基于EnKF的致密气藏离散裂缝模型自动历史拟合  

Automatic history matching of discrete fracture model of tight gas reservoirbased on EnKF method

作　　者：廉培庆[1] 赵华伟 吴双 商晓飞 段太忠[1] LIAN Peiqing;ZHAO Huawei;WU Shuang;SHANG Xiaofei;DUAN Taizhong(Sinopec Petroleum Exploration and Development Research Institute,Beijing,100083,China)

机构地区：[1]中国石化石油勘探开发研究院,北京100083

出　　处：《天然气与石油》2023年第2期73-79,共7页Natural Gas and Oil

基　　金：国家自然科学基金“基于多点地质统计学的离散裂缝网络建模新方法”(41702359);中国石油化工股份有限公司基础前瞻项目“基于应力场数值模拟与智能优化的裂缝建模方法”(P22208-2)。

摘　　要：近年来,离散裂缝模型是描述裂缝水淹的常用模拟模型,但由于涉及的地质和流体参数较多,手动修改参数工作量大、效率低,而自动化历史拟合是提高离散裂缝模型拟合精度的有效方法。以四川须家河组致密气藏为例,建立了基于集合卡尔曼滤波(Ensemble Kalman Filter,EnKF)的致密气藏离散裂缝模型自动历史拟合方法。将裂缝划分为大、中、小三个级别,大裂缝采用离散裂缝模型,中、小裂缝采用等效介质模型,运用EnKF方法对须家河组X2区块气水生产数据进行了历史拟合,通过自动调整各砂组水体能量和生产井周围孔渗使得生产井的整体拟合符合率达到86%。基于EnKF的离散裂缝自动历史拟合方法为裂缝性致密气藏数值模拟提供了有效借鉴。Discrete fracture model is a commonly used numerical simulation model to describe fracture water flooding in recent years.Due to many geological and fluid parameters involved,artificially modifying these parameters requires a lot of work,yet is inefficient.The automatic history matching method is an effective method to improve the matching accuracy of discrete fracture models.Taking Xujiahe tight gas reservoir in Sichuan province as an example,this paper establishes an automatic history matching method for discrete fracture model of tight gas reservoir based on Ensemble Kalman Filter(EnKF).The fractures are divided into three levels:large,medium and small scales.Discrete fractures model are used for large fractures,and equivalent methods are used for small and medium fractures to establish a geological model.The EnKF method is used for historical matching of gas and water production data of X2 block,Xujiahe formation.By automatically adjusting the water energy of each sand zone and the porosity and permeability around the production wells,the overall matching rate reaches 86%,which provides an effective reference for numerical simulation of fractured tight gas reservoirs.

关 键 词：致密气藏 离散裂缝 集合卡尔曼滤波 自动历史拟合 

分 类 号：TE37[石油与天然气工程—油气田开发工程]