Research of methanol content in technological flows of facilities that process gas preparation by low-temperature separation method

The object of research is methanol as an inhibitor, which is used in the process of collecting and preparing products from gas, gas condensate, and oil fields to protect against hydrate formations. It is important to ensure the rational consumption of this inhibitor, taking into account its solubility in gas, water, and liquid hydrocarbons. This work is aimed at analyzing the use of the methanol hydrate formation inhibitor in the process of low-temperature gas preparation and determining ways to use it more effectively. The work presents the results of modeling the distribution of the hydrate formation inhibitor along the technological flows of low-temperature gas separation units according to the following schemes: – low-temperature separation with gas cooling due to the Joule-Thompson effect; – compression of gas from wells using PCS (pressure compressor station) + low-temperature separation with gas cooling due to the Joule-Thompson effect; – compression of gas from wells using PCS + low-temperature separation with gas cooling due to the operation of a turboexpander unit; – compression of gas from wells using PCS + low-temperature separation with gas cooling due to the operation of an artificial refrigeration unit (propane refrigeration unit). The use of a computer simulator allowed to track in detail the distribution of methanol during the gas preparation process. The iteration method determined the minimum values of methanol consumption at which the hydrate-free operation mode of the equipment is maintained. Based on the modeling results, an analysis of methanol content in technological flows was performed. And the patterns of inhibitor separation in the separation equipment were also determined, namely, the dependence of methanol distribution on gas pressure in separators, and the methanol content in the output lines of gas preparation units. It was established that the results of the study can be applied in the development of technologies for the collection, regeneration and reuse of methanol in technological processes of low-temperature gas preparation. The practical value of the results lies in the possibility of improving typical methods of protecting equipment from hydrate formations by developing an automated inhibitor supply system that, by monitoring the parameters of the technological process, changes the inhibitor dosage and ensures its economical use.