System Design And Finite Element Analysis Of Secondary Perforating Device

During a perforating completion operation,the perforating charge will consume too much energy to penetrate the casing,cement ring and formation,resulting in short perforation distance,small aperture and lower oil yield,which seriously limits the improvement of oil and gas well productivity.In order to solve this problem,this paper puts forward the design idea of secondary perforation,and systematically designs a set of secondary perforation device to ensure that the two perforations are perforated and the perforation charges are shot out from the same position of the casing to achieve the purpose of increasing the perforation distance,expanding the perforation aperture and increasing the permeability.It is of great significance and practical value to improve the recovery rate of low permeability oil field,prolong the production life of oil field and maximize the potential remaining oil.The secondary perforating device consists of two parts: mechanical system and positioning control system.The key to the design of the secondary perforating device is to ensure that the gun body position of the second perforating device is consistent with that of the first perforating device.Therefore,the paper designs a downhole hydraulic support device to provide support and horizontal orientation for the secondary perforating device.The depth locator and gyroclinometer are used to detect the depth of the downhole hydraulic support device and the azimuth of the horizontal azimuth key.The depth positioning of the secondary perforating device and the azimuth positioning of the horizontal azimuth key and the positioning slot are realized through the command issued by the single chip computer,that is,the accurate docking of the unit perforator and the hydraulic support device in the well is realized,and the purpose of secondary perforating at the same position in the perforating layer is completed.First of all,the whole scheme of the secondary perforating device is designed,the composition of the secondary perforating device is introduced in detail,and the working principle of the whole device,the docking principle of the key components and the process flow of the secondary perforating operation are expounded.Then,combined with the knowledge of elasticity and material mechanics,mechanical analysis and strength check were carried out on the perforated pipe string.The analysis process was programmed and solved by MATLAB to verify the safety and reliability of the perforated pipe string.Then,the core components of the device were modeled by Auto CAD and Solid Works software,the mechanical model was established according to the actual working conditions,and the mechanical analysis and calculation were completed.The key components of the hydraulic support were analyzed by ANSYS software,and the contact process between slips and pipe wall was studied.The maximum stress of slip,the depth of embedment in casing and the amount of slip are verified theoretically that the design of downhole hydraulic support is reasonable and its performance is reliable,which can ensure the smooth secondary perforating operation.After that,LS-DYNA software was used to simulate and analyze the blasting process of the perforator,study the stress,strain and radial deformation of the perforator tube sleeve under the three-dimensional network model,compare the influence of different material properties on the shaped jet jet,and finally choose 32 Cr Mo4 alloy structural steel as the tube sleeve material,which meets the national and industry standards.It is proved theoretically that the unit perforator meets the working requirements.Combined with the working principle of the device and the special working environment of the mine,the control system is designed and selected.At the same time,the control program is written and simulated by Keil and Proteus,and the correctness of the control program is verified.Finally,the whole device was manufactured and simulated in the laboratory and in the test well.The test results show that the unit perforator and the hydraulic support can be connected accurately,and the perforating trajectory of the perforating projectile is consistent in two perforating operations,which verifies the feasibility and reliability of the secondary perforating device.The successful development of the secondary perforating device and the successful experience of the simulation test provide a solid foundation for the follow-up field test to improve the productivity of oil and gas Wells.