Stored Gas Research Articles

3D baseline seismics at Ketzin, Germany: The C O2 SINK project

A 3D 25-fold seismic survey with a bin size of 12 by [Formula: see text] and about [Formula: see text] of subsurface coverage was acquired in 2005 near a former natural gas storage site west of Berlin, as part of the five-year EU funded [Formula: see text] project. Main objectives of the seismic survey were to verify earlier geologic interpretations of structure based on vintage 2D seismic and borehole data and to map, if possible, the reservoir pathways in which the [Formula: see text] will be injected at [Formula: see text] depth, as well as providing a baseline for future seismic surveys and planning of drilling operations. The uppermost [Formula: see text] are well imaged and show an anticlinal structure with an east-west striking central graben on its top that extendsdown to the target horizon. About [Formula: see text] of throwis seen on the bounding faults. No faults are imaged near the planned drill sites. Remnant gas, cushion and residual gas, is present near the top of the anticline in the depth interval of about [Formula: see text] and has a clear seismic signature; both higher amplitudes in the reservoir horizons and velocity pulldown are observed. Amplitude mapping of these remnant gas horizons shows that they do not extend as far south as the injection site, which is located on the southern flank of the anticline. Amplitude anomalies, gas chimneys along an east-west striking fault, show that the stored or remnant gas either has been or is presently migrating out of the reservoir formations. Summed amplitude mapping of the planned injection horizon indicates that this lithologically heterogeneous formation may be more porous at the injection site.

Design criteria for thermo-mechanical stability of rock mass around lined rock cavern for underground LNG storage

This paper presents new design criteria for evaluating thermo-mechanical stability of rock mass around lined rock cavern for underground LNG storage, or any other liquid with comparative properties. The new criteria for evaluating thermo-mechanical stability of lined rock cavern are concerned with both initiation of new fractures and propagation of existing fractures. Initiation and propagation of such fractures will cause instability of the rock mass around the cavern, and in extreme cases, it may accompany leakage of stored gas leading to ultimate failure of the system. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.

A field application experience of integrating hydrogen technology with wind power in a remote island location

This paper aims to share the field application experience related to the development of an innovative stand-alone sustainable energy system known as the PURE project. The PURE project has been developed alongside a Knowledge Transfer Partnership (KTP) scheme, which is supported by the UK Department of Trade and Industry and executed by siGEN in collaboration with The Robert Gordon University. The system has been constructed within an industrial estate on the island of Unst in Shetland, 200 miles north of the Scottish mainland. The energy system now supplies five business properties with clean reliable power and utilises wind turbine and hydrogen technology to provide a sustainable energy source. The stored hydrogen gas generated by the system is used as an energy source for periods when electrical demand within the business properties exceeds wind turbine production. The hydrogen is also utilised as a fuel source for transportation and as a transportable energy source for mobile power generation. The paper therefore gives a detailed description of the PURE project and discusses the field experience accumulated during the development and installation of the system. It also shares a number of practical issues that had to be overcome during its integration and operation. The installation of the PURE project has resulted in a number of unexpected conclusions being identified and marks a significant step forward in the accessible deployment of this technology for community use.

A study on failure characteristic of spherical pressure vessel

Currently many aerospace vehicle systems require lightweight, high performance pressurized tank for storage of propellant, nitrogen, oxygen, or other medium. Aircrafts have several needs for high-pressure stored gas, like aircraft escape slide inflation systems, emergency oxygen supply, landing gear actuator, engine pressurized air start system and on-board inert gas generating system nitrogen enriched air receivers. For spacecraft application, the high-pressure gas is utilized for attitude control of the vehicle and propulsion purpose. Therefore, the leakage of the pressure vessel results in serious malfunction of the vehicle system causing a mission failure or mishap. It is prudent to recognize the fact that pressure vessels can fail in spite of high standard of qualification program. This paper reports an experimental investigation of the failure behavior of pressure vessels during high pressure of hydraulic loading. The pressure vessels were manufactured by two different procedures. One method is spin forming and tungsten inert gas (TIG) welding process and the other is blow forming and solid-state diffusion bonding process. The failure behavior has been studied and the effect of forming method has been analyzed. The result shows that the pressurization rate and the acoustic emission signal increasing rate provide a similar tendency for a vessel of integrity, while the signal increasing rate is much higher than the pressurization rate for a vessel with defects. It is clear that the acoustic emission response of the vessel to the pressure loading can be successfully applied to predict the structural integrity and failure behavior of the vessels manufactured with both methods.

Design and construction of the Ningbo underground LPG storage project in China

NCC International, Sweden and Chiyoda, Japan were awarded the EPC (Engineering, Procurement, and Construction) contract to design and construct the LPG gas storage project of Ningbo, China. Chiyoda was responsible for the process and pipe-work and NCC the civil construction. The basic design of the civil works was provided at the bidding stage by Geostock of France. The client was BP Amoco with 93% and Ningbo Huadong LPG Company Limited of China with the remaining 7%. The well known and proven design concept is to trap the gas in unlined caverns where the structural rock is fully saturated. That means that all joints and pores of the rock are filled with water under a pressure that exceeds the pressure of the stored gas. To ensure a safe and steady ground water table of the required height, infiltration of fresh ground water is a must as there is a continuous flow of water into the caverns. This recharging of ground water is provided by a number of mainly horizontal infiltration holes that are being drilled from purpose constructed infiltration galleries. In all there are five storage rooms giving a total storage volume of 0.5 million m3. The largest caverns are 20 m wide, 22 m high and 290 m long and hold 125.000 m3. For construction purposes the original design of the storage rooms were altered in order to favor a fast and economic excavation of them. It was judged that the quality of the rock was good enough to go for a larger a more square shaped cross-section which certainly favored a fast excavation. It is obvious that the as built one from production point of view has great advantages. The caverns were excavated in three and four steps by starting with an 8 m high top heading which was split in two equal halves. One of the halves was advancing a few rounds ahead of the other mainly to allow for a faster excavation as this concept offers another face to work at. Beside that the face is so wide that it cannot be covered by one set up of a drill rig. The three Atlas Copco drill rigs Boomer 353 E were provided by NCC and utilized by subcontractor, The Sixth Engineering Bureau of Hydropower & Water Conservancy was employed for the drilling and blast operations. The drilled length of the rounds were generally 4.5 m. The benching that was made in two steps each 7 m high. Thanks to the new design the benching could be performed with vertical drilling which here has meant savings on both time and cost. For the drilling drill rigs AC ROC 542 were provided by NCC and used by subcontractor. The explosive for both the top heading and the benches was cartridged emulsion provided by a local manufacturer. This project had a slow start with re-bidding and alteration of scoop of work. The client having very limited experience from these kind storage facilities had an opened mind and took the advantage of the knowledge provided by both the designer Geostock and the contracting JV of Chiyoda and NCC. The contract form EPC (Engineering Procurement & Construction) gave an easy access to the skill of the parties involved. There was a good understanding and acceptance of alterations in the design and construction process. A strong ambition to fulfill the time schedule at the requested quality standard together with no major geological deviations from the geological settings brought this construction project to completion two months ahead of schedule. (A) Reprinted with permission from Elsevier. For the covering abstract see ITRD E124500.

Role of surface chemistry in hydrogen adsorption in single-wall carbon nanotubes

A combination of tight-binding molecular dynamics and grand-canonical-ensemble Monte Carlo is used to model adsorption of molecular hydrogen in chemically modified matrices of single-wall carbon nanotubes. We study the effects of chemical modification of the nanotube surface by including different coverages of chemisorbed atomic hydrogen and surface oxidation by removing islands of missing carbon atoms with H-saturated bonds. Chemisorbed hydrogen reduces the gas storage capabilities of carbon nanotubes, while the opening of cavities by oxidation tends to increase the mass of stored hydrogen gas in terms of both gravimetric and volumetric capacity.

Improvement of hydrogen storage by adsorption using 2‐D modeling of heat effects

AbstractThe use of hydrogen storage based on an adsorption process for cars operating on a fuel cell will be seriously considered when the amount of stored gas is high enough, the tank safe and economically viable, and the filling process fast enough. To maximize the storage capacity for rapid filling, it is necessary to minimize heating of the adsorbent bed and to imagine means to extract energy toward the outside. Numerical simulation of such a hydrogen storage tank, based on a 2‐D model where mass and thermal energy balances are coupled, is presented. Results from simulations agreed well with experiments, when various modified parameters were calculated. Solutions for improving adsorbent beds for hydrogen storage tanks are then proposed.

Performance and CO Production of a Non-Azide Airbag Propellant in a Pre-Pressurized Gas Generator

This paper presents a numerical study of the transient operation of a pre-pressurized (augmented) airbag inflator. Augmented inflators dilute hot gaseous products of propellant combustion with ambient temperature, high-pressure stored gas before discharging the mixture into the airbag. The solid propellant selected for this study is a non-azide propellant composed of a mixture of azodicarbonirnide, potassium perchlorate, and cupric oxide, Predicted performance of the inflator is presented in terms of pressure, temperature and mass flow rate profiles in the inflator and discharge tank which is used to simulate an airbag. This work also predicts first-order estimates of gas-phase species exit concentrations and characteristic residence times in the inflator. Carbon monoxide. produced as a product of combustion from the high flame temperature propellant, is partially converted to COz as it flows from an internal combustionchamber to the pressurized plenum before being discharged into the airbag, Specifically. the production/destruction of CO is tracked using three different gas-phase reaction models: I) chemically frozen. 2) local (shifting) equilibrium. and 3) finite-rate elementary kinetics. Results presented in this paper demonstrate the necessity of an airbag combustion program that includes finite-rate, gas-phase kinetics. Results from the finite-rate CO chemistry model are qualitatively consistent with experimental results reported by others for the same propellant formulation in a similar operating environment.

Evaluation of Forward Sales And Options Created Through Natural Gas Storage

Abstract As the North American natural gas market becomes further integrated, Canadian natural gas will increasingly be sold under contracts. with indexed, as opposed to fixed, prices. Analytical methods used in other commodity exchange markets will become useful in quantifying and managing price risk, but will require some adaptation to handle the specific transportation and marketing environment of natural gas. Seasonality of demand, and the related transportation constraints, along with the price and availability of gas storage services, will likely have some unique implications for an integrated continental market in natural gas. In such an environment, there may be occasional opportunities for producers and marketers to use gas storage and financial market instruments in price risk management or arbitrage. In this paper, we will examine expected returns from a natural gas storage/withdrawal. scheme and the implications of market volatility price of risk, the local cost of storage, and observations regarding the convenience yield (a difference between the current spot market price and futures market price for future periods). This work will include analysis of gas storage proposals of specific duration as well as evaluation of potential put options created when the storage duration is not fixed. Introduction Natural gas storage activity has historically been predominantly limited to large market players such as utility consumers, as a means of managing peak demand periods. However, the use of storage is becoming more common among gas producers, marketers, and consumers as facilities are being developed and utility storage services unbundled. Often the need for storage facilities is related to physical requirements driven by production and transportation constraints. However, there may be occasional opportunities to consider the use of storage in price arbitrage or as a means of managing price risk by creating physical forward sales and options. While natural gas spot prices continue to exhibit some seasonality and considerable volatility, there appear to be obvious incentives for gas sellers to consider procuring storage services. At the same time, as various continental trading hubs and price indices evolve, futures markets and various financial instruments will be used to reveal price and manage risk in the market place. It is conceivable that most gas in North America will eventually be traded in a similar manner as crude oil-with a continental index (or indices) such as NYMEX, linked to various delivery points and trading hubs throughout the continent (Morton, 1994). The purpose of this paper is to evaluate gas storage services as a means of creating physical forward sales and options and comparing this to paper instruments which might accomplish the same. This will involve determining the value for fixed-term and optional storage scenarios and to examine the parameters (price forecast, volatility, price of risk, storage cost) which affect futures prices and the related options. The first two cases evaluated herein will examine the value of gas storage for a known duration to take advantage of an anticipated seasonal and/or secular price increase, using financial instruments (futures and options) to lock in selling prices for the stored gas.

Automated analysis of gases stored in Vacutainer vials

Trace gas research is often constrained by the number of samples to be analyzed. We report here, modifications to a commercially available headspace gas autosampler for sampling stored gas in blood...

Fuel cells for telephone networks

Abstract Telephone networks normally draw power from the commercial electric utility grid. Critical telephone network systems are classed as “protected” loads. This means they are protected from electric utility power failures by a backup system consisting of lead-acid batteries and an engine-alternator. In this paper we consider an alternative power system for protected telephone equipment. In this alternative system, less expensive off-peak commercial electricity electrolyzes water, while fuel cells draw continuously on the stored gas products to provide direct current (d.c.) for the protected equipment. The lead-acid backup batteries are eliminated. We have compared the benefits and costs of the existing and alternative systems in scenarios with various system efficiencies, capital costs, and electric utility rates and incentives. We have found that given today's efficiencies, costs and incentives the alternate system is not economical. However, we have identified cost and performance domains where the alternative power system would be economically feasible.

Plunger Lift Application in Wells With Set Packers or Permanent Tubing

E&P Exchange Plunger lift is an artificial-lift method that uses energy from a well's own gas to lift accumulated fluids in the wellbore. The plunger acts as a mechanical interface between the gas and liquid in a well, with the gas forcing the plunger up the tubing, thus displacing the fluid above it. Plunger lift is successful primarily in high-gas/liquid-ratio oil and gas wells for constant liquid removal. Low bottomhole pressure from natural depletion normally causes fluid accumulation in the bottom of a well as the flowing velocity slows. Through intermittent pressure buildups and the use of bottomhole tools, the load can be delivered to the surface in a slug for a clean wellbore operation. This allows maximum production and more drawdown than natural flow, extending the life of the well. The various well conditions encountered when plunger lift is installed are somewhat similar, but each well's recovery, gas volume, and fluid load determine the proper equipment arrangement and the technique to be applied. Flexibility to adapt the plunger lift to the well conditions is a very important key to success. To determine whether a well is a good candidate for a plunger lift installation, a simple formula can be used. A minimum of 500 scf of gas per barrel of fluid per 1,000 ft depth is required for plunger lift to work. If this requirement is met, the well should have enough gas production and reservoir energy to lift the plunger and the fluids accumulated in the bottom of the well. Conventional use of plunger lift is in wells with an annulus that is open or in communication with the pay zone. The casing or annulus is used to store gas during the shut-in period. When the well is opened at the surface, the stored gas rises up the tubing, driving the plunger up the tubing, and delivering the well's fluid and gas to the surface. Until recently, the use of plunger lift in wells with set packers or permanent tubing was very uncommon.

Effect of Water Vapor on the Release of Fission Gases from Uranium Oxycarbide in High‐Temperature, Gas‐Cooled Reactor Coated Fuel Particles

The hydrolysis of uranium oxycarbide (UCO) was studied by injecting water vapor into a fuel element containing a known number of high‐temperature, gas‐cooled reactor (HTGR) coated particles with exposed fuel kernels. The experiments were conducted in the High Flux Isotope Reactor (HFIR) at temperatures between 700° and 1000°C, a system pressure of 200 kPa, and partial pressures of water vapor between 21 and 199 Pa. The general sequential response of the exposed fuel kernels to water vapor addition consisted of (1) a rapid release of stored fission gas with a concomitant increase in the steady‐state release and (2) a period of constant steady‐state release. Upon cessation of the addition of water vapor, a decline in the release to prehydrolysis values generally occurred. The release of stored fission gas was dependent on the square of the partial pressure of water vapor. The ratio of the constant steady‐state release to the prehydrolysis value was independent of the partial pressure of water vapor. The time constant for the decline in the release was the same in all of the hydrolysis tests.

Total Volatile Organic Concentrations in 2700 Personal, Indoor; and Outdoor Air Samples collected in the US EPA Team Studies

Concentrations of total volatile organic compounds (TVOC) exceeding 1 mg/m3 have been implicated in the Sick Building Syndrome. Very few measurements of TVOC have been made in homes and buildings in the United States. However, stored gas chromatography-mass spectrometry (GC-MS) data on 12-hour average values of individual VOCs from 750 homes and 10 buildings were available from EPA's Total Exposure Assessment Methodology (TEAM) Studies (1981-88). An initial study to determine the feasibility of obtaining a TVOC value from stored GC/MS data showed that TVOC estimates could be obtained with adequate precision. Therefore TVOC values were calculated for about 2700 personal, indoor, and outdoor air samples collected in the TEAM Studies. More than half of the personal and indoor air samples had TVOC levels exceeding 1 mg/m3, compared to only about 10% of the outdoor air samples. However, these calculated values may not be directly comparable with values determined using different sampling and analytical techniques. Nonetheless, since all samples were collected on Tenax cartridges, which (like all sorbents) adsorb only a portion of the organic chemicals in the air, these values are likely to be underestimates of the total volatile organic loading.

Superconducting magnet and on-board refrigeration system on Japanese MAGLEV vehicle

Running tests on the Miyazaki test track are repeatedly carried out to speeds over 300 km/h using the magnetically levitated (MAGLEV) vehicle MLU002. The development of the MAGLEV system for the new test line has already started, and a new superconducting magnet for it has been manufactured. An onboard refrigerator is installed in the superconducting magnet to keep the liquid-helium temperature without the loss of liquid helium. The helium gas produced when energizing or deenergizing the magnet is stored in onboard gas helium tanks temporarily. The onboard refrigerator is connected directly to the liquid-helium tank of the magnet. Thus, the stored helium gas can be reliquefied easily by the onboard refrigerator. In order to minimize the volume of the helium gas produced when energizing and deenergizing the magnet, the power leads of the magnet, superconducting coils and persistent current switches have been improved. The energization and deenergization of the magnet can be finished in 1 to 2 min.

Aqueous Foams for Control of Gas Migration and Water Coning in Aquifer Gas Storage

Abstract Two causes of poor recoverability are migration of stored gas far from the injection well and upward coning of water into withdrawal wells. The authors conducted laboratory and numerical simulation investigation of the use of aqueous foams to block the flow of gas or liquid to ameliorate these problems. Experiments in sandstone cores showed that foam reduces the permeability to gas and liquid by approximately three orders of magnitude. A numerical simulation study showed that water coning could be significantly delayed by placing a horizontal foam lens just above the gas-water interface. Also discussed are the conditions for forming foam in situ, the feasibility of emplacing a foam bank, and the durability of permeability reduction. Laboratory experiments and numerical simulation indicate potential for significantly improving the efficiency of aquifer gas storage with aqueous foams. A field trial of foam to prevent water coning is recommended.

Using line broadening to study a stored ion gas

Resonant analog detection of ions stored in a Penning trap shows broadening of the ion resonances due to the presence of other ions in the trap. This broadening is reduced when certain m/q ratios are selectively removed. Linewidths have been studied with both axial and radial ion detection systems, for ions produced with different charge using synchrotron radiation photoionization, and for ions with different mass and charge produced using electron impact ionization. Linewidths increase when more ions are confined, apparently due primarily to space charge effects, but initial ion energy may also play a role. The multicharged ions produced using synchrotron radiation had significantly narrower linewidths, due to lower densities and energies.

Development of compliance chamber diaphragms with reduced permeability

The implantable ventricular assist systems currently undergoing clinical readiness testing shuttle the displaced gas between the non-blood side of the pumping diaphragm and an elastic chamber generally called a "compliance chamber" or variable volume device. The movement of the stored gas allows the pump to fill and empty without compression or expansion of the gas behind the pump diaphragm. The material used for the construction of compliance chambers should be fatigue resistant to withstand the 63 million flexes per year of the blood pump. The material should also be biocompatible and highly impervious to gases. Significant diffusion of gases from the compliance system necessitates external make-up gases to somehow be added to the internal system. Material selection is complicated by the fact that most fatigue-resistant elastomers also have high gas permeability. In order to solve this problem, bilayer compliance chambers have been developed using biocompatible and fatigue-resistant polyolefin rubber comolded with relatively impervious butyl rubber.

COMMERCIAL ASPECTS OF UNDERGROUND GAS STORAGE IN AUSTRALIA

Underground gas storage is becoming increasingly important in Australia with the discovery of significant gas reserves, mostly in places distant from the expanding markets for gas.Gas has been stored in the offshore Barracouta Field since 1971 and storage projects are either being considered or underway in New South Wales, South Australia, Western Australia and the Northern Territory.Although not a great deal of attention has been paid to the legal, tax and administrative aspects of underground gas storage, the position is likely to change the more it becomes apparent that such storage is commercially and technically viable.The applicable legal regime will depend on the location of the storage. Offshore gas storage on the continental shelf beyond the coastal waters of a state is subject to Commonwealth jurisdiction. In state coastal waters, it is subject to state laws. Onshore, it is subject to the jurisdiction of the state or territory in which the storage occurs.Offshore beyond state coastal waters the Australian government has sovereign rights over the continental shelf for the purposes of exploring the continental shelf and exploiting its natural resources.There are a number of legal uncertainties which arise from gas storage which will be of concern to financiers as well as gas storers. With certain exceptions, there is doubt as to ownership of stored gas, and the right to inject and store gas. The right of withdrawal however would appear to fall under the right which normally exists under a production lease to 'mine' petroleum, or to conduct 'petroleum mining operations'. Except in Victoria, and to a significantly lesser extent South Australia, there is very little legislative guidance on the topic and related issues.The question whether stored gas is trading stock is the subject of Income Tax Ruling 2190 of 10 September 1985. This puts at rest, in practical terms, in any event, some of the doubts which existed as to the characterisation for income tax purposes of gas stored near the place of original extraction — the ruling concluded that 'reinjected processed gas should not be treated as trading stock for income tax purposes'.It is concluded that there is a good case for those Australian jurisdictions in which gas storage is occurring, or is about to occur, to provide legislation to eliminate the uncertainties.

Oil and National Security: An Integrated Program for Surviving an Oil Crisis

A number of supply-side measures have been considered to soften any ill effect from a major interruption of Persian Gulf oil supplies, in addition to the use of oil stockpiles and emergency tariffs. The combined potential of the incremental-supply possibilities for the United States in a crisis comes to the equivalent of around 2 million bbl/d average for one year. The major components of this addition are: stored natural gas, fuel switching to coal by electric utilities and industry, increased oil and gas production, and more-intensive operation of nuclear power plants. Outside of the United States, the principal extra non-Persian Gulf supplies for an emergency are: increasing oil production to capacity levels (assumed to add a million bbl/d), storage of natural gas, and more-intensive use of coal and nuclear plants (which is likely to require substantial coal stock-piling). This potential adds up to a total of 2.5 million bbl/d for one year. 55 refs.