低渗透滩坝砂油藏CO_2近混相驱生产特征及气窜规律

PERFORMANCES AND GAS BREAKTHROUGH LAW FOR CO_2 NEAR-MISCIBLE FLOODING IN THE LOW-PERMEABILITY BAR AND SHOAL OIL RESERVOIRS

正理庄油田高89块低渗透滩坝砂油藏CO_2驱先导试验取得较好开发效果,基于区块驱油井日产油量、吸气剖面、气油比、井口CO_2含量等数据,研究了连续CO_2近混相驱油井生产特征和气窜规律。结果表明:先导试验较好利用CO_2驱提高采收率机理,原油流动性得到较大改善,增油效果明显,油井见气差异较大;建立高89块CO_2近混相驱气窜标准,根据气窜标准和矿场实践提出各气窜阶段改善气驱效果的主要措施和做法。

The much better development effects are achieved for the CO_2near-miscible flooding pilot test in the low-permeability bar and shoal reservoirs of Block Gao 89 in Zhenglizhuang Oilfield. Based on the daily production,gas-absorbed profiles,GOR,wellhead CO_2 contents and other data,the performances and gas breakthrough law are researched for the continuous CO_2near-miscible flooding. The results show that the mechanism enhanced oil recovery by CO_2 is made full use,the crude oil flowability is well improved,oil increment is obvious,the gas breakthrough is shown in different levels for some oil wells; the standards of the gas breakthrough are established in Block Gao 89,the main stimulations and measures are presented to improve the gas flooding effects in each breakthrough stage by means of the above standards and field test practice.