Study On Co-mining Technology In Du-column Structure Coal-bearing Gas

At present,there are large-scale unconventional superimposed oil and gas reservoirs in the Ordos region of China,known as superimposed coal-bearing gas reservoirs.The superimposed coal-bearing gas reservoirs are characterized by multiple strata,and have a single development value that is not significant.Some domestic research groups have The above problems were studied and analyzed,and it was proposed to adopt combined exploitation technology for this type of gas reservoir in order to increase recovery.In order to find a more suitable combined production process,this article reviews the combined technologies of conventional oil and gas production and summarizes them.Based on the above conditions,the drainage gas production layer and the lower pressure layer are combined formation conditions,and a set of designs can be applied to The combined coal-bearing gas accumulation gas accumulation technology is used to solve the problem of insignificant single-coal gas recovery in domestic coal-bearing series gas reservoirs.The main research progress is as follows:1.Applicability analysis of coal-bearing gas co-mining technologyBased on the current existing combined mining technologies,by summarizing various technical features,the combined mining technology is classified by power source,number of columns,number of pumps,and extraction mode,and at the same time,the characteristics of the coal-gas combined mining are analyzed.The feasibility of various technologies in coal gas combined mining operations.Then use AHP to establish the measure layer,criterion layer and target layer to verify the feasibility of the theoretical analysis and selection of the combined mining technology.It is determined that under the condition that the upper layer is the drainage gas production layer and the lower layer is the high pressure layer,a more appropriate combination mining technology is adopted.2.Technology and structure design of double-tube partial pressure coal-bearing gas systemCombining the existing double-column technology,the process of coal-gas combined gas well completion fracturing is analyzed to improve the existing measures.From the structure,the production channel is changed from two to three,and the pressure in the combined production work is respectively carried.Layer production water,low pressure layer gas production and high pressure layer gas production.The design of the process mainly solves the problem that the downhole tool such as the isolation device and the downhole tool do not match the fracturing process,and completes the overall structure and process flow of the combined mining technology.3.Key components design and selectionAfter the completion of the design of the overall structure and technology of the dual-column coal mining technology,the selection of various components on the structure was analyzed,including the use of carbon fiber continuous sucker rods as the "three pumping" system equipment,carbon fiber continuous sucker rod stroke loss Calculation methods,size selection of the column,and safety check of the wellhead device.Through further design calculations,the applicable characteristics of the double-column sub-compression combined coal gas technology are improved.Provide a theoretical basis for this new combination of mining technology.4.Structure design and operation calculation of bridge plugAs the most important part of the double-column sub-compression coal mining gas system,it is not only necessary to set up and seal repeatedly in the operation process,but also requires the bridge plug to be available under the specific operating environment requirements of the combined coal gas system.To achieve the entire technology process,the overall structure of the bridge plug is designed and the unsealing process is designed according to the principle of hydraulic setting.By designing double-screw thread blocking,the bridge plug can be accessed,and the downhole torque can be established through the superposition of torque.The model is used to determine the feasibility of operating thebridge plug in the well to further improve the double-column sub-compression combined coal gas technology.