Study On Reservoir Of Liushagang Fm. And Weizhou Fm. In The East Part Of Maichen Sag

On the basis of core observation and laboratory test data analysis, well sedimentary facies of 3 wells and typical log facies are set up, sandstone isogram and sedimentary facies diagram are established, sequence stratigraphy framework of Weizou Fm. and Liushagang Fm. are built up.On the basis of little well data, the inter-well sedimentary facies are represented by well-seismic integration analysis method. The seismic sedimentolgy study process and method are set up with the method of well data analysis integrated by seismic attribution analysis, seismic inversion, seismic facies analysis.The sedimentation of Weizhou Fm. and Liushagang Fm. were controlled by palaeogeomorphology and difference of depression. The strata is thicker in the south than it in the north. The sag is a south fault north onlap fault depression lake basin. The nearshore underwater aprons are developed in the south of tha sag, the fluvial facies and delta facies are developed in the north, shallow lake facies and semi-deeplake facies are developed in the middle of the sag. The sedimentary system includes delta, braided river, meandering river, delta from bottom to top.The main rock type of Liusan Member is feldspar lithic sandstone. The main pore type is secondary pore. Dissolution pore is therein the main secondary pore. The pore structure is complex. The rock is tight with bad porosity, permeability. The main rock type of Weizhou Formation in the north ramp region is feldspar lithic sandstone. The rock is tight with average porosity, permeability. The main rock type of Weizhou Formation in the south fault region is lithic arkose. The main pore type is secondary pore. Dissolution pores and fracturesis are therein the main secondary pore. The pore structure is complex. The rock is tight with bad porosity, permeability. The diageneses type includes compaction, cementation, denudation and metasomasis.The sandstone of Liusan Member is thicker in the north ramp region and south fault region than in the middle of the sag predicted by sesmic attribution analysis.