Intelligent Lifting System for Simultaneous Balance of Fluid Volume and Pumping Effciency in Low Permeability Reservoirs

Abstract Low-permeability reservoirs constitute a substantial proportion of global oil reserves. These reservoirs are characterized by complex geological conditions, high extraction difficulty, low productivity, and poor economic benefits. A significant issue faced in these reservoirs is the mismatch between the pumping speed of wells and the fluid supply capacity. This study introduces an intelligent artificial lift technology designed specifically for these reservoirs, focusing on optimizing both liquid volume and pump efficiency. The technology includes an integrated device for measuring liquid production and water cut, alongside a variable frequency intelligent speed control cabinet. Sensors ensure high accuracy, with liquid production errors of less than 3% and water cut errors less than 5%. The pump stroke of the pumping unit is calculated based on the motor operating frequency, ultimately determining the pump efficiency. The intelligent control system employs an economic benefit evaluation index, aiming to maximize pump efficiency while maintaining liquid production levels. This ensures operation with a reasonable pump stroke. Field trials in the Jilin Oilfield involved ten wells, showing promising results: a 23.4% average increase in pump efficiency, 42% reduction in motor frequency, and 1.8-stroke decrease in average pump stroke across six wells. For three more sensitive wells, pump stroke reductions led to smaller adjustments in efficiency (3.6% increase), frequency (9.8% decrease), and stroke (0.4-stroke decrease), maintaining stable liquid production. Overall, this technology achieved a 30% average reduction in power consumption compared to fixed frequency operations, demonstrating substantial energy savings. The field trials indicate that this technology can enhance pump efficiency while maintaining stable liquid production, with notable energy-saving effects. Future work will focus on integrating this technology with time-of-use electricity pricing and new energy generation to achieve more significant economic benefits.