注气过程中沥青质沉淀对孔隙型碳酸岩油藏储层伤害的实验研究  

Laboratory Simulation of Asphaltene Deposition for Pore Type Carbonate Reservoir Damage during Gas Injection

作　　者：徐文斌[1,2,3] 尚希涛[3] 谭学群[2] 

机构地区：[1]中国石油大学,北京102249 [2]中石化勘探开发研究院 [3]中石化国际石油勘探开发有限公司,北京100083

出　　处：《内蒙古石油化工》2014年第19期1-4,共4页Inner Mongolia Petrochemical Industry

基　　金：国家科技重大专项"孔隙型碳酸盐岩油藏提高采收率关键技术"(2011ZX05031-003)

摘　　要：中东地区大部分油藏属于孔隙型碳酸岩油藏,开发初期采用衰竭开采,中后期二次采油基本采用注气方式。而无论是衰竭开采还是注气提高采收率,沥青在地层和井筒沉淀都是一个普遍现象。它是制约原油生产的一个重要因素,本次重点研究了实验模拟条件下注气过程中沥青沉淀对储层的伤害程度。这对于中后期注气开发过程中控制沥青沉淀,提高原油采收率有重要的意义。实验表明:沥青沉淀会对储层的孔隙度和渗透率造成伤害,不同的注入速度对储层的伤害程度不同,注入速度较高时,沥青沉淀对储层的伤害更严重;气驱后注入气体突破对储层的伤害进一步加剧。因此在对油藏特别是孔隙型低渗透碳酸岩油藏实施注气时,尽量延长气体突破的时间,同时针对沥青沉淀需采取一定的预防措施。Most oil fields in Middle East belong to pore type carbonate reservoirs. The depletion devel- opment will be implemented during early time, and gas injection method is used in middle--late time for secondary development. But weather depletion or gas flooding, the asphaltene deposition in formation or well bore--hole is common phenomenon, which is an important factor to restrict the oil production rate. This paper addresses the damage level of formation due to asphaltene deposition during gas injection by laboratory simulation. A laboratory experiment is performed to investigate the asphaltene deposition in long core, which is very helpful to enhance oil recovery through gas injection method in middle --late devel- opment time. The results show that asphaltene deposition in long core will lead to reduction of porosity and permeability. During natural gas injection, the increase of gas injection rate will increase asphaltene deposition. At same time, pore plugging, porosity reduction and permeability damage will happen due to gas injection, especially after gas breakthrough. Hence, it is very important to prolong the time of gas breakthrough for pore type carbonate reservoir with low permeability during nature gas injection, mean- while, the relevant preventive measures for avoiding asphaltene deposition will be considered.

关 键 词：注气 沥青沉淀 储层伤害 长岩心实验 碳酸岩油藏 

分 类 号：TE357.14[石油与天然气工程—油气田开发工程]