ANALYSIS OF METHODS FOR DETERMINING GAS LOSSES DURING BLOWDOWN OF GATHERING PIPELINES AND WELLS TO REMOVE LIQUID ACCUMULATIONS

Abstract

The process of blowdown the internal cavity of gathering pipelines and wells of gas and gas condensate fields from accumulated liquid was considered as one of the methods of stabilizing their operation mode, which does not require additional capital investments. The "well - gas collection pipeline" system blowdown through the flare pipeline to the blowdown pit in order to remove the accumulated liquid, which creates excess pressure losses and negatively affects the production potential of the fields, is accompanied by irreversible gas losses, on the vol-umes of which, moreover, according to the legislation of Ukraine, rent payments are distributed. At the same time, the gas that is consumed during blowdown into the atmosphere belongs to the category of greenhouse gases and has a negative impact on the environment. To assess the reliability of the results obtained by the analytical meth-od, the research analyzed the methods of gas enterprises for determining gas losses during blowdowns gathering pipelines and wells of gas and gas condensate fields into the atmosphere. In the study have been determined and analyzed the major parameters of the main equations on which the calculation formulas of the considered methods are based. The results of calculations for the determination of gas losses during blowdowns according to existing methods were considered and compared with actual measurements by a gas meter. It was established that there are significant discrepancies in the results. Thus, the error for methods based on the parameter of the critical flow rate is from 250,6 % to 1065,2 %, for methods that depend on the working flow rate and the correction factor for the flow rate, it is from -48,5 % to 99,3 %. The reasons for the significant calculation error by the considered methods are determined.  It was described and defined in the PipeSim software the operating parameters of the gathering pipelines and wells, which result in the formation of a gas flow with a significant liquid content during their blowdowns.