Optimization of Conventional Acid Jobs and the Historical Trend Leading to Multistage Acid Fracturing Stimulation to Increase Gas-Condensate Productivity in Carbonate Reservoirs in Saudi Arabia

The majority of the gas-condensate reserves, currently being developed from fields located in southern Saudi Arabia, come from tight carbonate reservoirs, which require acid stimulation to achieve gas rate targets and field development objectives.Most of the gas producers drilled at the beginning of the gas development program were vertical completions, the majority of which were acid fractured and achieved excellent post-stimulation results. As the development scope expanded to areas with tighter reservoir characteristics, the majority of new wells were drilled as open hole single or dual lateral completions to achieve maximum reservoir contact (MRC). A significant number of these wells did not require acid stimulation, but many others did, either to increase productivity in underperforming wells, or to remove drilling induced formation damage. The most recent approach in the evolutionary process is to drill single lateral open hole horizontal producers and fit them with a completion designed for multistage fracturing treatments.This recent approach has allowed Saudi Aramco to effectively stimulate the entire horizontal section, optimize treatment designs, and achieve excellent post-stimulation results and high gas rates from wells drilled in even tighter reservoirs. This paper describes the historical trend leading to the selection and implementation of multistage fracturing technology as a fit-for-purpose technology to maximize productivity in long horizontal gas producers, and shares post-stimulation results achieved in typical wells drilled and completed throughout the different development phases.