INJECTION WATER ALTERNATELY SIMULTANEOUSLY WITH GAS TO REDUCE GAS MOBILITY AND INCREASE OIL RECOVERY DISADVANTAGES OF GAS INJECTION : POOR SWEPT EFFICENTCY HIGH COST DUE TO LIMITATION OF GAS SOURCE ADVANTAGE S OF WAG INJECTION INCREASE SWEPT EFFICENTCY REDUCE GAS VLUME FOR INJECTION – REDUCE COST
ĐẠI HỌC QUỐC GIA TP HCM TRƯỜNG ĐẠI HỌC BÁCH KHOA TIỂU LUẬN MƠN HỌC ĐẶC TRƯNG ĐỊA CHẤT KHAI THÁC WAG FOR MIOCENCE BACH HOA CASE STUDY TP HỒ CHÍ MINH-THÁNG 11/2014 Present by: NCS Nguyen Manh Hung WATER ALTERNATE GAS INJECTION (WAG) INJECTION WATER ALTERNATELY/ SIMULTANEOUSLY WITH GAS TO REDUCE GAS MOBILITY AND INCREASE OIL RECOVERY DISADVANTAGES OF GAS INJECTION : - POOR SWEPT EFFICENTCY - HIGH COST DUE TO LIMITATION OF GAS SOURCE ADVANTAGE S OF WAG INJECTION - INCREASE SWEPT EFFICENTCY - REDUCE GAS VLUME FOR INJECTION – REDUCE COST WAG INJECTION MECHANISM ON DOUBLET MODEL WATER WATER OIL OIL GAS WATER OIL OIL WATER WATER GAS OIL GAS WATER VISCOUS FINGERING AND GRAVITY SEGREGATION Gas Mobile Gas & Water Mobile Gas Mobile Virgin Oil Water Mobile SIMULTANEOUS INJECTION Virgin Oil Water Mobile ALTERNATE INJECTION (SLUG) FACTORS EFFECT ON EFFECTIVE OF WAG INJECTION -INJECTION RATE -SLUG SIZE -WAG RATIO -WETTABILITY -TYPE OF RESERVOIR EFFECT OF FLOW RATE Ultimate Oil Recovery, % PV 100 98 96 94 92 Blackwell, 1960 10 100 Horizontal to Vertical Force (VGR) Hung, 2000 1000 VISUALISATION EFFECT OF FLOW RATE 1st slug of gas 1st slug of water 2nd slug of gas EFFECT OF WAG SLUG (Andrew, 1985) EFFECT OF WAG RATIO Ultimate Oil Recovery, % PV 100 96 92 88 84 80 0.2 0.4 0.6 0.8 Volume Fraction of Water in Total Slug During WAG 0:1 1:1 2:1 WAG ratio( Water:Gas) (Andrew, 1985) (Hung, 200) 3:1 5:1 7:1 1:0 EFFECT OF WETTABILITY Tehrani,2001 REPORT OF CORE ANALYSIS ON CMS 300 STT Pore volume F, % Ka, md Kl, md b GD, g/cc 12.718 22.36 15.64 13.20 9.92 2.63 12.573 21 93 37.79 33.91 5.84 2.62 13.218 22.97 36.13 32.27 6.12 2.62 10.569 25.03 545.41 543.46 0.16 2.62 14.717 29.09 631.82 620.72 0.80 2.64 15.572 26.17 403.91 397.58 0.73 2.63 10.628 20.91 24.24 21.55 6.53 2.63 14.797 24.65 17.83 14.91 10.47 2.64 18.978 30.5 740.64 725.17 0.95 2.63 10 9.364 22.52 37.2264 32.46 7.49 2.63 11 9.579 23.06 147.97 141.76 2.09 2.68 12 9.571 22.14 152.34 146.21 1.99 2.67 13 13.054 24.32 249.43 242.02 1.42 2.65 14 11.189 24.51 93.34 87.41 3.3 2.66 15 11.396 27.01 389.47 381.59 0.94 2.66 16 13.160 28.82 644.86 627.41 1.25 2.66 17 7.725 19.32 42.56 38.97 4.65 2.68 18 13.020 28.7 726.10 713.49 0.79 2.66 19 10.267 24.4 100.63 94.30 3.26 2.65 COMPOSITION OF OIL AND INJECTION GAS Composition Injection gas Reservoir oil CO2 0.004 0.0003 N2 0.0036 C1 Sampling condition P Separator = 12 bar T Separator =50 o C 0.0023 % Water = 21.4% 0.71167 0.4376 Date sampling : 27/6/04 C2 0.1327 0.0944 C3 0.0990 0.0916 Reservoir oil charateristic I-C4 0.0111 0.0137 Pb N-C4 0.0228 0.0348 Bg @ 150 bar = 0.01 Bo @ 150 bar = 1.32 I-C5 0.0043 0.0099 r@ 350 bar r@ bar = 150 bar Tr = 0.7671 = 105o C = 0.86 GOR(m3/m3) = 79 N-C5 0.0044 0.0134 C6 0.0027 0.0217 C7+ 0.0037 0.2803 m@150 bar = 1.45 mPa.s; m@ bar m@350 bar =2 mPa.s = 2.9 mPa.s MMP DETERMINATION TO DETERMINE OIL RECOVERY ON SLIMTUBE AT INJECTION PRESSURES MMP MEASUREMENT ON SLIMTUBE Injection pressure at 380 bar Injection pressure at 360 bar 35000 20000 0.6 15000 0.4 10000 0.2 5000 0.0 0.4 0.6 0.8 1.2 20000 0.6 15000 0.4 10000 Injection pressure at 200 bar 0.8 30000 20000 0.6 15000 0.4 10000 0.2 Gas recovery, cc 35000 25000 5000 0.2 0 0.2 0.4 0.6 0.8 1.2 Injection volume, PV Gas recovery Oil recovery 0.6 0.8 Injection pressure at 310 bar 35000 1 30000 0.8 25000 20000 0.6 15000 0.4 10000 0.2 0 1.2 Injection volume, PV Gas recovery Oil recovery 5000 0.4 Injection pressure at 280 bar Oil recovery, PV 30000 0.0 Injection volume, PV Gas recovery Oil recovery 35000 0.2 5000 0.2 0.4 0.6 0.8 1.2 Injection volume, PV Gas recovery Oil recovery Gas recovery, cc 0.2 0.8 25000 Oil recovery, PV Gas recovery, cc 0.8 25000 0.8 25000 20000 0.6 15000 0.4 10000 0.2 5000 0 0.2 0.4 0.6 0.8 1.2 Injection volume, PV Gas recovery Oil recovery Oil recovery, PV 30000 Gas recovery, cc 1.0 30000 Oil recovery, PV 1.0 Oil volume recovery, PV Gas volume recovery, cc 35000 MMP DETERMINATION ON SLIMTUBE 1.0 Oil recovery, PV 0.9 350 BAR 0.8 0.7 0.6 0.5 0.4 200 300 Injection Pressure, bar 400 WAG EXPERIMENT DESIGN • WAG INJECTON BEFORE WATER FLOODING • WATER FLOODING • WAG INJECTION AFTER WATER FLOODING ápsuất đầu Dp Dp Dp Xả van chiều Xả composite core Nướ c Dầ u Khí ápsuất Câ n nén hông Bơm Dp Bơm Thủ y ngâ n Mẫ u lọc thủy ngân bơm không khí không khí thủy lực pump WAG INJECTION PARAMETER ON COMPOSITE CORE Averagre Permeability, Kl, md Average Porosity, % Initial Water saturation Type of rock 206.38 29.11 29.80 Sandstone Total injection volume : 40% HCPV Volume of gas slug : 5% HCPV Total gas slugs injection :8 Total water slugs injection :8 Water: Gas ratio : 1:1 Injection rate : 16.2 cc/hour Angle of coreholder : 45o Injection direction :down-dip Injection pressure : 350 bar Confining pressure : 380 bar HC MISCIBLE WAG INJECTION BEFORE WATER FLOODING Recovery volume, PV 0.8 0.6 0.4 0.2 0 0.5 1.5 Injection volume, PV Oil recovery Gas recovery Water produce HC MISCIBLE WAG INJECTION AFTER WATER FLOODING Recovery, PV 0.8 0.6 0.4 0.2 0 0.5 1.5 Injection Volume, PV Water recovery Oil recovery Gas recovery HC MISCIBLE WAG INJECTION RESULTS Recovery, PV 0.8 0.6 0.4 0.2 0 0.5 1.5 2.5 Injection volume, PV WAG injection before water flooding Water injection WAG injection after waterflooding OIL RECOVERY ON HC MISCIBLE WAG EXPERIMENT Injection type INJECTION VOLUME, PV % RECOVERY WAG injection before water flooding 1.5 80.2 Water flooding 1.5 60.5 WAG injection after water flooding 1.5 17.8 LIMITATION ON HC MISCIBLE WAG INJECTION ON MIOCENE BACHHO LIMITATION Injection pressure at 350 bar is higher than current reservoir pressure at 270 bar TECHNICAL SOLUTION Enriched injection gas with LPG to reduce MMP Change separator condition to get separator gas with low %C1 Injection or slugs with enriched gas and then injection with dry gas or lean gas Injection at near MMP depend on economical aspect of oil recovery and % LPG enrichment CONCLUSIONS In gas injection, HC miscible injection is possible to be the most effective injection cost due to available of source gas, no separation cost and no corrosion protective cost for VietNam oil field HC miscible WAG injection before water flooding increase oil recovery to 80.2%, higher than water flooding about 20% HC miscible WAG injection after water flooding is possible to increase oil recovery about 17.8% extra and about 44.9% residual oil after water flooding CONCLUSIONS The earlier WAG injection is injected, the higher oil recovery will be First or slugs of gas is enriched with LPG and the following slug of gas is lean gas or dry gas may provide cost effective THANK FOR YOUR ATTENTION! ... (74) 108° 00’ E 109° 00’ E 7° 00’ N CASE STUDY FOR WAG INJECTION MIOCENE, WELL 920 FROM BACH HO FILED BACHHO IS OLDEST FIELD IN VIETNAM NOT TOO BIG FOR PILOT TEST DESIGN VERY HIGH WATER CUT... volume, PV WAG injection before water flooding Water injection WAG injection after waterflooding OIL RECOVERY ON HC MISCIBLE WAG EXPERIMENT Injection type INJECTION VOLUME, PV % RECOVERY WAG injection... RECOVERY WAG injection before water flooding 1.5 80.2 Water flooding 1.5 60.5 WAG injection after water flooding 1.5 17.8 LIMITATION ON HC MISCIBLE WAG INJECTION ON MIOCENE BACHHO LIMITATION Injection