The Analysis of Hydrates Frozen Blocking in Fire Flooding Exhaust Gas of Heavy Oil

Abstract

The No. 56 desulfurization tower pipeline network of Dawn production plant in Liaohe Oilfield is fire flooding exhaust gas collecting pipe. Since put into production, because of the large amount of gas and liquid, fine pipelines and big quantities of bends, the frozen blocking often occurs in winter. The site only adds methanol inhibitors on the basis of production experience, although the frozen blocking phenomenon is eased, it also shows frozen blocking phenomenon in the well interchanges and ups and downs. Now aiming at the problem, based on the percentage of hydrate cross-sectional area, through the establishment of exhaust gas pipe network model and mathematical model, we analyzed how the various factors (temperature, pressure, ground temperature, throughput) influenced the frozen blocking of pipe networks, and the results showed that the cross-sectional area percentage of 37.6% is frozen blocking break points, and the input’s effect on the frozen blocking is the largest. The error in this mathematical model between the prediction of frozen blocking position and actual position is within the scope of the permit (5%). So it can guide the production work in the winter, to reduce the loss of oil field, and increase the economic benefit.
Key words: Fire flooding exhaust; Frozen blocking; Mathematical model; Frozen blocking prediction