability data is based on SVBI model

Core Permeability Vs MRI Permeability Models MRI Permeability Models (md) Core Permeability (md) MRI Permeability Models Vs Core Permeability N.B.: MRI Permeability data is based on SVBI model

Reservoir Properties & MRIL Life Cycle Met reservoir Objectives Specify Objectives Reservoir Properties & Problems Borehole Conditions Size, mud, temp….etc Test Results Yes MRIL Pre-job Planning Compare No Data Processing & Interpretation Prognosis Selection of Zones to Test STIMRIL Activation Selection @ Logging speed Field Log QC Resistivity log Core Analysis if available

Acquisition Parameters MRI Forward Model water oil gas Tool Physics Acquisition Parameters G, TE, TW water oil gas MRIL Forward Modeling Planner Expected Fm. Fluid Properties Temp., Pressure & Viscosity water oil Mud Properties Borehole Size

Petrophysical Solution!!! MRI Specific Acquisition and Interpretation Techniques “one logging pass” EDM Enhanced Diffusion Method (Hydrocarbons 2-50 cp) TDA Time Domain Analysis (Hydrocarbons < 2 cp)

But….!!!

1800 L/H 75 % SW 2400 L/H 100 % SW MRI Prognosis: Heavy OIL ShortTE LongTE MRI Prognosis: Heavy OIL 1800 L/H 75 % SW MRI Prognosis: Water 2400 L/H 100 % SW

Special Design for Heavy OIL detection… MRIL Ultra Long TE Activation How can we distinguish Heavy OIL from Water ??? Special Design for Heavy OIL detection… MRIL Ultra Long TE Activation

1800 L/H 75 % SW 2400 L/H 100 % SW MRI Prognosis: Heavy OIL ShortTE LongTE UltraLongTE MRI Prognosis: Heavy OIL 1800 L/H 75 % SW MRI Prognosis: Water 2400 L/H 100 % SW

Heavy OIL Detection Example ShortTE LongTE UltraLongTE Initial Test Result (8hs Swabbing): 2400 L/H – 100% SW Final Test Result (24hs Swabbing): 2400 L/H – 88% SW

Halliburton Question regarding details on test results Dear Customer: “…If We understand well, the formation was producing water for 8 hours before starting to produce Oil …?? You have insisted to keep it producing because there was a very good signal on the MRI Ultra-Long Te activation,….. Is that correct …??...” Customer’s response “It's correct...It has been a very good news today, because up to yesterday, we couldn't believe that from that signal it would be only water... We insisted and it was 2400 l/h x 88% of water (may be the amount of water would have declined if we would wait more time... but for us it was enough seeing some oil)…”

Fluid Typing: Light OIL MRI Prognosis Light Oil w/ HGOR Composite Log MRI Interpretation EDM + TDA Shot-Te/Long-Tw TDA Long-Te/Long-TW Dif. S.-Te/L.TW-S.Tw EDM Flow 920 L/H 40 % SW PVH1083

Fluid Typing: GAS Flow x 12mm Wet GAS P/D 280psi P/E 1560 psi PVH990 MRI Prognosis Light OIL MRI Prognosis GAS Flow x 12mm Wet GAS P/D 280psi P/E 1560 psi PVH990 MRI Prognosis GAS

Halliburton’s Reservoir Fluids Prognosis Sheet Based on MRIL Interpretation

Conclusions Magnetic Resonance Imaging (MRI) Logs as a fundamental evaluation tool in the reservoir Management Determination of Porosity, Independent to Matrix Determination of Bulk Volume Irreducible Water Reliable Permeability Indicator (absolute after Calibration) Identify Fluid Type (Gas, Oil & Water) by zone Identification of Rock Quality…Permeability, Porosity & Clay Determine variations of Hydrocarbon types (Resistivity independent)… …Heavy, Intermediate, Light Oil or Gas Halliburton Energy Services – Provides products, services, and integrated solutions for oil and gas exploration, development and production. Includes Sperry-Sun, Baroid Drilling Fluids, Security DBS, Dresser Oil Tools, Mono Pumps, and Westport Technology from Dresser and Drilling Systems, Logging & Perforating, Zonal Isolation, Tools, Testing & Tubing Conveyed Perforation, Production Enhancement, Completion Products & Services, Integrated Solutions, Integrated Technology Products and NUMAR from Halliburton.