Surface and Subsurface Development Strategy of a Carbonate Stringer with Halite Production in Southern Oman

Abstract

Abstract Stringer reservoirs in south of Oman are carbonate bodies encapsulated in thick zones of Ara salt. The pressure in these reservoirs is varying from lithostatic to hydrostatic regime. Halite production in field HL-3A has been a major challenge throughout the years of production; hence, a thorough investigation was needed to tackle the issue and come up with a strategy to decrease salt migration to the wellbore. Fluid sampling and pulsed neutron logging (PNX) were done to study salt content and free water fraction variations over the well production timeline. Additionally, well testing was performed to identify the suitable offtake envelope to control halite production by monitoring wellhead pressure, water cut, and salt concentration at different choke sizes. Such an approach led to a reliable well offtake envelope to constraint plugging issues caused by salt; the strategy was more sustainable than previous short-term strategies, like regular freshwater flushing. Plus, it contributed to lowering field development cost by 30%. This paper describes actual experience shared from HL-3A reservoir management and learnings. The approach could be beneficial for comparable depletion cases elsewhere and valuable in deferment reduction, field development planning, and halite production management steering to operational excellence.