Modeling and Simulation of Naturally Fractured Reservoirs

Transcription

1 Modeling and Simulation of Naturally Fractured Reservoirs Prepared for the EORI Joint EOR Commission & Technical Advisory Board Meeting Shaochang Wo EORI, University of Wyoming Laramie, July 23, 2009

2 2007 Average Water Cut from Wyoming Oil Producing Reservoirs is 96.9%

3 Idealization of A NFR System (Warren and Root 1963) 3

4 4 Dual Porosity/Permeability Model of Single Phase Flow t p C p k f tf f f f = ϕ τ μ ) ( t p C p k m tm m m m = + ϕ τ μ ) ( ( m) f m p p k = μ σ τ + + = / ) ( z mz y my x mx mz my mx L k L k L k k k k S σ Fracture: Matrix: Transfer Function:

5 Some of Proposed Shape Factor Constants for Single-Phase Dual-Porosity Model 1 set of fractures 2 sets of fractures 3 sets of fractures Warren & Root (1963) Kazemi et al. (1976) Coats (1989) Lim & Aziz (1995) π 2 (9.87) 2π 2 (19.74) 3π 2 (29.61) 5

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9 Transfer Function in Multiphase Flow (i.e. Oil, Water, & Gas Phases) Fluid Expansion Gravity Drainage Imbibition Relative Permeability Molecular Diffusion Transfer function of oil-water 2-phase flow with gravity effect τ w kmkrw σ z = σ {( p f pm) + ( ) γ w( hwf hwm)} μ σ w (Kazemi and Gilman 1993) 9

10 Working on Tensleep Reservoirs Reservoir data from Mahoney Dome, Hatfield, East Salt Creek, and Teapot Dome fields Matrix and fracture characterization Peigui Yin, John Lorenz, Scott Cooper Reservoir rock wettability analysis Sheena Xie, Norman Morrow Students Michael Presho, Matthew Johnson

11 Petrel Fracture Modeling Workflow Well data Data Analysis Upscale & Simulate Model Parameters Create DFN 11

12 Petrel, Schlumberger 12

13 Conductive and Storage Fractures Number of Fractures Storage Fractures Conductive Fractures (<10%) Open Fracture Size

14 Proposed Works with A Focus on Tensleep Reservoirs Continuing the work on fracture characterization Research on transfer function for multiphase flow Regression method to estimate the distribution of conductive open fractures from matching well production/injection history Benchmark cases based on actual field data Simulation of CO2 flooding with dual porosity/permeability models

15 Potential Application of Fly Ash in Injection Profile Control and EOR Flooding Prepared for the EORI Joint EOR Commission & Technical Advisory Board Meeting Shaochang Wo and Peigui Yin EORI, UW Sheena Xina Xie and Norman Morrow Chemical & Petroleum Engineering Dept., UW Laramie, July 23, 2009

16 100 μm 16

17 Mechanisms of Particle Capture by Porous Media Big Particles Medium Particles Small Particles SURFACE CAKE STRAINING DEPOSIT

18 Fractures in Tensleep Sandstone Outcrop Core 18

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21 100 μm 21

22 Characteristics of Fly Ash Particles Collected from the chimneys of coal-fired power plants by electrostatic precipitators or filter bags Generally spherical in shape Particle size: 0.5~300 μm True density: 2~2.3 t/m 3 Packing density: 550~658 kg/m 3 Packing porosity: 60%~75% 22

23 Measurement of Fly Ash True Density 23

24 Chemical Composition of Collected Fly Ash Samples State Basin Power Plant SiO2 AI2O3 CaO Fe2O3 LOI WT% WT% WT% WT% WT% Wyoming GRB Jim Bridger Wyoming Overthrust Belt Naughton Craig Wyoming PRB Dave Johnson Hayden Wyoming Denver Basin Laramie River (LRP Unit 1) Wyoming PRB WyoDak BCR

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26 Potential Application of Fly Ash in EOR For Improving Water Injection profile Fly ash + polymer Fly ash + polymer + bentonite + coagulant For Use in Combination with CO2 flooding Surfactant flooding Steam flooding

27 Measured Viscosities of Polyacrylamide Solution with Wall Creek-2 Brine 27

28 Fly Ash Suspension in Polymer Solution At 0 hour After 48 hours 28

29 Project Status Collected ten fly ash samples, including samples from all major Wyoming power plants Purchased a GilSonic Ultraseiver Completed chemical composition analysis on collected fly ash samples and selected Jim Bridger ash for further lab tests Identified a potential field test site at ROMTC Ongoing works on sieve analysis and suspension tests of fly ash in polymer solution Further works including lab core flooding tests, modeling of fly ash transport and straining, and design of fly ash injection for the pilot test site

30 Potential Test Site in Wall Creek-2 at RMOTC 30