塔中北坡顺南地区走滑断裂样式、变形机理及石油地质意义

塔中北坡顺南地区奥陶系储层具有良好的油气勘探前景。结合三维地震精细解释、属性提取等方法，从剖面形态和平面展布特征探讨了走滑断裂的变形样式、形成机理及其石油地质意义，拟为该区地质构造建模和油气勘探提供新的思路。研究表明，顺南地区主要发育NE向、NEE向、NW向 3组走滑断裂，其中NE向、NEE向为2组左行走滑断裂，NW向为规模较小的右行走滑断裂；变形样式上，NE向断裂以典型的“花状”构造为主；NEE向和NW向断裂则较为简单，多为单条陡立的隐伏断层。加里东中期Ⅲ幕，塔中Ⅰ号断裂在由南向北挤压作用下强烈逆冲；在其构造变形分段处，产生与塔中Ⅰ号断裂垂直的走滑分量，在顺南地区则分别发育了2组NE向和NEE向的走滑断裂。在上述2条左行走滑断裂的制约下，夹持在断裂间的地块发生逆时针旋转，导致地块内部发育NW向的右行剪切变形。该区走滑断裂对热液岩溶的控制作用主要表现在沿NE向和NEE向走滑断裂的线状岩溶作用，以及NW向断裂参与下的面状岩溶作用；同时也是油气垂向运移的通道。

The Characteristics,Formation and Petroleum Geology Significance of the Strike-slip Fault System in Shunnan Area,Northern Slope of Tazhong Uplift

The Ordovician reservoir of the Shunnan area showed a good oil and gas exploration potential.Based on the 3D seismic interpretation and attribute extraction technique,the structural characteristics,formation mechanism and petroleum geology significance were discussed in the profile as well as the section,providing a new idea for the geological structure modeling and oil and gas exploration.Studies show that there are three different trending strike-slip faults.The NE- and NEE-striking faults show sinistral strike-slip,while the smaller-scale,NW-striking faults were characterized by dextral strike slip.The NE-striking fault formed a typical flower structure,while the NEE and NW are relatively simple,manifested as single and vertical fault.In the III screen of middle Caledonian,Tazhong No.1 Structural Zone thrust fault was formed by a nearly N-S-striking compression.In its tectonic deformation divisions,there occurred strike-slip component perpendicular to Tazhong No.1 Structural Zone,and developed NE- and NEE-trending strike-slip faults in Shunnan area.The blocks restricted by the two sets of sinistral strike-slip faults have a counterclockwise trend,resulting in NW-striking dextral shear deformation in the internal blocks.The controlling of strike-slip faults on hydrothermal karst mainly manifested in linear karstification along the NE- and NEE-trending strike-slip fault,and planar karstification involved in the NW strike-slip faults.The strike-slip fault is also taken as the path of vertical oil and gas migration.