含硫气藏天然气水合物生成预测及防治

Prediction and prevention on natural gas hydrate formation in sour gas reservoirs

在川东北含硫气藏的勘探开发过程中,天然气水合物冰堵一直是影响开发进程的一个问题。其预测与防治是急需解决的难题,而目前在国内关于这方面的研究却很少,仅有的方法也只是针对一般气井,而对于含硫气井的预测结果偏差就很大。通过现场实践研究,采用分子热力学模型法进行计算,分析得到了压力、组分等对天然气水合物温度的影响,尤其是硫化氢的存在对天然气水合物形成的影响,为含硫气藏天然气水合物的防治提供了依据,并在天然气水合物形成温度预测的基础上,结合河坝1井的实际情况进行了水套炉型号的优选。实践证明:利用该方法预测的天然气水合物生成温度和预防方法是准确、可靠的。

In development and exploration of sour gas reservoirs in north-eastern Sichuan basin,hydrate ice blockage is always the key problem to influence development process whose prediction and prevention are difficulties urgent to be solved. However,there is little research on this issue in China. The only existed method just points to common gas wells,so it has a relatively bigger error on prediction result of sour gas wells. Through research on field experiment,this paper adopts molecular thermodynamic model to calculate it,gets the impacts of pressure and component etc. on natural gas hydrate temperature especially that of hydrogen sulfide existence on natural gas hydrate formation after analyzing,which provides reference for controlling natural gas hydrate in sour gas reservoirs. Then on the basis of prediction on hydrate forming temperature,water jacket furnace's type is selected optimistically in combination with the well Heba-1 actual situation. It is proved by practice that this prediction method and prevention countermeasures are correct and reliable.