The reinforcement and cementation of cement sheath to gas storage well

In this paper, the friction resistance between cementation process's cement sheath and well bore of gas storage well and the critical length of gas storage well cementation is obtained through establishing a stress model for gas storage well to calculate the pressure on the interface between cement sheath and well bore. In an ideal well cementing state, the well bore will not separate with cement sheath and run out from the ground if the well cementing length exceeds 0.7 m for gas storage well at ϕ177.8 and ϕ₂44.48. In the case of the cement sheath not separating from the formations, the continuous well cementing length for ϕ177.8 and ϕ₂44.48 gas storage wells should reach 43 m and 60 m respectively when the formation soil is fine sand. The reinforcement of reinforced concrete to the well bore of gas-storage well is analyzed according to the situation of well wall reduction due to corrosion and unqualified cementation. If efficient reinforcement treatments and sufficient anti-corrosion measures are taken for well head interval of gas-storage well, even if the reduction of wall thickness of gas storage well exceeds the corrosion allowance, the actual pressure of gas storage well bores under normal working pressure is also lower than the allowable stress.