一种研究致密气藏物质平衡的新方法
|
摘要
定容封闭气藏确定原始地质储量一般通过压降图的外推法或线性回归分析法。但致密性气藏呈地层压力系数p/Z与累积产量G_p非线性趋势,不能用常规物质平衡法计算。非线性受两个参数的影响:气井测试时间和气藏自身特性。由于在实际应用中致密气藏测试时间达不到气藏平均压力,也不可能关井恢复气藏压力。因此,本文提出用关键交叉点和斜率方法来确定地质储量,更好了解气藏特性。
Gas material balance in conventional,volumetric reservoirs is described by a linear relationship between pressure/Z-factor(p/Z) and cumulative production.Unfortunately,tight gas reservoirs develop a nonlinear trend,which is not amenable to conventional analysis.The nonlinearity is a function of two items,the testing time and the reservoir characteristics.In practical application,the test time of tight gas reservoir can not reach the average pressure of gas reservoir,and it is also impossible to close wells and restore the pressure of gas reservoir.Therefore,a method has been developed to use key intersection points and slopes from a tight gas material balance plot to better understand the reservoir behavior.
Gas material balance in conventional,volumetric reservoirs is described by a linear relationship between pressure/Z-factor(p/Z) and cumulative production.Unfortunately,tight gas reservoirs develop a nonlinear trend,which is not amenable to conventional analysis.The nonlinearity is a function of two items,the testing time and the reservoir characteristics.In practical application,the test time of tight gas reservoir can not reach the average pressure of gas reservoir,and it is also impossible to close wells and restore the pressure of gas reservoir.Therefore,a method has been developed to use key intersection points and slopes from a tight gas material balance plot to better understand the reservoir behavior.
引文
[1] Arps J.J.Analysis of Decline Curves[M].Trans.AIME,1945:228-247.
[2] Fetkovich,M.J.Decline Curve Analysis Using Type Curves[J].JPT,1980,32(6):1065-1077.
[3] Fetkovich,M.J.,Vienot,M.E.,Bradley,M.D.and Kiesow,U.G.Decline-Curve Analysis Using Type Curves-Case Histories[J].SPEFE,1987,(12):637-656.
[4] Sunde,A.,Chen,H.,and Teufel,L.W.Characteristic sand Drainage Volume of Dakota Reservoirs,San Juan Basin,New Mexico[J].SPE,2000,(3):60288.
[5] Thomas W.Engler.A New Approach to Gas Material Balance in Tight Gas Reservoirs[J].SPE,2000,(11):62883.
[2] Fetkovich,M.J.Decline Curve Analysis Using Type Curves[J].JPT,1980,32(6):1065-1077.
[3] Fetkovich,M.J.,Vienot,M.E.,Bradley,M.D.and Kiesow,U.G.Decline-Curve Analysis Using Type Curves-Case Histories[J].SPEFE,1987,(12):637-656.
[4] Sunde,A.,Chen,H.,and Teufel,L.W.Characteristic sand Drainage Volume of Dakota Reservoirs,San Juan Basin,New Mexico[J].SPE,2000,(3):60288.
[5] Thomas W.Engler.A New Approach to Gas Material Balance in Tight Gas Reservoirs[J].SPE,2000,(11):62883.