考虑等效井网密度的南海东部水驱砂岩油藏采收率预测  

Recovery prediction of waterflooding sandstone reservoir in eastern South China Sea considering effect of equivalent well pattern density

作　　者：杨勇 李伟 唐放 张团 崔传智[2] 钱银 吴忠维 YANG Yong;LI Wei;TANG Fang;ZHANG Tuan;CUI Chuanzhi;QIAN Yin;WU Zhongwei(CNOOC Shenzhen Company,Shenzhen 518067,China;MOE Key Laboratory of Unconventional Oil&Gas Development,China University of Petroleum,Qingdao 266580,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司,广东深圳518067 [2]中国石油大学(华东)非常规油气开发教育部重点实验室,山东青岛266580

出　　处：《大庆石油地质与开发》2022年第4期67-73,共7页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家自然科学基金项目“致密油藏多段压裂水平井时空耦合流动模拟及参数优化方法”(51974343);山东省青岛市博士后应用研究项目“致密油藏体积压裂支撑剂分布模拟与参数优化研究”(qdyy20200084)。

摘　　要：南海东部水驱砂岩油藏一般采用直井和水平井共同开发,井网密度计算存在困难,传统的采收率经验公式不适用,因此亟需建立适用于海上油田的采收率预测模型。运用数值模拟与回归分析方法,建立水平井与直井井数折算比计算模型,然后基于采收率主控因素分析结果,使用多元回归,得到南海东部水驱砂岩油藏采收率预测模型。研究表明:当流度一定时,边水油藏、底水油藏的采收率随等效井网密度增加呈现出先增加快后增加慢的规律,当井网密度增加到3口/km2时采收率增加幅度明显降低;当等效井网密度不变时,边水油藏、底水油藏的采收率随流度的增加而增加,且边水油藏采收率的增幅要小于底水油藏。实例验证表明,预测模型计算结果与实际采收率的相对误差均在5%以内,该模型具较高的预测精度。Waterflooding sandstone reservoirs in eastern South China Sea are generally developed mutually by vertical wells and horizontal wells.It is difficult to calculate well pattern density and traditional empirical formula of recovery factor is not applicable.Therefore,it is urgent to establish a recovery factor prediction model suitable for offshore oilfields.With the help of numerical simulation and regression analysis,calculation model of conversion ratio of numbers of horizontal and vertical wells are established.And then,based on analysis of main controlling factors of recovery,multiple regression is used to obtain prediction model of water flooded sandstone reservoirs in eastern South China Sea. The results show that when fluidity is constant,with increase of equivalent well pattern density,recovery factors of edge water reservoir and bottom water reservoir increase rapidly at first and then slowly.When well pattern density increases to 3 wells/km2,incremental recovery factor decreases significantly.When equivalent well pattern density is constant,recovery factors of the above 2 types of reservoirs increase with the increase of mobility,and increment of edge water reservoir is less than that of bottom water reservoir. Case verification shows that relative error of recovery between calculation by prediction model and actual recovery is less than 5%,proving high accuracy of this model.

关 键 词：南海东部 砂岩油藏 等效井数折算比 采收率预测 回归分析 

分 类 号：TE343[石油与天然气工程—油气田开发工程]