考虑重力因素的断溶体储层“井-洞-缝”模型试井解释方法  

An Interpretation Method with “Well-Cave-Crack” Model of Dissolves Reservoir Considering Gravity Factors

作　　者：徐燕东 XU Yandong(Sinopec Northwest Oil Field Branch Petroleum Engineering Technology Research Institute,Urumqi,Xinjiang 830011,China)

机构地区：[1]中石化西北油田分公司石油工程技术研究院,新疆乌鲁木齐830011

出　　处：《计算物理》2020年第2期189-197,共9页Chinese Journal of Computational Physics

基　　金：国家“十三五”示范工程(2016ZX05053);中石化科技重大专项(ZDP18022-1)资助项目。

摘　　要：顺北油田属于大型断裂构造运动形成的断溶体储层,纵向裂缝系统和垂向分布的溶洞是主要的储集体空间.本文提出溶洞中的压力变化是由流动和波动共同产生的,依此把能量守恒方程与试井理论相结合,建立考虑重力因素的断溶体储层试井解释方法.定义无量纲量,并对无量纲方程进行Laplace变换,得到Laplace空间上的井底压力.由Stehfest数值反演算法得到试井分析所需的图版曲线.对重力因素进行敏感性分析表明:重力因素只影响双对数曲线的末期,当重力因素很明显时,曲线特征类似于定压边界.对新疆油田的某井进行分析,解释了曲线后期下掉原因,并给出溶洞体积以及波动相关参数等,分析结果与生产实际情况相吻合.Shunbei oilfield belongs to fault reservoir formed by movement of large fracture structures. Longitudinal fracture system and vertical distribution of caves are main storage collective spaces. It is proposed that the pressure change in a cavern is caused by flow and fluctuation. According to this, energy conservation equation is combined with well test theory, and a method is established to explain well test of dissolvable reservoir considering gravity factors. With dimensionless quantity and Laplace transformation of dimensionless equation, bottom pressure on Laplace space is obtained. Plate curve for well test analysis is obtained with Stehfest numerical inversion algorithm. Sensitivity analysis of gravity factors shows that gravity factors affect end of the double logarithmic curve. As gravity factors are obvious, curve characteristics are similar to fixed pressure boundary. A well in Xinjiang oilfield is analyzed, in which the reason why it fell down in the later stage of the curve is explained and the valume of karst cave and other related parameters are given. The results are consistent with actual production situation.

关 键 词：顺北油田 断溶体储层 重力 缝洞 

分 类 号：TE371[石油与天然气工程—油气田开发工程]