Information and software for forecasting and planning technological modes of gas injection and withdrawal at underground gas storage facilities

The purpose of the work is to study salt deposition processes during the operation of wells and technological facilities of underground gas storage (UGS) facilities. Measures aimed at predicting and timely preventing the process of salt deposition in wells and technological facilities of UGS have been developed.The research methodology focuses on improving the efficiency of UGS operations under salt deposition conditions. Operational parameters of wells during gas extraction at UGS facilities were analysed. The processes of salt deposition in wells and at UGS facilities were investigated. It has been identified that wells operate under difficult conditions due to salt deposition in various areas along the gas flow path, from the bottomhole zone of the reservoir to the gas gathering station. The research determined the intensity of salt deposition, which leads to the partial or complete blockage of the internal diameter of the pipeline cross-section. It negatively affects well operation and decreases or completely stops gas withdrawal. Based on the results, measures have been developed to control salt deposition at the UGS facility. The measures will enable the timely identification and prevention of complications.The research results have identified the most likely locations for salt deposition in underground gas storage facilities. The locations include the perforation interval, the internal cavity of lift pipes, the wellhead equipment, and the internal cavity of the flowline. The available methods to prevent and combat salt deposition were analysed. Based on the findings, preventive measures have been developed to prevent salt deposition and ensure the stable operation of gas and gas condensate wells under challenging conditions. The approach is also appropriate for Ukraine's underground gas storage facilities. An analysis of the operation of underground gas storage wells, calculation of forecast results for salt deposition in wells using established methods, and a comparison of these results with actual data were used to develop measures to control the process of salt deposition in Ukraine's gas storage facilities.To enable timely forecasting of salt deposition, the development of software "Monitoring of Salt Deposition at UGS Facilities" is proposed. The software will enable analysis of operational indicators and calculations to determine specified parameters and forecast salt deposition based on actual data using known methods.To ensure the timely resolution of salt deposition problems in UGS facilities, it is advisable to introduce new forecasting approaches, particularly the use of diverse measures and the application of effective prevention and combat methods based on research.Implementing developed measures to control salt deposition at UGS facilities will increase their efficiency in difficult conditions and ensure a stable gas withdrawal volume in accordance with the technological regime.The software "Monitoring of Salt Deposition at UGS" is proposed for the timely detection of UGS complications. The approach enables the prediction of salt deposition on UGS and the timely implementation of urgent measures.

The objective of this article is the analysys of methods for preventing and eliminating hydrates formations, classifying them and choosing the best ones for use in underground gas storage facilities. Comprehensive measures for the stable operation of gas storage facilities in the presence of conditions for the occurrence of hydrates formations were developed. Zones, being potentially prone to the hydrates formation during the gas storage facilities operation were identified. The operational parameters of gas storage wells during gas withdrawal are analyzed. The identified wells were operated under difficult conditions due to the deposition of hydrates on the wellheads, in flowlines and process equipment of gas storage facilities. The places of the highest hydrates accumulation on underground gas storages were determined: from the bottomhole of wells to the gas purification unit of the gas gathering station. Hydrate-prone zones were identified by computational fluid dynamic (CFD) modeling at the location of regulating choke installations in underground gas storage facilities. The zones of the greatest hydrates accumulation on underground gas storages were determined: from the bottomhole of wells to the gas purification unit of the gas gathering station. The analysis of the methods used in gas storage facilities of Ukraine to prevent and eliminate hydrates formation was out. A set of measures was proposed to prevent the hydrates formation in storage facilities to ensure their stable operation. Based on the Euler approach (Mixture model) by CFD modeling, zones prone to hydrates formation were determined at the installation site of regulating chokes in underground gas storages. The influence of the degree of fittings opening on the location of potential zones prone to hydrates formation was estimated. The gas-dynamic processes in the internal cavity of the gas pipeline at the installation site of the control fittings were studied and their influence on the distribution of bulk particles of the gaseous and liquid phases was established. Based on the studies performed, it was recommended to change periodically the mode of well operation for a certain time by opening or closing the regulating choke under favorable conditions for the formation of hydrates, especially at low ambient temperatures. The obtained results of experimental studies and calculations showed that in order to solve the problem of hydrates formation at gas storage facilities, it is advisable to use diverse measures through the introduction of modern intelligent systems for monitoring and controlling the technological process. Further refinement of the algorithm of the proposed monitoring and control system with its approbation in production was provided. The results of the experimental studies and CFD modeling carried out allowed providing a more reasonable approach to the application of various available methods and measures to prevent hydrates formation in underground gas storage facilities. This approach made it possible to develop new effective ways and measures to prevent such complication. Based on the conducted experimental studies and modeling, the major zones prone to hydrates formation in underground gas storages were determined. The developed measures will allow timely detection and prevention of hydrates formation at gas storage facilities are original.

The Gas Research Institute (GRI) is currently involved in the development of concepts aimed at an enhancement of natural gas service to the consumer. In order to maintain the attractiveness of the gas options to industrial consumers, and to reinforce the "value-in-use" of natural gas to residential as well as commercial customers, it is essential to develop efficient, economical, and safe means of reducing the "cost-of-service", including that of natural gas storage in underground formations. Specifically, research and development (R&D) is needed to explore ways to better utilize existing storage fields and also to develop new storage facilities at minimum cost. GRI is currently examining the feasibility of using foam in underground gas storage fields as a mobility control agent to reduce gas migration. Research is also being conducted to establish economic viability of substituting less-costly inert gas(es) for a portion of the base gas, to understand the gas-gas phase mixing behavior in gas storage fields via laboratory experiments and reservoir modeling, and to develop cost-effective gas separation processes using membranes. This paper provides an overview of the GRI's Gas Storage R&D Program and highlights key results achieved to-date for selected research projects.

The objective of the study is to develop software for analysing the performance characteristics of individual technological facilities of underground gas storage (UGS) facilities. The software will determine the forecasted performance indicators and operating modes of gas storage facilities.The paper provides an in-depth analysis of the technological processes involved in withdrawing and injecting gas from/into underground gas storage facilities. Following an analysis of the initial data from the technological equipment, a database structure was developed and created. The software provides an object-by-object analysis of performance characteristics for individual technological units of gas storage facilities, enabling users to determine their predicted performance indicators, technological limitations, and optimal operating modes. Modules were developed to collect, process, and view data, as well as perform the necessary calculations.Based on the results of the work carried out, specialists will be able quickly to solve problems related to determining the forecast indicators of operation of UGS facilities and conduct an object-by-object analysis of their operation mode to identify the least efficient sections of the technological scheme in terms of hydraulic efficiency and productivity in different operating modes.To enhance the efficiency of UGS operations, it is recommended that the necessary software be implemented to calculate the predictive modes of operation of UGS technological units and to create a catalogue of their performance characteristics.The results of the work carried out allow specialists to create design schemes for UGS facilities that provide the ability to conduct a detailed, facility-by-facility analysis of the performance characteristics of individual process units. The analysis allows users to determine the forecast performance of both individual process facilities and UGS facilities as a whole.It is proposed that software be developed to determine UGS modes, considering the performance of the relevant technological equipment. Applying the approach ensures the efficiency of analysing UGS modes and selecting the optimal one.

The aim of the work is to develop software for digitising nomograms of production parameters of wells, technological equipment of underground gas storage (UGS) facilities, and the creation of electronic catalogues for storage and operational use in solving various problems.The paper analyses the existing downhole and separation equipment installed at UGS facilities. An electronic catalogue of equipment performance characteristics was created. The information on the characteristics of the X-mas tree of the well, column heads, tubing, flowlines, vertical and horizontal separators, dust collectors and absorbers was systematised. Industrial studies were conducted to measure the volume of transported gas and liquid contaminants coming with the gas flow from wells. The software has been developed to digitise nomograms of productive parameters of wells and UGS facilities and create an electronic catalogue of their productive characteristics. The developed electronic catalogue has a user-friendly interface that allows the user to decide on the optimal UGS operation mode quickly.Based on the results of the work carried out, the user gets an opportunity to digitise and create electronic catalogues of performance characteristics of all technological equipment of the gas storage facility, which will allow the use of performance indicators when determining the technological modes of the UGS facility.In order to improve the efficiency of UGS operation, it is advisable to introduce modern approaches to timely analysis and forecasting of UGS process equipment operation using information technologies, in particular, the development and implementation of electronic catalogues of digitised information.Thanks to the developed software, it is possible to quickly find the necessary information in the electronic catalogue, as opposed to a traditional paper archive, which will allow faster and more accurate forecasting of UGS operation modes and operational work.It is proposed that software be developed to form an electronic catalogue of performance characteristics of downhole and separation equipment. The use of this approach generally ensures the efficiency of analysis of UGS regimes and timely action.

The EU Directives implementing the climate and energy package will result in the increased demand for natural gas in all EU countries, especially in Poland, whose energy management is coal-based. In the following decades we will observe the substantial increase in demand for natural gas as an energy carrier in power and heating sectors. Another factor, which will contribute to the increase in gas consumption, is the expansion of gas transmission and distribution network. In order to secure natural gas supply for the customers in is necessary to ensure the proper gas storage capacity, expand the existing underground gas storage facilities (UGS) and build new ones. Currently used Polish underground natural gas storage facilities allow storing 1.6 billion m3. Taking into consideration the expansion of investments in underground natural gas storage facilities and the projected increase in demand for natural gas, it is justified to build the new large salt cavern underground gas storage facility in Poland.

The aim of the study is to create a gas-dynamic model of the Dashava underground gas storage (UGS) facility. It studies reservoir properties and well operation parameters during underground gas storage facility (UGSF) operation in the seasons of withdrawal and production.The research methodology comprehensively examines the findings from geophysical, seismic, and gas-dynamic investigations. It also encompasses data on well design, operational indicators, and the primary parameters associated with the underground storage facility’s operational performance during its operational lifespan. Additionally, geological and gas-dynamic models are created. The geological model will be refined by adapting its filtration and capacitance characteristics to align with the actual gas-dynamic parameters of cyclic operation. Additionally, a gas-dynamic model will be developed and adapted to align with the calculated reservoir pressures in the wells and the actual reservoir pressure in the actively drained zone.The reservoir and operational parameters of the gas storage wells were analysed, and gas-dynamic calculations were performed using the Petrel software package. The Petrel software package was used to build a 3D geological model of the Dashava structure for the gas-bearing horizons ND-8 (XIV) and ND-9 (XV), and the physical properties of gas reservoir rocks were substantiated. A gas-dynamic model was developed and adapted by comparing the main indicators of the gas storage facility between the calculated and actual values of the Dashava UGSF. Based on the results obtained, it was found out that the discrepancy between the average calculated and actual pressure values is minimal. The developed gas-dynamic model provides forecasting of the main indicators of the gas storage facility with a reliability of more than 90%, which indicates the feasibility of using the model for approximate calculations of the predictive mode of operation of the Dashava UGSF.The results of the research and calculations have shown that it is advisable to consider various criteria, including the geological and gas-dynamic model of UGS facilities, to draw up operating modes for wells in gas storage facilities.The studies performed by means of gas-dynamic modelling of UGS facilities allow for a more thorough approach to the study of the reservoir system of gas storage facilities and promptly perform forecasting of the main indicators of its operation during gas withdrawal and production.The application of the developed gas-dynamic model of the UGS facility will provide an opportunity to quickly analyse the main indicators of its work to solve problematic issues in a timely manner.

PurposeThe purpose of this study is to investigate the impact of the construction and operation of underground gas storage (UGS) facilities, under the prism of the recent rise in energy prices. The focus is on developing energy markets interconnected with gas producers through pipelines and has access to liquefied natural gas (LNG) facilities in parallel.Design/methodology/approachThrough a focal market in Europe, the authors estimate the economic value for both stakeholders and consumers by introducing a methodology, appropriately adjusted to the specificities of the domestic energy market. The Transmission System Operator, the Energy Market Regulator, the Energy Exchange and Eurostat are the main data sources for our calculations and conclusions.FindingsThe authors investigate the perspectives of UGS facilities, identifying financial challenges considering specific energy market conditions which are barriers to new storage facilities. Nevertheless, the energy price rocketing coupled with the security of gas supply issues, which arose in autumn 2021 and were continuing in 2022 due to the Russia–Ukraine crisis, highlight that gas storage remains, at least for the midterm, at the core of European priorities.Originality/valueThe paper emphasizes on developing markets toward green transition, proposing tangible policy recommendations regarding gas storage. A new methodological approach is proposed, appropriate to quantify the economic value of UGSs in such markets. Last, a mix of energy policy options is suggested which include regulatory reforms, support schemes and new energy infrastructures that could make the gas storage investments economically viable.

Investment strategy for underground gas storage facilities based on real option model considering gas market reform in China

Dynamic risk assessment for underground gas storage facilities based on Bayesian network

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.

The article analyzes the data on the creation of North Caucasus underground gas storage facilities (UGS) in1960-1971 and the injection and production of gas into storage facilities during exploration and industrial operation.The followings have been obtained as a result of the analysis. Increased gas injection and extraction from gas storagefacilities in the former USSR; change in the absolute value of gas over time, while it is pumping into storage, takingout and its rising; a decrease in the volume ratio of gas injection and extraction over time. Compression of water withgas is not very large. Therefore, it is hardened as follows. Under formation conditions, gas has a lower density thanwater, i.e. it is light and its viscosity is less than water, gas has a large mobility. In underground gas storages (UGS),gas is divided into active and buffer. The part of the gas that is extracted from the storage is called the active part(when the demand for gas decreases in the summer). Buffer gas refers to the part that is constantly in undergroundgas storage (UGS). It provides pressure in the reservoir and is sufficient to supply active gas to the production wells.The maximum and minimum pressures are obtained in underground gas storages (UGS-s) where the share of buffergas is very high. The volume of active and buffer gas in underground gas storages (UGS) depends on its geometricdimensions, shape, depth of deposition, porosity, rock permeability, minimum and maximum pressure in the annulus,gas injection and extraction technologies.

Natural oil and gas deposits in most fields include some fluid contacts, such as oil–water, gas–water, or gas–oil. Monitoring the position of the gas–water contact in underground gas storage (UGS) facilities is crucial for monitoring the safety of the subsurface environment. As UGS facilities are geological features of long-term operation, the condition of these features must be regularly monitored for possible gas leaks due to various reasons, whether geological or technical. Periodic surveys of production wells using geophysical methods make it possible to timely detect the reasons for abnormal technical conditions and higher-than-normal water cuts of reservoirs, and to assess shifts in gas–water contact. The suite of production logging methods for surveying and monitoring underground gas storage facilities includes nuclear logging with the use of steady radiation sources (i.e., gamma ray logging and neutron logging). Analysis and interpretation of these methods make it possible to track the shift over time of the gas–water contact in gas-saturated sandstones with an interparticle porosity of >15%. Data from nuclear logging, temperature logs, and composition-based and flow-based surveying are processed and interpreted with the use of known methods and diagnostic indicators to achieve the following goals: to determine the intervals of inter-reservoir and behind-the-casing fluid movement on the base of the well log, to assess the technical condition of the wellbore, to monitor the position of the gas–water contact in the reservoir, to assess the gas saturation of the reservoir, and to monitor the thickness and integrity of the clay caprocks of UGS facilities [1]. This paper discusses the results of automated processing and interpretation of well data recorded during the survey of an UGS facility to determine the current position of the gas–water contact in the reservoir and the gas–water interface in the well. Quantitative interpretation of the neutron logging data with the use of steady radiation sources was performed, and the current gas saturation factor was estimated. Keywords: gas–water contact (GWC); gas saturation; underground gas storage; processing algorithm; gas–water interface (GWI).

Underground hydrogen storage is a long‐duration energy storage option for a low‐carbon economy. Although research into the technical feasibility of underground hydrogen storage is ongoing, existing underground gas storage (UGS) facilities are appealing candidates for the technology because of their ability to store and deliver natural gas. We estimate that UGS facilities in the United States (U.S.) can store 327 TWh (9.8 MMT) of pure hydrogen. A complete transition to hydrogen storage would reduce the collective working‐gas energy of UGS facilities by ∼75%; however, most (73.2%) UGS facilities could maintain current energy demand using a 20% hydrogen‐natural gas blend. U.S. UGS facilities can buffer 23.9%–44.6% of the high and low hydrogen demand projected for 2050, respectively, which exceeds the current percentage of natural gas demand buffered by storage. Thus, transitioning UGS infrastructure to hydrogen could substantially reduce the number of new hydrogen storage facilities needed to support a hydrogen economy.

The storage of natural gas by re-injection into the surface has become quite commonplace in various developed countries around the world. It is a relatively new phenomenon in Australia, and issues, not yet resolved, remain. The ability to store gas underground has enormous implications for the competitiveness of the gas market in Australia. Underground storage allows producers effectively to manage their gas flow in times of high and low demand. For gas users, underground storage has the potential to increase the choice of suppliers. For gas commodity traders, underground storage provides increased ability to hedge gas contracts which in turn will help to foster a strong spot market for gas in Australia. As a result of the increased interest in, and the development of, underground gas storage facilities in Australia, most of the relevant petroleum legislation in each State and Territory in Australia has been amended, or is currently being reviewed, in order to deal with the legal and technical issues that arise with underground gas storage. Some of the issues that arise, and yet to be finally resolved from underground gas storage include: Who owns the re-injected gas? The Crown or the producer? This is particularly relevant to avoid the double payment of royalties. The issue becomes quite complex where processed gas is injected into a partially depleted petroleum reservoir.What regulatory regime should regulate underground gas storage?Who is responsible in the event that liability arises from the underground storage of gas?What rights do the owners of land affected by an underground gas storage facility have to the underground gas? Our paper discusses these issues and provides a brief overview of the current legislative regime regulating the underground storage of gas in specific Australian jurisdictions.