As the pressure-bearing part of the floating coupler

the strength of the spherical cover directly affects the pressure-bearing and sealing function of the floating coupler in the process of lowering the casing.Firstly

the theoretical analysis and simulation of the stress of the spherical cover were carried out

and the strength calculation formula of the spherical cover was established based on the spherical shell model under three-way stresses

taking into account the material and compression the damage failure form.Borosilicate glass was selected as the material and its compressive strength was obtained by the compression test.The stress state of the spherical cover was obtained by simulation calculation and the dangerous area was determined.Then the burst pressure of the spherical cover was obtained by the pressure test

and the test and calculation results were compared.The results show that the opening pressure of the spherical cover was 46.2 MPa±3.8 MPa

and no residual glass was inside the floating joint after breaking.The maximum broken particles are less than 10 mm×9 mm×3 mm

which meets the strength requirement of the spherical cover.The results of the study are of great significance to the application of floating coupling in horizontal wells under casing.