Analysis Of Annular Pressure In Deep Water Gas Wells And Prevention Measures

With the continuous exploration and development of offshore oil and gas resources,the problems faced by offshore oil and gas wells in testing and production processes are receiving more and more attention,especially the problem of annular pressure in deep water gas wells,especially in the later production process.Leading to gas well annulus pressure,when the pressure exceeds the maximum allowable annulus pressure value,it will lead to safety accidents such as blowout,and even threaten the production platform where the well is located.Therefore,the analysis and prevention of the annulus pressure in deep water gas wells The preferred study of measures is imminent.Based on the research at home and abroad,this paper mainly analyzes the causes of the annulus pressure in deep water gas wells(oil casing leakage,operation reasons,gas enthalpy),and combines the actual conditions of deep water gas wells based on PVT equation of state and temperature-pressure coupling model.The closed-loop air pressure calculation model is obtained and the influence of different factors(the isothermal compression coefficient of the annulus liquid,the thermal conductivity of the annulus liquid,and the annulus saturation)on the annulus pressure is analyzed.The ring caused by the gas enthalpy is established.The air pressure calculation model is used to analyze the influence of different factors(air top height,permeability,annulus liquid density,leakage point)on the annulus pressure;the calculation model of the maximum allowable pressure value of the wellhead is established,and the model is used.The effects of wear and corrosion on casing strength were analyzed.The strength check model of oil casing was established and an example calculation was carried out.Then,the stress,displacement field and stress field of the cement ring under the joint-cement-soil elastic interaction are analyzed.According to the failure of the oil and gas well cement ring,the criterion of cement ring failure is discussed,and the elastic modulus of the cement ring is The strength of the cement ring was analyzed in three aspects:the thickness of the cement ring and the absence of the cement ring.Finally,the prevention and control measures of the annulus pressure are given for the cause of the annulus pressure.