油藏CO_(2)驱过程中最小混相压力的动态变化及其影响因素分析  

Dynamic analysis of minimum miscibility pressure during CO_(2) flooding reservoirs and its influencing factors

作　　者：韩波 翟志伟 于伟东 李坤潮 马雄强 曹士文 石悦 包兴 黄峰 任韶然[3] HAN Bo;ZHAI Zhiwei;YU Weidong;LI Kunchao;MA Xiongqiang;CAO Shiwen;SHI Yue;BAO Xing;HUANG Feng;REN Shaoran(Mining Engineering Department, Shanxi Institute of Energy, Taiyuan 030000, China;China United Coalbed Mathane Co. Ltd., Beijing 100016, China;Petroleum Engineering College, China University of Petroleum (East China), Shandong Qingdao 266580, China)

机构地区：[1]山西能源学院矿业工程系,太原030000 [2]中联煤层气有限责任公司,北京100016 [3]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《非常规油气》2022年第1期98-104,共7页Unconventional Oil & Gas

基　　金：“十二五”国家科技重大专项“CO 2驱油藏动态监测与方案优化技术”(2011ZX05016-005);“十三五”国家油气重大专项“准噶尔盆地CO 2驱油与埋存先导试验关键技术研究”(2016ZX05056004-003);山西省科技重大专项“构造煤区煤层井下增透及瓦斯高效抽采技术”(20191102002);晋中市科技重点研发计划(工业)项目“煤层受迫振动增产煤层气技术研发”(Y201026)。

摘　　要：为了进一步研究CO_(2)驱过程中最小混相压力(MMP)的动态变化,为油气CO_(2)驱产出伴生气回注提供理论依据,针对吉林油田CO_(2)驱示范区的油藏工况,利用经验模型法和PVT方法分析计算MMP,进行了CO_(2)驱过程中油气组分及MMP变化的动态分析,研究了MMP的变化规律及其影响因素。结果表明,2种方法所得MMP差值为4%~8%,与实验值的误差为5.36%。在油藏CO_(2)驱生产过程中,由于CO_(2)的抽提作用使原油中的中轻质组分(C_(2)~C_(6))减少,导致MMP增大。注入气的组分对MMP也有较大影响,纯CO_(2)中加入C_(2)H_(6)等轻质组分会降低MMP。CO_(2)驱油藏产出气中含有CO_(2),CH_(4)和(C_(2)~C_(4))等轻质组分,可以将其与纯CO_(2)混合后回注,当产出气中CO_(2)含量在80%之上,(C_(1)+N_(2))含量在10%以下时可以直接将产出伴生气进行回注。该研究成果对CO_(2)驱油藏最小混相压力动态变化及CO_(2)产出伴生气的处置及回注具有借鉴价值。In order to study the dynamic change of minimum miscibility pressure(MMP)during CO_(2) flooding and to provide theoretical basis for the reinjection of produced gas.Components of oil and gas in process of CO_(2) flooding and dynamic variations of MMP were analyzed based on reservoir conditions of CO_(2) flooding demonstration block in Jilin Oilfield,and their influence factors were also discussed and analyzed.Results showed that MMP errors between two methods were 4%~8%,and the error with the experimental value is 5.36%.MMP would increase along with the production of CO_(2) flooding reservoir,as the light component decreased because of CO_(2) extraction.The composition of the injection gas also has an effect on the MMP,and MMP would decreased with the injected gas(CO_(2))mixed with C_(2)H_(6) and other light components.The produced gas in CO_(2) flooding reservoir contains CO_(2),CH_(4) and(C_(2)~C_(4))light components,which can be recycle-injected with pure CO_(2) to achieve the purpose of CO_(2) storage and EOR.In this paper,the effect of injected gas on MMP in reservoir is analyzed,and it showed that produced gas could be recycle-injected directly when the gas had more 80%CO_(2) and less 10%C1+N2.

关 键 词：CO_(2)驱 最小混相压力(MMP) PVT模拟 计算模型 MMP影响因素 伴生气回注 

分 类 号：TE992.1[石油与天然气工程—石油机械设备]