Аннотация. При транспорте газа по шлейфам от скважин к установке комплексной подготовки газа (УКПГ) происходит понижение температуры и потери давления, что в ряде случаев может привести к образованию гидратных пробок и возникновению нештатных и аварийных ситуаций. В статье подробно проанализированы условия, при которых происходит гидратообразование, и выявлены наиболее характерные места образования гидратных пробок от скважины до входа в УКПГ. Основным направлением борьбы с гидратообразованием является создание условий термодинамической нестабильности гидратных соединений. Для этого используются тепловые, технологические и химические методы. Если же гидратная пробка все-таки образовалась, ее ликвидируют понижением давления, закачкой метанола, локальным прогревом или комбинацией этих приемов. Выбор конкретного метода 102 © Электронный научный журнал «Нефтегазовое дело». 2016. №1 http://ogbus.ru зависит от размера пробки, ее местоположения, температуры окружающей среды и других факторов. 103 © Электронный научный журнал «Нефтегазовое дело». 2016. №1 http://ogbus.ru It's necessary to raise the level of making decisions when emergency situations occur. For that reason authors have offered to use expert system of operative management. This system should generate control instruction using cooperative processing. Database is formed by real-time data and by knowledge system formed by experts. There is database structure shown in the article.
During the production of gas in the Far North and the Arctic, the formation of hydrate and ice plugs in intrafield flowlines is a major concern. The existing methods for determining the onset of hydrate formation are mostly based on the analysis of pressure-and-temperature conditions and therefore they only allow to detect the occurrence of conditions for hydrate formation. They do not allow to localize the specific place where hydrates start to form. The recently developed methods based on echolocation technology have a number of limitations due to the physical nature of the radiation used in them. The proposed method for the monitoring of hydrate formation processes in intrafield flowlines is based on a combination of analysis of pressure-and-temperature conditions in the flowline and the results of flowlines echolocation obtained by means of periodic generation of scanning pressure waves at the end of the flowline (from the side of the switching valve building). The flowlines are divided into characteristic sections bound by characteristic points linked to the structure of the flowline. The propagation speed of the scanning pressure wave is determined in each measuring cycle within the reference section. This can be any section between the characteristic points to which the distance is precisely known and which produce well-defined waveforms and time-stable reflections of scanning pressure waves, for example, the first section located adjacent to the switching valve building. The obtained echograms are compared with the model echogram, which is obtained from a flowline, which is known to be unclogged. Any abnormal change in the signal amplitude is indicative of an onset of the formation of a new local resistance. The proposed recursion formula makes it possible to calculate the temperature in the proximity of this local resistance and, taking into account the pressure value using the diagram of three-phase equilibria for hydrate-forming gases, to diagnose the possibility of existence of crystalline hydrates at a given point. Since pressure-and-temperature conditions for the formation of ice and hydrates are different, the proposed method is selective and enables accurate prediction of the nature of potential buildups.
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