Prediction of the wellhead uplift caused by HT–HP oil and gas production in deep-water wells

Abstract

In the oil and gas production process in deep-water high-temperature–high-pressure (HT–HP) wells, the occurrence of wellhead uplift is often induced by the heat carried by oil and gas flow from the well bottom to the wellhead. This directly leads to the seal failure of wellhead device, causing the great potential safety hazard. Therefore, the wellhead uplift needs to be studied in cementing designing. The calculation model for the wellbore temperature and pressure field as well as the wellhead uplift height was established, we have developed a wellhead uplift experimental device, and experiments for the wellhead uplift under different working conditions were conducted. It was found that the increase of wellbore temperature and trap pressure cause the wellhead uplift, the calculation error of model is less than 10% compared with the experimental data. This could be used to predict the wellhead uplift height under different working conditions. It has certain guiding significance for cementing optimization and improvement of the wellhead integrity.

Keywords

• Wellbore temperature
• Trap pressure
• Wellhead uplift
• Free elongation
• Multiple string coupling