松南新区与长岭凹陷断陷期盆地构造解析与对比分析及有利勘探方向预测

Structural Analysis and Comparative Analysis of Fault Depression Basin between Songnan New Area and Changling Sag as well as the Favorable Exploration Direction

樊薛沛 刘玉虎 栾颖 张美华

FAN Xuepei LIU Yuhu LUAN Ying ZHANG Meihua

中国石油化工股份有限公司东北油气分公司, 吉林长春 130062

SINOPEC Northeast Oil and Gas Company, Changchun Jilin 130062, China

松南新区与长岭凹陷在早白垩世均受到近EW向弧后伸展构造背景的影响，形成断坳叠置盆地，前人对于断陷期的成因机制作了大量研究，对松辽盆地断陷层划分为东、西、中三个断陷带，文章通过对松南新区与长岭凹陷断陷期盆地构造解析及其对比分析，发现松南新区与长岭凹陷断陷期的成盆机制存在较大差异。但共同点均表现出基底断裂分段发育特点，而长岭凹陷龙凤山地区的油气成功突破揭示了分段式基底断裂带“控洼—控沉—控源—控藏”的经验。因此，以长岭凹陷成功突破的经验和启示为指导，预测松南新区断陷群的有利勘探方向可在分段基底断裂附近寻源，在最大断距处寻找沉积中心，依据“主控断裂寻源、前缘相带寻储、稳定沉积寻盖、构造复原寻聚、动态演化寻藏”的思路寻找和发现新的油气藏。

In early Cretaceous, both Songnan New Area and Changling Sag were influenced by the approximately latitudinal backarc extensional tectonic setting, with the characteristics of fault depression superposed on the depression. The generation mechanism for the fault depression have been studied in the previous studies, and the fault depression interval in Songliao Basin is divided into three zones, namely, East, West and Middle faulted depression zone. The structural analysis and comparative analysis of fault depression basin between Songnan New Area and Changling Sag shows that there is signifcant difference in the formation mechanism. However, the common point is that the basement faults in these two study area all are in the form of segments. The breakthrough of hydrocarbon exploration from Longfengshan area of Changling Sag demonstrates that the segmented basement faults controlled the distribution of sag, sedimentation, source rock and reservoir. Guided by the experience in Changling, the authors suggest that the exploration in Songnan New Area should focus on the area near segmented basement faults for the source rocks, on the area with maximum fault throw for the depocenters. The authors also believe that the following exploration thinking will beneft the discovery of new reservoirs, i.e. the major faults for source rocks, the front facies for reservoir rocks, the stable deposition for cap rocks, the paleostructure for accumulations, and the tectonic evolutions for reservoirs.

https://doi.org/10.3969/j.issn.1008-2336.2018.01.028