摘要
致密砂岩储层是我国重要的油气接替领域,有着丰富的资源量。但致密砂岩储层孔喉结构复杂,在钻完井及开采过程中极易受到伤害,导致储层渗透率下降,并最终影响油气的流动和产量。以库车坳陷迪北段阿合组致密砂岩储层为研究对象,利用铸体薄片、XRD等测试,在明确砂岩矿物组分、孔渗特征和储集空间类型的基础上,开展钻井液伤害评价实验,并结合微米CT原位扫描技术,分析钻井液伤害前、后的砂岩孔喉变化特征。结果表明,研究区砂岩平均渗透率为0.92 mD,平均孔隙度为5.84%,孔隙类型以微孔隙为主;钻井液对该储层伤害程度整体偏低,平均伤害率为20.2%。通过机理分析表明,钻井液对储层造成的伤害类型主要为水敏伤害,黏土矿物和砂岩孔喉形态是钻井液对储层造成伤害的主要因素,黏土矿物中的伊/蒙混层含量和储层喉道类型决定了钻井液污染伤害程度。研究结果对于阿合组致密砂岩储层的高效开发具有指导意义。
Tight sandstone reservoir is an important field of oil and gas replacement in China,with abundant resources.However,the pore throat structure of tight sandstone reservoir is complex,and it is very easy to be damaged in the process of drilling,completion and exploitation,which leads to the decrease of reservoir permeability and ultimately affects the flow and production of oil and gas.Taking the tight sandstone reservoir of the Ahe Formation in the Dibei section of the Kuqa Depression as the research object,using casting thin sections,XRD and other tests,on the basis of clarifying the mineral composition,porosity and permeability characteristics and reservoir space types of sandstone,the drilling fluid damage evaluation experiment was carried out.Combined with the micro-CT in-situ scanning technology,the characteristics of sandstone pore throat changes before and after drilling fluid damage were analyzed.The results show that the average permeability of sandstone in the study area is 0.92 mD,the average porosity is 5.84%,and the pore type is mainly micropore.The damage degree of drilling fluid to the reservoir is generally low,and the average damage rate is 20.2%.The mechanism analysis shows that the damage type of drilling fluid to the reservoir is mainly water sensitive damage.Clay minerals and sandstone pore throat morphology are the main factors of drilling fluid damage to the reservoir.The content of illite/smectite mixed layer in clay minerals and the type of reservoir throat determine the degree of drilling fluid pollution damage.The research results have guiding significance for the efficient development of tight sandstone reservoirs in Ahe Formation.
作者
陈锐
陈绍宁
梁睿
寇双锋
陶志杰
马斌玉
杜皓
CHEN Rui;CHEN Shaoning;LIANG Rui;KOU Shuangfeng;TAO Zhijie;MA Binyu;DU Hao(Chuanqing Drilling Engineering Company Ltd,CNPC,Chengdu 610051,Sichuan;School of Geosciences,Yangtze University,Wuhan 430100,Hubei;Laboratory of Reservoir Microstructure Evolution and Digital Characterization(Yangtze University),Wuhan 430100,Hubei)
出处
《长江大学学报（自然科学版）》
2024年第4期104-112,共9页
Journal of Yangtze University(Natural Science Edition)
基金
国家自然科学基金项目“凝灰质填隙物沉积一成岩分异特征及其对砂砾岩储层物性的控制作用——以玛湖凹陷三叠系百口泉组为例”(42072121)。
关键词
库车坳陷
致密砂岩
钻井液伤害评价
阿合组
微米CT原位扫描
Kuqa depression
tight sandstone
drilling fluid damage evaluation
Ahe Formation
micron CT in situ scanning
