超深高温高压气藏水合物预测及防治

Gas Hydrate Prediction and Prevention in Ultra-Deep High-Temperature and High-Pressure Gas Reservoirs

超深高温高压油气藏的勘探与开发已成为我国油气的主攻方向之一,由于储层埋藏深、高温高压、物性差、含有H2S、CO2酸性气体等复杂地质情况,在高速气流和压力波动下极易产生水合物,堵塞生产井筒,造成开采难度加大,对开采的安全性、高效性提出更高的要求。因此对超深高温高压气井开展水合物研究对指导现场生产具有重要的现实意义。研究采用PIPESIM节点分析软件,建立超深高温高压气井的组分模型,对气井井筒压力与温度分布、水合物生成临界温度–压力曲线、水合物形成位置进行了预测,模拟研究了产气量、油管尺寸、地层压力三项敏感性参数对水合物生成的影响,从而确定最佳的配产方案。同时研究了井下节流降压的水合物防治技术,解决了水合物防治在超深、高温、高压条件下的技术难题,研究成果指导并应用于塔里木油田克深区块开发方案的编制,对类似气藏水合物预测及防治具有较强的指导意义。

The exploration and development of ultra-deep high-temperature and high-pressure oil and gas reservoirs has become one of the main directions of oil and gas in China. Due to the complex geological conditions of deep buried reservoirs, high temperature and pressure, poor physical properties, and H2S and CO2 acid gases, it is extremely easy to move under high-speed airflow and pressure fluctuation. The production of gas hydrates will block the production wellbore, which will increase the difficulty of mining and raise higher requirements for the safety and efficiency of mining. Therefore, it is of great practical significance to carry out hydrate research on ultra-deep high-temperature and high-pressure gas wells. The research uses PIPESIM node analysis software to build a composition model of ultra-deep high-temperature and high-pressure gas wells. The wellbore pressure distribution, wellbore temperature distribution, critical temperature-pressure curve of hydrate formation, and hydrate formation location are predicted, and the gas production is simulated and studied. The effects of gas production, tubing size and formation pressure on hydrate formation were simulated and studied, and the optimal production plan was determined. At the same time, the gas hydrate prevention and control technology for down hole throttling and pressure reduction were studied, and the technical problems of hydrate prevention and control under ultra-deep, high temperature, and high pressure conditions were solved. The research results guided and applied to the development of the Keshen’s reservoirs of Tarim oilfield development plan. It has a strong guiding significance for the prediction and prevention of hydrates in similar gas reservoirs.