Influence of Cement Return Height on the Wellhead Uplift in Deep-Water High-Pressure–High-Temperature Wells

Abstract

In oil and gas production in deep-water high-pressure−hightemperature (HP−HT) wells, wellhead uplift may cause the seal failure of wellbore integrity. Aiming at the oil and gas production stage in deep-water HP−HT wells, we considered the influence of cement sheath cementation and developed a model for calculating the height of wellhead uplifts, and simulation experiments for wellhead uplifts were carried out under the condition of the double pipe string at different cement return heights and multilayer pipe string coupling cementing and noncementing based on a self-developed HP−HT wellhead uplift simulation device. The results show that the elongation of the double pipe string under the condition of a cement return height of 100% is reduced significantly compared with that under the condition of a cement return height of 50%. Also, the maximum elongation of the multilayer pipe string under the condition of coupling and cementing is significantly reduced compared with that under the condition of noncementing. These show that cement sealing has a binding effect on wellhead uplifts. The error between the calculated and the experimental results is less than 10%; thus, the model can be used to predict the wellhead uplift height under different working conditions and provide technical guidance for designing scientific measures to prevent wellhead uplifts.

Analytical Perspectives on Cement Sheath Integrity: A Comprehensive Review of Theoretical Research

“…After completing a stage of drilling and casing installation, cement slurry is injected into the annular space between the wellbore and casing, where it solidifies, forming a continuous and robust cement sheath. Failure to perform proper well cementing practices can lead to several problems, such as casing damage, sustained casing pressure, harmful gas and liquid leakage, , and wellhead lift . These issues can severely impact well integrity and productivity.…”

“…Failure to perform proper well cementing practices can lead to several problems, such as casing damage, 3 sustained casing pressure, 4 harmful gas and liquid leakage, 5,6 and wellhead lift. 7 These issues can severely impact well integrity and productivity.…”