Maximizing well performance strongly depends on artificial lift installation (AL), operational maintenance, and reservoir performance over time. Operators in the Permian Basin often follow neighboring operators' AL methods without further optimization. While implementing one form of AL could maximize initial production and yield quicker payout, these installations could hinder long-term hydrocarbon recovery and economics. Therefore, an AL strategy using a holistic reservoir performance analysis could optimize production and operators' economics.
This study evaluates additional applications of various AL strategies in Northern Midland and Delaware Basins based on production histories, general operation practices, and reservoir modeling. The study reviews the regional reservoir characteristics and general AL practices in Third Bone Spring and Lower Spraberry formations and built and calibrated numerical simulation models with production histories. The study then used those calibrated models to run various cases with different AL methods. Finally, the study performed economic analyses for different AL methods.
This paper reviews the workflow to select an optimal AL strategy, compares strategies in the Northern Midland Basin Lower Spraberry and in the Delaware Basin Third Bone Spring, and reviews additional opportunities on University Lands. The study suggests best practices that can be used by other Permian Basin operators. Similar previous findings in other parts of the Midland Basin, these new case studies confirm that operators who implement AL strategies on a larger scale have a larger probability of success in their economics.
The productivity index (PI) of wells decline with time in unconventional reservoirs, and characterizing well PI over time should benefit these long term AL strategies decision. The scale of development has a large influence on the AL strategy.
Production wells in unconventional reservoirs require a flexible AL strategy because of a wide range of production rates and high decline rate of well productivities with depletion and time. Initial rates observed from those wells on University Lands in the Permian Basin are often greater than 5000 BFPD but decline rapidly to hundreds of BFPD within six to twelve months. From general observations among the 270+ operators on University Land acreage, operators follow their peers of similar company size on AL strategies. Smaller operators generally start wells using an ESP and convert to rod pump once fluid rates are below 350 to 400 BFPD. After some early trials, larger and even some smaller operators are now generally using gas lift (GL) before converting to rod pump or other positive displacement pumps.