Enhancing Offshore Gas Dehydration Efficiency and Design Optimization for Sour Gas Field Development Project

Abstract One of sour gas field projects in Sarawak, Malaysia is currently under development. The offshore facilities mainly comprise of separation, gas and condensate processing with dehydration. The gas dehydration system plays a vital role by reducing the water content in gas to achieve 5 lb/MMscf, preventing corrosion and hydrate at the export pipeline. This paper focuses on enhancing the efficiency of glycol dehydration process, along with its cost optimization. A comprehensive evaluation of key parameters influencing the glycol dehydration process, such as temperature, pressure, flow rate, is conducted to identify optimal operating conditions. To optimize the glycol dehydration process, a systematic approach combining process simulation, and the supplier's proprietary method are employed. The experimental modeling is conducted to vary the process conditions and predict the performance of the glycol dehydration and regeneration system. Furthermore, an economic analysis is performed to evaluate the capital investment cost, operating expenses, and energy consumption. The results of the study revealed a significant correlation between the gas inlet temperature of glycol contactor and the dehydration efficiency. Lowering the inlet temperature improved the dehydration process, as evidenced by reduced water content in the feed gas for the optimized design case. Moreover, the glycol regeneration system exhibited enhanced overall performance by decreasing the glycol circulation rate and lowering energy consumption by approximately 35%, as well as reducing fuel gas consumption for stripping gas. The optimal operating conditions were determined, considering both technical and economic assessments. The equipment size of gas dehydration was optimized, including at least a 20% reduction in weight, benefiting the total investment cost by 2.6 million USD. Additionally, a positive impact was observed in fuel gas consumption reduction, which provides long-term benefits for both operating costs, with approximately 10 million USD in savings over the entire project lifetime, and GHG emissions with up to 17 KTPA of CO2 reduction in total. In conclusion, this study highlights the significant impact of optimizing process parameters on the gas dehydration and regeneration design. The integration of process simulation, and supplier validation, and economic analysis provides valuable insights into improving the efficiency, cost-effectiveness, and sustainability of gas dehydration processes in offshore development projects.