Wells Intervention Cost Optimization Through Curing Formation Damage in Sabriya Wells- Case Study from Kuwait

Abstract

North Kuwait Sabriyah wells have massive formation damage and enormous fluid losses occurring during workover operations in the Upper Burgan Formation. This challenge causes wellbore plugging, as well as incremental operational costs (rig days & brine cost) and delayed production. It is noteworthy that the Upper Burgan (UB) Formation is balanced with 5.5 PPG kill fluid. This is due to the significant differential pore pressure and 8.4 PPG brackish water, which would impose a high risk of losses and formation damage. A unique solution" salt pill" has been selected as an optimum solution to this challenge. The solution is a filtration control agent that allows work over activity with temperature stability up to 350 Deg. F and it is applicable for Gas & Oil wells with over 2% water cut. It is sustained casing pressure for workover with a constant fluid level at surface during the intervention. The customized fluid is being flowed back and it is 100% dissolvable in produced or any under saturated water, with no need for acid breaker. This unique feature allows to keep the formation up to 5000 Psi overbalance thus eliminating potential well control issues by maintaining the static fluid level in the well. This salt pill technology was successfully tested in the candidate Sabriyah wells, the results were satisfactory & the trail has shown good success. The well was put back to the original rate, and oil showed at surface after unloading only one well volume. This successful pilot will be a best practice solution for KOC assets in term of cost optimization and added value. The technology will support KOC to solve some of the other faced challenges in various wells integrity and WO issues demonstrating how much cost savings can be attained along with keeping the reservoir damage free and restoring its productivity to original levels after the Salt Pill technology has been deployed.