Shuqin Xiao

Development of Emergent Shut-off Valve at Gas Wellhead in Sulige Gas Field

Sulige gas field lies in the desertification area of Ordos Basin, and the natural environment is adverse there. The difficulty of using traditional methods to manage thousands of gas wells there is great. A kind of emergent shut off valve is developed and introduced in this paper, and the problems of gas well management are solved. Firstly, the development background of emergent shut off valve at gas wellhead is introduced, and the gas collection pattern of medium and low pressure in Sulige gas field is involved. Then, the design requirements of the valve are described. Subsequently, the structure, working principle, and design parameters of the valve are illustrated. Finally, field application of the valve is introduced. By the end of 2016, thousands of the valves developed in this paper have been applied in Sulige gas field. Good adaptability and performance have been shown in application. It could be remote controlled and the protection functions of overpressure and under pressure are reliable. The difficulties of gas well production and management could be solved by application of emergent shut-off valve at gas wellhead. The level of the gas well management could be improved with remarkable benefits.

Thinking on Problems of Ice Blockage During Gas Well Opening in Sulige Gas Field

Aiming at the problem of ice blockage which leads to well opening failure using needle valve during gas wells opening procedure of some high-pressure gas wells in Sulige gas field, the reasons are analyzed and solutions are proposed in this paper. Firstly, gas collection pattern of medium and low pressure in Sulige gas field is introduced in this paper, and then the needle valve of wellhead is equivalently simplified and simulation analysis is implemented by using the software of FLUENT. The results of the simulation show that the pressure and temperature during gas well opening in Sulige gas field could match the formation conditions of gas hydrate. Meanwhile, through mechanism analysis on the wellhead equipment and field testing, flow channel of the wellhead flowmeter is proved to be the main region where ice blockage occurred. Based on the result of the above analysis, three solutions are put forward innovatively in this paper and one of them is mainly recommended. The problems of well opening failure are hopeful to be solved through the solutions in this paper, and the success rate of gas well opening in Sulige gas field could be improved.