Successful Applications of a New Sand Screen Technology to Mitigate Water Injection Challenges, A Case Study for X Field, Nigeria

Abstract

A number of techniques have been applied to improve the integrity and therefore long-term performance of injection wells to eventually enhance oil recovery in one of the fields in Nigeria. Comprehensive data analysis suggested formation solids due to the phenomena of water hammer, backflow and crossflow are major integrity problems in several injection wells in the targeted field, especially with fines migration and accumulation inside the lower completion during sudden or prolonged well shut-in. Formation solids are normally resident in the reservoir during the steady injection but can be mobilized into the wellbore during sudden shut-ins due to powerful transient flow effects such as water Hammer, cross flow and backflow. This would result in high bottom hole injection pressure (BHIP), diminished or loss of injectivity, screen plugging and erosion of downhole equipment which may lead to the inability to maintain pressure support to pair producer. Therefore, an intervention, remediation, side-track or loss of wellbore may be deemed inevitable. Application of other technologies has proven unsuccessful in these wells for various reasons. A new sand control technology specifically developed for such projects was chosen as the best option among all available alternatives based on a matrix of requirements for the new campaign. This technology which would be installed on the closest point to the sandface was chosen as it isolates the reservoir from wellbore during well shut in, constitute no obstruction to Intervention tools, provides full access to the lower completion sand face during injection and/or intervention without restriction or pressure drop, withstands well conditions for the entire well life, is compatible with SAS, GP completions and direct wrap or metal mesh screens and it is a low CAPEX solution compared to other alternatives. Rigorous compatibility tests and practices including modelling, backflow, cross flow, erosion and plugging tests were performed to ensure that well completions and operations requirements were met for field X. The results from all studies were positive and successful and therefore the technology was approved to be installed in the wells. The NRV technology has already been installed in 3 wells to date. In this paper, the pre-qualification studies, the full qualification test results and post-installation well performance would be discussed. Also, the lesson learnt from these installations will be shared. The wells’ performance data shows that this completion technology has successfully delivered the target rate and desired performance so far and provided the field X team with a robust solution to mitigate the common issues with the injection wells while avoiding costly interventions.