Investigating the Influence of ESP on Wellbore Temperature, Pressure, Annular Pressure Buildup, and Wellbore Integrity

Abstract

Abstract The electrical submersible pump’s (ESP) impact on wellbore temperatures and integrity is seldom discussed in literature. Most literature discusses ESP run life and failure. The ESP heat dissipation increases the wellbore temperatures. Therefore, direct and indirect thermal-induced stresses are applied to the casings and tubing. At the same time, the trapped annular pressure buildup (APB) also increases, thereby applying additional stress on the casings and tubing. This raises the question—is the safety factor still valid? This is crucial in high-temperature/high-pressure (HT/HP) and deepwater/ultra-deepwater wells that have narrow design margins. This paper presents studies on the prediction of wellbore temperature and pressure profiles, which account for the ESP heat dissipation effect on APB. The heat dissipation from the ESP electric motor, pump, and cable are considered. Then, the convective and conductive heat transfer through the wellbore are described in a transient wellbore temperature model. The updated temperature profile is then applied, and the APB and tubular stress analysis is revisited. The model is integrated into an advanced casing and tubing design software platform. Case study results show increasing temperatures along the wellbore. The increased temperatures induce the APB and the strings axial compressive stress increase. In the studied case, the APB increased up to 23.6%. The increased APB induced additional loads on the tubing and casings, which can result in collapse/burst failures. Both theoretical analysis and case studies show that if the original design did not consider the use of ESP, induced APB can cause casing/tubing failure and result in wellbore integrity issues. The findings indicate ESP heat dissipation does affect the wellbore integrity. Attention should be paid to the possible allocation of ESP in the future to achieve an accurate APB prediction during the modern wellbore completion design and planning phase. The findings are of particular interest in production monitoring and control, wellbore completion, ESP selection, casing/tubing design, and wellbore integrity, especially for mature-field and offshore wells.