摘要
四川盆地莲池油田属于超低孔（孔隙度3％左右）、超低渗（渗透率0．0001-0．1mD）致密油藏，一次采收率仅为2．51％，开发难度大，针对该油藏目前的开发现状探索性地提出了注CO2提高莲池致密油藏采收率的研究思路。依据莲池致密油藏大安寨段的储层特征、流体特性和原油高温高压物性参数拟合结果，建立了莲7井区CO2驱双重孔隙介质的组分模型。依据CO2换油率和采收率增加量评价了莲池致密油藏注CO2开发的效果，结果表明：莲池油田注CO2开发的最佳注气方式为循环吞吐；最佳焖井时间为3个月，合理注采周期为4年。最终通过对比分析确定了最佳注气方案，为四川盆地致密油藏注CO2开发提供了技术支撑。
In Sichuan Basin, Lianchi gasfield is a tight oil reservoir with extra-low porosity of about 3% and permeability ranging from 0.0001 m D to 0.1 m D, and its primary recovery is only2.51%, further bringing about great difficulties in its development. So, a scheme to implement CO2 injection is proposed. One reservoir of Daanzhai Member from this reservoir was taken as a case study. Based on its reservoir characteristics, reservoir-fluid features, and some physical parameters of crude oil, a compositional model of CO2-displacement dual porosity media was established for Lian 7 well block. Furthermore, according to CO2 oil displacement rate and recovery increment,an effect of CO2-injection was evaluated. Results show that periodic huff and puff can be taken as the best gas-injection way during a CO2-injection; and the best soak time and reasonable injection-production cycle should be three months and four years, respectively. The best gas-injection scheme obtained provides technological evidence of CO2 injection for other tight oil reservoirs in Sichuan Basin.
出处
《天然气勘探与开发》
2016年第2期45-49,12-13,共5页
Natural Gas Exploration and Development
基金
中国石油重大科技专项(2012E-2601-04)"四川盆地侏罗系非常规石油勘探开发关键技术研究"
中国石油西南油气田公司科研项目(20130305-07)"川中侏罗系致密油藏注CO2开发的可行性数值模拟研究"
关键词
致密油藏
注CO2
实验拟合
数值模拟
换油率
方案优选
tight oil reservoir
CO2 injection
experimental match
numerical simulation
oil displacement rate
scheme optimization
