松辽盆地南部断陷群控陷断层组合样式及其对油气成藏的影响

Combined Pattern of Controlled Depression Fault and its Influence on Hydrocarbon Accumulation in Southern Part of Songliao Basin Fault Group

基于松辽盆地南部断陷群控陷断层形态和断层组合的分析,划分了多种控陷断层组合样式,并分析不同断层组合样式在南部断陷群的构造特征及其对油气成藏的影响。结果表明,松辽盆地南部各断陷往往由多条控陷正断层控制形成,且断层控制了断陷内的次级洼陷。依据各控陷断层平面展布特征,把松辽盆地南部断陷群控陷断层划分为同向倾斜正断层组合样式、背向倾斜正断层组合样式、相向倾斜正断层组合样式3种组合样式。不同控陷断层组合样式在断陷内部形成位置各异的深洼区、构造斜坡及变换构造带,对油气聚集成藏产生重大影响。在这些断陷陡缓坡反转构造带、走滑断裂带、陡坡变换构造带及缓坡地层超覆带多已形成油气聚集。

By analyzing the pattern and combination of controlling-depression fault in southern part of Songliao Basin, multiple combined styles of controlled depression faults have been divided, and analyzed the structural characteristics of different fault combinations and its influence on hydrocarbon accumulation in southern fault groups. The results showed that all the fault depressions in the south of Songliao basin were often controlled or formed by multiple normal faults, and the faults had controlled the secondary sags inside the fauh depression. According to the plane distribution characteristics of controlled depression fault, it has been divided into three kinds of combination patterns at the southern part of Songliao basin, i.e. synthetic, divergent and convergent combination of normal faults. Different combination patterns have formed all kinds of deep depressions, tectonic slope and transfer tectonic belts inside the fault depression, which has a significant impact on the hydrocarbon accumulation, and had formed the hydrocarbon reservoir in overturned structure zone, strike slip fault zone with steep-gentle slope, and transfer tectonic belt with steep slope, as well as overlap zone with gentle slope, etc.