Expanding the Utilization of Low-Cost Light Workover Unit's LWU Operational Envelopes, Yields a Substantial Upturn in Rig Resources Allocations Efficiency and Well Cost Economics

Abstract Embarking on an initiative to expand the Low-Cost Light Workover Units (LWU) operational envelopes. By utilizing the LWU units to perform well integrity evaluation and Lower completion with Inflow Control Devices (ICD) installations in Workover wells, the perspective of operational excellence allows to maximize the operational scope of low cost LWU replacing Higher cost Heavy Rigs utilization and Activity. Consequently, improving well delivery economics, business plan budget and resource allocating to drilling activities. The main objective of deploying this practice and approach is mainly to utilize light work over rigs to run ICD lower completion in old producing wells, which are saving a big drilling units days and rental cost that led to optimize well production. Hence, controlling water shut off and water cut percentage in production is a big gain. The practice was optimized, and the learning curve was developed to provide optimum procedures for those wells that can be generalized as retrieval of old completion string, verification of well integrity in terms of cement casing through corrosion logs and pressure testing. In addition, a key factor is drifting the open hole through proper accessibility run using Non-Damaging Fluid (NDF) and optimized Bottom Hole Assembly (BHA) after conducting engineering analysis and simulation studies for the well trajectory and actual survey, close supervision and mutual engineering / operations follow up for execution of lowering the lower completion. By following this proven practice, we successfully delivered three wells in same field with +/- 5500 ft of ICD lower completion for a gas lift and ESP producing wells on light Work Over rig with multiple limitations such as: limited Hook load capacity hence minimum "Margin of Overpull" availability that was challenging for freeing stuck situations while lowering lower completion strings, as well having one mud pump available in rig equipment added another burden to work with possibility of differential sticking while pump is under mechanical failure. Moreover, practice can be spread to other fields that can make a significant rig days’ saving and cost saving of rental bigger units. This practice leads to enhanced utilization of light work over rigs for running long ICD lower completion exceeding 5000 ft of lateral holes in existing producing wells saving us big rig days and rental cost and even sustainable less carbon footprint for optimizing production rate and decreasing water cut ratio from these reservoirs.