Production optimization in fractured geothermal reservoirs by coupled discrete fracture network modeling

被引:89
作者
Gan, Quan [1 ,2 ,3 ]
Elsworth, Derek [1 ,2 ]
机构
[1] Penn State Univ, Dept Energy & Mineral Engn, EMS Energy Inst, University Pk, PA 16802 USA
[2] Penn State Univ, G3Ctr, University Pk, PA 16802 USA
[3] Univ Aberdeen, Sch Geosci, Dept Petr Geol & Geol, Aberdeen AB9 1FX, Scotland
关键词
Geothermal reservoir; Fracture; Thermal breakthrough; Manifold stimulation; Heat transfer; ROCK MASSES; FLUID-FLOW; HYDRAULIC-PROPERTIES; FAULT REACTIVATION; SEISMIC-SLIP; PERMEABILITY; HYDROCARBON; SYSTEMS; STRESS; LENGTH;
D O I
10.1016/j.geothermics.2016.04.009
中图分类号
TE [石油、天然气工业]; TK [能源与动力工程];
学科分类号
0807 ; 0820 ;
摘要
In this work, a stimulation then heat production optimization strategy is presented for prototypical EGS geothermal reservoirs by comparing conventional stimulation-then-production scenarios against revised stimulation schedules. A generic reservoir is selected with an initial permeability in the range of 10(-17)-10(-16) m(2), fracture density of similar to 0.09 m(-1) and fractures oriented such that either none, one, or both sets of fractures are critically stressed. For a given reservoir with a pre-existing fracture network, two parallel manifolds are stimulated that are analogous to horizontal wells that allow a uniform sweep of fluids between the zones. The enhanced connectivity that develops between the injection zone and the production zone significantly enhances the heat sweep efficiency, while simultaneously increasing the fluid flux rate at the production well. For a 10 m deep section of reservoir the resulting electric power production reaches a maximum of 14.5 MWe and is maintained over 10 years yielding cumulative energy recoveries that are a factor of 1.9 higher than for standard stimulation. Sensitivity analyses for varied fracture orientations and stimulation directions reveal that the direction of such manifolds used in the stimulation should be aligned closely with the orientation of the major principal stress, in order to create the maximum connectivity. When the fractures are less prone to fail, the output electric power is reduced by a decrease in the fluid flux rate to the production well. (C) 2016 Elsevier Ltd. All rights reserved.
引用
收藏
页码:131 / 142
页数:12
相关论文
共 39 条
[1]   Optimization of well placement geothermal reservoirs using artificial intelligence [J].
Akin, Serhat ;
Kok, Mustafa V. ;
Uraz, Irtek .
COMPUTERS & GEOSCIENCES, 2010, 36 (06) :776-785
[2]  
[Anonymous], P INT S FUND ROCK JO
[3]   Hydraulic properties of fractured rock masses with correlated fracture length and aperture [J].
Baghbanan, Alireza ;
Jing, Lanru .
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES, 2007, 44 (05) :704-719
[4]   FUNDAMENTALS OF ROCK JOINT DEFORMATION [J].
BANDIS, SC ;
LUMSDEN, AC ;
BARTON, NR .
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES, 1983, 20 (06) :249-268
[5]  
Barton N., 1977, Rock Mechanics, V10, P1, DOI 10.1007/BF01261801
[6]  
Crouch S.L., 1991, Bound Elem Solid Mechanics
[7]   Hydraulic stimulation of geothermal reservoirs: fluid flow, electric potential and microseismicity relationships [J].
Darnet, Mathieu ;
Marquis, Guy ;
Sailhac, Pascal .
GEOPHYSICAL JOURNAL INTERNATIONAL, 2006, 166 (01) :438-444
[8]   Hydraulic properties of two-dimensional random fracture networks following a power law length distribution 2. Permeability of networks based on lognormal distribution of apertures [J].
de Dreuzy, JR ;
Davy, P ;
Bour, O .
WATER RESOURCES RESEARCH, 2001, 37 (08) :2079-2095
[9]   EARTHQUAKE NUCLEATION ON FAULTS WITH RATE-DEPENDENT AND STATE-DEPENDENT STRENGTH [J].
DIETERICH, JH .
TECTONOPHYSICS, 1992, 211 (1-4) :115-134
[10]   A COMPARATIVE-EVALUATION OF THE PARALLEL FLOW AND SPHERICAL RESERVOIR MODELS OF HDR GEOTHERMAL SYSTEMS [J].
ELSWORTH, D .
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH, 1990, 44 (3-4) :283-293