四川盆地梓潼地区须家河组储集层裂缝特征及控制因素

发布时间：2018-08-14 09:26

【摘要】：基于野外露头、岩心、薄片及样品实验测试等资料,对四川盆地梓潼地区须家河组储集层裂缝特征与控制因素进行了精细分析与解释。须家河组致密砂岩储集层主要发育3种类型的裂缝,分别为构造裂缝、成岩裂缝以及与异常流体高压有关的裂缝,并以构造裂缝为主。裂缝走向主要为近东西向、近南北向和北西向,平均密度0.56条/m,多为层内发育。平面上,沿老关庙—文兴场—柘坝场构造,裂缝密度依次减小;纵向上,以须四段裂缝最为发育。有效裂缝比例在老关庙地区最低,向北东至柘坝场构造呈带状递增趋势。该区储集层裂缝的分布主要受岩性、岩层厚度、构造部位及异常流体压力等因素控制,其中断层对裂缝分布的控制作用最为显著。细粒级、薄层砂岩更容易产生裂缝,断裂带附近与构造高部位也是该区裂缝发育的有利区域,且断层对裂缝的控制作用远大于构造高部位的影响作用。此外,异常流体高压的存在也有利于该区裂缝的发育,尤其是张裂缝,其密度在高压区明显增大;异常高压也能导致早期闭合缝重新开启,并且对裂缝中矿物的充填程度与溶蚀强度有重要的控制作用。
[Abstract]:Based on field outcrop, core, thin slice and sample test data, the fracture characteristics and controlling factors of Xujiahe formation reservoir in Zitong area, Sichuan Basin are analyzed and interpreted in detail. There are mainly three types of fractures in the tight sandstone reservoir of Xujiahe formation, which are structural fractures, diagenetic fractures and fractures related to abnormal fluid pressure, and structural fractures are the main fractures. The fracture strike is mainly near EW, NNE and NW, and the average density is 0.56 / m. On the plane, along the Laoganmiao-Wenxing Chang-Zhe dam structure, the fracture density decreases in turn, and in the longitudinal, the four segments of Xuzhou fracture are the most developed. The effective fracture ratio is the lowest in Laoganmiao area and the trend of belt increasing from north to east to Zhe dam field. The distribution of reservoir fractures in this area is mainly controlled by lithology, rock thickness, structural position and abnormal fluid pressure, among which fault has the most significant effect on the distribution of fractures. The fine grained sandstone is more likely to produce fractures, and the fault zone and the high structural position are also favorable areas for the development of fractures in this area, and the effect of faults on fracture control is much greater than that on the high structural positions. In addition, the existence of abnormal fluid pressure is also conducive to the development of fractures in this area, especially the tensile fracture, the density of which is obviously increased in the high pressure area, and the abnormal high pressure can also lead to the reopening of the early closed fracture. It also plays an important role in controlling the filling degree and dissolution strength of minerals in fractures.
【作者单位】：中国地质调查局武汉地质调查中心;中国石油大学(北京)地球科学学院;中国石化中原油田分公司勘探开发科学研究院;东北石油大学地球科学学院;
【分类号】：P618.13

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