Challenges and Remedy for Cementing of HPHT Wells in Nigerian Operation

Abstract As hydrocarbons are being depleted from some formations, the search is on for greater reserves in difficult regions. Some wells are now drilled in more hostile downhole conditions, which include high temperature and high pressure. A well is considered to be high pressure and high temperature (HPHT) if the pressure exceeds 15000psi (1020 bar) and the temperature exceeds 300°F (149°C). The challenges created by these, make drilling and cementing in these regions difficult. The study reveals that in order to meet up with the challenges of HPHT drilling and cementing operations, issues such as effect of temperature and pressure, large stresses, degradation of set cement at elevated temperature, small ECD windows, efficient fluid design and displacement among others must be addressed for successful job execution and excellent job delivery. The objective of the study therefore is to highlight various challenges associated with HPHT wells, the Best Practices that have been adopted in several HPHT wells and the way forward. This will provide a learning point for operators, researchers and other Engineering professionals especially for the emerging HPHT operations in Nigeria and Gulf of Guinea.