大尺度溶洞型油藏压力响应特征  

Pressure Response Characteristics in Large Scale Cavity Type Reservoir

作　　者：刘洪[1] 王新海[2] 

机构地区：[1]油气资源与勘探技术教育部重点实验室.长江大学,湖北荆州434023 [2]石油工程教育部重点实验室.中国石油大学(北京),北京昌平102249

出　　处：《西南石油大学学报（自然科学版）》2012年第4期94-99,共6页Journal of Southwest Petroleum University(Science & Technology Edition)

基　　金：国家重大专项"高压气藏高效安全开发技术研究"(2011ZX05015))

摘　　要：由于多重连续介质模型无法有效模拟大尺度溶洞与地层流动过程,需要建立新的缝洞型油藏试井解释模型研究非均质缝洞型油藏流体流动规律。将溶洞简化为一个等势体,内部压力处处相等,溶洞外流体流动满足达西定律,利用溶洞质量守恒建立了含大尺度溶洞缝洞型油藏数学模型,基于直接边界元方法对数学模型进行了求解。绘制了溶洞压力导数曲线及井底压力双对数曲线和井底压力导数曲线,研究发现,溶洞在井底压力导数曲线双对数图上反映的是一个先上凸后下凹的特征,溶洞半径越大,井底压力曲线上凸下凹幅度越大;溶洞离井距离越大,井底压力导数曲线上凸出现的时间越早。相同溶洞半径情况下,离井距离越小溶洞压力导数峰值越大;相同溶洞离井距离情况下,溶洞半径越大,压力导数峰值越小。Because the multiple continuous media model couldn＇t describe the tlow process between large scale cave and stratum effectively, new well-test interpretation model of fracture-cavity type reservoir need to be established to study the fluid flow rules of heterogeneous fracture-cavity type reservoir. The cave is simplified as an equal-potential body with equal internal pressure anywhere, and the fluid flow outside of cave conforms to Darcy law. The fracture-cavity type reservoir mathematical model is established based on the cave system mass conservation. The cave system pressure and wellbore pressure are calculated by direct boundary element method. The cave pressure derivative curve and wellbore pressure and pressure derivative curve in double-log axes are plot afterwards. The research shows that： the large scale cave bears an earlier-upward and later downward characteristics in wellbore pressure derivative curve in double-log axes is. The larger cave radius induces larger upward and downward scale; and the earlier cave distance from well induces the upward time. The smaller cave distance from well with same radius induces larger peak value of cave pressure derivative; and the bigger cave radius with same distance from well induces smaller peak value of cave pressure derivative.

关 键 词：缝洞油藏 井底压力 等势体 溶洞压力 边界元 

分 类 号：TE312[石油与天然气工程—油气田开发工程]