Bob Trentham CEED / UTPB RESERVOIR CHARACTERIZATION Is Your Reservoir Ready For CO 2 ?

HOW MUCH MORE DO I NEED TO KNOW? How much do I know? How heterogeneous is my reservoir Core and Log based Reservoir Characterization Historic well data Historic Field Studies Digitized data Base line data set If the Answer is – “Not Much” or “Not Enough”, Then - What are my Options and Tools?

HOW HETEROGENEOUS IS MY RESERVOIR? Eunice Monument – Thin, high Perm streaks McElroy – Solution enhanced Fractures East Cowden – Vertical ten fold Perm differences Foster – Horizontal and vertical Perm differences Foster/South Cowden – Dead Zones w / low pressure South Cowden – Dual Porosity / Dual Perm North Ward Estes – SHR, Red beds Slaughter - Shingling

CORE/LOG BASED RESERVOIR CHARACTERIZATION More Core????? Utilizes Existing and New Data Develops Reservoir Model – Time for Testing? Sets a Base Line For Expected Results – WARNING Can Fine Tune to Engineering Needs “No Brainers” Number of Layers Data Quality – Time Dependant

HISTORIC WELL DATA Most Fields are 50 to 60 Years old Most Floods are 30 to 40 Years old Info on Permeability – Multiple Early Fracs Info on Water Saturations Info on Pressure Info on Problem Areas Multiple Owners – Raw & Interpretive Data Oil (Gas) Out / Water In Historic Production and Injection Logs Thinking Changes Over Time

HISTORIC FIELD STUDIES Geologic/Engineering At Waterflood Inception Realignment Unitization Signs of Future Trouble

DIGITIZED DATA How many WEllS are enough? How many LOGS are enough? How much interval is enough? Normalization of Logs

BASE LINE DATA SET Establish both GEOLOGIC and ENGINEERING PARAMETERS Water Chemistry - Periodic? $75/per test Bottom Hole Pressure Tests – Static and Transient (21 to 30 Days or more) Production Tests – 3 Days

OPTIONS AND TOOLS Determined by Data Available Determined by Needs vs. Costs Determined by Time Available

RESOURCE ALLOCATION Limited Time, Manpower and $$$$ First Pass – Target “Sweet Spots” Avoid Poor Performance Areas Avoid Geologically Complex Areas

CORING OPTIONS Sponge Coring – Sorw Pressure Coring – Reservoir Conditions Conventional Coring – Reservoir Model Sidewall Coring – Problem areas Analysis - Conventional – Porosity, Permeability, Oil/Water Sat Special Core Analysis for Relative Permeability Capillary Pressure Data Mini - Permeameter

LOGGING OPTIONS Full Modern Suites in New Wells Imaging Logs in wells with core Porosity Logging over time in Monitor Wells RFT’s – Pressure Data

WELL TESTING BOTTOM HOLE PRESSURE TESTS WATER ANALYSES INJECTION PROFILES PRODUCTION PROFILES

GEOLOGIC RESERVOIR CHARACTERIZATION Synergy In House VS. Contract Confidence Level Needs to be Verified - Iterations Should be Scalable

YOUR RESERVOIR: IS IT “JUST LIKE THE FLOOD NEXT DOOR”? Heterogeneity on ALL SCALES Depositional and Diagenetic variations Connectivity Production History