启动压力梯度和应力敏感效应对低渗透油藏直井产能的影响  

Effects of kickoff pressure gradient and stress sensitivity on the productivity of vertical wells in low permeability reservoirs

作　　者：张楠[1] 王晓琴[1] 徐锋[1] 贾莎[1] 冉艳[1] 

机构地区：[1]油气藏地质及开发工程国家重点实验室西南石油大学,四川成都610500

出　　处：《特种油气藏》2012年第1期74-77,139,共4页Special Oil & Gas Reservoirs

基　　金：国家科技重大专项"低渗透油藏注气补充能量方法及配套技术研究"(2008ZX05013)

摘　　要：由于低渗透油藏普遍具有低孔、低渗特征,导致其油水渗流存在非线性和流态的多变性,使得流体的渗流不再符合经典的达西定律。考虑启动压力梯度和基于岩石本体有效应力理论的应力敏感效应的综合影响,推导出修正的低渗透油藏直井产能方程。以某低渗透油藏为例,研究启动压力梯度和应力敏感效应对其产能的影响。结果表明,低渗透油井中启动压力梯度比应力敏感对产能的影响大,建议进行产能预测时充分考虑启动压力梯度的影响。The low permeability reservoirs are generally characterized by low porosity and low permeability,resulting in the nonlinear oil/water flow with diverse flow regimes and making the fluid flow no longer conform to the classical Darcy law.In the paper,a modified productivity equation for vertical wells in low permeability reservoirs has been derived taking into consideration of the comprehensive influences of the kickoff pressure gradient and the stress sensitivity based on the theory of primary effective stress of rocks.A low permeability reservoir was taken as an example to study the effects of the kickoff pressure gradient and stress sensitivity on its productivity.The study results indicated that the kickoff pressure gradient affected more on the productivity of oil wells in low permeability reservoirs than the stress sensitivity did,so it is recommended that the effects of kickoff pressure gradient should be sufficiently considered in predicting the productivity of oil wells.

关 键 词：低渗透油藏 启动压力梯度 应力敏感 产能方程 本体有效应力 

分 类 号：TE348[石油与天然气工程—油气田开发工程]