特低渗油藏CO_2非混相驱生产特征与气窜规律  

Performance and gas breakthrough during CO_2 immiscible flooding in ultra-low permeability reservoirs

作　　者：高云丛[1] 赵密福[2] 王建波[1] 宗畅[1] 

机构地区：[1]中国石化东北油气分公司勘探开发研究院 [2]中国石化东北油气分公司开发处

出　　处：《石油勘探与开发》2014年第1期79-85,共7页Petroleum Exploration and Development

基　　金：国家863计划'CO2驱油的油藏工程设计技术研究'课题(2009AA063402);中国石油化工股份有限公司油气开发重要先导项目(KF-2010-18)

摘　　要：基于吉林腰英台油田CO2非混相驱先导试验区生产动态数据、吸水(气)剖面监测、示踪剂监测、原油和地层水组成分析,研究CO2非混相驱油井生产特征和气窜规律。先导试验中较好地利用了CO2的萃取、降黏、膨胀原油体积、增大地层有效孔隙等特点,增油效果较明显。对于特低渗、强非均质性油藏,水驱或气驱过程均存在单层突进、平面指进现象,水气交替注入可有效提高波及体积,有助于缓解气窜,注水转注气后产油量增幅低于注气转注水,水气交替注入过程中注水半周期的调整对气驱开发效果改善起主要作用。腰英台油田油井见气类型包括沿裂缝方向见气、沿高渗条带见气和低渗区域见气。根据建立的油井气窜标准,保持油井见气但不气窜、减缓气油比上升速度是改善非混相驱效果的关键。关停气窜井、调整生产井井底流压、实施水气交替注入是控制气窜的良好措施。The performance data, water/gas injection profile monitoring, tracer monitoring, and composition of crude oil and formation water are analyzed in the CO2 immiscible flood pilot area of Yaoyingtai Oilfleld, Jilin Province, to examine the well production characteristics and gas breakthrough law of CO2 immiscible flooding. In the pilot, the characteristics of CO2 extraction, viscosity reducing, oil volume distension and effective formation opening increment are combined, reflecting obvious effects of recovery enhancement. For the ultra-low permeability and strong heterogeneity reservoir, monolayer breakthrough and plane fingering may take place in either water flooding or gas drive. The alterative water/gas injection can increase the sweep volume effectively and help to mitigate gas breakthrough. The increment of oil production is less when the injection shifts from water to gas than when the injection shifts from gas to water. So, the adjustment of water injection half-cycle plays a dominant role in improving gas drive effect. In the Yaoyingtai Oil field, gas show is mainly observed along fractures, along the high permeability bands, and in low-permeability zones. According to the established standard of gas breakthrough in oil well, the key to improving the immiscible flooding effect is to keep the oil well to see gas but avoid gas channeling and also to slow down the gas/oil ratio ascending. Once gas breakthrough occurs in a well, it is necessary and effective to shut down the well, adjust the bottom hole flowing pressure in production well and implement the alternative water/gas injection.

关 键 词：特低渗透油藏 CO2非混相驱 水驱 连续注气 水气交替注入 生产特征 气窜规律 

分 类 号：TE357.7[石油与天然气工程—油气田开发工程]