Oil And Gas Accumulation Of Shallow Reserviors In Shenshe Area Abstract

In this paper, Chang 2 and Chang 3 of Triassic Yanchang Formation in the Shihe area of Ordos Basin are studied. According to the electric logging curve and the lithologic characteristics, the Chang 2 is subdivided into three sublayers:Chang 21, Chang 22 and Chang 23, and Chang 3 is subdivided into three sublayers:Chang 31, Chang 32 and Chang 33. Combining sedimentology and logging geology, The sedimentary facies and sedimentary microfacies in this area are analyzed and studied. It is believed that the Shishe area belongs to the delta depositional system, and the delta plain and subfacies are mainly developed.Combining with reservoir petrological characteristics, physical characteristics, pore structure types, The reservoir characteristics of Yanchangchang 2-Chang 3 reservoir in Shishu area were analyzed, research shows:The types of rocks are mainly feldspar lithic sandstones and lithic arkosporic sandstones. The classification is good, and the contact point is the main point, The pore structure is mainly composed of intergranular pores and feldspar dissolved pores, and the types of throats include pore narrow throats and necking throats. The distribution of reservoirs is controlled by the sedimentary facies. The reservoirs of type ?,? and ? are mainly developed in the main body of the river channel, while the IV type reservoirs are mainly distributed in the flank of the channel sand body.The study shows that a set of high quality source rock is developed in Chang 7 section, which is the main oil source of Chang 2-Chang 3 reservoir in Shishe area. The formation of reservoirs is superior to that of reservoirs, Forming reservoirs with self-generating and self-generating reservoirs and lower reservoirs, and favorable reservoir forming conditions.Permeable sandbodies, microfractures and paleosols are the dominant channel for oil and gas migration. The delta sandstone is a favorable reservoir space for oil and gas. Shunting bay, diversion of inter-river depression and marshes and other shale deposits and the development of coal seams as favorable occlusion conditions. The east-west row-shaped nose-up structure controls the distribution of oil and gas. Based on the study of oil and gas enrichment and combined with the favorable area classification scheme, the favorable evaluation of four small layers of Chang2-Chang3 is carried out, which provides favorable basis for exploration and development of shallow reservoirs in Shishu area.