Hydrate formation prediction in deepwater gas well testing

Hydrate formation is a big problem during deepwater gas well testing, and it would even lead to the failure of test opera-tion, and causes a major accident. In order to ensure the safety and success of deepwater gas well testing, it is necessary to analyze the formation law of hydrate during the testing and forecast region that hydrate may emerge to strengthen the hydrate prevention program. Based on the deepwater testing procedure, the calculation models of temperature and pressure have been established in conditions of flowing at open-up and requiring pressure at shut in, and then the prediction method of hydrate form region at different construction stage in testing is obtained combining with the formation condition of hydrate. A calculation result for a deepwater well shows that at the stage of flowing test, flow rate is an important factor of hydrate formation. The less output, the larger hydrate region. Another indication of the result is that high pressure and low temperature will cause serious hydrate problem at the stage of shut in and beginning of flow period. Measures must be taken to prevent the occurrence of hydrate in these periods.