Использование облачных технологий при проектировании и эксплуатации нефтегазовых и геотермальных месторождений

Abstract

Добыча нефти и газа на северных нефтегазовых месторождениях, расположенных в зоне распространения многолетнемерзлых пород (ММП), имеет свою специфику и оказывает существенное влияние на деградацию ММП из-за выделения тепла от горячей нефти, нагревающей трубы в скважинах, что в свою очередь может приводить к авариям и даже к разрушению скважин. Моделирование таких процессов с учетом фазовых превращений приводит к рассмотрению задач тепломассопереноса в сложных трехмерных средах. Если не учитывать фазовый переход, то могут, в частности, возникнут задачи, связанные с оптимальным проектированием геотермальных месторождений. Обе эти задачи требуют больших вычислительных мощностей и затрат машинного времени на проведение численного моделирования по долгосрочному прогнозированию распространения тепловых полей в неоднородном грунте со сложной литологией. В предложенной работе рассматриваются результаты, направленные на разработку методик, ориентированных на облачные технологии и многопроцессорные ЭВМ, для расчета тепловых полей как в вечной мерзлоте, от различных технических систем, влияющих друг на друга, так и при проектировании оптимальных геотермальных циклических систем.

Design and operation of oil, gas, and geothermal fields generates a number of problems that require massive computations, related with series of numerical simulations in a complex three-dimensional region of heat and mass transfer processes. Mathematical formulation of some of these problems for northern oil and gas fields are presented in [1-3] for the problems associated with using geothermal heat sources are in [4]. In the presented paper the results are considered which deal with the methods focused on cloud computing and multiprocessor computations to simulations of thermal fields in permafrost around of various technical systems influenced each other, which can be a heat source (surface and underground) and a cold source (in the soil). In Russia, permafrost takes place about 60% of the total area, these areas are extremely important for economy, because produces about 93% of Russian natural gas and 75% of oil. Thawing of ice-saturated rocks due to global warming, or various technological impacts, is accompanied by subsidence of earth's surface and development of dangerous cryogenic geological processes, which called thermokarst.Over the last 10 years, only in the cities of Norilsk area about 50 high-rise buildings are demolished due to weakened of foundations. In 2007-2009, on the territory of Yamburg gas condensate field approximately 8000 pillars of pipelines are cut off because of frost heave. In permafrost about 40% of all engineering structures are subjected to a strain. According to foreign sources, annually Gazprom spends more than $1.9 billion USD to restore infrastructure affected by permafrost thawing. It was found that not only climate change, but human activities lead to permafrost degradation and it leads to big efforts to recovery the infrastructure and environment.As a rule these three-dimensional problems have to be considered in different scales of various physical and climatic factors that have to be included in the mathematical model with no popular simplification of some researchers. The paper considers a model which takes into account the following factors: emissivity, leading non-linear boundary conditions at the surface; various thermal parameters of soils constituting the permafrost, changing not only in the vertical plane; seasonal fluctuations in air temperature in the area (in summer time there is a seasonal thawing of the upper layer of soil, in winter there is freezing); possible phase transition; engineering characteristics of technical systems (various insulating materials, seasonal cooling devices used for thermal stabilization of soil), etc. The developed model, cloud environment and software package “Wellfrost” (State Registration Number 2012660988, Dec. 4, 2012) was corrected according to monitoring data for technical systems (such as production and injection wells) and permafrost by “Nordeco Eurasia” company. The computational core (software package «Wellfrost»), included in the cloud environment, from 2010 was tested in 8 oil and gas fields located in permafrost zone and is in a good (about 5%) agreement with the experimental data. The calculations showed that for solving such problems powerful multiprocessor computers are required and it is necessary to develop a user-friendly interface for cloud computing for a specific range of applications. The considered models may include problems associated with evaluation of the effects of climate change and other important problems, for example, effective extraction of geothermal heat (software package GeoTerm, State Registration Number 2014616246, Feb. 10, 2014).