AI-Based Technology Enables Real-Time GOR Control in Oil-Rim Reservoir Management

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 24751, “Novel AI-Based iGOR Technology for Real-Time GOR Control: A Case Study Pilot Plan for Enhanced Oil-Rim Reservoir Management,” by Ahmad Khanifar, SPE, Sai Ravindra Panuganti, SPE, and M. Imran Iskandar B. Ibrahim, Petronas, et al. The paper has not been peer-reviewed. Copyright 2025 International Petroleum Technology Conference. _ Controlling the gas/oil ratio (GOR) is important in safeguarding ensured recoverable reserves and optimizing production in oil-rim reservoirs or fields subjected to water-alternating-gas injection schemes. This paper presents the results of an artificial intelligence (AI)-based high-GOR well-control (iGOR) solution, which was piloted in an oil-rim reservoir. The technology aims to stabilize and optimize production from wells experiencing gas breakthrough and high GOR using differential pressure measurements and an automated surface choke for continuous well operations. Introduction The aim of the pilot project was to develop and validate a digital process technology for real-time GOR control, targeting wells affected by gas coning or high-GOR issues. This project served as proof of concept, with a plan for full-field deployment in the next phase across all candidate oil wells. The fundamental technology behind iGOR uses pressure-drop measurements across a restriction to control flow streams, which is not a new concept. However, applying this method to control well production, GOR, and subsurface drawdown is unique. The solution aligns with the upstream industry’s efforts to reduce operating costs, prevent unplanned production deferments, and maximize field production. Problem Statement Field A, one of the largest oil fields offshore Malaysia, lies at a water depth of 250 ft and contains 15 main hydrocarbon-bearing reservoir units. Some of the wells in this field produce from oil-rim reservoirs and display gas-coning behavior. The severity of gas coning depends on the wellbore’s proximity to the gas/oil contact, the reservoir’s drive mechanism, and the level of drawdown applied. In high-GOR wells, frequent gas breakthrough has been a recurring issue. The increase in tubinghead pressure, accompanied by a decrease in tubinghead temperature owing to the differing heat capacities between gas-dominated and liquid-dominated flow at the same choke setting, reflects this behavior. These events lead to a sharp reduction in real-time oil production, often requiring immediate responses such as choking back the well (beaning down) or, in some cases, completely shutting the well for several hours. Production wells in thin reservoirs with a gas cap are highly susceptible to excessive gas breakthrough. Complex production behavior wherein the same choke setting yields different production outcomes often has been attributed to reservoir drainage dynamics. The fundamental issue in managing these wells is not the size of the choke but the inherent instability of the equilibrium between maximum oil and minimum gas production. At this optimal point, even small disturbances can shift the balance, resulting in either excessive gas production or low oil production.