The Study Of Sedimentary Microfacies Of The Middle Assemblage In Taikang Region Of Songliao Basin

This study not only comprehensively adopt the latest theoris and methods of sequence stratigraphy, sedimentology, seismic stratigraphy, reservoir geology, etc, but also apply seism, logging, log, core, and analytical materals. This item profoundly analyses and studies the sequence stratigraphic framewok and sedimentary facies in the middle assemblage of Taikang region in northern Songliao Basin, and then preliminarily analyses and predicts their favorable reservoirs and lithologic trap. The achievements enrich the sequence stratigraphy in continental lake basin and lake basin sedimentology, furthermore, the achievements have important reference value for oil and gas exploration and exploitation in this region in future.The study area locates Taikang region in northern Songliao basin. In structure it locates western slope region in Songliao basin. According to the traditional stratigraphic division, the study formation consists of Qingshankou, Yaojia group, and the member-one of Nenjiang group, and classified into two sequences by the bottom of Yaojia formation(Ti'). From down to up they respectively are named sequence 1 and sequence 2. Qingshankou formation borders by G3 sandbody. The formation inside its is lake expanding system tract of sequence 1, and on its is lake contracting system tract. Yaojia formation and the member-one Nenjiang group are lake expanding system tract of sequence 2.According to the principle of seismic datas being distinguished and well and well being contrasted, the study formations are divided into 12 sand-groups. The thickness of each sand-group is about 30 meters. Each sand-group basically correspongs one seismic reflection event. Member-one of Qingshankou is Gao 5 sand-group. Member-two and three of Qingshankou are divided into Gao 4~ Gao 0 five sand-groups. The distribution of Gao 3 sand-group is relatively large, and of Gao 0 sand-group is relatively little. Member-one of Yaojia group are divided into Pu 2 and Pu 1 two sand-groups. The distribution of Pu 2 sand-group is the lest. Member 2~3 of Yaojia group are divided into Sa 3~ Sa 1 three sand-groups. Member-one of Nenjiang group is divided into Sa 0 sand-group.The same points of medimentary microfacies types and distribution by developed in many sand groups lies in that they dominate with river delta and shore-shallow lake in west and dominate with deep lake-semi-deep lake and contain gravity flow. The change of sediment scope of each sand-group makes deep lake-semi-deep lake and sublacustrine fan sediment of Ga 0 and Pu 2 sand-groups not being developed during the lest sediment area, but the deep lake-semi-deep lake and sublacustrine fan sediment during the largest sediment scope of Sa 0 is well developed.The most favorable reservoirs of study formatioms in study area are delta river mouth bar sand body and sublacustrine fan sand body. The sublacustrine fan sand body region developed in each sand group and the river mouth bar sand body region developed in Gao 5 sand-group are the most favorable regions of developing lithologic traps...