致密砂岩气藏应力敏感性及其对产能的影响  

EFFECT OF STRESS SENSITIVITY ON WELL PRODUCTIVITY IN TIGHT GAS RESERVOIR

作　　者：杨朝蓬[1] 高树生[1,2] 郭立辉[3] 熊伟[1,2] 叶礼友[1,2] 谢昆[1] 

机构地区：[1]中国科学院渗流流体力学研究所 [2]中国石油勘探开发研究院廊坊分院 [3]中国石油新疆油田公司实验检测研究院

出　　处：《钻采工艺》2013年第2期58-61,9,共4页Drilling & Production Technology

基　　金：国家科技重大专项基金"致密砂岩气有效开发评价技术"(NO.2011ZX05013-002)资助

摘　　要：前人普遍采用的变围压定内压的应力敏感实验方法并不适用于致密气藏,为了研究应力敏感对致密砂岩气藏开发的影响,对苏里格致密气藏岩样进行了定围压变内压的应力敏感性实验。致密气藏存在较强的应力敏感性,储层渗透率越低,应力敏感性越强。通过对实验数据进行拟合,无因次渗透率与无因次净围压数据符合乘幂关系,并定义乘幂关系式指数的负数为致密气藏应力敏感性系数。同时得出苏里格气田某区块储层渗透率与应力敏感系数的经验公式,可由此式求得该区块不同渗透率储层的应力敏感系数。建立了考虑应力敏感效应的致密砂岩气井产能方程,应力敏感对致密气井产能有较大影响,随着井底流压的下降,应力敏感对产能的影响逐渐增大,因此有必要避免过快地降低井底流压。The traditional stress sensitive experimental method of confining pressure changing—pore pressure unchanging is not fit to the tight gas reservoirs. The stress sensitive experiment with confining pressure unchanging—pore pressure changing was conducted in order to study the effect of stress sensitivity on the well productivity in tight gas reservoir. The strong stress sensibility in tight gas reservoir was evidenced through experiment. The lower the permeability was, the stronger the stress sensibility was. There was a power correlation between the dimensionless permeability and the dimensionless net confining pressure. And the negative number of the power index was defined to be the stress sensitivity coefficient. Meanwhile, the empirical relation between permeability and stress sensitivity coefficient in a block of Sulige gas field was obtained. Thus, the stress sensitivity coefficient could be determined through this empirical relation. The productivity equation of tight gas well considering stress sensitivity was established. The effect of stress sensitivity on the tight gas well productivity was strong, and the effect would increase with the decrease of bottom hole flowing pressure. Therefore, it is necessary to control the descent speed of the bottom hole flowing pressure.

关 键 词：致密砂岩气藏 渗透率 应力敏感 敏感指数 产能 

分 类 号：TE34[石油与天然气工程—油气田开发工程]