A Block Of Ordos Basin Region Qi Chang 4 + 5 Characteristics And Potential Carbon Sequestration Assessment

Carbon dioxide (CO2) is believed to be the main cause of global climate change. Carbon Capture and Storage (CCS) into rock underground is considered as a effective option to mitigate CO2emission. Trapping of CO2in depleted hydrocarbon reservoirs will likely be implemented first because the geological conditions are already well known and infrastructure is already partially in place. Shaanxi province is one of the largest CO2emission province in China, recently Shaanxi advocates low-carbon development. Wuqi oilfield is located in Shaanxi province. Chang4+5formation of X block in Wuqi oilfield is recognized as major oil producing interval and is considered to sequestration of CO2. In this study, multi-disciplinary theories and methods is applied to evaluate sequestration potential in X block comprehensively. On the basis of logging, core, test data and other related data,the stratigraphy, structure, sedimentary, reservoir characteristic of Chang4+5reservoir are analysis deeply. Then3D geological model of Chang4+5reservoir is established by software, which give a quantitative description of target layer. Base on3D geological model, numerical simulation is applied to research migration and distribution of CO2plume at vertical and horizon direction, and the change of formation pressure under different gas injection scheme in a period of100years. Calculate storage capacity base on the volumetric approach, production approach and material approach,and analysis influence factors of different result.The conclusions obtained in this thesis can be summarized as follows:(1)The reservoir structure in the studying area is simple, being chiefly the gentle west-dip monocline with a low tectonic intensity. There are only mini structure in the studying area. The depth of Chang4+51and Chang4+52is about1900~2100m, it meet the depth demand of CCS. Chang4+5reservoir sand bodies distribute widely, the average thickness of sand body is between9to15meters.(2)The result of numerical simulations shows that after50years injection of CO2, gas saturation at most part of reservoir reach a stable state and did not exceed the boundary of the storage area. At the same time, it could not be possible for CO2to bread widely any more. So CO2could be storage underground safely. The simulation result also shows that Chang4+5could storage at least1.581X105t CO2in future.(3) The effective storage capacity of Chang4+5can be reached1.9116X105t through volume method and1.6507X105t through production method and material balance method. The study indicate that the geological characteristic of Chang4+5meet the geological demand of CCS, and the study area have the condition of storage space to ensure effective implementation of large-scale CCS project. Finally, it indicate that X block have CO2geological storage potential.