关键词: 构造样式, 走滑断裂, 控储控藏特征, 顺北油气田, 塔里木盆地

Abstract: Based on fine analysis of strike-slip faults and comprehensive use of imaging logging, well testing and production performance data, this paper explores the control effect of the segmented differential deformation of Shunbei No.1, Shunbei No.5 and Shunbei No.4 strike-slip fault zones in Shunbei oil and gas field on the development of large-scale reservoir bodies and the distribution of oil reservoirs. There are significant differences in geometry, kinematics and activity characteristics of the main strike-slip fault zones in Shunbei area, showing the characteristic of "one zone as one world". Specifically, there are 9 geometric segments with left-stepped diagonal distribution in the 3D working area in Shunbei No.1 fault zone, where spliced and pull segments are developed. The north section of Shunbei No.5 fault zone is dominated by the development of uplift and translation segments, translation segments and splay fractures are mainly found in the middle section, and the south section shows the compound tectonic development pattern of "graben section on both sides and main strike-slip section in the middle". Shunbei No.4 fault zone is distributed in an "S" shape in the 3D working area and can be divided into north section, middle section and south section according to the strike changes. It is characterized by a segmented structure of "north-south compression and middle tension". The internal structure of the strike-slip faults of Shunbei area is controlled by the intensity of fault activity. With the increase of activity intensity, the internal structure of carbonate fault zone has gradually evolved from a fracture zone with low development degree to the broken gravel zone and fracture zone with high development degree, and the scale of reservoir bodies is expanded accordingly. Shunbei No.1 fault zone witnesses the segmental development of the large-scale fault-controlled reservoir bodies. The internal structures of reservoir bodies in different segments are significantly different, and most of them are disconnected. The reservoir bodies in the same segment are interconnected, characterized by "one reservoir for one section". The differential accumulation of oil and gas is controlled by the differential deformation of strike-slip fault. In detail, the gas-oil ratio of the northern segmented well group of Shunbei No.1 fault zone is generally higher than that of the southern well group, which is controlled by the difference of late activities with the characteristic of "being strong in the north and weak in the south". The middle main strike-slip section of the southern section of Shunbei No.5 fault zone is directly communicated with source rocks, characterized with "reservoir control, accumulation control and enrichment control". The graben section is not directly communicated with source rocks, and the scale of the drilled reservoir body and oil-gas reservoir is much smaller than that of the middle main strike-slip section. The section of strike-slip fault is vertically heterogeneous. As controlled by activity intensity of the section and competency of the formation. The scale of the targets drilled into the reservoir bodies with different depths in the same section is significantly different, which shows the characteristic of "one target for one scale". The study will deepen the understanding on the differential deformation characteristics of the strike-slip faults in Tarim Basin and serve as an important reference for the exploration and evaluation of fracture-controlled and fractured-vuggy type reservoirs in strike-slip faults.

Key words: structural styles, strike-slip faults, fault control on reservoir rocks and hydrocarbon accumulations, Shunbei oil and gas field, Tarim Basin