

THEORETICAL RESEARCH OF METHODS TO CREATE THERMODYNAMIC INSTABILITY OF THE HYDRATE PHASE FOR GAS HYDRATION CONTROL IN PIPELINES
Musakaev N.G.^{1}, Urazov R.R.^{2}
^{1} Khristianovich Institute Of Theoretical And Applied Mechanics SB RAS, Tyumen Branch, Tyumen, Russia ^{2} Ufa State Aviation Technical University, Ishimbay Branch, Ishinbay, Russia
Citation:
Musakaev N.G. Theoretical research of methods to create thermodynamic instability of the hydrate phase for gas hydration control in pipelines / N.G. Musakaev, R.R. Urazov // Modern Science: Researches, Ideas, Results, Technologies.  Dnepropetrovsk: SPIC "Triacon".  2013.  Iss. #1(12).  PP. 7  12

Keywords: gas hydrates; mathematical model; methods of gas hydration 
Abstracts:
The objective of the work is the theoretical research of ways of gas hydration control in pipelines. The current state of research of ways of gas hydration control in pipelines is characterized by a significant increase in interest in the construction of adequate mathematical models of twophase flow in channels of variable crosssection due to hydrate formation under different conditions of production and transportation of natural gas. The theoretical research was carried out by methods of mechanics of multiphase media and computational mathematics. Taking into account the existing mathematical model of the hydrocarbon gas ﬂow in a horizontal channel, a numerical research of methods to create thermodynamic instability of the hydrate phase for struggle against the hydrate formation in pipelines was conducted. In the work the relations for calculating the intensity of gas hydrate deposition in two modes are obtained, namely, the heat balance and «deﬁciency» of water. The conditions which conducive to the formation of solid deposits on the inner wall of a pipeline during the ﬂow of wet hydrocarbon gas are indicated. When researching the method of gas hydration control, based on the removal of water from the gas ﬂow, the inequality which indicates the upper limit of moisture content on the inlet pipe, wherein the formation of solid deposits on the inner walls of the channel not occurs, was received. Shown that the application of insulating material on the outer surface of the pipeline leads to reduction of the intensity of gas hydrates formation of or elimination this negative phenomenon. The numerical analysis of the method reducing the value of the equilibrium temperature of hydrate formation by moving to lower pumping pressures was carried out. Calculations show that when the pressure decrease the intensive gas hydrate decomposition occurs along all tube length, i.e. this method of gas hydration control can achieve the desired results. In the paper it is shown the effectiveness of the inhibitor (methanol) as a means to struggle against the hydrate deposits with a little thickness. With a signiﬁcant narrowing of the channel cross section the methanol feed does not prevent the complete overlap of the channel by deposits of gas hydrates. 
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