Reservoir Evaluation Of The Second Segment Of Xujiahe Reservoir In Yuanba Gas Field

The second segment of Xujiahe reservoir in Yuanba gas field is dense,and has complex pore structure and strong heterogeneity. In addition, the yuanba gas field uses rolling exploration and development. Moreover, the pre-drilling are mainly for marine Changxing Formation, and continental strata are not included in the focus. Overall there are still some limitations on preliminary studies and awareness in yuanba continental gas reservoirs. Therefore, we need to carry on finer step study.on the Second Segment of Xujiahe reservoir.On the basis of geological, seismic, logging, coring, drilling, logging, testing and commissioning of gas and other information, combined with the results of previous studies, this paper systematically studies the sedimentary facies, reservoir characteristics, log interpretation of reservoir parameters and control factors of reservoir development of the second segment of Xujiahe reservoir, and then get a comprehensive evaluation.The studies show that, the sedimentary facies types of the Second Segment of Xujiahe reservoir include the delta plain, delta front, and shore shallow lake subfacies. The favorable sedimentary microfacies are distributary channel and underwater distributary channel.The main rock types of the Second Segment of Xujiahe reservoir are fine to medium-grained lithic sandstone and lithic quartz sandstone, and the under sub physical properties is the best. By collecting and analyzing the typical drilling core data and logging data, the thesis carried out researching on the logging reservoir parameters. By processing and analyzing the core data of physical properties (data standardization and core homing), the thesis established the shale content, porosity, permeability and water saturation log interpretation models for the district. Based on this, we carried on lithology and fluid recognition of the Second Segment of Xujiahe reservoir. The main controlling factors affecting the reservoir development are deposition and diagenesis, The favorable sedimentary microfacies are distributary channel and underwater distributary channel. The constructive diagenesis includes dissolution and fracturing, and appropriate development of the rim chlorite cementation is conducive to the preservation of the pore. Above the comprehensive research,it can be concluded that the low limit ofporosity is3%and the low limit of permeability is0.03±103μm2. Based on the established classification evaluation criteria, we carried on reservoir integrated classification and evaluation of all single well in the study area. The favorable reservoirs are developed in the1sand group and2sand group of the under sub reservoir and located in the western part of the work area.