Papers by Author: Xian Long Liu

Abstract: The bridge plug is a staple tool used in downhole operation and the performance of the slips has a directly influence on the oil well productivity and production safety. We raised an optimize method based on BP network and genetic algorithm to make sure the slips satisfy the high temperature and high pressure demands. Establishing the slips system and making finite element analysis by ANSYS, abtaining sixteen group datas to constitute the BP network training samples, establishing the BP simulation model reflecting curvature radius of the slip fluke, dip angle of the fluke, angle of the fluke and distance between flukes using nonlinearity mapping ability of the neural network, applying optimize design for the simulation model using global optimization ability of the genetic algorithm and abtaining the optimum structure parameters of the slip. The optimized results indicate the whole performance of the slips system has increased notably.

Abstract: Based on finite element analysis software ANSYS, the deformation and force condition of the rubber sealing o-ring pre and post with back-up ring under different oil pressure conditions was analyzed. The von mises stress distribution of the o-ring and the change of contact pressure between o-ring and sealing interface pre and post with back-up ring under different oil pressure conditions were discussed. The results show that, the maximum von mises stress of the o-ring is smaller and the maximum von mises stress of the sealing system concentrates on the left top and the right bottom of the back-up ring after using it; the o-ring will not be extruded into the gap of the groove because of the existence of back-up ring which prevents gap-bite and prolongs service life of the o-ring; the contact pressure between o-ring and sealing interface increased, thus the sealing reliability of the system increased.

Abstract: According to the demand of exploiting the poor-thin oil layer in Daqing oilfield, Y422 retrievable fracture bridge plug is designed. Match usage of this bridge plug and other instruments can fracture multiple oil reservoirs with one-trip string, which is characterized by simple technology and safety operation. This bridge plug has realistic significance and practical value for improving oilfield economic benefits and provides an extensive application prospect. After setting process, the slips brace the bridge plug whose performance have a directly influence on the oil well productivity and production safety. In order to make sure that the bridge plug slips can meet the anchoring requirement, the actual working state of the slips system was analyzed by using finite element software, and the stress distribution rules were obtained. The results provide theoretical basis for optimizing slip structure and improving working reliability.