Restoring Value in Gas Production Through Successful Deployment of Foam Assisted Lift Technology for Gas Well Deliquification

Abstract In the Oil and Gas business, continuous production optimization and enhancement at lower cost is key for optimal field management and recovery. As moderate to strong aquifer supported gas reservoirs deplete, water to gas ratios increases and gas rates decline thus resulting in high liquid loading tendencies and frequent well quitting. To sustain production, there is need to deploy cost-effective vertical lift solutions. The VZTX field is a matured onshore Niger Delta field within Nigeria's flagship and largest oil and gas facility supplying circa 50% of Liquefied Natural Gas to Nigeria (NLNG) for over 10 years. Some of the wells are producing with high water to gas ratios in depleted reservoirs thus requiring frequent vertical lift support to sustain production. In the past, nitrogen lift deployed on coiled tubing has been a successful but expensive option. The successful deployment of chemical liquid foam technology marked a significant milestone in the successful de-liquefication and restoration of two gas wells (VZTX-01 & VZTX-02) to deliver circa 20-25 MMscf/d. This pioneering application, the first of its kind in the operating unit (OU) was necessitated by production challenges caused by liquid loading, leading to well quitting or producing intermittently. The innovative chemical foam solution was technically and strategically chosen for its lower cost (ca. 50% of nitrogen lift cost) and ability to lower surface tension, enhance gas flow, and efficiently remove accumulated liquids in the tubing. Extensive integrated team planning, and field trials ensured optimal liquid foamer qualification, technical assurance, well selection, dosing strategies, deployment techniques and co-ordinated execution strategy tailored to the unique operating conditions of the wells. The results were insightful and transformative, with both wells achieving 90% restoration of expected production rates from the selected wells. This success underscores the potential of liquid foam technology as a cost-effective and environmentally friendly alternative to conventional well-intervention methods, particularly in mature gas fields. The case study provides a blueprint for replication across similar wells and facilities in Nigeria and globally, showcasing the benefits of integrating advanced technologies into oil and gas operations. It also highlights the value of collaboration and integrated work carried out by the Production Technology/Production Chemistry, Well Intervention & Completions, Wells Reservoir and Facility Management (WRFM), Asset Production Operations teams, service providers, and technology experts in driving innovation and overcoming this industry challenge.