Reducing Water in Gas Wells with Autonomous Inflow Control Technology

Abstract Energy is critical for the global population, and natural gas is a reliable, affordable and transportable source. Water breakthroughs in gas wells can reduce productivity and recovery, leading to early well shut in. A new Autonomous Inflow Control Technology for gas wells (gas AICT) has been developed to autonomously detect and choke unwanted water production while allowing gas and condensate production, improving both economic and sustainability measures of gas wells. This novel AICT leverages the Hagen-Poiseuille equation and Bernoulli's principle to differentiate between gas, condensate, and unwanted water. The gas AICT autonomously chokes zones with water production. Extensive flow performance tests have been conducted as part of the qualification program, initially in a multiphase flow loop with model fluids and subsequently with hydrocarbon gas, condensate, and formation water under downhole conditions. A reservoir and well simulation model, based on a Norwegian gas discovery, was constructed to evaluate the impact of the gas AICT. This model also aids in understanding future development directions for the technology. The experimental results demonstrate that the gas AICT effectively chokes water while remaining open for gas and partially open for light condensate. The valve exhibits an acceptable flow rate for gas, which can potentially be further enhanced in the future. Reservoir simulation modelling predicts the performance of the gas AICT under downhole conditions and explores various scenarios for the lower completion. For the long horizontal gas wells in this study, the impact of annulus phase segregation is quantified. Potential solutions for the clean-up of heavier completion fluids are also briefly discussed. To our knowledge, this is the first published flow performance test of an AICT that autonomously detects and chokes water while allowing gas and light condensate at downhole conditions. This technology has the potential to extend well life and increase gas recovery, with estimates in the range 13-37% in the field case studied. Additionally, water production is significantly reduced. The reduction in water production and the improvement in gas recovery (reducing the need for new wells by enhancing recovery from existing ones) provide clear environmental benefits. In summary, the gas AICT studied here shows clear potential to enhance both economic and sustainability outcomes for new gas wells at risk of water production.