STUDY ON THE SEISMIC FACIES OF THE FIRST MEMBER OF THE YINGCHENG FORMATION IN XINGCHENG DEVELOPMENT AREA OF XUSHEN GAS FIELD

The Xingcheng development area of Xushen gas field lies in the shengping-xingcheng tectonic belt of Xujiaweizi fault-depression, and the main reservoir rocks are acid volcanic rocks which include rhyolite and volcaniclastic rocks. The volcanic facies include outburst facies , overflowed facies, subvolcanic facies, outcroachment facies and erupted facies. Among them , outburst facies and overflowed facies are advantageous facies with capacious area and fine property. By the seismic reflect parameters, the inner reflect texture and exterior geometrical shape,five seismic facies can be identified, which are hillock seismic facies, sphenoid seismic facies, inferior parallel seismic facies, pillar seismic facies and umbrella seismic facies. The seismic facies are coincident with the volcanic facies. On the basis of the identification of the seismic facies, the plan of the volcanic facies is drawn. The plan will become the foundation of the preferential election of the establishing area and the deploy of the developing site.