页岩储层组构特征对自发渗吸的影响

发布时间：2019-05-30 11:41

【摘要】：自发渗吸是利用水力压裂和水平钻井技术在开发页岩油气过程中出现的重要现象。孔隙结构和矿物组成是影响页岩储层自发渗吸的重要因素。通过对页岩样品进行自发渗吸实验,探讨其孔隙连通性、页理方向和矿物组成对页岩储层自发渗吸速率的影响,并利用自发渗吸曲线斜率评价页岩储层的孔隙连通性。结果表明,与常规油气储层相比,页岩储层孔隙连通性较差,自发渗吸曲线斜率明显低于理论值。页理方向也会对自发渗吸产生影响,顺层自发渗吸曲线斜率通常较高,但是也有样品表现为穿层自发渗吸曲线斜率与顺层自发渗吸曲线斜率相当,这可能是由于页岩储层中亲水性矿物含量较高,使水在页岩储层中对运移的方向依赖性减弱。自发渗吸与页岩矿物组成密切相关:当页岩中粘土矿物含量较高时,吸水膨胀使页岩储层中原有孔隙结构发生改变,导致重复实验时页岩储层自发渗吸的曲线斜率逐渐减小;当页岩中石英等脆性矿物含量较高时,自发渗吸曲线变化不大,说明实验的重复性较好。页岩储层的自发渗吸曲线斜率越大,其渗透性越好,越有利于页岩油气的开发。
[Abstract]:Spontaneous aspiration is an important phenomenon in the process of shale oil and gas development by using hydraulic fracturing and horizontal drilling technology. Pore structure and mineral composition are important factors affecting spontaneous infiltration of shale reservoir. The effects of pore connectivity, paging direction and mineral composition on the spontaneous permeability rate of shale reservoir are discussed by means of spontaneous infiltration experiment of shale samples, and the pore connectivity of shale reservoir is evaluated by using the slope of spontaneous permeability curve. The results show that compared with the conventional oil and gas reservoirs, the pore connectivity of shale reservoirs is poor, and the slope of spontaneous permeability curve is obviously lower than the theoretical value. The slope of bedding spontaneous infiltration curve is usually high, but some samples also show that the slope of bedding spontaneous infiltration curve is the same as that of bedding spontaneous infiltration curve, but some samples also show that the slope of bedding spontaneous infiltration curve is the same as that of bedding spontaneous infiltration curve, and the slope of bedding spontaneous infiltration curve is usually higher than that of bedding spontaneous infiltration curve. This may be due to the high content of hydrophilic minerals in shale reservoirs, which weakens the directional dependence of water on migration in shale reservoirs. Spontaneous infiltration is closely related to shale mineral composition: when the content of clay minerals in shale is high, the original pore structure in shale reservoir is changed by water absorption expansion, which leads to the decrease of the slope of spontaneous infiltration curve of shale reservoir during repeated experiments. When the content of quartz and other brittle minerals in shale is high, the spontaneous osmotic curve does not change much, which indicates that the repeatability of the experiment is good. The larger the slope of spontaneous permeability curve of shale reservoir is, the better the permeability is, the more beneficial to the development of shale oil and gas.
【作者单位】：中国石油大学(北京)油气资源与探测国家重点实验室;中国石油大学(北京)科学技术研究院;中国石油大学(北京)非常规油气协同创新中心;
【基金】：国家“973”计划“中国东部古近系陆相页岩油资源潜力与分布规律”(2014CB239105) 国家自然科学基金项目“页岩储层基质孔隙连通性及其定量评价方法”(41502125) 国土资源部项目“南方富有机质页岩储集能力及其控制因素调查”(ZX20150274)
【分类号】：TE312

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