三肇凹陷扶杨油层断裂密集带样式及有利成藏部位

Types and Favorable Oil Accumulation Parts of Fault Dense Belts in Fuyang Formation of Sanzhao Depression,Songliao Basin

从三肇凹陷扶杨油层断裂密集带组合特征入手,结合油气分布规律,分析断裂密集带对油气优势运移方向控制作用,分源内和源外探讨断裂密集带中有利成藏部位.研究表明:三肇凹陷扶杨油层主要发育4种断裂密集带样式,即反向-地堑-反向断阶、地垒-地堑-反向断阶、反向-地堑-顺向断阶和地垒-地堑-顺向断阶等;当断裂密集带走向与地层倾向呈小角度相交时,其走向指示油气平面优势运移方向;源内断裂密集带中地垒和反向断阶是油气聚集优势部位;源外断裂密集带走向与地层倾向呈小角度相交时,地堑两侧反向断阶和地垒是油气优先聚集部位,其次为断裂密集带中部地堑,若呈大角度相交则断裂密集带靠近生烃凹陷一侧的反向断阶和地垒优先聚集油气.

The controlling effect of fault dense belts on the preferred direction of oil-gas migration is discussed and favorable parts of fault dense belts for oil accumulation inside and outside oil source area are discussed based on the characteristics of fault dense belts of Fuyang Formation in Sanzhao Depression, combining with the oil and gas distribution of in Fuyang Formation of study area in this paper. The results show that there are four types of fault dense belts in Fuyang Formation of Sanzhao Depression, namely antithetic-graben-antithetic fault terrace, horst-graben-antithetic fault terrace, antithetic-graben-consequent fault terrace, and horst-graben-consequent fault terrace. The strike of fault dense belt is the preferred direction of oil-gas migration and horsts and antithetic inside oil source area of fault dense belts are favorable parts for oil accumulation where the strikes of fault dense belt and the layer are parallel or small-angle intersection. Inside oil source area horst and antithetic of fault dense belts are favorable parts for oil accumulation. And horsts and antithetic outside oil source area are favorable parts for oil accumulation and the grabens are secondary favorable ones where the angle of the strikes of fault dense belt and layer ranges from 0 to 45 degrees. The antithetic and horsts are preferential for oil accumulation where the angle ranges from 45 to 90 degrees.