- Scientists from China and Singapore propose a new geothermal-based method for offshore gas hydrate production.
- The innovation could boost gas output by 73%, significantly reducing extraction costs.
A group of scientists from China and Singapore has introduced a groundbreaking technique for offshore gas hydrate production. The method uses geothermal energy and depressurisation to enhance gas recovery while cutting operational costs. Their study, published in Engineering, presents a significant step towards making gas hydrate extraction commercially viable.
The research team, led by Baojiang Sun of the China University of Petroleum and Praveen Linga of the National University of Singapore, developed a unique loop well design. This structure efficiently channels geothermal energy from deep layers to stimulate gas release. The method achieves higher production rates with lower energy losses by combining geothermal coupling and depressurisation.
Traditional extraction techniques often struggle with limited efficiency and high costs. However, this new system integrates a heat-extraction well, a heat-injection, and a production. Together, they form a closed loop that transfers heat more effectively within the hydrate reservoir.
Simulations in the Shenhu area of the South China Sea demonstrated the method’s strong potential. The results showed a 73% increase in gas output compared to conventional systems. Economic analysis further revealed methane could be produced at just 0.46 USD per cubic metre, dropping even lower under favourable conditions.
The study highlights how geothermal energy improves hydrate dissociation. When fluid temperatures exceed 62°C, most heat is absorbed by the rock, not directly by the hydrate. Therefore, controlling the temperature threshold is crucial for maximising gas recovery.
The researchers also analysed different flow rates in the loop system. They found that increasing the flow rate slightly lowers fluid temperature but does not significantly affect gas yield. This finding suggests that extreme heat injection is unnecessary for efficient extraction.
Furthermore, their model indicates strong commercial potential. When reservoir porosity and hydrate saturation rise, production costs fall sharply. At optimal conditions, gas costs could reach as low as 0.14 USD per cubic metre.
The team concludes that this dual horizontal well system could transform offshore gas hydrate production, combining geothermal energy with depressurisation for cleaner and more efficient extraction. The innovation marks a crucial step towards sustainable and affordable natural gas development.