高倾角低渗断块油藏顶部注气规律研究

对于高倾角低渗透断块油藏,水驱对顶部剩余油的动用效果较差。采用顶部注气的驱替方式,充分利用高倾角的地质特征,能有效提高该类油藏的采出程度。从角度对比了气体辅助重力驱,以及人工气顶驱两种主要的顶部注气方式,利用数值模拟方法,建立了某区块的油藏数值模型;以区块采出程度为目标优选了顶部注气驱方式。研究表明,人工气顶驱对该类油藏具有较好的适应性,可大幅度提高采收率。针对人工气顶驱的开发特征对相关工艺参数进行单因素分析,并加以正交试验优化工艺参数。结果表明:对于高倾角低渗透断块油藏进行人工气顶驱时,注气量为主要影响参数,其次为注采周期及闷井时长,注气速度对采出程度的影响最不敏感;同时,对于所研究的区块,优选注气速度为7 000 m3/d、注气量为9.00×107m3、注采周期时长为30 d,闷井时长80 d。

The study on crestal injection for fault block reservoir withhigh dip and low permeability

Water flooding has bad effect on the use of remaining oil for fault reservoir with low permeability and high dip. The drive of crestal injection can make the best of high dip and effectively enhance recovery. This paper compare gas-assisted gravity drainage with artificial gas cap drive. And favor a better way for a block with numerical simulation method. Artificial gas cap drive has good adaptability for this kind of reservoir, and with the development feature of it, univariate analysis and optimization study are made for relative technical parameters. The result shows that for artificial gas cap drive the volume of gas injection is the key point to recovery, and then the injection-production cycle and the closed time, gas injection velocity is the least sensitive factor. For the block, optimizing gas injection velocity is 7000 m3/d, the volume of gas injection is 9.00×107 m3, the injection-production cycle is 30 days and the closed time is 80 days.