南海低渗敏感性油藏产能分析方法  

Productivity analysis method of low permeability sensitive reservoir in South China Sea

作　　者：管琳 赵楠 蒋开 吕新东 陈建华 周春香 GUAN Lin;ZHAO Nan;JIANG Kai;LV Xindong;CHEN Jianhua;ZHOU Chunxiang(CNOOC(China)Co.,Ltd.,Hainan Branch,Haikou Hainan 570312,China;Exploration and Development Research Institute of Zhenhua Oil,Chengdu Sichuan 610066,China)

机构地区：[1]中海石油(中国)有限公司海南分公司,海南海口570312 [2]振华石油勘探开发研究院,四川成都610066

出　　处：《石油化工应用》2025年第1期26-32,共7页Petrochemical Industry Application

基　　金：“十三五”国家科技重大专项课题“南海西部海域低渗油藏勘探开发关键技术”(2016ZX05024006)。

摘　　要：压裂是低渗油藏增产的主要手段,但由于低渗油藏面临非达西渗流、储层敏感以及油井出水等复杂条件,往往压裂后油井产能难以精准预测。基于油水两相渗流理论,考虑非达西渗流以及储层多重敏感性,建立了基质、微裂缝-基质、大裂缝-微裂缝-基质共3种渗流模式下的产能方程,并研究了启动压力梯度、应力敏感系数、水敏、水油比、上覆地层压力对产能的影响作用。研究结果表明,低渗油藏产能随启动压力梯度和应力敏感系数的增大而减小,上覆地层压力对产能影响程度较小,压裂后出水对油井产能影响很大。采油指数随着水油比的增加而减小,但递减速度逐渐减慢。当水油比小于1.0 m^(3)/m^(3)时,采油指数随着水油比的增加而迅速减小,当水油比大于1.0 m^(3)/m^(3)时,采油指数随之缓慢减小并趋于稳定。单因素分析可以看出对产能影响作用从大到小依次为水油比、应力敏感系数、水敏、启动压力梯度及上覆地层压力。而综合分析多重影响因素后可以影响产能30.0%以上。在低渗压裂井产能计算中更应注重多因素的影响作用从而提高预测精度。Fracturing is the main means to increase production in low permeability reservoirs,but it is difficult to accurately predict the productivity of oil wells after fracturing because of the complex constraints of non-Darcy seepage,reservoir sensitivity and water production in low permeability reservoirs.Based on oil-water two phase seepage theory,considering non-Darcy seepage and multi-sensitivity of reservoir,the productivity equation of three seepage modes,namely matrix,micro-fracture-matrix and large-fracture-micro-fracture-matrix,was established.The effects of starting pressure gradient,stress sensitivity coefficient,water sensitivity,water-oil ratio and overburden formation pressure on productivity were studied.The results show that the productivity of low permeability reservoirs decreases with the increase of starting pressure gradient and stress sensitivity coefficient,and the influence of overburden formation pressure on productivity is small.Water production after fracturing has a great influence on the productivity of oil wells.The oil recovery index decreases with the increase of water-oil ratio,but the deceleration rate decreases gradually.When the water-oil ratio is less than 1.0 m^(3)/m^(3),the oil recovery index decreases rapidly with the increase of water-oil ratio.When the water-oil ratio is more than 1.0 m^(3)/m^(3),the oil recovery index decreases slowly and tends to be stable.From single factor analysis,it can be seen that the influence on productivity from large to small is water-oil ratio,stress sensitivity coefficient,water sensitivity,starting pressure gradient and overburden formation pressure.The comprehensive analysis of multiple factors can affect production capacity by more than 30.0%.In the calculation of productivity of low permeability fractured wells,more attention should be paid to the influence of multiple factors so as to improve the prediction accuracy.

关 键 词：非达西渗流 油水两相 应力敏感系数 水敏 产能方程 

分 类 号：TE312[石油与天然气工程—油气田开发工程]