Working Mechanism Analysis And Structure Improvement Of Bracketer Bracket

BOP is well control equipment of the exploration and development the high-pressure oil and gas fields, to prevent blowout accidents and critical pressure balanced drilling.The shear ram blowout preventer can cut the well string, close the wellhead to achieve safe production, in case of emergency. In order to study the mechanism of shear ram, the paper analyze the working mechanism and the ability of the shear rams to cut and seal. Based on the analysis, for further improve the reliability of shear ram work the paper put forward some effective improvement measures.For shear mechanism analysis of drill pipe material deformation under shear the drill pipe and the constitutive model and fracture criterion; dynamic analysis module of the mechanical behavior of shear rams were Abaqus finite element software display simulation analysis showed that: ISR -type shear rams can be successfully cut 5" and the following drill, cut 5" drill, if cut more than 5" it may be dangerous failure. SBR-type shear rams can reliably cut 4" drill and that below it. By analyzing the effect of the structural parameters of the shearing process to obtain ISR -type shear ram optimal structural parameters, reducing stress on the gate peak displacement and deformation, shear ram to improve reliability.The use of ISR-type and SBR-type shear ram shear experiments showed shear fracture of experiments is looks highly consistent to the drill fracture of simulation analysis, contact area of ram shear to cut the drill pipe was the same as the high stress area of simulation analysis. It verified the correctness of the simulation analysis. A shutter blade sheared plastic deformation is small, does not affect the subsequent sealing. While scans and contrast the ram’s shearing edge before and after ram shear the drill pipe by use of the 3D-Scaner. Concluded that the plastic deformation of shear blade is small after only one shear of drill.Using the Ram-type sealing mechanism carried on the simulation analysis of sealing process. Firstly,according to hydrodynamics and related theory, taking advantage of Fluent hydrodynamics simulation software, analyzing the process of shutoff ram-type and sand bearing gas eroded the gate edge by the method of numerical simulation,which indicating the solid’s influence is limited, will not affect its shear drill pipe and sealing. Secondly, the key of SBR-type, ISR-type two kinds of shear ram-type seal parts of the finite element analysis, two types of shear ram-type sealing ability than 100Pa, can meet the requirements of field use. The ISR type shear ram is improved in design, floating the improved sealing structure can not only reduce the gate on the sealing rubber extrusion shear damage, but also enhance the sealing ability, the structure is very simple and effective.SBR-type and ISR-shear rams working mechanism were analyzed with the principles and methods of analysis ISR.SBR-type shear rams can reliably cut 4" drill and that below it; sealing pressure reached 100MPa or more, to meet the requirements of drilling field. Compared to two kinds of type shear rams, in the course of shear the stress peak of ISR-type is lower and the deformation of the ram’s edge is smaller, so the ISR-type shear rams cut performance is better. Also it has the better seal structure, because the ram’s edge will not damage rubber when it squeeze the rubber. So the rubber has longer life.Through this article analyze the ISR-type and the SBR-type shear rams to cut and seal mechanism and the work ability. That has some significance for field use this type of shear ram. And the structural parameters of the rams’ edge and bottom sealing structure been improved, that can improving the ram shear capacity and sealing ability, enhance their ability to work and reliability, have great significance for ensure the safety of the drilling site.