Intervention with the temperature field of shallow and low-temperature gas wells in super-deep South China Sea

In super-deep South China Sea there exist rich hydrocarbon resources. However low temperature on the seabed may cause extremely high risks related to formation of hydrates during gas well test. By studying the distribution pattern of the temperature field in shallow and low-temperature gas wells in super-deep water, accurate prediction models for temperature fields in the entire well can be constructed to highlight necessary interventions for sectioned temperature fields of testing fluids. Research results show that there are high-temperature layers in upper section of the seawater. On the other hand, low-productivity boreholes in upper sections of seawater may have temperature higher than that of high-productivity boreholes. In this way, temperature interventions can be performed node by node. Testing fluid systems with different properties can be deployed above and below each node to construct separate layers for intervention with the temperature field. Research results have been applied to test the first super-deep gas well in China. Field performances show the newly-developed system may effectively prevent hydrates from formation and may provide necessary guidelines for future research.