Papers by Author: Shi Min Zhang

Abstract: The carbon aerogels doped with nickel were produced by sol-gel, supercritical ethanol drying, and high-temperature carbonization, using resorcinol-furfural as carbon source, nickel nitrate as nickel source, absolute ethanol as dispersion medium, 1,2-epoxypropane as gel initiator, polyacrylic acid as the chelating agent. The carbon aerogels were characterized by nitrogen adsorption and XRD. The effects of the molar ratio of 1,2-epoxypropane to nickel on porosity of the Ni-doped carbon aerogels were investigated. It is found that the Ni-doped carbon aerogels have abundant mesopores and the doped nickel is dispersed in samples in metallic state and oxide or pure metal depending on the preparation conditions. The mesopore volume and average mesopore size all increase with the ratio of 1,2-epoxypropane to nickel.

Abstract: Zhejiang Province is Located in the Yangtze River Delta which the Soft Soil has Large Thickness and the High Underground Water Level.There is a Higher Requirement for the Optimization Design and Safety Construction of Deep Foundation.According to the Summary and Analysis of some Common Cause Failure of the Foundation Pit Engineering，we can Conclude that there are some Failure Mode in Soft Soil Area of Underground Diaphragm Wall Structure such as Foundation Pit System Instability，Basal Failure，Piping and the Flow of Sand Damage，Support Structure Instability and the Support of Low Strength or Buckling，and Summarizes some Prevention Measures on the Destruction of Underground Diaphragm Wall in the Light of these Failure Modes.

Abstract: Foreign development regarding devices for speed regulating of in-pipe robot inspection has been commercially applied in gas pipeline this decade, however, the results of theoretical and structural research on bypass device were scaled in and abroad after the research of literature. First, this paper deals with the new structure of a butterfly bypass-valve, the basic parts and working principle on this speed regulating unit. The using of a butterfly disc in bypass-hole of PIG (pipeline inspection gauge) can achieve a speed regulating purpose in bypass-PIG. Next, the theoretical model of pressure loss and regulating feasibility or ability of PIG are introduced by the similar mathematical model with a throttle valve. Finally, give the conclusion.

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: High pressure isolation plug train is a remote control, tetherless, highly piggable and high pressure isolation tool. The advantage of using the pressure isolation tool is to minimize production down time. Domestic research has started recently because of the foreign blockade of its core technologies, there are no relative products coming out currently. The smartplug that have been mentioned consist of plugging module, pigging module, hydraulic power module and communication and control module. The paper describes design ideas of each module in detail respectively and according to the design methods the prototype with diameter of 12 inches has been produced so far. Sealing pressure achieves 10Mpa by experiment. Looking forward to the technology would be applied in pipeline valve replacements and repairs, riser replacements and repairs, pressure test of risers and pipelines, midline pipeline repairs and relative engineering areas.

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.