【作者】 欧志杰；

【导师】 吴景春；

【作者基本信息】 东北石油大学 ， 油气田开发工程， 2011， 硕士

【摘要】 低渗透油藏石油储量已成为我国石油资源的重要组成部分,我国的大部分低渗透油田主要以注水开发方式为主,低渗透油藏普遍存在着孔喉细小、渗透率低、渗流阻力大等特征,加之储层中存在敏感矿物、注入水不配伍等因素导致油层伤害,油层吸水能力不断降低,注水压力不断上升,直接影响油田的采油速度。常规的压裂酸化等增注措施作用范围较小且有效期短,而表面活性剂增注伴随着注水进行,处理半径较大,已经在中高渗透油藏开发过程得到了良好的开发效果,因此,研究低渗油藏表面活性剂驱降压增注机理及方法,对有效开发低渗油藏、缓解开发中存在的问题具有重要的意义。本文以室内实验为手段,首先对储层敏感性、水驱渗流特征及储层孔隙结构进行了研究,以界面张力为主要评价指标,筛选出适合低渗透储层的表面活性剂,研究了表面活性剂浓度、地层水矿化度和pH值等对表面活性剂性能的影响。通过天然岩心降压实验,系统研究了表面活性剂段塞尺寸、注入速度以及注入时机对天然岩心降压增注效果的影响。研究表明,所筛选的表面活性剂可以有效降低注入压力,改善油水两相渗流特征,提高油水相对渗透率,扩大油水两相共渗区范围;降压增注效果随表面活性剂段塞尺寸增大而增大,随注入速度的增大而减小;表面活性剂的最佳注入参数为:表面活性剂NS-1的最佳浓度为0.5%,最佳注入量为1PV;表面活性剂SR-1的最佳浓度为0.3%,最佳注入量为1PV。更多还原

【Abstract】 the reserve of low permeability reservoirs has become an important part of petroleum resources in our country. Most of the low permeability oilfield in China is mainly waterflooding development approach.The physical properties of low permeability reservoirs are usually different from common reservoirs,and pore small, low permeability and large flow resistance are commonly found in low permeability reservoirs.In addition sensitive minerals are in the reservoir and the injection of water is not compatible.These factors cause great damage to the formation.The injection pressure is increasing and the injection rate is reducinge.Furthermore, the scope of the common fracture and acid is small and the effective time is short.Surfactant associated with water injection to deal with larger radius,surfactant flooding in high permeability reservoirs has achieved good results.So the study of surfactant flooding in lowering injection pressure is significant to the development of low permeability reservoirs.In this paper, laboratory experiments as a means of water flooding characteristics in low permeability reservoir were studied.The interfacial tension is the main evaluation index of the surfactant used for reducing injecting pressure.The concentrations of surfactant,salinity and pH on interfacial tension behaviors are investigated.Carried out chemical flooding to reduce injecting pressure tests,evaluated the influence of surfactant flooding in low permeability reservoirs.Also,the surfactant slug size,injection rate and injection opportunity on reducing injecting pressure are investigated.Research indicates that surfactant flooding can reduce the injection pressure of lowpermeability cores,improve the two phase flow characteristics,increase the relative permeability of both phases,widen two phase flow region Detection results exhibit that with the increase of the surfactant slug size,the lowering injection pressure effectiveness rises,which decreases with the injection rate.There is a best parameter combination in surfactant flooding. surfactant concentration of NS-1 is 0.5%, the best injection volume is 1PV, the optimal concentration of surfactant SR -J3 is 0.3%, the best injection volume is 1PV.更多还原