底水稠油油藏水平井复合增产技术

针对桩西油田强底水稠油油藏水平井单井产液量高、含水率高、开发效果差、剩余油动用难度大的问题,进行了底水稠油油藏复合增产技术研究。利用水平井二氧化碳吞吐可视化试验,分析了底水油藏水平井二氧化碳吞吐提高采收率的机理,同时针对单一二氧化碳驱易指进的问题,优选发泡剂和稳泡剂,研制了增黏型泡沫体系,并配制了乳化沥青堵水剂以封堵高渗透通道,形成了包括二氧化碳吞吐、增黏型泡沫体系和乳化沥青堵水剂的水平井复合增产技术。复合增产技术在桩1块底水稠油油藏应用7井次,平均含水率降低27.5百分点,累计增油量3 205 t,取得了明显的降水增油效果。现场应用表明,复合增产技术可以解决底水稠油油藏水平井含水率高、剩余油动用难度大的问题。 

Compound Stimulation Techniques for Heavy Oil Reservoirs with Bottom Water

In the Zhuangxi Oilfield, horizontal wells in heavy oil reservoirs with strong bottom water are characterized by high liquid production, high water cut, poor development output and difficulty in producing the remaining. In order to solve these problems, a series of studies was carried out to develop compound stimulation techniques for heavy oil reservoirs with bottom water. First, the mechanisms of carbon dioxide huff and puff for improving oil recovery of horizontal wells with bottom-water were analyzed through visualization experiments. Secondly, a viscosity increasing foam system was prepared by optimizing foaming agent and foam stabilizer so as to deal with carbon dioxide flooding fingering. And thirdly emulsified asphalt blocking agent was prepared by optimizing emulsifier so as to blocking high-permeability paths. The compound stimulation techniques were designed based on carbon dioxide huff and puff, viscosity increasing foam system and the development of an emulsified asphalt blocking agent. These techniques were applied seven times in heavy oil reservoirs containing bottom water of Block Zhuang 1. The techniques resulted in a remarkable increase in oil production with a corresponding decrease in water production,, with average water cut reduction 27.5% and cumulative oil incremental 3 205 tons. Based on field application, these compound stimulation techniques application in horizontal wells of heavy oil reservoirs containing bottom water could decrease water content and solve the difficulties of producing remaining oil.