Investigation of the hydraulic efficiency of gathering gas pipelines

Abstract

The current state of two gathering gas pipelines was analyzed in the article: the first – from the gas gathering station (GGS) of the Narizhnianske oil and gas condensate field (OGCF) to the complex gas treatment unit-2 (CGTU-2) of the Yuliivske OGCF; the second – from the CGTU-1 of the Skvortsivske OGCF to the CGTU-2 of the Yuliivske OGCF. At different times of the year the hydraulic efficiency of gathering gas pipelines was determined, which was in a wide range from 75 % to 98 % on the first, and from 69 % to 96 % on the second gathering gas pipeline respectively. The operating modes of gathering gas pipelines were studied. The volume of contamination in the fields was determined using calculations. The industrial research to measure the volume of contamination, transported together with gas on the CGTU-2 measuring lines, was performed in separators and segregators. It was established that the volume of contamination, determined based on the results of experimental investigations, was higher than the calculated value. The main factors that negatively influence the hydraulic efficiency of gas pipelines were defined. The monitoring of these main factors will prevent the reduction of the hydraulic efficiency coefficient and decrease in the volume of transported gas, it will also help to achieve the planned production figures. The authors determined the main reasons for the reduction in the hydraulic efficiency of gathering gas pipelines resulting from the accumulation of liquid contaminants in the inner cavity and hydrates formation. The proposed solutions to these problems were introduced and are still used in production. In particular, a surfactant solution is fed using a mobile pumping unit, a high-speed gas stream is created to remove the accumulated liquid from the internal cavity of field gas pipelines operating with the CGTU-2 of the Yuliivske OGCF and methanol is supplied using the available pumps from the GGS of the Narizhnianske OGCF and CGTU-1 of the Skvortsivske OGCF. The authors proposed a series of measures to prevent the emergencies and failures and ensure the reliable operation of gathering gas pipelines. The consistency of performed investigations will help to estimate the occurrence probability of complications caused by the accumulation of liquid and hydrates formation.