致密油二氧化碳吞吐动态特征及影响因素  

Dynamic characteristics and influencing factors of CO_(2) huff and puff in tight oil reservoirs

作　　者：汤翔 李宜强 韩雪[3] 周永炳[3] 战剑飞[3] 徐苗苗[1,2] 周锐 崔凯 陈小龙 王雷[5] TANG Xiang;LI Yiqiang;HAN Xue;ZHOU Yongbing;ZHAN Jianfei;XU Miaomiao;ZHOU Rui;CUI Kai;CHEN Xiaolong;WANG Lei(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249,China;Petroleum Engineering Institute,China University of Petroleum(Beijing),Beijing 102249,China;Exploration and Development Research Institute of Daqing Oilfield Co Ltd,Daqing 163712,China;Exploration and Development Department,China Southern Petroleum Exploration and Development Corporation,PetroChina,Haikou 570100,China;PetroChina Coalbed Methane Company Limited,Beijing 100028,China)

机构地区：[1]油气资源与探测国家重点实验室(中国石油大学(北京)),北京102249 [2]中国石油大学(北京)石油工程学院,北京102249 [3]大庆油田有限责任公司勘探开发研究院,大庆163712 [4]中国石油南方石油勘探开发有限责任公司勘探开发处,海口570100 [5]中石油煤层气有限责任公司,北京100028

出　　处：《石油勘探与开发》2021年第4期817-824,共8页Petroleum Exploration and Development

基　　金：国家科技重大专项“松辽盆地致密油开发示范工程”(2017ZX05071)。

摘　　要：采用大型露头方形岩心与长岩心,开展了不同注采参数、不同焖井时间等多种注采方式下的CO_(2)吞吐实验,分析了CO_(2)吞吐的动态特征、影响因素及波及方式对采收率的贡献。研究表明:CO_(2)吞吐开发可分为CO_(2)返排、产气携油、高速产油、产油速率减缓4个阶段。产气携油阶段以游离气驱为主,高速产油阶段以溶解气驱为主;CO_(2)注入量与开采速度是影响吞吐效果的主要因素,CO_(2)注入量越大,开采速度越低,采收率越高,合理的CO_(2)注入量与开采速度需结合现场需求及经济评价确定;CO_(2)吞吐开发存在合理焖井时间,超过该时间继续焖井对提高采收率贡献不大,现场应用中,可通过井底压力是否稳定判断焖井是否充分。CO_(2)吞吐开发采收率的贡献主要来源于流动波及与扩散波及,焖井时间足够长时,采收率的贡献主要来源于扩散波及。图16表2参36。CO_(2) huff and puff experiments of different injection parameters,production parameters and soaking time were carried out on large-scale cubic and long columnar outcrop samples to analyze dynamic characteristics and influencing factors of CO_(2) huff and puff and the contribution of sweeping mode to recovery.The experimental results show that the development process of CO_(2) huff and puff can be divided into four stages,namely,CO_(2) backflow,production of gas with some oil,high-speed oil production,and oil production rate decline stages.The production of gas with some oil stage is dominated by free gas displacement,and the high-speed oil production stage is dominated by dissolved gas displacement.CO_(2) injection volume and development speed are the major factors affecting the oil recovery.The larger the injected CO_(2) volume and the lower the development speed,the higher the oil recovery will be.The reasonable CO_(2) injection volume and development speed should be worked out according to oilfield demand and economic evaluation.There is a reasonable soaking time in CO_(2) huff and puff.Longer soaking time than the optimum time makes little contribution to oil recovery.In field applications,the stability of bottom hole pressure is important to judge whether the soaking time is sufficient during the huff period.The oil recovery of CO_(2) huff and puff mainly comes from the contribution of flow sweep and diffusion sweep,and diffusion sweep contributes more to the oil recovery when the soaking time is sufficient.

关 键 词：致密油 CO_(2)吞吐 动态特征 采收率 影响因素 驱油机理 

分 类 号：TE327[石油与天然气工程—油气田开发工程]