井筒和集输管线中水合物生成条件的预测

高压、低温条件下,天然气中含有一定的水分,在管道、井筒以及地层多孔介质孔隙中形成水合物,水合物的形成会造成巨大的危害。水合物的结构有I、II和H型,大多数水合物理论预测模型均在VanderWaals-Platteeuw模型的基础上发展起来的。在统计热力学理论基础上,推导的水合物相平衡理论模型,适用于井筒和地面集输多相管流中水合物生成条件的预测,适用于I、II和H型水合物的相平衡计算。实例证明,这种模型的计算精度能够满足现场的要求。

PREDICTION OF HYDRATE FORMATION CONDITIONS FOR WELL BORE AND TRANSPORTING PIPE

Under the conditions of higher pressure and lower temper-ature, the hydrate may be formed within the transporting pipe,wellbore, and multi-pore medium, when the nature gas contains some water, the gas hydrate will be dangerous for the produc-tion. Structures of hydrate have three types I, II and H. Atpresent, most hydrate theoretical prediction models have been developed based on the Vander Waals model. In this paper, based on the statistical thermodynamics, a new hydrate phase e-quilibrium model was derived. The new model is applied not on-ly to the prediction hydrate formation conditions for wellbore and transporting pipe, but also for the calculation of the phaseequilibrium of hydrate types I, II and H. It is proved that the model is good agreement with field data.