综合物探在博格达山前古牧地复杂构造中的应用

准噶尔盆地南缘古牧地地区具有丰富的油气勘探潜力,但由于中深层地震成像存在盲区,长期以来对古牧地构造特征认识不清,制约了油气勘探进程.笔者采用高精度重磁和电法CEMP综合物探技术对古牧地地区构造特征进行了研究,取得了有价值的新认识.研究成果表明,古牧地构造为博格达山前褶皱冲断带的前锋构造,受阶梯状断裂控制.古牧地构造纵向上具多层构造特征,其中浅层为紧闭型逆冲倒转背斜,中层为受阶状逆冲断层控制的屋脊状断块,深层为潜山披覆型冲断背斜.重力异常显示古牧地背斜西围斜可能是一完整的背斜构造,古牧地中深层构造和古牧地背斜西围斜评价为有利的油气勘探目标.

THE APPLICATION OF INTEGRATED GEOPHYSICAL EXPLORATION TECHNIQUE TO THE STUDY OF COMPLEX STRUCTURES IN BOGEDA PIEDMONT ANCIENT GRAZING AREA

The ancient grazing area on the southern margin of Junggar Basin has abundant oil and gas exploration potential; nevertheless, due to the existence of blind areas in medium and deep layer seismic imaging, the structural characteristics of this area remain unclear, which has restricted the oil and gas exploration process. Using high-precision gravity and magnetic and electrical CEMP integrated geophysical technique, the author studied the structural characteristics of the ancient grazing area and obtained valuable new understanding. The results show that the structure of the ancient grazing area is the front structure of Bogeda piedmont folded thrust zone. Controlled by step fault, the ancient grazing area is longitudinally characterized by multi-layer structure, in which the shallow layer is tight type thrust overturned anticline, the medium layer is ridge-shaped fault block controlled by step thrust, and the deep layer is thrust anticline covered by buried hill. Gravity anomaly has revealed that the western pericline of the ancient grazing anticline is probably a complete anticline structure. The medium and deep structure of the ancient grazing area and the western pericline seem to be favorable targets for oil and gas exploration.