摘要
鄂尔多斯盆地华庆地区长8段油层组局部区域水层电阻率偏高,导致水层易被误判为油层,限制了华庆地区长8段油层组的勘探开发进程。针对高阻水层发育的问题,运用流体包裹体技术及扫描电镜技术并结合华庆地区地质资料分析了长8段高阻水层形成原因。结果显示,华庆地区长8段油层组接受了3期充注,规模最大的第三期充注破坏了早期形成的油水关系,从侏罗世末期开始的盆地构造活动加剧了原生油水关系的破坏程度,复杂的油水关系导致残余油滞留于部分孔隙,泥质隔夹层和致密层进一步抑制了残余油向外运移,孔隙中的残余油增加了储层电阻率;绿泥石矿物在高阻水层区较发育,其在高阻水层的相对含量为34.32%~81.11%,比油层中的绿泥石含量高,颗粒表面的绿泥石矿物吸附孔隙中的原油造成水层电阻率偏高;长8段储层中的碳酸盐胶结物也是引起水层高电阻率的因素,它的含量超过4.9%可导致水层表现为高阻。研究结果揭示了华庆地区长8段油层组高阻水层形成机制,为华庆地区长8段高阻水层识别、油水分布规律研究、提高勘探成功率奠定了基础。
The resistivity of water layers of part of Chang-8 oil formation of Huaqing area in Ordos Basin is higher than that of conventional ones,which leads that the water layers are often explained to be oil layers and limit the process of exploration and development of this area.In order to solve this problem,the reason is analyzed by fluid inclusions,scanning electron microscope and geology data.The results show that Chang-8 oil formation has three times of hydrocarbon flooding,the third that is the biggest extent destroyed the early formed oil-water relation.The tectonic activity from the beginning of the late Jurassic emphasizes the destroyed extent,which result in residual oil detained in the pores.Shaly interbeds further the restrain the residual oil migrating outward.The residual oil in the pore increases the resistivity of reservoir.Chlorite mineral is developed in water layers with high resistivity,whose relative content distributes in 34.32%~81.11%,higher than that of oil layers.The higher resistivity of water layer is caused by the adsorption of crude oil in pores by chlorite minerals on the surface of particles.In addition,carbonate minerals is also a factor of high water layer resistivity.When its content is more than 4.9%,it will lead to high resistance of the water layer.The results reveal the formation mechanism of water layers with high resistance in Chang-8 formation in Huaqing area,which lays a foundation for the identification of high resistivity water layers in Chang-8 oil formation,the study of oil and water distribution rules and the improvement of exploration success rate in Huaqing area.
作者
赵阳
段毅
ZHAO Yang;DUAN Yi(Liaoning Shihua University,Fushun,Liaoning 113000,China;Northwest Institute of Eco-Environment and Resources,CAS,Lanzhou,Gansu 730000,China)
出处
《油气藏评价与开发》
CSCD
2020年第1期118-122,128,共6页
Petroleum Reservoir Evaluation and Development
基金
国家自然科学基金项目“沉积单体烷烃生物标志化合物氢同位素组成的成岩作用影响机制及其示踪研究”（41772108）
关键词
高阻水层
华庆地区
长8段油层组
绿泥石
碳酸盐
water layer with high resistivity
Huaqing area
Chang-8 oil formation
chlorite
carbonate
