0 International Joint Study on CO2-EOR - Study on Applicability of CO2-EOR to Rang Dong Field, offshore Vietnam - Sunao Takagi, Komei Okatsu IEA Collaborative Project on Enhanced Oil Recovery 30thAnnual Workshop and Symposium 21-23, September, 2009, Australia

1 Objectives To study the CO2 EOR applicability to the offshore oil field in Vietnam through an international joint study between Japan and Vietnam Laboratory Study Slimtube Test Interfacial Tension Swelling Coreflood Simulation Study Geological Model Upscale History Match EOS Model Optimized CO2 EOR CO2 Source Study Site Survey Facility Modification Cost Estimation International Joint Study

2 Outline Reservoir Description and Model Laboratory Study Compositional Model Study CO2 Source Selection Conclusions

3 Reservoir Description and Model  Offshore Vietnam, Water Depth meters  Production from 1998, Cumulative Production >150MMbbls  Reservoir : Fractured Basement and Lower Miocene Sand  Water Injection for both Reservoirs  Production Depletion Phase Pressure Depletion High GOR High Water Cut Field Overview

4 Reservoir Description and Model  Depth / Thickness ： 2,100 m / 50 m Thin Layered Sand Porosity : 25% average Permeability : md ~ 1,000 md Heterogeneity  Light Oil, API 38 deg, Viscosity<1cp  Cumulative Production >70 MMbbls Reservoir Pressure Depletion <Pb Areal Difference High P, High WC Area Low P, High GOR Area  Wells : 24 Production Wells (1km well spacing) 2 Injection wells 7 km 12 km Reservoir Overview (Lower Miocene)

5 Reservoir Description and Model Reservoir Pressure Depletion Maintained Pressure High Water Cut Depleted Pressure High GOR Production History Water Drive

6 Reservoir Description and Model Porosity - Permeability Geological Model

7 Reservoir Description and Model Old Model New Model Simulation Model and History Match Simulation Model Grid X : Y : Z = 97 : 116 : 40 History Matching Old ModelNew Model

8 Laboratory Study Injection Pore Volume: 1.2 PV Measurement point: 5 points Packing media: Glass beads Length: m Internal Diameter4.6 mm Porosity: Pore volume:80.25 cc Permeability: 9 Darcy Slimtube Test

9 Laboratory Study Interfacial Tension

10 Laboratory Study Coreflood Test

11 Compositional Model Study EOS Model PVT Matching Slimtube Matching Pseudoization

12 Compositional Model Study Simulation Results Peripheral > Dispersed WAG> Continuous

13 Compositional Model Study Simulation Results

14 CO2 Source Selection CO2 Sources CO2 Rich Gas Field 1.0 Million Ton/Year 520 Km from Target Field 1.0 Billion $ ( incl. Rang Dong Mod.) Fertilizer Plant 0.4 Million Ton/Year 135 Km from Target Field 700 Million $ (incl. Rang Dong Mod.)

15 Conclusions Environmental friendly project (CCS oriented) Suitable reservoir fluid for CO2-EOR Preferable MMP (2,950 psi) High microscopic sweep efficiency (about 90%) Unlikely asphaltene damage around miscible pressure Successful EOS model to match to the experimental data Gross CO2 utilization factor : 5.5 MSCF/STB Peripheral CO2 WAG injection selected Costly Project (Distant CO2 source) Further Study (1)Cost reduction / optimization study (2)Further laboratory and simulation studies on enriched hydrocarbon gas injection case (3)Pilot test design for both CO2 injection and hydrocarbon gas injection cases

16 Thank You!! Arigato!! Xin Cam On !!