深水井筒水合物生成风险预测

Risk Prediction of Hydrate Formation in Deepwater Wellbore

水合物生成风险是深水油气开发过程中的重要挑战之一。本文结合我国南海某深水气田的特征,考虑不同井深处的管柱结构差异,建立了深水气田开发过程中的井筒温压场计算模型及求解算法,模型计算结果与现场数据吻合较好。结合含有不同气体组分的水合物相平衡计算模型,最终得到了深水管柱内水合物生成区域的有效预测途径。应用本文建立的模型,对南海某深水气井开发过程中测试工况下的水合物生成区域进行了定量预测。本文研究可以为深水气田开发过程中的水合物风险预测及防治提供参考。

Hydrate formation risk is an important challenge in the development process of deepwater gas field.Considering the characteristics of a deepwater gas field in the South China Sea and the difference of pipe string structure at different depth,a model for the calculation of wellbore temperature and pressure during deepwater gas field development process is proposed.The model is verified by the field data.Combining the calculation model of gas hydrate phase equilibrium under different gas component conditions,the prediction method of hydrate formation region in deepwater wellbore is obtained.By using the proposed model,the hydrate formation region under testing conditions for a deepwater gas well in the South China Sea were predicted.This work provides helpful advice for the prediction and prevention of hydrate formation risk in the development process of deepwater gas field.