Reservoir Characteristics of Member One of Nantun Formation and Comprehensive Evaluation in Wuerxun Depression
|School||Northeast University of Petroleum|
|Course||Mineralogy,petrology, Mineral Deposit Geology|
|Keywords||Wuerxun Depression Reservoir Characteristics Reservoir Evaluation Adaptive Network-based Fuzzy Inference System Excellent Reservoirs|
The first member Nantun Formation of Wuerxun depression shows better characteristic. For this reason, it is necessary to carry out the research of lithology, diagenesis types, signs, diagenetic sequences and division of diagenetic stage, reservoir characteristics and physical properties of reservoir storage space types, characteristics and to forecast the distribution of high quality reservoir area.There are about 3 types of reservoirs lithology, common sandstone, volcanic-sedimentary rocks and dawsonite-bearing sandstone in the first member of Nantun Formation in Wuerxun depression. The main rock type is composed of common sandstone, composed mainly of feldspar to lithic sandstone, arkose and feldspathic lithic sandstone supplement. Diagenesis of common sandstone is characterized by the overgrowth of quartz, siderite, kaolinite, the dissolution of the feldspath and the volcanic debris. The diagenesis of dawsonite-bearing sandstone is characterized by overgrowth of quartz, kaolinite, dawsonite precipitation and the feldspar dissolution. The diagenesis of volcanic-sedimentary rocks is characterized by microcrystalline quartz, chlorite, smectite precipitation, plastic, semi-plastic vitric, volcanic dust and debris dissolved feldspar grain.The first member of Nantun Formation in Wuerxun depression has overall good pore structure. The reservoir space is dominated by secondary pores, followed by the original intergranular pores. Pore structure is closely related to rock types. Pebbly feldspathic lithic sandstone and fine sandstone pore structure are better than the pore structure of volcanic rocks. The pore structure of sandy conglomerate, grain sand stone, and feldspathic lithic sandstone pore structure are not bad. The secondary pore of dawsonite-bearing sandstone is provided by the feldspar and lithic grain dissolution. Common sandstone has more dissolution of feldspar grains, and mold hole rare. According to the reservoir level of physical parameters of evaluation criteria, the overall physical properties of the first member of Nantun Formation in Wuerxun depression is of medium porosity and low permeability/low porosity and low permeability.Taking full account of the impact of reservoir evaluation factors based on the selected area of the carbonate content of each well, the average porosity and permeability as parameters of comprehensive evaluation. The evaluation method based on adaptive neural fuzzy inference system of the first Nantun Formation in Wuerxun Sag. After reservoir evaluation, the plane distribution of sedimentary facies, contour map of porosity, and the distribution of the cladding plane distribution of sandstone thickness plane are used to carry out the composite group. The oil and gas drilling is also referred to predict the distribution in the study area of reservoir.