摘要
针对目前多层合采试井模型m主要为单一边界类型的现状,以双层合采储层为例,建立了纵向组合边界储层渗流模型,依次利用Laplace变换、Bessel函数、Stehfest数值反演得到了压力响应半解析解,绘制了三类纵向组合边界储层的压力响应特征曲线,并划分了流动阶段,系统地分析了边界组合、边界占比对压力响应的影响。结果表明:“封闭+无限大”边界会引起拟径向流,拟径向流阶段压力导数值与封闭边界占比的乘积为定值;“定压+无限大”边界会引起拟定压边界流,且拟定压边界流阶段压力导数斜率与定压边界占比成线性正相关;“定压+封闭”边界会先引起主导层边界流、后引起定压边界流,且定压边界流压力值与定压边界占比的乘积为定值。根据压力响应曲线形态可直接定性诊断纵向组合边界的类型,边界流阶段的压力响应特征值可快速确定纵向组合边界的占比;当储层压力响应出现物性变差的径向复合储层以及双重介质储层特征时,应结合实际储层地质信息谨慎选择试井模型解释。
Given current commingled reservoir well test model is single boundary type,this paper takes the doublelayer reservoir as an example to establish a vertical combined boundary(VCB)reservoir model,and the pressure response semi-analytical solution is obtained by Laplace transformation,Bessel function,Stehfest inversion.The pressure response curves of three VCB types were drawn and the flow stages were divided.The effects of VCB types,proportion on the pressure response were analyzed.The result is shown as follows:(1)The"closed and infinite"boundary will cause pseudo-radial flow regime,and the product between the pressure derivative in pseudoradial flow stage and closed-boundary proportion is constant.(2)The"constant-pressure and infinite"boundary causes the pseudo constant-pressure boundary flow regime,and the pressure derivative slope in pseudo constantpressure boundary flow stage is linearly related to the constant-pressure boundary proportion.(3)The"constantpressure and closed"boundary appears the dominant layer boundary flow regime first,followed by the constantpressure boundary flow regime,and the product between pressure value in constant-pressure boundary flow stage and constant-pressure proportion is constant.It is concluded that the pressure response can directly diagnose the VCB type,and pressure response feature value in the boundary flow stage can quickly determine the VCB proportion.In addition,when the pressure response appears the features of the radial composite reservoir with poor permeability outer zone or dual-porosity reservoir,the well test analysis model should be carefully selected in combination with the actual reservoir geological information.
作者
史文洋
程时清
石志良
张城玮
李虹
屠坤
张郁哲
SHI Wenyang;CHENG Shiqing;SHI Zhiliang;ZHANG Chengwei;LI Hong;TU Kun;ZHANG Yuzhe(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Sinopec Research Institute of Petroleum Exploration and Production,Beijing 100083,China;No.1 Gas Production Plant,Sinopec North China Oil and Gas Company,Zhengzhou 450006,China)
出处
《岩性油气藏》
CSCD
北大核心
2021年第4期156-165,共10页
Lithologic Reservoirs
基金
国家自然科学基金项目“致密油藏注水诱发微裂缝机理及反演方法”(编号:11872073)资助。
关键词
多层合采
纵向组合边界
渗流
试井分析
multilayer commingled reservoir
vertical combined boundary
seepage flow
well test analysis
