0 International Joint Study on CO 2 EOR

0 International Joint Study on CO 2 -EOR - Study on Applicability of CO 2 -EOR to Rang Dong Field, offshore Vietnam - IEA Collaborative Project on Enhanced Oil Recovery 30 th. Annual Workshop and Symposium 21 -23, September, 2009, Australia Sunao Takagi, Komei Okatsu

1 Objectives To study the CO 2 EOR applicability to the offshore oil field in Vietnam through an international joint study between Japan and Vietnam International Joint Study Laboratory Study Slimtube Test Interfacial Tension Swelling Coreflood Simulation Study Geological Model Upscale History Match EOS Model Optimized CO 2 EOR CO 2 Source Study Site Survey Facility Modification Cost Estimation

Outline l. Reservoir Description and Model l. Laboratory Study l. Compositional Model Study l. CO 2 Source Selection l. Conclusions 2

Reservoir Description and Model Field Overview Ø Offshore Vietnam, Water Depth 50 -60 meters Ø　Production from 1998, Cumulative Production >150 MMbbls Ø　Reservoir : Fractured Basement and Lower Miocene Sand Ø Water Injection for both Reservoirs Ø Production Depletion Phase üPressure Depletion üHigh GOR üHigh Water Cut 3

4 Reservoir Description and Model Reservoir Overview (Lower Miocene) 12 km Ø Depth / Thickness ： 2, 100 m / 50 m üThin Layered Sand üPorosity : 25% average üPermeability : md ~ 1, 000 md üHeterogeneity Ø　Light Oil, API 38 deg, Viscosity<1 cp Ø Cumulative Production >70 MMbbls üReservoir Pressure Depletion <Pb üAreal Difference üHigh P, High WC Area üLow P, High GOR Area Ø Wells : ü 24 Production Wells (1 km well spacing) ü 2 Injection wells 7 km

5 Reservoir Description and Model e Production History Reservoir Pressure Depletion r e t a iv r D W Maintained Pressure High Water Cut Depleted Pressure High GOR

Reservoir Description and Model Geological Model Porosity - Permeability 6

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

8 Laboratory Study Slimtube Test Injection Pore Volume: 1. 2 PV Packing media: Glass beads Measurement point: 5 points Length: 12. 192 m Internal Diameter 4. 6 mm Porosity: 0. 3748 Pore volume: 80. 25 cc Permeability: 9 Darcy

Laboratory Study Interfacial Tension 9

Laboratory Study Coreflood Test 10

Compositional Model Study EOS Model PVT Matching Pseudoization Slimtube Matching 11

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

Compositional Model Study Simulation Results 13

CO 2 Source Selection CO 2 Sources CO 2 Rich Gas Field 1. 0 Million Ton/Year 520 Km from Target Field 1. 0 Billion $ (incl. Rang Dong Mod. ) 14 Fertilizer Plant 0. 4 Million Ton/Year 135 Km from Target Field 700 Million $ (incl. Rang Dong Mod. )

Conclusions n. Environmental friendly project (CCS oriented) n. Suitable reservoir fluid for CO 2 -EOR üPreferable MMP (2, 950 psi) üHigh microscopic sweep efficiency (about 90%) üUnlikely asphaltene damage around miscible pressure n Successful EOS model to match to the experimental data n Gross CO 2 utilization factor : 5. 5 MSCF/STB n Peripheral CO 2 WAG injection selected n Costly Project (Distant CO 2 source) n 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 CO 2 injection and hydrocarbon gas injection cases 15

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