Gas Compressor Stations Research Articles

ВЛИЯНИЕ ГАЗА В ЗАЗОРАХ ЛАБИРИНТНЫХ УПЛОТНЕНИЙ НА ДИНАМИЧЕСКОЕ СОСТОЯНИЕ РОТОРА

When transporting natural gas over long distances, it is necessary to build gas compressor stations that compensate for the gas energy losses due to friction. The uninterrupted supply of natural gas to consumers depends on their reliability. Current trends in increasing power with a simultaneous decrease structure stiffness leads to the occurrence of previously unpredictable oscillations of the compressor rotor. The article describes the main causes of compressor rotor vibrations and some methods of dealing with them. Due to the limitations of the considered phenomena with this methods, the article proposes the use multiphysics modeling of gas and structure interaction using the 2FSI approach. Simulation performed for a simplified labyrinthseal compressor rotor model. To solve the problem, the ANSYS software product was chosen, which implements the 2FSI method. The calculations were carried out on a high-performance computing complex PNRPU. For the model structure, an analysis of natural frequencies is performed and a Campbell diagram is constructed. The trajectories analysis of a point on shaft rotation axis at different rotation frequencies of the rotor is carried out. The influence of the imbalance on the dynamics of the system is noted. Further, the results of numerical modeling of the structure taking into account gas dynamics are presented and the results comparison by dynamic modeling of the structure is carried out. To identify the factors influencing the rotor dynamics, taking into account gas dynamics, numerical calculations were carried out with various options for taking into account the effect of gravity and imbalance.

Эффективность применения рабочих тел в цикле Ренкина в энергосберегающих системах транспортировки природного газа

In this paper, the application of various non-ozone-depleting low-boiling working fluids for the Rankine cycle is analyzed based on exergy efficiency. The Rankine cycle is used for high-efficiency waste heat recovery from flue gases generated in gas transport systems at natural gas compressor stations. The system was modelled based on calculations using the CHEMCAD software in conjunction with the “Energy unit” module compatible with the main program interface, which was used for assessing system energy efficiency. It was concluded that the neopentane Rankine cycle with a regenerator is more efficient. Preliminary economic analysis has shown that the proposed system has an acceptable payback period (up to 6 years).

Determination of Fuel Gas Flow Rate in Gas Pumping Unit and Compressor Station

Formulas for drive power of centrifugal supercharger of natural gas are obtained, where efficiency factor (EF) of centrifugal supercharger is equal to product of three EF of centrifugal supercharger: mechanical, polytropic, gas-dynamic. The gas dynamic EF of the centrifugal supercharger is usually not taken into account and is taken equal to one. Gas dynamic EF takes into account the pressure loss of the centrifugal supercharger pumped in the stages and the energy loss due to friction of the centrifugal supercharger impellers in the gas medium. Also in the formula of calculation of drive power of the operated centrifugal supercharger the presence of condensate and water vapors in the natural gas is taken into account, which affects the accuracy of measuring the flow rate of pumped gas in the diaphragm flowmeter. Pumping of pure natural gas is impossible in reality and there are always impurities in natural gas, which must be taken into account to estimate the mass flow rate of gas. For formulas of practical (operated) and theoretical calculations of the drive power of the centrifugal natural gas blower received constant (equal to 0.004) for daily standard gas flow, which simplifies the calculation. The paper presents both precise and simplified formulas for the drive power of a centrifugal natural gas blower.

Analysis and Research on Pipeline Vibration of a Natural Gas Compressor Station and Vibration Reduction Measures

The abnormal vibration of natural gas station pipelines seriously threatens the safety of pipeline transportation, and improper handling will cause huge economic losses. For the abnormal vibration of the pipeline, reasonable treatment must be carried out. The Yongchang gas station belongs to the west–east gas pipeline system in China. Since its production, abnormal vibration has often occurred in the west-third outbound pipeline of the Yongchang gas station, and the vibration changes according to the different gas transport volumes. In this paper, the outbound pipeline of the Yongchang pressure station is taken as the research object, and the vibration analysis of the station yard pipeline is carried out. The numerical model of the station yard pipeline is established, and the correctness of the model is verified by the field vibration test. The fluid–solid coupling method is used to analyze pipeline vibration under different working conditions. Then, three kinds of vibration reduction schemes are proposed and verified by simulation. The main conclusions are as follows: (1) The fluid pressure fluctuation in the pipeline is the root cause of abnormal vibration in the station. (2) When the gas transmission volume is large, the vibration of the pipeline system will become more severe. (3) The scheme of increasing pipe diameter and adding appropriate constraints has the best vibration reduction effect.

Investigation of the Spatial Distribution of Methane Sources in the Greater Toronto Area Using Mobile Gas Monitoring Systems.

For methane emission reduction strategies in urban areas to be effective, large emitters must be identified. Recent studies in U.S. cities have highlighted the contribution of methane emissions from natural gas distribution networks and end use. We present a methane emission source identification and quantification method for the Greater Toronto Area (GTA), the largest metropolitan area in Canada, using mobile gas monitoring systems. From May 2018 to August 2019, we collected 77 surveys of methane mixing ratios, covering a distance of about 6400 km, and sampled emission plumes from sources such as closed landfills, natural gas compressor stations, and waterways. Our results indicate that inactive landfills emit less than inventory estimates. Despite this discrepancy, we confirm that the waste sector is the largest methane emitter in the GTA. We also report that the frequency of methane leaks from the local distribution system ranges between 4 and 22 leaks per 100 km of roadway in downtown Toronto, which is comparable to the range observed in U.S. cities, which have invested in modern natural gas distribution infrastructure. Last, we find that engineered waterways, whose emissions are currently not reported in inventories, may be a significant source of methane.

Spatial Analysis of Membrane Distillation Powered by Waste Heat from Natural Gas Compressor Stations for Unconventional Oil and Gas Wastewater Treatment in Weld County, Colorado

The effective treatment of unconventional oil and gas (UOG) wastewater is a promising and potentially necessary strategy of wastewater management in the UOG industry. While tremendous efforts have ...

Supercritical CO2Heat Recovery System Finds Application in Oil and Gas Operations

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 197965, “Transforming Waste Heat to Electric Power in Oil and Gas Compression Systems Using Supercritical Carbon Dioxide,” by Thomas Soulas, Siemens, prepared for the 2019 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 11-14 November. The paper has not been peer reviewed. The complete paper describes an advanced Rankine cycle process-based system that converts waste heat into usable electrical power to improve the efficiency of gas-compression stations on gas-production platforms and pipelines. Instead of steam, this system uses industrial-grade carbon dioxide (CO2) in the supercritical state as the working fluid. Introduction Globally, rejected heat is estimated to correspond to approximately 65% of net energy input across the industrial infrastructure, with numbers varying from 60 to 70% depending on the region. Considerable waste heat is ejected from equipment such as the gas turbines commonly used in mechanical drive applications found in the compression processes of gas-production platforms and transmission pipelines. Recently, a technology that supports energy recovery from heat rejected from a broad range of industrial processes has become available to the oil and gas industry. The system recovers usable, but often wasted, heat and converts it into higher-value, usable electrical power. While most gas turbine heat-recovery systems use a bottoming steam cycle to improve thermal efficiency, the system described in the complete paper is based on an advanced Rankine cycle process. With revenue and cost predictability, the technology generates power at a competitive installed cost and delivers an estimated 10% increase in baseline efficiency for a gas-compression station to reduce effectively the overall cost of electricity. The main innovation of the technology lies in the selection of CO2 as the working fluid. Advantages of CO2 in Heat-Recovery Cycles CO2 has relatively moderate conditions for the supercritical state, with a critical pressure of 1,071 psi and a critical temperature of just above 88°F. With an approximately 50% increase in specific heat capacity at approximately the critical point and likely cycle conditions, and a reduced compressibility factor near the critical point, CO2 is ideally suited to recover heat energy across a broad range of temperatures and sources such as those found in exhaust gas streams.

Layout Optimization of Gas Compression Station Equipment with Branch and Bound Algorithm

Layout Optimization of Gas Compression Station Equipment with Branch and Bound Algorithm

Проблема равномерного распределения газового потока в адсорберах осушки газа при подготовке газа к транспорту

The article highlights the important factors of gas treatment. The dew point of commercial gas is one of the main normalized indicators, since the moisture content in commercial gas has a significant impact on the uptime of automatic equipment, on reducing corrosion of gas pipelines, process equipment and compressor stations during gas transportation. Adsorption drying of natural gas is a widely used method in the Russian gas industry. This method is characterized by the high level of environmental safety. Besides, the advantages of the method include the absence of the liquid phase and corrosive fluids in the commercial gas, low specific adsorbent consumption and the high degree of process automation. The article presents an overview of practical methods of adsorption drying of natural gas when preparing it for transportation. The advantages of adsorption drying over other methods are considered; the constructive disadvantages of absorber types are described; the ways of eliminating them are proposed

A Case Study of the Supercritical CO2-Brayton Cycle at a Natural Gas Compression Station

Heat losses caused by the operation of compressor units are a key problem in the energy efficiency improvement of the natural gas compression station operation. Currently, waste heat recovery technologies are expensive and have low efficiency. One of these technologies is organic Rankine cycle (ORC) which is often analyzed in scientific works. In this paper, the authors decided to investigate another technology that allows for the usage of the exhaust waste energy—the supercritical Brayton cycle with CO2 (S-CO2). With a thermodynamic model development of S-CO2, the authors preformed a case study of the potential S-CO2 system at the gas compressor station with the reciprocating engines. By comparing the values of selected S-CO2 efficiency indicators with ORC efficiency indicators at the same natural gas compression station, the authors tried to determine which technology would be better to use at the considered installation. Investigations on parameter change impacts on the system operation (e.g., turbine inlet pressure or exhaust gas cooling temperatures) allowed to determine the direction for further analysis of the S-CO2 usage at the gas compressor station. When waste heat management is considered, priority should be given to its maximum recovery and cost-effectiveness.

Natural gas pipeline compressor stations: VOC emissions and mortality rates

Increasing reliance on natural gas for energy has resulted in expansion of the natural gas infrastructure, including pipelines and compressor stations to transport gas. Compressor stations emit numerous particulate and gaseous pollutants including volatile organic compounds (VOCs) but studies of human health in association with compressor stations are almost completely absent from the literature. The objective of the study was to test for associations between VOC emissions from compressor stations and adjusted mortality rates. We conducted a county-level ecological study, using VOC emission data from the 2017 National Emissions Inventory, 2017 age-adjusted total mortality per 100,000 population from CDC data, and covariates from the County Health Rankings data. Results of multiple linear regression models showed that total age-adjusted mortality, controlling for covariates (race/ethnicity, education, poverty, urbanicity, smoking and obesity rates), was significantly higher in association with greater non-methane VOC emissions from compressor stations. Twelve individual VOCs were also associated with significantly higher adjusted mortality. Results provide preliminary evidence that compressor stations along natural gas pipelines are sources of pollutant exposures that may contribute to adverse human health outcomes.

PRCI ambient NO2 AERMOD performance assessment and model improvement project: Modeled to observed comparison

ABSTRACT On January 22, 2010, the U.S. Environmental Protection Agency (EPA) established a new one-hour probabilistic National Ambient Air Quality Standard (NAAQS) for nitrogen dioxide (NO2) at 100 parts per billion (ppb) or approximately 188 micrograms per cubic meter (µg/m3). The 1-hr NO2 NAAQS is considerably more stringent than the longstanding annual standard of 53 ppb or approximately 100 µg/m3. AERMOD is the EPA recommended dispersion modeling tool for predicting impacts from emission sources, including compressor station reciprocating engines. Existing datasets were previously reviewed to evaluate and improve AERMOD 1-hr NO2 model performance. However, these datasets were not representative due to either an absence of accurate concurrent hourly emission inventories, being associated with larger electric generating units, shorter duration tracer studies, or were too site-specific (e.g., external influences such as terrain). To address this data gap, an intensive 13-month field data program was undertaken by Pipeline Research Council International (PRCI) to collect a comprehensive dataset including concurrent emissions, meteorological, and ambient ozone and nitrogen oxide measurements. This paper describes the Balko, OK natural gas compressor station host site and the design of the meteorological, ambient NOx and O3 monitors and continuous Parametric Emissions Monitoring System (PEMS). Two comparisons are made between the monitored data and AERMOD results. First, the measured onsite data (ambient air, meteorological, and emissions) were used as input to AERMOD to make comparisons between measured and modeled NOx and NO2. These comparisons showed that NOx was both over and under predicted, sometimes beyond a factor-of-two. The second comparison uses the typical permitting approach where onsite data are not available to contrast how conservative input assumptions for emissions, background O3, NO2, and offsite meteorology cause significant over predictions especially for this site where engines have a low annual utilization rate and operate infrequently throughout the year. Implications: This project resulted following the promulgation of the new 1-hr NO2 NAAQS and the challenges that natural gas pipeline compressor stations have in modeling intermittent emissions using AERMOD to demonstrate compliance with this standard. AERMOD was developed and validated with a primary focus on large sources with tall stacks, such as electric utility boilers. A recently collected dataset at a gas compressor station in Balko, Oklahoma shows that the use of permitted allowable emission values compared to actual hourly emission values causes over predictions using typical regulatory methods. Comparison of model results using actual hourly emission values to coincident ambient air monitoring values at the site shows that AERMOD over predicts near-field impacts due to simplifying assumptions including building downwash, plume dispersion, chemistry, and 1-hr invariant meteorological conditions.

Connecting the dots: NOx emissions along a West Siberian natural gas pipeline

New high quality satellite measurements of nitrogen dioxide (NO2) of the TROPOspheric Monitoring Instrument (TROPOMI) over snow-covered regions of Siberia reveal previously undocumented but significant NO2 emissions associated with the natural gas industry in Western Siberia. Besides gas drilling and natural gas power plants, also gas compressor stations for the transport of natural gas are sources of high amounts of nitrogen oxides (NOx = NO + NO2), which are emitted in otherwise pristine regions. The emissions per station from these remote gas compressor stations are at least an order of magnitude larger than those reported for North American gas compressor stations, possibly related to less stringent environmental regulations in Siberia compared to the United States. This discovery was made possible thanks to a newly developed technique for discriminating snow covered surfaces from clouds, which allows for satellite measurements of tropospheric NO2 columns over large boreal snow-covered areas. While retrievals over snow-covered areas were traditionally filtered out, we used the retrieved column of air in these observations to distinguish clouds higher in the atmosphere from the snow at the surface. This results in 23% more TROPOMI observations on an annual basis. Furthermore, these observations have a precision four times better than nearly any TROPOMI observation over other areas and surfaces around the world. These new results highlight the potential of TROPOMI on Sentinel 5P as well as future satellite missions for monitoring small-scale emissions and emissions at high latitudes.

Diagnostics of Sediment Occurrence in Interblade Channel of Injector Impeller of Gas Compressing Station by Changes of Gas Flow and Torque

Today no gas purification method exists which can be considered absolutely efficient. Thus, when gas compilation in conducted a problem of sediment formation occurs in a flow passage of the gas compression station (GCS) injector. The paper considers the mathematical simulation of the force moment change at the injector impeller of GCS caused by sediment occurrence in the interblade channel of impellers. In addition, the authors study the change of force moment in relation to the thickness of a sediment layer. Also, the research concentrates on the change of circumferential force at the impeller due to the change of force moment.

Shale gas produced water management using membrane distillation: An optimization-based approach

A linear programming (LP) model is presented to investigate optimal shale gas wastewater management strategies for Marcellus shale play in Pennsylvania (PA) focusing on membrane distillation (MD) as the treatment technology. The optimization framework established in this study incorporates (1) detailed treatment cost obtained from techno-economic assessment (TEA) of MD, (2) cost of wastewater transportation from shale gas sites to treatment or disposal facilities, and (3) cost of injection into salt water disposal (SWD) wells. The optimization model is applied to four case study areas with significant shale gas extraction: Greene and Washington counties in Southwest PA and Susquehanna and Bradford counties in Northeast PA. The results reveal that onsite treatment in combination with shale gas wastewater treatment at natural gas compressor stations (NG CS) where available waste heat can be utilized for the treatment process are the most economically advantageous management options. The optimal solution could result in over 60% benefit over direct disposal in SWD, which translates to over $16 million/year savings in the counties in Northeast PA. Furthermore, the results of sensitivity analysis indicate that transportation cost is a major contributor to the overall cost of shale gas wastewater management.

A global gridded (0.1° × 0.1°) inventory of methane emissions from oil, gas, and coal exploitation based on national reports to the United Nations Framework Convention on Climate Change

Abstract. Individual countries report national emissions of methane, a potent greenhouse gas, in accordance with the United Nations Framework Convention on Climate Change (UNFCCC). We present a global inventory of methane emissions from oil, gas, and coal exploitation that spatially allocates the national emissions reported to the UNFCCC (Scarpelli et al., 2019). Our inventory is at 0.1∘×0.1∘ resolution and resolves the subsectors of oil and gas exploitation, from upstream to downstream, and the different emission processes (leakage, venting, flaring). Global emissions for 2016 are 41.5 Tg a−1 for oil, 24.4 Tg a−1 for gas, and 31.3 Tg a−1 for coal. An array of databases is used to spatially allocate national emissions to infrastructure, including wells, pipelines, oil refineries, gas processing plants, gas compressor stations, gas storage facilities, and coal mines. Gridded error estimates are provided in normal and lognormal forms based on emission factor uncertainties from the IPCC. Our inventory shows large differences with the EDGAR v4.3.2 global gridded inventory both at the national scale and in finer-scale spatial allocation. It shows good agreement with the gridded version of the United Kingdom's National Atmospheric Emissions Inventory (NAEI). There are significant errors on the 0.1∘×0.1∘ grid associated with the location and magnitude of large point sources, but these are smoothed out when averaging the inventory over a coarser grid. Use of our inventory as prior estimate in inverse analyses of atmospheric methane observations allows investigation of individual subsector contributions and can serve policy needs by evaluating the national emissions totals reported to the UNFCCC. Gridded data sets can be accessed at https://doi.org/10.7910/DVN/HH4EUM (Scarpelli et al., 2019).

Оценка ущерба от пожара на основе многофакторного анализа сценариев развития пожаров газокомпрессорных станций

Introduction. The article provides an algorithm for assessing the damage from a fire on the territory of gas compressor stations using a multifactor model of scenarios for the development of a fire. The causes of fires at the facilities of gas compressor stations are analyzed on the basis of statistical data. The established algorithm was verified by calculating the damage from fires, and the most dangerous causes of fires on the territory of gas compressor stations were established by the values of the frequency of emergency ruptures. The purpose of the study is establishing an algorithm for assessing fire damage based on a multivariate analysis of scenarios for the development of fires at gas compressor stations. Research methods. To obtain the results, general scientific and special methods of scientific knowledge were used. These are analysis, generalization, economic analysis, analysis of empirical data, which were based on the general provisions of the theory of analysis and systems analysis. The results of the study. A multivariate analysis of scenarios for the development of fires on the territory of gas compressor stations is carried out. An algorithm is found for assessing fire damage based on a multivariate analysis of scenarios for the development of fires at gas compressor stations. Conclusion. Using the results of the analysis of scenarios of fire development on the territory of gas compressor stations and calculations of indicators of economic damage from fires at these facilities, it is possible to draw up an algorithm for assessing fire damage on the territory of gas compressor stations. Key words: efficiency, analysis, statistics, fire, gas compressor stations, state fire control authorities, damage calculation.

Investigating the potential human health impacts of coal seam gas development at a study site in the Surat Basin in southern Queensland

This paper reports on an ongoing study of the potential human health impacts of coal seam gas (CSG) development at a study site in the Surat Basin in Queensland. This study follows the methodology established in GISERA’s human health effects of CSG activity study design project and focuses on potential physical (dust, noise, light) and chemical stressors. The study will focus on an area bounded by the Warrego Highway to north, between Chinchilla and Miles, extending south towards Tara. This area contains a diverse range of CSG activities involving two operators, over 2300 wells, 70 water storage ponds, four water treatment plants and over 20 gas treatment or compression stations. The area has a range of land uses with low to moderate population densities. These activities have been characterised to determine the physical and chemical stressors present and an exposure pathway assessment is being conducted to determine whether any of the stressors identified have a complete exposure pathway to humans. This assessment considers controls and other strategies already in place to mitigate and alleviate the impacts of stressors. The project involves a high degree of engagement with stakeholders, including the local community, industry and government, with the aim of ensuring the research is independent and trustworthy. The results of this research will assist government and industry in the regulation and conduct of CSG activities by providing an evidence base on potential health impacts, allowing the development of risk mitigation actions to reduce the potential for human health impacts, should any be identified.

SETTLEMENT STRUCTURE OF THE TYUMEN REGION IN THE AREA OF THE MAIN OIL AND GAS PIPELINES: SPATIAL LAYOUT AND SOCIOCULTURAL DYNAMICS

The article analyses the settlement of the Tyumen Region from the perspective of the interaction between the traditional settlement scheme that has developed over the last four centuries, and a group of settlements, where oil pumping and/or gas compressor stations of main oil and gas pipelines are located and maintained. The genesis of this interaction revealed two main directions: eastern and northern. In the first case, the junction points of the Trans-Siberian Railway, which served as administrative outposts, initiated the process of forming agricul-tural, commercial and then industrial zones (and, accordingly, new settlements); the north direction reflects the main stages of Russia's advancement to the North, including the massive industrial development of a unique West-Siberian oil-and-gas province. The homogeneity of the considered settlements in terms the production, terri-torial and social aspects allows us to interpret them as a territorial and production cluster. The organising role of the pipeline transport network in the further development of this cluster is shown. Firstly, it contributed to the emergence of new settlements, and secondly, former small settlements turned into the nodal points of the trans-formed settlement scheme. The result of the cluster formation is correlated with the dynamics of the urbanisation process and is presented in the form of a framework for the development and settlement of the Tyumen Region and its scheme. The consideration of the subject matter is multidisciplinary in nature due to its complex and multi-aspect character. In this study, elements of various methods and approaches were employed: historical-geographical and economic-geographical when studying the genesis of the settlement structure; ethno-demographic when considering the processes of natural and forced migration; socio-cultural and economic-organisational when trying to create a sociocultural scheme of a territorial community.

Satellite Discovery of Anomalously Large Methane Point Sources From Oil/Gas Production

AbstractRapid identification of anomalous methane sources in oil/gas fields could enable corrective action to fight climate change. The GHGSat‐D satellite instrument measuring atmospheric methane with 50‐meter spatial resolution was launched in 2016 to demonstrate space‐based monitoring of methane point sources. Here we report the GHGSat‐D discovery of an anomalously large, persistent methane source (10–43 metric tons per hour, detected in over 50% of observations) at a gas compressor station in Central Asia, together with additional sources (4–32 metric tons per hour) nearby. The TROPOMI satellite instrument confirms the magnitude of these large emissions going back to at least November 2017. We estimate that these sources released 142 ± 34 metric kilotons of methane to the atmosphere from February 2018 through January 2019, comparable to the 4‐month total emission from the well‐documented Aliso Canyon blowout.