介质变形和长期导流裂缝性气藏压裂产能模拟研究  

NUMERICAL SIMULATION OF POST-FRAC PERFORMANCE IN NATURALLY FRACTURED GAS RESERVOIR WITH MEDIUM DEFORMATION AND LONG-TERM FRACTURE CONDUCTIVITY

作　　者：李勇明[1] 罗剑[2] 郭建春[1] 赵金洲[1] 

机构地区：[1]西南石油大学."油气藏地质及开发工程"国家重点实验室 [2]中国石油塔里木油田公司哈得作业区

出　　处：《天然气工业》2006年第9期103-105,共3页Natural Gas Industry

基　　金：四川省天然气开采重点实验室基金项目(编号:GPL04-06)资助。

摘　　要：在气藏开采过程中,由于孔隙压力的不断降低,使得介质变形而导致渗透率的变化,进而影响井的产量。针对这一问题,提出了各种流体与固体耦合的数值模拟模型。然而,对于裂缝性储层和多相渗流问题,流固耦合模型中许多参数不易获取,且求解难度很大,使得耦合模型存在一定的应用局限性。很少有文献在气井产能模拟时将介质变形和就地的长期导流能力加以综合考虑。文章考虑介质变形引起的天然裂缝渗透率的变化和裂缝导流能力随时间递减的影响,建立了裂缝性气藏压裂后气水两相渗流数学模型,推导出了数值计算模型;本模型易于编程求解,对于研究裂缝性气藏的渗流特征,特别是进行单井压后产能预测具有一定的实用意义。计算表明:不考虑介质变形和导流能力递减所预测的气产量偏高;目前普遍使用的气藏数值模拟软件中,假定渗透率、裂缝导流能力为常数,以致模拟计算结果比实际偏高。During the process of gas/oil field development, continuous decrease of pore pressure results in the change of formation permeability because of the medium deformation and hence well performance is influenced. Aiming at solving the problem, different numerical fluid-solid coupled models have been set up. For fractured reservoir and multi-phase percolation, however, some parameters of fluid-solid coupled models are difficult to obtain or determine by calculation and therefore coupled models have their limitations for application. The effects of medium deformation and in-situ fracture conductivity on the productivity were rarely considered in previous literatures. In this paper, the mathematical model of post-frac gas-water percolation for fractured gas reservoir with the change of natural fracture permeability and the decline of the in-situ fracture conductivity is set up from which the numerical model is derived. Because the model is easily programmed shown from example calculation, it has practical meanings for studying post-frac performance in fractured formation, particularly, single well post-frac productivity prediction. The simulation shows that the predicted productivity is higher than real value without considering the effects of the change of natural fracture permeability and the decline of the in-situ fracture conductivity. At present, in most simulation software of gas reservoirs the permeability and the fracture conductivity are assumed constant so that the result of simulation is higher than the real situation.

关 键 词：裂缝性油气藏 压裂 变形(地质) 导流能力 生产能力 数值模拟 

分 类 号：TE377[石油与天然气工程—油气田开发工程]