Underground Gas Storage Facilities Research Articles

A comprehensive stability evaluation method of multiple salt caverns underground gas storage with interlayers

Underground gas storage (UGS) is usually constructed in a formation with complex geological characteristics, which makes the operation monitoring and safety management of this facility more difficult. This paper aims to develop a method for comprehensive stability evaluation of multiple salt caverns UGS with interlayers. An index system is established as the foundation of the analysis for evaluation, which includes six important factors: cavity shape, operation pressure, interlayer parameters, surrounding salt rock parameters, mechanical properties, and cavity spacing. The improved analytic hierarchy process (AHP) and entropy method are used to calculate the subjective and objective weights of each index respectively. Then the index weights are constructed in the form of combination weights. The fuzzy membership function method is applied to obtain a quantitative evaluation result. Based on the established evaluation model, the stability level of four multiple salt caverns UGSs with interlayer are successfully evaluated. The results show that the stable states of the four UGS facilities are all good. There is only a slight threat of instability in UGS2, which has the defects of too many interlayers, too large interlayer thickness and too small space between adjacent cavities.

Features of monitoring storage of methane-hydrogen mixtures

The storage of methane-hydrogen mixtures (MHM) in existing underground gas storage facilities (UGS) is a prerequisite for the development of a "carbonneutral" strategy of the Russian Federation. The use of technologies for storage and delivery of MHM in industrial volumes should be ensured by experimental research, the creation of a regulatory framework and the introduction of modern methods for maintaining the operational reliability of the existing Unified Gas Transportation System (UGSS). The need for scientific and project work is determined by the peculiarities of the storage of MHM and the assessment of the likelihood of negative technogenic and mechanical consequences during the operation of the equipment. The materials provide the main risk models of the processes that arise in the case of hybrid storage of MHM. The use of cluster technology for storage and transportation of MHM is proposed, and the need to ensure constant monitoring of the component composition of gas as part of the implementation of an integrated automated flow technology is shown. Keywords: methane-hydrogen mixtures; hydrogen energy; underground gas storage; hardware control; risks.

Determination of the lower boundaries of the natural gas hydrates stability zone in the subpermafrost horizons of the Yakut arch of the Vilyui syneclise, saturated with bicarbonate-sodium type waters

This paper considers the possibility of the underground gas storage facilities creating in a hydrate state on the north-western slope of the Yakut arch of the Vilyui syneclise. For this, the boundaries of the hydrate stability zone were determined for 6 promising areas of the considered geological structure. Equilibrium conditions of the natural gas hydrates formation in the model porous media containing bicarbonate-sodium type water (mineralization 20 g/l), characteristic for the subpermafrost horizons of the Yakut arch, have been studied by the method of differential thermal analysis. On the basis of the obtained results, the boundaries of the natural gas hydrates stability zone were determined. It was shown that the upper boundaries of the hydrate stability zone are located in the thickness of permafrost rocks. It was found that the lower boundaries of the natural gas hydrates stability zone in moist unsalted porous medium lie in the range from 930 to 1120 m. When the samples are saturated with mineralized water, the boundaries are located 80-360 m higher. The obtained experimental results allow us to conclude that in subpermafrost aquifers of the Yakut arch has favorable conditions for the formation of natural gas hydrates. Keywords: natural gas hydrates; aquifers; underground gas storage; hydrate stability zone; geothermal gradient; equilibrium conditions of the hydrate formation; bicarbonate-sodium type water.

OPTIMIZATION OF CONTROL OF OPERATING MODES OF GAS TRANSPORT SYSTEM USING UGS

The Soyuz, Urengoy-Pomary-Uzhhorod and Progress gas pipeline systems form the basis of the trans-Ukrainian trans-Ukrainian pipeline system. The complex gas transmission system contains a number of gas pipelines forming a linear part and several compressor stations. The amount of capacity of pipelines depends on the number and characteristics of compressor stations. Reliability of work, regulation of transit flows and ensuring uninterrupted gas supply is carried out with the help of underground gas storage facilities, which are an integral part of the GTS of Ukraine. The use of underground storage facilities is considered to be one of the most efficient ways of gas supply, improving the quality of gas supplies to consumers and the efficiency of gas sales within the country and abroad. With the use of storage, you can reduce the unevenness of seasonal consumption and ensure security of supply. The use of underground storage facilities is an integral part, as during the year the maximum daily gas extraction exceeds the minimum more than three times, and the supply of gas through the main gas pipelines is almost constant. The maximum storage capacity cannot be represented as the sum of the absolutely free flow rates of all production wells. This is explained by the fact that the productivity of the underground gas storage during the extraction period is affected by the hydraulic resistance of the gas collection system to the underground storage and its technical condition, which is determined by the coefficient of hydraulic efficiency of loops and collectors.
 Studies show that the location of gas storages in the system has an impact on the amount of energy consumption. Therefore, the strategy of rational use of underground gas storage facilities in pipeline transport (in terms of minimizing energy consumption) is based on the study of the impact of their location in the gas transmission system. The principle of energy efficiency of the use of underground gas storage facilities for long-distance transportation (in order to equalize the unevenness of gas consumption) is based on the sequence: the most remote UGS should be used first. These are the objects that are located at the end points of the GTS route and whose location corresponds to the proximity to consumers.

Кліматичні ресурси як об’єкти природоресурсних правовідносин

The article is devoted to the study of scientific approaches to the characteristics of the objects of natural resource relations. Theoretical positions of the representatives of legal science on the definition of the concept of natural resources as objects of natural resource legal relations, the separation of their legal features are revealed. Scientific approaches to the legal nature of climatic resources and their place in the modern system of natural resource legal relations are analyzed. Natural resource relations consist of the use and reproduction of natural resources or their properties (for example, the potential energy of water, which is converted into electricity, water surface for water transport, the properties of atmospheric air to contain and dissolve (reduce concentration) pollutants, the property of subsoil underground gas storage facilities, etc.). Climatic resources are called inexhaustible natural resources, which include solar energy, moisture, wind energy, etc. and are determined by the peculiarities of the climate. The use of certain properties of climatic resources as, first of all, alternative energy sources is extremely important. Climatic resources in most of Ukraine are favorable for the development of alternative energy. However, the current state of legal regulation of activities aimed at ensuring the rational and efficient use of climate resources needs to be improved. Keywords: natural resource law, natural resource legal relations, natural resources, climatic resources, climate

Workflow for Probabilistic Resource Estimation: Jafurah Basin Case Study (Saudi Arabia)

This study provides a workflow and preliminary estimations of the estimated ultimate recovery (EUR) volumes for natural gas and condensate liquids in the Tuwaiq Mountain Formation, the principal target in the Jafurah Field development project in Saudi Arabia. The strategic need for the field development is reviewed and the field characteristics are outlined based on public data sources complemented with data from analogous reservoirs. The target zone in the Jafurah Basin is a carbonaceous shale, being developed with up to 10,000-ft-long multistage-fractured laterals with 30 ft perforation cluster spacing and an assumed typical 1250 ft well spacing. The field will come on stream in 2024, when the gas-gathering pipeline system, natural gas processing plant, and underground gas storage facilities will all be in place. The range of uncertainties in the key reservoir parameters is taken into account to estimate preliminary EUR volumes (P90, P50, and P10) for both gas and condensates. Based on the present and prior EUR estimations, it can be concluded that the Jafurah Basin comprises one of the largest unconventional field development projects outside of North America.

A deep learning model for gas storage optimization

To the best of our knowledge, the application of deep learning in the field of quantitative risk management is still a relatively recent phenomenon. In this article, we utilize techniques inspired by reinforcement learning in order to optimize the operation plans of underground natural gas storage facilities. We provide a theoretical framework and assess the performance of the proposed method numerically in comparison to a state-of-the-art least-squares Monte-Carlo approach. Due to the inherent intricacy originating from the high-dimensional forward market as well as the numerous constraints and frictions, the optimization exercise can hardly be tackled by means of traditional techniques.

Optimal cooperative model for the security of gas supply on European gas networks

Natural gas infrastructures play a key role in the transition towards the new energy model, with a high share of renewable energies, both ensuring the firm capacity of electric power systems and integrating all energy vectors. The European Union (EU) strongly depends on external natural gas suppliers and is thus particularly vulnerable. In the event of supply problems due to natural phenomena, technical failures or other threats, cooperation between EU countries would be essential to best solve a supply crisis. This study proposes an EU cooperative model to meet the gas demand over a fourteen-day crisis, using a mathematical optimisation approach for resources and infrastructure. The model considers the dynamic management of underground gas storage facilities, limiting daily withdrawal based on the amount of working gas available in each storage facility. The ability of the model to make quick decisions is illustrated in six gas-demand case studies of the European cold wave in January 2017 and hypothetical supply disruptions.

Biomonitoring Studies and Preventing the Formation of Biogenic H2S in the Wierzchowice Underground Gas Storage Facility

The article discusses the results of biomonitoring research at the Underground Gas Storage (UGS). Hydrogen sulphide, as one of the products of microbiological reaction and transformation, as well as a product of chemical reactions in rocks, is a subject of interest for global petroleum companies. The materials used in this research work were formation waters and stored natural gas. The biomonitoring of reservoir waters and cyclical analyses of the composition of gas stored at UGS Wierzchowice enabled the assessment of the microbiological condition of the reservoir environment and individual storage wells in subsequent years of operation. Investigations of the formation water from individual wells of the UGS Wierzchowice showed the presence of sulphate reducing bacteria bacteria (SRB), such as Desulfovibrio and Desulfotomaculum genera and bacteria that oxidize sulphur compounds. In the last cycles of UGS Wierzchowice, the content of hydrogen sulphide and sulphides in the reservoir waters ranged from 1.22 to 15.5 mg/dm3. The monitoring of natural gas received from UGS production wells and observation wells, which was carried out in terms of the determination of hydrogen sulphide and organic sulphur compounds, made it possible to observe changes in their content in natural gas in individual storage cycles. In the last cycles of UGS Wierzchowice, the content of hydrogen sulphide in natural gas from production wells ranged from 0.69 to 2.89 mg/dm3, and the content of organic sulphur compounds converted to elemental sulphur ranged from 0.055 to 0.130 mg Sel./Nm3. A higher hydrogen sulphide content was recorded in natural gas from observation wells in the range of 2.02–25.15 mg/Nm3. In order to explain the causes of hydrogen sulphide formation at UGS Wierzchowice, isotopic analyses were performed to determine the isotope composition of δ34SH2S, δ34SSO4, δ18OSO4 in natural gas samples (production and observation wells) and in the deep sample of reservoir water. The results of isotope tests in connection with microbiological tests, chromatographic analyses of sulphur compounds in natural gas collected from UGS Wierzchowice and an analysis of the geological structure of the Wierzchowice deposit allow us to conclude that the dominant processes responsible for the formation of hydrogen sulphide at UGS Wierzchowice are microbiological, consisting of microbial sulphate reduction (MSR). The presented tests allow for the control and maintenance of hydrogen sulphide at a low level in the natural gas received from the Wierzchowice Underground Gas Storage facility.

Performance analysis of a horizontal well located in an underground gas storage facility

Nowadays, energy raw materials, especially environmentally friendly raw materials, are becoming increasingly important. These raw materials include natural gas called the "blue fuel". As it is known, natural gas is extracted from deposits located at often great depths by means of both vertical and horizontal drilling. It is important that both vertical and horizontal wells are characterised by high efficiency in terms of obtaining the highest possible productivity, which will allow to exploit the existing resources of the deposit in the shortest possible time. 
 The paper analyses the influence of such factors as reservoir pressure, thickness of reservoir, length of a horizontal section, average permeability of a reservoir, turbulence coefficient and water exponent on the process of lifting a liquid phase during operation of a horizontal well. The calculations were carried out using data concerning exploitation of the "B" natural gas field. The calculations were carried out using the "IHS PERFORM" computer programme, which is the leading industry software for carrying out analyses of productivity changes in gas wells. The following correlations were used in the horizontal well performance analysis:
 - Joshi's correlation for calculating productivity for a horizontal well
 - Hagedorn & Brown correlation for determining the course of pressures in a well for two-phase flow,
 - Lee, Gonzalez & Eakin correlation for calculating changes in gas viscosity, and
 - Dranchuk & Purvis - Robinson correlation for calculation of deviation factor of real gas "z".
 The results of the calculations are presented in the form of graphs. In the final part of the article, conclusions are given, summarising the results of the analysis. In the further part of the article the author focused on the course of operation of a horizontal well located at an underground gas storage facility.

Seismicity at the Castor gas reservoir driven by pore pressure diffusion and asperities loading

The 2013 seismic sequence at the Castor injection platform offshore Spain, including three earthquakes of magnitude 4.1, occurred during the initial filling of a planned Underground Gas Storage facility. The Castor sequence is one of the most important cases of induced seismicity in Europe and a rare example of seismicity induced by gas injection into a depleted oil field. Here we use advanced seismological techniques applied to an enhanced waveform dataset, to resolve the geometry of the faults, develop a greatly enlarged seismicity catalog and record details of the rupture kinematics. The sequence occurred by progressive fault failure and unlocking, with seismicity initially migrating away from the injection points, triggered by pore pressure diffusion, and then back again, breaking larger asperities loaded to higher stress and producing the largest earthquakes. Seismicity occurred almost exclusively on a secondary fault, located below the reservoir, dipping opposite from the reservoir bounding fault.

Underground Gas Storage Process Optimisation with Respect to Reservoir Parameters and Production Equipment

The storage of natural gas in geological structures such as depleted fields, aquifers and salt caverns plays an important role in a gas supply system as it balances the fluctuation of gas demand and price. Hydraulic loss due to fluid flow through gas storage production equipment and an interfering effect from nonequal productivity index of storage wells may have an important influence on gas storage performance. An integrated mathematical model is developed based on underground gas storage facility production data. Using this model, the hydraulic loss is determined. A real test case that consists of a gas storage reservoir linked to the surface facility is analysed. The mathematical model uses an experimentally determined pressure drop coefficient in chokes. The base case scenario created using real gas storage facility data enables the achievement of a good history match with the given parameters of the gas storage reservoir. Using the history match simulation case as an initial scenario (a base case), two different scenarios are created to determine the injection and withdrawal performance of the gas storage field. The results indicate that the pressure drop in chokes, when fully open as a constraints in an underground gas storage facility, has a significant impact on gas storage operations and deliverability.

Influence of deposits on rotor impellers of a centrifugal blower of a gas-pumping unit on static imbalance

Compressor station equipment undergoes a sensitive adjustment process before commissioning. One of its most important tasks is balancing the blower rotor, as a result of which the forces acting in the system are balanced. Unbalance is the imbalance of the rotor, leading to the occurrence of forces and moments that cause vibration, both of the rotor itself and of the entire machine as a whole. Currently, there is no absolutely effective method for gas purification, which negatively affects the flow path of the equipment. This is especially true for gas pumping units that compress associated petroleum gas, as well as for GPUs operating in underground gas storage facilities and used in cases where the pressure of the sampled gas is lower than the pressure in the pipeline and must be raised. All this contributes to the emergence of an imbalance in the system. The work mathematically simulates the effect of deposits on the static balance of the rotor of a centrifugal blower.

Проявление техногенных процессов при создании и эксплуатации подземных хранилищ газа

The features of man-made deformation processes during the creation and operation of underground gas storage facilities in developed gas and gas condensate deposits, as well as in water-saturated reservoirs, are shown. The possibility of deformation of reservoirs in underground gas storage facilities with the lowering of the Earth’s surface is justified, provided that the sea pressure is lowered below the value achieved at the end of the field development, as well as the initial one at the time of the creation of a storage facility in the water-saturated reservoirs.

Analysis of the effectiveness of ways to improve the performance in underground gas storage wells

The article provides an assessment of the effectiveness of various ways to improve the productivity of wells in underground gas storage facilities. We conducted comparisons of the performance of wells of increased diameter in the interval of the productive reservoir with wells in which hydraulic fracturing or horizontal ending was carried out.

Physics‐Based Evaluation of the Maximum Magnitude of Potential Earthquakes Induced by the Hutubi (China) Underground Gas Storage

AbstractThe world's largest underground gas storage facility in Hutubi (HUGS), China, is a unique case where cyclic gas injection‐extraction induced both seismicity and ground deformation. To assess the potential for future induced seismicity, we develop a framework physically based on a well‐constrained hydro‐geomechanical model and on fully‐coupled poroelastic simulations. We first interpret the spatiotemporal distribution and focal mechanisms of induced earthquakes and take it as a key step and a premise to estimate the magnitude and location of the largest potential earthquake. The sharp increase in seismicity was controlled by poroelastic loading on secondary southwest‐dipping thrust faults with spatial scales too small to be resolved by 3D seismic surveys. Both operational and local geological factors affect the seismic productivity at the HUGS site, distinguishing it from most cases of seismicity induced by wastewater disposal and hydraulic fracturing. We then conduct slip tendency analyses for major faults imaged by the seismic data, including the largest reservoir‐bounding Hutubi fault hydraulically connected to injection wells. The reactivation potentials of these imaged faults are estimated to be extremely low. Accordingly, future seismicity would most likely occur on failure‐prone secondary faults in regions with positive stress perturbation due to poroelastic loading. The maximum magnitude likely depends on the spatial scales of the secondary faults. As the occurrence of detected earthquakes is spatially and temporally consistent with the simulated evolution of Coulomb stress perturbation, the location of the largest potential earthquake probably depends on the sizes of the poroelastic stressing regions.

Monitoring for seismological and geochemical groundwater effects of high-volume pumping of natural gas at the Stenlille underground gas storage facility, Denmark

The large natural gas storage facility at Stenlille, Denmark, has been monitored to investigate the effect of pumping large amounts of gas into the subsurface. Here, we present a new dataset of microseismicity at Stenlille since 2018. We compare these data with methane in groundwater, which has been monitored since gas storage was established in 1989. Further, we conducted a controlled 172 day microcosm experiment of methane oxidation on an isolated microbial community under both aerobic and anaerobic conditions. For this experiment, water was filtered from a well at Stenlille with elevated levels of thermogenic methane and ethane. No microseismic activity was detected in the gas storage area above an estimated detection level of ML 0.0 for the established network. The long-term monitoring for methane in groundwater has still only detected one leak, in 1995, related to a technical problem during injection. The microcosm experiment revealed that oxidation of methane occurred only under aerobic conditions during the experiment, as compared to anaerobic conditions, even though the filtered water was anoxic

НАПРАВЛЕНИЯ РАЗВИТИЯ ЭКСПОРТНЫХ ПОСТАВОК ПРИРОДНОГО ГАЗА С ИСПОЛЬЗОВАНИЕМ ПХГ

The relevance of the topic of the article is determined by the trends that have emerged in recent years, the diversification of primary energy sources and their suppliers in the EU countries, which, with increased competition in the energy markets, requires Gazprom to optimize the export of natural gas. Underground storage facilities for natural gas (UGS) are an important element of the company's export logistics. The purpose of the study was a systematic analysis of the problems, prospects and strategic directions of the development of underground gas storage facilities in the export of Russian gas to Europe. The role of UGS in the system of ensuring the sustainability and efficiency of contractual supplies of natural gas to consumers of the European Union (EU) is determined. The dynamics and forecast of the development of gas storage facilities of the Gazprom Group of Companies in European countries are determined. The dynamics and forecast of the development of gas storage facilities of the Gazprom Group of Companies in Russia and European countries are determined. The main UGS used by the Gazprom Group of Companies abroad are considered. The optimal solution for gas storage facilities with active use of natural gas in the energy balance of the countries is shown. The concept and directions of reconstruction of existing UGS based on digitalization of business processes of storage and selection of natural gas to consumers are justified. The prospects for the development of a system of intelligent underground natural gas storage facilities are determined. The seasonal balance of gas storage capacity in the EU countries is analyzed, including the assessment of gas filling and UGS productivity in the EU countries. On this basis, the necessary capacities of gas storage facilities to cover the peak demand for natural gas importing countries are justified. The article also traces the dynamics of changes in the gas storage capacities of the main natural gas importing countries of the Gazprom Group and the Central European countries for the period 2016–2020 and provides recommendations for their strategic development.

Surface Deformations Caused by the Convergence of Large Underground Gas Storage Facilities

The article presents a method of forecasting the deformation of the land surface over large fields of underground gas storage facilities located in salt caverns. The solution allows for taking into account many parameters characterising the operation of underground gas storage facilities, such as cavern processes (leaching, enlargement, operational, etc.), their depth, distribution, diameter, shape, and many others. The advantage of the applied method over other available options is the possibility of using it for large fields of caverns while keeping the calculations simple. The effectiveness of the method has been proven for predicted surface subsidence for the EPE field with 114 underground caverns. The hypothesis was compared with the measurement outcomes.

Hydration of natural gas hydrogen mixture test equipment

The use of hydrogen as an energy source is advantageous because its combustion processes only produce water vapor, but not carbon dioxide. This excess energy can be stored in underground gas storage facilities, where it is delivered mixed with natural gas. In gas- and oil industry the formation of hydrate crystals can cause significant damages. A huge amount of hydrate crystal is formed, it can cause hydrate plugs in the pipeline. Like natural gas, hydrate formation occurs in the case of a natural gas-hydrogen mixture. The paper presents a method which can be used to study hydrate formation in natural gas-hydrogen mixture.