Abstract:
Wellhead tubing pressure, production rate and tubing string buckling deformation of gas storage wells were studied thoroughly based on the casing program and gas production process of gas storage wells in Huabei Oilfield.Three critical loads under which the pipe string suffers sinusoidal or helical buckling deformation in the wellbore and the buckling states between these three critical loads were discussed.And accordingly, the new critical load for the classification of unstable sections was determined and the mathematical model for calculating the axial force at the bottom of tubing was derived.Based on the mechanical analysis and theoretical research on the pipe string with packer, the mathematical model for calculating various effect changes on packer strings and the established mathematical model for calculating critical buckling load of pipe string, a set of safety evaluation software for injection and production string of gas storage well was developed by means of VB2013.And then this software was used to study the injection and production string of gas storage well S-x in Huabei Oilfield.It provides the theoretical basis for the parameter selection of gas storage wells (e.g.wellhead tubing pressure and production rate) and for the safety evaluation of injection and production strings.