The Design Of A New Type Of Horizontal Well Casing Sliding Sleeve

Sichuan Basin is the pilot test base of China's shale gas exploration and development.Multistage bridge plug fracturing technology is maiuly used for its production currently.Although this technology works well in field,there still exist problems of long operating cycle,high operating costs and difficulty in later operational period of multistage production.Therefore,having investigated and analyzed the development and research status at home and abroad of horizontal well casing sliding sleeve,underground wireless communication technology,underground micro hydraulic system,and erosion wear of horizontal well casing sliding sleeve,combined with the characteristics and requirements of shale gas development in Sichuan Basin,a new horizontal well casing sliding sleeve(NHWCSS)is designed which uses low frequency electromagnetic wave wireless communication technology and downhole hydraulic power switching device.The NHWCSS is connected with casing as components of cementing string,making wireless communication with the ground through the low-frequency electromagnetic waves to achieve the transmission and reception of operation instruction and monitoring data.The opening and closing action of the NHWCSS is controlled by hydraulic system.Then,fracturing treatment or production control of shale gas reservoir can be realized.Based on the NHWCSS's overall scheme research,mechanical structure design and simulation,hydraulic system design and simulation,erosion wear law research has been made.The following work has been done based on the research above.(1)Research on the overall scheme of the NHWCSS.According to the design principle of downhole operation string,the structure design and the geometric condition analysis of the NHWCSS operation string were completed.Based on the operational parameters of typical shale gas wells in Sichuan Basin,the operational parameters of the NHWCSS were designed.The overall scheme design of the NHWCSS was completed,including underground wireless communication system scheme design,mechanical structure scheme design,hydraulic system scheme design.Construction process design of the NHWCSS is completed based on the overall scheme.(2)Research on the mechanical structure design and simulation of the NHWCSS.According to the operational parameters of the NHWCSS,wall thickness design of the NHWCSS is completed.Based on the above,the mechanical structures of communication short section,hydraulic short section and sliding sleeve short section were completed.Then,seal design,thread design and its check calculation were completed.Finally,the overall structure of NHWCSS was obtained.The finite element simulation software ABAQUS was used to verify the strength reliability of the NHWCSS in extreme operational conditions.(3)Research on the hydraulic system design and simulation of the NHWCSS.According to the friction of the NHWCSS,the calculation of hydraulic system working pressure was completed.Based on the working pressure,selection and design of the NHWCSS hydraulic system's hardware devices were completed.In order to verify the feasibility of hardware devices selection and design,the calculation of main performance parameters of hydraulic system was completed.Three-dimensional modeling software Solidworks was used to design the hydraulic system integrated block.Hydraulic simulation calculation software AMESim was used to realize the modeling and simulation of hydraulic system,which verifies the feasibility of the hydraulic system.(4)Research on the erosion wear law of the NHWCSS.Sliding sleeve short section is the main erosion wear area of the NHWCSS.Computational fluid dynamics simulation software Fluent was used to build the simulation model of erosion wear of the sliding sleeve short section,and the erosion wear of the NHWCSS was analyzed under the fracturing condition of large displacement and high sand content.The laws of change of the maximum erosion rate,maximum fluid velocity,inlet pressure under the different conditions of sand discharge capacity,export pressure,sand content,sand particle size were discussed,which provide reference for the NHWCSS design and fracturing construction.The evaluation and calculation of erosion wear performance was completed to obtain the service life of the NHWCSS's fluid orifice.In summary,designs of the NHWCSS were made based on design,theoretical calculation,simulation analysis.Its size parameters are 90mm/190mm/3251.4mm(internal diameter/external diameter/length).It can work at 140MPa/70MPa(intemal pressure/extemal pressure)and 150oC.It can work at the fracturing condition where fracturing parameters are 8?16m3/min(flow)and 2%?30%(sand content).It has the ability of switching,and the cycle of opening or closing action is 18.5min.The NHWCSS can complete the multistage fracturing construction operation and follow-up production control operation with only one run,which provides a reference to the development of shale gas resources in China.