Research On Mechanical Properties And Structure Design Of Petroleum Tube And Casing Hydrostatic Test Unit

By analyzing the study of the domestic and foreign petroleum tube and casing hydrostatic test technology and current application status quo of the equipment, the structure of the different forms of petroleum tube and casing hydrostatic test unit is put forward, the sealing mechanism and the working principle is disclosed. According to the work characteristics of petroleum tube and casing hydrostatic test unit, a new type of petroleum tube and casing hydrostatic unit is developed. The unit is mainly composed of carrying rack, driving mechanism, clamping mechanism, sealing assembly.Welding steel structure and"I"form beam as the main beam are adopted, and finite element analysis is done for the carrying rack.Driving mechanism include motor, reducer, chain driving and lead screw-nut pairs. The mechanical model of the lead screw-nut pairs is built, wear resistance, self-locking, strength and stability are checked. Finite element analysis of the driving mechanism is done.Both of the sealing head are mobile, and they are driven by driving car. The sealing style of steel skeleton, big gaps, radial, outside compelling hermetic is adopted, the sealing part is the steel skeleton radial compressible, deformation will occur under the effect of the sealing pressure source, forming the hermetic force in order to seal the petroleum tube and casing. Seal pressure amounts to 70 MPa. Finite element analysis of the driving mechanism is done, an sealing shell is carried out to structural improvements, appropriate sizes are increased, stress value is reduced, the purpose of reducing costs is achieved by changing another material.Structure design of clamping mechanism include composition, working principle, the mechanical model of clamping mechanism set up, the calculation of clamping force, as well as the safety factor calculations of tube and casing's stability.On the basis of theory study, field test research on hydrostatic properties of the tube and casing hydrostatic test system is carried out. Experiment shows that tube and casing have no leakage in the pressure 70MPa and keeping pressure 10~20s, the performances of the hydrostatic test unit are good and can meet the design requests.