气井井下节流降压工艺方法探讨

结合气井生产特点，对汪家屯气田水合物的生成机理及产生规律进行了研究，阐述了水合物形成机理，即天然气水合物是天然气中的水和气体在低温高压下的产物，其形成与天然气组分和地层水的矿化度、温度和压力有关。为探索新的水合物的预防技术，在易形成水合物气井上，开展了井下节流防治水合物工艺试验，其原理是将地面气嘴移到井下产层上部油管内，使天然气的节流降压膨胀过程发生在井内。通过井下油嘴节流、降温后的天然气仍可吸收地层温度，降低井筒内天然气压力，提高采出天然气的井口温度，破坏水合物的生成条件，达到防止水合物生成的目的。

Process Method of Downhole Throttle and Decompression in Gas Well

This paper analyzed the synthetic mechanism of hydrate according to the production performance of gas well. The form of the hydrate is related to the component of natural gas, the salinity of formation water, temperature, and pressure. In order to explore the new preventive technique of the hydrate form, carried out experiment of downhole throttle techniques.The principle is that the ground air tap is positioned downhole along the oil tube near the top of pay zones to make the throttle and decompression expending of natural gas occur in the oil tube. The gas passed downhole choke can still absorb formation temperature and lower the gas pressure in the wellbore. As a result, the gas temperature coming out of the well top is raised, the condition for forming the hydrate is destroyed, and the aim of prevention the form of the hydrate is fulfilled.