塔北地区多期走滑断裂地球物理响应特征及精细识别  

Characteristics of geophysical response and fine identification of multi-stage strike-slip fault in Tabei area

作　　者：李凤磊[1,2,3] 林承焰 张国印[1,2,3] 任丽华 朱永峰[4] 张银涛 关宝珠[4] LI Fenglei;LIN Chengyan;ZHANG Guoyin;REN Lihua;ZHU Yongfeng;ZHANG Yintao;GUAN Baozhu(State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;Shandong Key Laboratory of Oil Reservoir Geology,Qingdao 266580,China;School of Geosciences in China University of Petroleum(East China),Qingdao 266580,China;Research Institute of Petroleum Exploration and Development,Tarim Oilfield Company,PetroChina,Korla 841000,China)

机构地区：[1]深层油气全国重点实验室(中国石油大学(华东)),山东青岛266580 [2]山东省油藏地质重点实验室,山东青岛266580 [3]中国石油大学(华东)地球科学与技术学院,山东青岛266580 [4]中国石油塔里木油田勘探开发研究院,新疆库尔勒841000

出　　处：《中国石油大学学报（自然科学版）》2024年第3期1-14,共14页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金项目(42002144);中石油重大科技项目(ZD2019-183-006)。

摘　　要：通过对野外地质露头考察、无人机扫描、探地雷达探测、岩心观察、成像测井资料综合分析,建立塔北地区走滑断裂地质模式。根据塔北地区不同地层特点,分析多期走滑断裂与不同时期地层组合关系。针对不同的地层岩相背景下的走滑断裂特征,分析对应的地球物理响应特征,为小断距、小位移的走滑断裂识别提供依据。结果表明:加里东中晚期,在挤压应力作用下区域走滑断裂形成,发育X型共轭断裂和单剪切断裂,其中NNE向走滑断裂为左旋,NNW向走滑断裂为右旋;由于挤压应力差异分布,沿主干断裂方向寒武系膏盐岩滑脱面形成线性压扭隆起和平移错断的特点,结合膏盐岩层强地震反射特征,主干断裂可识别性强;中上奥陶统走滑断裂走向与古地貌趋势具有一致性;由于北部表层岩溶暴露期长,研究区形成大量的残丘、暗河、古水系,破坏了浅层断裂特征,而南部斜坡区暴露时间短,岩溶缝洞体主要沿断裂发育,断控岩溶缝洞体与基岩波阻抗存在较大差异,增强了断裂的可识别特征;海西期NNW方向、喜山期NNE方向发育单剪切走滑断裂,主要沿加里东中期断裂继承性发育,碎屑岩地层不整合面断距特征明显,平面上表现为雁列特征,剖面可见负花状构造。Through the comprehensive analysis of field geological outcrop inspection,UAV scanning,ground penetrating radar(GPR),core observation,and imaging logging data,a geological model of fault-controlled karst cavern in Tabei area was established.According to the characteristics of different strata in Tabei area,the relationship between multi-stage strike-slip faults and strata combination in different periods have been studied.According to the characteristics of strike-slip faults under different stratigraphic lithofacies backgrounds,the corresponding geophysical response characteristics are analyzed,which provides a basis for the identification of strike-slip faults with small fault throw and small distance of displacement.The results show that in the Middle to Late Caledonian,regional strike-slip faults formed under extrusive stress,developing X-shaped conjugate faults and single shear faults,with NE and NNE-oriented strike-slip faults being left-lateral slip and NNW-oriented faults being right-lateral slip.Due to the differential distribution of extrusive stresses,the linear compressional-torsional uplift and translational misfracture of the slip surface of the Cambrian gypsum-salt rocks along the direction of the trunk fracture,combined with the strong seismic reflection characteristics of the plutonic salt formation,the PDZ of slip fault is highly identifiable.The strike of the Middle and Upper Ordovician strike-slip fractures is consistent with palaeotopographic trends.A large number of remnant hills,underground karst conduits and ancient water systems have formed in the study area as a result of the long period of surface karst exposure in the north,destroying the shallow fault features.In contrast,the southern slope area is short exposed,karst reservoirs are mainly developed along the slip fault,and there are large differences in wave impedance between fault-controlled karst reservoirs and carbonate bedrock,enhancing the identifiable characteristics of the fault.Single-shear strike-slip faults develop in the N

关 键 词：探地雷达 走滑断裂 岩溶缝洞 多属性分析 塔北地区 

分 类 号：P631[天文地球—地质矿产勘探]