摘要
针对聚合物驱存在厚油层顶部或各韵律段顶部的中低渗透油层动用差、聚驱效果差、层间矛盾更加突出等问题,为进一步提高中低渗透油层的驱油效率,利用天然气具有在地层中自然膨胀效应和重力分异作用,更容易进入中低渗透率油层的特点,开展了天然气与聚合物交替驱油室内研究。通过岩心驱油实验,研究了气体段塞大小、气液比、聚合物相对分子质量、聚合物溶液质量浓度、段塞组合等对天然气与聚合物交替驱油提高采收率效果的影响。注入参数优化实验结果表明,天然气与聚合物交替驱油比聚合物驱多提高采收率11%;交替周期、聚合物相对分子质量和前置段塞等对提高油层存气率和气体突破速度的影响实验表明,缩短交替周期,利用中分子聚合物交替并增加高浓度聚合物前置段塞,可有效减缓气窜。
In the light of the problems such as the poorer development of low and medium permeability oil layers,poorer polymer oil-driving effects,rather serious and obvious interlayer contradiction and so on for the polymer driving on the top of thick or each rhythmic interval,in order to enhance the oil flooding efficiency of these reservoirs and intervals,by means of the expansion effects and gravitational differentiation of the natural gas in the reservoirs and furthermore the superiority of the gas more easier penetrating into these layers,the indoor natural alternating polymer oil-flooding experiment is conducted.With the help of the core oil-displacing experiment,the influences are studied for the gas slug size,vapor-liquid ratio,the relative molecular weight/mass and solution concentration of the polymer,slug combination and so forth on the effects of enhancing the oiI flooding.The experimental results of the injection parameter optimization show that comparing with the polymer driving;the additional recovery factor of the alternate flooding can reach 11％;the influences of the alternate cycle,relative molecular mass and pre-slug of the polymer etc.on the gas deposit rate of the oil reservoirs and gas breakthrough velocity show that the gas channeling can be effectively slowed down via shortening the cycle of the alternating,medium-molecule-weight polymer alternation and even higher concentration polymer pre-slug.
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2015年第3期120-123,共4页
Petroleum Geology & Oilfield Development in Daqing
基金
中国石油股份公司重大科技专项"大庆油田原油4000万吨持续稳产关键技术研究"支撑项目部分成果
关键词
天然气
聚合物
交替注入
驱油效果
natural gas
polymer
alternately injection/driving
oil displaced effect/result
