应力环境对克拉苏构造带盐下储层的影响

发布时间：2018-08-17 18:57

【摘要】：相同挤压背景下的相邻井区,由于区域应力的差异,造成了构造形态的不同,而构造形态又影响了地应力的分布。克拉苏构造带储集层白垩系巴什基奇克组储层非均质性强,构造位置间产量差异大,研究表明储层除了受沉积相控制外,地应力的大小及方向对储层的影响较大。基于挤压的应力环境将克拉苏构造带自北向南以克拉苏断裂为界分为斜向挤压区及水平挤压区。斜向挤压区的水平挤压应力、水平应力差、垂向应力较水平挤压应力区小。为了进一步验证测量应力值的准确性,利用离散元数值模拟的方法,以地震解释模型为基础,以实钻资料为约束,对构造演化过程中的断裂发育及应力、应变的分布特征进行了研究。模拟结果表明,水平挤压区与斜向挤压区的垂直应力相差较小,但水平挤压区的水平挤压应力较强,高出斜向挤压区30%~50%。强水平挤压应力对储层的影响具体体现在:储集层物性、储集空间、裂缝发育程度。代表斜向挤压区的克拉段,水平挤压应力小,储集层物性高,溶蚀现象显著,储集空间以原生孔隙为主,裂缝欠发育;水平挤压区的克深段,储集空间以粒间溶蚀扩大孔,粒内溶孔为主,储集层孔隙度低,岩性致密,裂缝极其发育,从微观薄片、岩心、FMI成像、微地震检测上均能发现大量规模性的裂缝,规模性裂缝极大地增强了克深段的储层连通性,提高了储集层渗流能力,保证了其在超过6000 m高应力储集层中仍存在日产百万方天然气的稳产高产井。
[Abstract]:Because of the difference of regional stress, the adjacent well areas under the same extrusion background have different structural forms, which in turn affect the distribution of in-situ stresses. The reservoir of the Cretaceous Bashiqike formation in the Klassou structural belt has strong heterogeneity and great difference in production between structural locations. The study shows that the reservoir is not only controlled by sedimentary facies, but also influenced greatly by the magnitude and direction of in-situ stress. Based on the stress environment of extrusion, the Klassou structural belt is divided into oblique compression zone and horizontal compression zone from north to south with Klassou fault as the boundary. The horizontal extrusion stress, the difference of horizontal stress, and the vertical stress in oblique extrusion region are smaller than those in horizontal extrusion stress region. In order to further verify the accuracy of the measured stress values, using discrete element numerical simulation method, based on the seismic interpretation model and taking the real drilling data as the constraint, the fault development and stress in the process of tectonic evolution are studied. The distribution characteristics of strain were studied. The simulation results show that the vertical stress in the horizontal extrusion region is smaller than that in the oblique extrusion zone, but the horizontal extrusion stress in the horizontal extrusion region is stronger than that in the oblique extrusion zone. The influence of strong horizontal extrusion stress on reservoir is embodied in: reservoir physical property, reservoir space and fracture development degree. The horizontal compression stress is small, the physical property of reservoir is high, the corrosion phenomenon is obvious, the reservoir space is dominated by primary pore and the fracture is underdeveloped, and the reservoir space in horizontal compression zone is enlarged by intergranular dissolution. The porosity of reservoir is low, the lithology is dense, and the fracture is extremely developed. A large number of large scale fractures can be found from micro slice, FMI imaging of core and microseismic detection. The scale fracture greatly enhances the reservoir connectivity of the Keshan formation, improves the percolation ability of the reservoir, and ensures that there are still stable and high production wells with millions of natural gas per day in more than 6000 m high stress reservoirs.
【作者单位】：中国石油天然气股份有限公司塔里木油田分公司勘探开发研究院;南京大学地球科学与工程学院;
【基金】：国家重大专项(2016ZX05003-004) 中国石油天然气股份公司专项(2014E-2101) 国家自然科学基金项目(41272227;41572187)
【分类号】：P618.13

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