Showing papers on "Natural gas published in 1996"

Standard handbook of petroleum & natural gas engineering.

Abstract: Preface. RESERVOIR ENGINEERING. Basic Principles, Definitions, and Data. Formation Evaluation. Pressure Transient Testing of Oil and Gas Wells. Mechanisms and Recovery of Hydrocarbons by Natural Means. Material Balance and Volumetric Analysis. Decline-Curve Analysis. Reserve Estimates. Secondary Recovery. Fluid Movement in Waterflooded Reservoirs. Estimating Waterflood Residual Oil Saturation. Enhanced Oil Recovery Methods. References. PRODUCTION ENGINEERING. Properties of Hydrocarbon Mixtures. Flow of Fluids. Natural Flow Performance. Artificial Lift Methods. Stimulation and Remedial Operations. Surface Oil Production Systems. Gas Production Engineering. Corrosion and Scaling. Environmental Considerations. Offshore Operations. References. PETROLEUM ECONOMICS. Estimating Oil and Gas Reserves. Classification of Petroleum Products. Methods for Estimating Reserves. Non-Associated Gas Reservoirs. Production Stimulation. Determining the Value of Future Production. The Market for Petroleum. Economics and the Petroleum Engineer. Preparation of a Cash Flow. Valuation of Oil and Gas Properties. Risk Analysis. References. Appendix: Units and Conversions (SI). Index.

Industrial Organic Chemicals

Abstract: The chemical industry chemicals from natural gas and petroleum chemicals and polymers from ethylene chemicals and polymers from propylene chemicals and polymers from the C4 stream chemicals and polymers from toluene chemicals and polymers from xylenes chemicals from methane chemicals from alkanes chemicals from coal fats and oils carbohydrates how polymers are made industrial catalysis.

Transport in shales and the design of improved water-based shale drilling fluids

Abstract: Transport of water and ions in shales and its impact on shale stability were studied to facilitate the improvement of water-based muds as shale drilling fluids. Transport parameters associated with flows driven by gradients in pressure and chemical potential were quantified in key laboratory and full-scale experiments. The experimental results show that the low-permeability matrices of intact, clay-rich shales can act as imperfect or leaky membranes that will sustain osmotic flow of water. Moreover, the ability of shales to act as osmotic membranes is shown to provide a powerful new means for stabilizing these rocks when exposed to water-based drilling fluids. Guidelines are presented for effective exploitation of shale membrane action and induced osmotic flows through optimized water-based drilling fluid formulation. In addition, special attention is given to induced electro-osmotic water flow in shales driven by electric potential gradients, which may provide an exciting, new, environmentally benign means for stabilizing shale formations.

Microbial generation of economic accumulations of methane within a shallow organic-rich shale

Abstract: ALTHOUGH methane of bacterial origin is ubiquitous in marine and freshwater sediments, economic accumulations of bacterial gases occur mainly at depths of several kilometres in Tertiary basins that had high sedimentation rates1,2. Here we present an integration of geochemical and isotopic data from gas and water extracted from the Upper Devonian Antrim shale, along the northern margin of the Michigan basin, which demonstrates that significant volumes of bacterial gas have been generated in organic-rich shales at depths of less than 600 metres. The Antrim shale is mainly a self-sourced reservoir, in contrast to conventional gas deposits that have migrated from a source to a reservoir, and has become one of the most actively exploited gas reservoirs3 in the United States. The gas-forming processes operating at shallow depths in the Antrim shale are not unique4, and an understanding of these processes should lead to the identification and development of other economic, non-conventional gas deposits around the world.

Reactor-membrane permeator process for hydrocarbon reforming and water gas-shift reactions

Abstract: New process designs are presented for reforming reactions of steam with hydrocarbons (such as methane, natural gas, light hydrocarbon feedstocks with one to four carbon atoms in each molecule), also for the water gas shift reaction that is of steam with carbon monoxide; also for carbon dioxide reforming of hydrocarbons (such as methane, acidic natural gas, coal gas, landfill gas, light hydrocarbon feedstocks with one to four carbon atoms in each molecule), and the combined reaction of steam carbon dioxide with same hydrocarbons. The processes employ organic polymer, organic polymer-inorganic support, and inorganic membrane permeators for species separation, with the permeators placed after the reactors where the above named reactions take place. The membranes in permeators separate selectively the H 2 and CO 2 species exiting from the reactors from the non-permeated reactants and products. The reject streams coming out of permeators can be recycled into the inlet of the first reactors; these reject streams can be also fed to consecutively placed steam reforming and water gas shift reactors for further conversion to H 2 and CO 2 products. The separated H 2 and CO 2 in membrane permeate and from the secondary reactions of permeator reject streams, can be used for direct methanol synthesis, feed to molten carbonate fuel cells, and other chemical syntheses; after the removal of CO 2 from the mixture, pure hydrogen can be recovered and used in chemical syntheses and as fuel in fuel cells and power generation cycles.

Low-temperature coupling of methane

Abstract: Introduction Methane is the main component of natural gas and its utilization amounts to ca. 1.7 × 109 tons of oil equivalent per year [1]. Since the present reserve of methane is located in remote places, its transportation is a major problem. Methane coupling to form C2+ hydrocarbons is, therefore, of a primary importance because before transportation methane should be converted into hydrocarbons with higher boiling points, such as ethane, propane, etc. The catalytic conversion of methane can be carried out in several ways which have excellently been reviewed in Refs. 1 and 2. Basically, three routes exist: (i) the indirect route in which methane is first converted into syngas in presence of water (steam reforming), CO2 (carbon dioxide reforming), or oxygen (partial oxidation) and the resultant syngas can be utilized in the traditional way; (ii) direct coupling in the presence of oxygen (oxidative coupling of methane, OCM) or hydrogen (two-step polymerization); and (iii) direct conversion in the presenc...

Methods and apparatus for low NOx emissions during the production of electricity from waste treatment systems

Abstract: Methods and apparatus for high efficiency generation of electricity and low oxides of nitrogen (NOx) emissions are provided. The electricity is generated from combustion of hydrogen-rich gases produced in waste conversion units using ultra lean fuel to air ratios in the range of 0.4-0.7 relative to stoichiometric operation in internal combustion engine-generators or ultra lean operation in gas turbines to ensure minimal production of pollutants such as NOx. The ultra lean operation also increases the efficiency of the internal combustion engine. High compression ratios (r=12 to 15) can also be employed to further increase the efficiency of the internal combustion engine. Supplemental fuel, such as natural gas or diesel oil, may be added directly to the internal combustion engine-generator or gas turbine for combustion with the hydrogen-rich gases produced in waste conversion unit. In addition, supplemental fuel may be reformed into a hydrogen-rich gas in a plasma fuel converter and then introduced into the internal combustion engine-generator or a gas turbine for combustion along with supplemental fuel and the hydrogen-rich gases produced in waste conversion unit. The preferred embodiment of the waste conversion unit is a fully integrated tunable arc plasma-joule heated melter with a common molten pool and power supply circuits which can be operated simultaneously without detrimental interaction with one another. In this embodiment, the joule heated melter is capable of maintaining the material in a molten state with sufficient electrical conductivity to allow rapid restart of a transferred arc plasma.

Mathematical modeling of atmospheric fine particle‐associated primary organic compound concentrations

Abstract: An atmospheric transport model has been used to explore the relationship between source emissions and ambient air quality for individual particle phase organic compounds present in primary aerosol source emissions. An inventory of fine particulate organic compound emissions was assembled for the Los Angeles area in the year 1982. Sources characterized included noncatalyst- and catalyst-equipped autos, diesel trucks, paved road dust, tire wear, brake lining dust, meat cooking operations, industrial oil-fired boilers, roofing tar pots, natural gas combustion in residential homes, cigarette smoke, fireplaces burning oak and pine wood, and plant leaf abrasion products. These primary fine particle source emissions were supplied to a computer-based model that simulates atmospheric transport, dispersion, and dry deposition based on the time series of hourly wind observations and mixing depths. Monthly average fine particle organic compound concentrations that would prevail if the primary organic aerosol were transported without chemical reaction were computed for more than 100 organic compounds within an 80 km × 80 km modeling area centered over Los Angeles. The monthly average compound concentrations predicted by the transport model were compared to atmospheric measurements made at monitoring sites within the study area during 1982. The predicted seasonal variation and absolute values of the concentrations of the more stable compounds are found to be in reasonable agreement with the ambient observations. While model predictions for the higher molecular weight polycyclic aromatic hydrocarbons (PAH) are in agreement with ambient observations, lower molecular weight PAH show much higher predicted than measured atmospheric concentrations in the particle phase, indicating atmospheric decay by chemical reactions or evaporation from the particle phase. The atmospheric concentrations of dicarboxylic acids and aromatic polycarboxylic acids greatly exceed the contributions that are due to direct emissions from primary sources, confirming that these compounds are principally formed by atmospheric chemical reactions.

Process for solids waste landfill gas treatment and separation of methane and carbon dioxide

Abstract: Waste landfill gases are treated and separated by a combination of gas cleaning, gas compression, gas cooling, and gas absorption processes to produce high quality liquefied natural gas, liquefied carbon dioxide and compressed natural gas products.

Oceanic methane hydrates: a “frontier” gas resource

Abstract: Methane hydrates are ice-like compounds consisting of natural gas (mainly methane) and water, whose crystal structure effectively compresses the methane: each cubic metre of hydrate can yield over 150 cu.m of methane. Hydrates “cement” sediments and impart considerable mechanical strength; they fill porosity and restrict permeability. Both biogenic and thermogenic methane have been recovered from hydrates. Hydrates occur in permafrost regions (including continental shelves), and are stable in ocean-floor sediments below water depths of about 400 m in the “Hydrate Stability Zone” (HSZ). This is a surface-parallel zone of thermodynamic equilibrium that extends down from the sediment surface to a depth determined by temperature, pressure and local heat flow. Methane and water are stable below the HSZ. Although the economic recovery of hydrates has taken place in Arctic regions, oceanic hydrates offer far greater potential as an energy resource. A variety of traps for methane gas can be formed by oceanic hydrates. In addition to the gas within the hydrates themselves, simple gas traps in closures beneath the HSZ in the vicinity of bathymetric highs, and complex traps involving both hydrate and structural/stratigraphic components, have been observed. It has been estimated that at least twice as much combustible carbon occurs associated with methane hydrates as in all other fossil fuels on Earth. The evaluation of methane in, and associated with, oceanic hydrates therefore constitutes a major energy exploration frontier.

Propane recovery process

Abstract: Increased recovery of propane, butane and other heavier components found in a natural gas stream is achieved by installing an absorber upstream from an expander and a separator. The separator is downstream from the expander and returns the liquid stream generated by the separator back to the absorber. Additionally, the recovery of propane, butane and other heavier components is enhanced by combining the upper gas stream from a distillation column with the upper gas stream from the absorber prior to injecting this combination into the separator. The upper gas stream removed from the separator is then subsequently processed for the recovery of a predominately methane and ethane gas stream while the bottom liquid stream from the absorber is subsequently distilled for the generation of a stream consisting predominately of propane, butane and other heavy hydrocarbon components. Alternate embodiments include an additional reflux separator in the system, or substitution of an additional absorber for the separator.

Reconsideration of methane isotope signature as a criterion for the genesis of natural gas - Influence of migration on isotopic signatures

Abstract: Experiments were performed in the purpose of studying the isotopic consequences of the diffusional transport of hydrocarbon gases through sediment rocks. Linked to a numerical model, these gas diffusion experiments through a shale porous plug allowed us to correlate porosity and diffusivity of the migration medium. Significant isotopic fractionations (carbon and hydrogen) of methane, and ethane at a lesser degree were observed. This is in contradiction with the actual dogma of isotope geochemistry of natural gases which claims that no fractionation occurs during gas migration. The genetic characterization of natural gases by using the isotopic signature of methane appears as an ambiguous method.

Process for producing syngas and hydrogen from natural gas using a membrane reactor

Abstract: Novel procedures are described for the production of syngas fuel intermediates from abundantly available natural gas. The novel procedures include: (a) providing a double tubular hydrogen transfer reactor having an inner tubular wall defining a heated reaction zone containing a catalyst and an outer tubular wall defining an annular zone between the tubular walls, said inner tubular wall including a hydrogen semipermeable membrane portion adapted to permit diffusion of hydrogen therethrough from the reaction zone to the annular zone while being impervious to other gases, (b) passing through said catalytic reaction zone of a feedstock comprising a mixture of methane and oxygen or a mixture of methane and carbon dioxide or a mixture of methane, carbon dioxide and oxygen, (c) continuously removing from the reaction zone at least part of the hydrogen being formed by diffusion thereof through said hydrogen semipermeable membrane into said annular zone, (d) continuously removing diffused hydrogen from said annular zone and (e) continuously removing a product mixture of carbon monoxide and hydrogen from the reaction zone.

Fuel gas admixing process and device

Abstract: In an internal combustion engine, natural gas is injected through a nozzle (17) into a curved feeding pipe (13), tangentially and in opposite direction to the flow of combustion air. Two nozzles (17) that are spaced apart in the flow direction and that alternatively inject the natural gas are preferably used in order to achieve a homogeneous distribution of fuel in the fuel/air mixture. A conical jet (21) ensures an impeccable mixture of gas with the totality of supplied air.

Natural gas fueling system

Abstract: A system is disclosed for handling, storing, transporting and dispensing cryogenic fluids, liquid natural gas, compressed natural gas, and their equivalents. A fuel injection system is disclosed for directly injecting LNG into an engine's combustion chamber. Such systems include a railroad system in which a container of fuel is carried on a flat car behind a locomotive and the, e.g. liquid natural gas, is conveyed to the locomotive with appropriate valves, conduits, pumps, and controls. In one aspect a fuel fluid, liquid, or vapor is injected into an intake (e.g., an air intake) of an engine. In one aspect a fueling station has been invented for providing services of dispensing LNG and/or CNG for engines.

An optimization model for planning natural gas purchases, transportation, storage and deliverability

Abstract: Natural gas local distribution companies (LDCs) face the problem of managing natural gas purchases under conditions of uncertain demand and frequent price change. In this paper, we present a stochastic optimization model to solve this problem. Unlike other models, this model explicity considers deliverability, the rate at which gas can be added to and withdrawn from a storage facility, as a variable, and considers its role in ensuring a secure supply of gas. Deliverability is often overlooked in gas supply planning, yet is a critical factor in achieving a secure gas supply. Using data from an LDC in Huntsville, Alabama, we show how this model can be used to minimize total cost while meeting constraints regarding the security of gas supply. We also demonstrate that security is dependent on the rate of deliverability, which in turn is affected by a number of factors including gas availability, storage and transportation considerations, and weather conditions.

Benefits of Compressor Inlet Air Cooling for Gas Turbine Cogeneration Plants

Abstract: Compressor inlet air cooling is an effective method for enhancing the performance of gas turbine plants. This paper presents a comparative analysis of different solutions for cooling the compressor inlet air for the LM6000 gas turbine in a cogeneration plant operated in base load. Absorption and evaporative cooling systems are considered and their performance and economic benefits compared for the dry low-NO{sub x} LM6000 version. Reference is made to two sites in Northern and Southern Italy, whose climate data series for modeling the variations in ambient temperature during the single day were used to account for the effects of climate in the simulation. The results confirmed the advantages of inlet air cooling systems. In particular, evaporative cooling proved to be cost effective, though capable of supplying only moderate cooling, while absorption systems have a higher cost but are also more versatile and powerful in base-load operation. An integration of the two systems proved to be able to give both maximum performance enhancement and net economic benefit.

Process for the removal of highly concentrated carbon dioxide from high-pressure natural gas

Abstract: This invention relates to a process for removing highly concentrated CO2 from high-pressure natural gas and recovering it in a high-pressure state. This process comprises the absorption step of bringing high-pressure natural gas having a CO2 partial pressure of 2 kg/cm2 or greater and a pressure of 30 kg/cm2 or greater into gas-liquid contact with a regenerated CO2 -lean absorbing fluid comprising a CO2 absorbing fluid of which the difference in saturated CO2 absorption level between 40° C. and 120° C. is not less than 30 Nm3 per ton of solvent at a CO2 partial pressure of 2 kg/cm2, whereby highly concentrated CO2 present in the high-pressure natural gas is absorbed into the CO2 -lean absorbing fluid to produce refined natural gas having a reduced CO2 content and a CO2 -rich absorbing fluid; and the regeneration step of heating the CO2 -rich absorbing fluid without depressurizing it, whereby high-pressure CO2 having a pressure of 10 kg/cm2 or greater is liberated and a CO2 -lean absorbing fluid is regenerated and recycled for use in the absorption step.

A Study of Natural Gas Origins in China

Abstract: The Chinese government has supported the development of the natural gas industry since the sixth "Five-Year Plan" (1981-1985) by studying natural gas and its origin, one of the key research projects in technology and science. This ongoing research has shown that natural gases in China are composed of three types: coal-type gas related to coal measures; high-temperature pyrolytic gas related to Paleozoic carbonates; and oil-type gas, which occurs in oil fields related to Cenozoic and Mesozoic lacustrine sediments. Each of these three types constitutes about one-third of the total observed reserves of natural gas in China. Since 1990, we have proposed a new genetic theory of natural gas multisource overlap and multistage continuity; a new biogenic-thermocatalytic transition l zone gas; and comprehensively identifying coal-type gas, which plays an important role in exploring for natural gas.

Methods of decomposing gas hydrates

Abstract: The present invention provides methods of decomposing gas hydrates in subsea or subterranean wells, the equipment associated with the wells and in subterranean reservoirs containing gas hydrates The methods basically comprise the steps of combining an acidic liquid with a basic liquid which chemically react exothermically to form a hot salt solution, contacting the gas hydrates with the hot salt solution to decompose at least a portion of the gas hydrates whereby natural gas and water are released therefrom and recovering the released natural gas, water and salt solution

Separation of gases by pressure swing adsorption

Abstract: A natural gas feed stream containing significant quantities of nitrogen and/or carbon dioxide can be increased to a content of greater than 95 percent by volume of natural gas, and preferably greater than about 98 percent, by passing the natural gas feed stream sequentially through three adsorbent beds that are cycled through seven phases comprising: an adsorption phase to adsorb a first gas, a first depressurization phase to remove feed gas from the voids in the adsorbent bed, a recycle phase to remove a second gas from the adsorbent by the passage of a second depressurization gas therethrough and to produce a recycle gas, a second depressurization phase to reduce the adsorbent bed pressure to about ambient and to produce the second depressurization gas, an evacuation phase where the pressure in the adsorbent is further reduced and an enriched primary gas product stream recovered, a pressurization phase where the pressure in the adsorbent bed is increased using secondary product gas from a bed in an adsorption phase, and further pressurizing the adsorbent bed in a pressurization phase by the flow of the recycle gas and feed gas into the adsorbent bed. Various gases can be separated using this process. Nitrogen can be removed from natural gas (adsorbed gas) and carbon dioxide (adsorbed gas) can be removed from natural gas.