松辽盆地十屋断陷反转构造与油气聚集

RELATIONSHIP BETWEEN INVERSION STRUCTURES AND HYDROCARBON ACCUMULATION IN SHIWU FAULT DEPRESSION OF SONGLIAO BASIN

晚期强烈构造反转是十屋断陷构造发育的一个重要特色。本文以高分辨率三维地震资料为基础,结合相干技术和三维可视化技术等先进地震资料处理和解释技术,对研究区反转构造进行了精细构造解释和研究。将研究区反转构造划分为四个反转构造带,在对反转构造样式再认识的基础上在十屋乃至松辽地区新发现了欺压式断层和截断型反转构造两种反转构造样式。进而将反转构造样式除坳陷层滑脱褶皱外,依据反转过程中形成的逆断层与早期伸展断层的组合关系归纳为五种类型:复活型、前展型、后展型、欺压型、截断型。并对反转构造与油气聚集之间的关系作了深入探讨,研究认为区内反转构造具有十分有利的成藏条件且四个反转构造带具有不同的圈闭类型和油气聚集特点。初步建立了十屋断陷基于反转构造的油气成藏模式,为进一步油气勘探提供了依据。

The late stage strong inversion structures are an important characteristic of Shiwu fault depression during the process of tectonic evolution. Based on the high-resolution 3-D seismic profiles and by applying several geophysical techniques such as coherence technique and 3-D visualization, the authors divided the inversion structures in the study area into four inversion structure traps. Two kinds of new inversion structural styles including tyrannizing fault and truncated inversion structure are first found in Shiwu fault depression even in Songliao basin on the basis of restudying the forms of inversion structures. Further more, except the detachment-type fold in depression formation, the inversion structural styles can be subdivided into five types: reviving type, forward-expanding type, backward-expanding type, tyrannizing type and truncated type according to the mode of association of the thrust faults and the early normal faults. Finally, the inversion structures in the study area show very good reservoir-forming conditions. And the four inversion structure traps show different trap types and different hydrocarbon accumulation characteristics. The hydrocarbon reservoir-forming model based on the inversion structures in the study area has been summed up. And the authors hold that it will be of benefits to oil and gas exploration in the future.