Water Gas Research Articles

The use of carbon monoxide and water gas as the flame-forming agent in the thermionic detector

The use of carbon monoxide were suggested as the flame-forming agent in the thermionic detector (TID). The main characteristics of this detector were studied. It was shown that the optimum flow rate of carbon monoxide is 40 ml/min at an air flow rate of 400–550 ml/min. The response increases twice with the positive potential on the collector. Molar responses of TID were compared with those obtained when using carbon monoxide and hydrogen. For instance, for phosphorus containing compounds they are approximately the same (∼102), while for nitrogen containing compounds in the case of carbon monoxide, there is a 2–5 fold increase in the response. The linear dynamic range for methaphose and azobenzene is 103.

Capacity of relief valves

The selection of relief values (RV) for an actual system is made on the basis of working pressure, the adjustment pressure, the pressure of the onset of opening, the pressure of full opening, and the closing pressure. The hydraulic quality of an RV is characterized by the capacity for the mass flow rate of the working medium through the RV at the specified temperature and pressure. Formulas for water vapor, gas and liquid are shown. The authors derive a more practical solution for the capacity of an RV than the one previously used, and create a more unambiguous calculation of discharge and the selection of control valves.

An inelastic electron tunneling study of the insulator formed on aluminum in a low pressure discharge containing SO 2

Vacuum deposited films of aluminum were exposed to a 400 V AC discharge plasma initially composed of SO 2 and of either oxygen or water gas. 18O substituted water and SO 2 were also used. The surfaces thus formed were studied by tunneling spectroscopy. From the observed peak positions and isotopic shifts it appears that, when SO 2 is initially about half of the discharge gas, the principal species present in the insulating layer is AlS x O y , where x and y are of the order of 3 and 7, respectively. A thin layer of AlO z probably underlies the SO containing film. Initial concentrations of SO 2 in excess of about 60% gave barriers having low reproducibility and showing large charge-trapping effects. The tunneling spectrum of the sulphate ion, doped from water solution, is also reported.

Ecology of Daldinia concentrica: Effect of abiotic variables on mycelial extension and interspecific interactions

Attached ash (Fraxinus excelsior) branches, colonized by Daldinia concentrica, were collected from locations in South-West Britain and the patterns of decay analyzed. A notable feature was the limited number of individuals of D. concentrica in branches and the considerable lengths and volumes of wood that they occupied. It is suggested that this fungus is a primary colonizer and that colonization may be by latent invasion. Mycelial extension, at optimal temperatures on malt agar, was rapid and D. concentrica was more tolerant of low water potentials than basidiomycetes found in attached branches. It is a combative fungus and it replaced most of the organisms with which it was paired in culture, although the outcome was modified, sometimes considerably, by water potential and gas regime.

Tazerka Multiwell FPSU: Design of Production Facilities Integrated With the Tanker

Summary This paper will review the design of the production facilities on the multiwell floating production and storage unit (FPSU) operated by Shell Tunirex in the Tazerka field, offshore Tunisia, on behalf of a joint venture with AGIP (Africa) and Entreprise Tunisienne d'Activits Petrolires. Economics and product specification dictated the application of special techniques in the production and utility designs regarding process flexibility, gas disposal, power generation, and pollution prevention. The field, containing estimated reserves of 8 to 10 million bbl [1.3 × 10(6) to 1.6 × 10(6) m3] of recoverable oil, is located in deep water (459 to 984 ft [140 to 300 m]). It was desirable to use a single-process train with as near a 100% on-stream factor as possible. While this is not the first application of a flow station on a weathervaning unit, it is believed to be the first to process crude directly from several subsea wells. Introduction The Tazerka field lies 35 miles [56 km] offshore the northeast coast of Tunisia in the Hammamet Grand Fonds permit. It has been in production since Nov. 1982 and currently produces some 10,000 B/D [1590 m3/d]. Oil is produced from four subsea completed wells in water depths ranging from 459 to 607 ft [140 to 185 m], flowing by Coflexip (TM) flowlines to the single anchor leg system (SALS) that holds the FPSU on location in 459-ft [140-m] water depth. Oil flows through swivels on the SALS to the FPSU-i.e, to the converted very large crude carrier (VLCC) tanker Murex (Fig. 1). The entire crude production facilities are integrated onto the converted unit, which then stores up to 140,000 tonnes [140,000 Mg] of crude. The system is completely independent of platforms and pipelines to shore, with off-take achieved by discharging, using the original VLCC cargo pumps, to trading tankers moored alongside. This approach to developing the field, instead of conventional methods such as steel or concrete platforms connected by pipeline to shore, was dictated by economics, which showed that conventional methods would have been too expensive. Facilities Description The initial field development plan called for reservoir natural depletion with provisions for future installation of water injection and gas lift facilities to enhance recovery. Fig. 2 shows a block flow diagram depicting the deck-mounted facilities/utilities that have been designed and engineered for the Tazerka FPSU. Crude Oil Production The Tazerka FPSU development is designed to receive 30,000 B/D [4770 m3/d] of produced liquids from up to eight subsea completed wells. All wells have provisions for future gas lifting. Three of these wells also have been designated for water injection. At present, the well fluids from the four installed subsea wells flow through 4-in. [10-cm] Coflexip seabed lines to the SALS manifold, then through a six-bore product swivel, and finally, through the mooring yoke to the receiving manifold on the FPSU. Well subsurface safety valves and wing valves are controlled hydraulically from a control panel on the FPSU deck by control lines routed through a 20-bore swivel on the SALS. Oil/Gas/Water Separation From the receiving manifold on the FPSU, the incoming stream is routed to a single-process train, consisting of a separation unit (HP, LP, and test) and a stabilizing unit. The possible combinations of the process train and the valve switching provide for an on-stream factor close to 100%. Oil can be produced through any one of the six product swivels to the receiving manifold. All separators are of identical design and are capable of handling the full production flow, therefore enabling any one separator to be out of service for maintenance or repair while still maintaining production through the others. The test separator also can be used as a stabilizer. Fig. 3 shows the changeover philosophy in detail. Produced water can be removed from the crude oil in two stages.1. Bulk separation in the three-phase separators ispossible in either series mode or parallel mode.2. Final separation of water occurs in the FPSU's dedicated crudereceiving tanks, where water can be taken off the bottom by theoriginal VLCC's stripping pumps. A dehydrator can be installed ifhigh water production or stable emulsions occur. JPT P. 1091^

Studies on the physiology and propagation of the ostrich fern, Matteuccia struthiopteris

SynopsisThe effect of photosynthetic photon flux density (PPFD), water, temperature and nutrition on frond emergence, vegetative frond production, fertile frond production, vegetative propagation and dormancy is examined. Ostrich fern plants will not break winter dormancy until they have received a minimum amount of cold exposure below a base temperature which is above 5.8°C and may be as high as 20°C. After the plants have received their chilling requirement, vegetative frond emergence does not occur until temperatures at or above ca. 9.3°C are reached. Percent germination and rate of emergence increases up to ca. 24°C. Photosynthetic photon flux density, water availability and mineral nutrition can affect both vegetative and fertile frond production but water availability appears to be the most critical. A mild water stress of −0.15MPa can have significant effects on water status and gas exchange in fronds. Sporophyte plants for field production have been produced vegetatively from detached meristems occurring naturally on the rhizomes, and through fertilization of axenic gametophytes.

Apparatus assembly for high-level water concentration sampling and gas chromatography analysis

In the course of a kinetic study of hydrocarbon steam cracking, water vapour concentrations as high as 90% had to be measured. Usually gas chromatographic analyses of large concentrations of water are highly irreproducible and the accuracy is very low, this inconvenience being related to adsorption of water vapour. By carefully controlling this phenomenon the authors have been able to obtain reproducible and accurate water vapour concentration measurements by gas chromatography without limitations.

The Secondary Recovery Project at Ogharefe Field, Nigeria

A secondary recovery project involving water injection and gas-lift facilities was installed in the Ogharefe field in 1979 following detailed reservoir simulation studies. Two years' operation provides the opportunity to discuss the progress of the project so far.

An IR cell for vacuum and high temperature

Much interest has been shown in IR cells capable of maintaining one or more samples at constant temperature, constant water vapour or gas pressure, or under vacuum conditions (Farmer, 1974). This note describes a cell capable of maintaining a vacuum between 10-3 torr and 10-4 tort from room temperature to 1000°C whilst the spectrum is being recorded; such cells have been constructed previously but for less severe conditions.The cell and associated vacuum system are shown schematically in Fig. 1. The vacuum in the cell body is produced by an Edwards rotary pump and a normal mercury diffusion pump. To obtain a vacuum of 10-3 to 10-4 torr, a liquid nitrogen trap and foreline trap are used. The trap is filled with activated alumina. The O-ring seals in the cell are made of Viton. The constant vacuum control is obtained with Pirani and Penning gauges.

Early-Time Pressure Buildup Analysis for Prudhoe Bay Wells

Summary A method of pressure buildup analysis is presented that distinguishes between two possible reasons for the decline in a well's productivity-near-wellbore damage and permeability loss in the well's drainage area. An extensive application is discussed for wells in the Prudhoe Bay field. Heterogeneity of this reservoir is such that semilog analysis methods are not reliable for identifying wells in need of remedial workover. Introduction The production rate of individual wells in the Prudhoe Bay field can decline for a variety of reasons, including workover damage, formation-water precipitate, fines migration, limited drainage area, and gas saturation. Calcium chloride brine was used originally as a workover and packer fluid. This brine, when mixed with formation water, precipitates calcium carbonate, which can practically plug the perforations and near-wellbore formation. Matrix acidization with hydrochloric acid gives only temporary relief. Carbonate scale forms again when the residual workover fluid contacts formation water or CO2 gas from crude-oil production. Fines also migrate to the wellbore. These particles of clay and/or microporous chert plug the perforations, which apparently leads to an insidious type of pressure buildup behavior. The perforation tunnels, perhaps, tend to collapse and thereby compress any fines and/or scale present. This compaction would increase as the amount of drawdown increases. When such a well is shut in and the pressure recovers, this compaction reverses to give a pressure-sensitive near-wellbore damage that can dominate a 24-hour buildup test entirely. Well 6 in Ref. 1 appears to be an example of such a situation at Prudhoe Bay. Factors other than true damage can cause production falloff. Prudhoe Bay field contains a number of mapped faults that limit the drainage area of nearby wells. Relative permeability can also reduce oil production. Since the field has an associated gas cap, the crude oil is at or near its bubblepoint pressure. Consequently, most wells flow at bottomhole pressures (BHP's) below the bubblepoint. These wells will have a near-wellbore region with gas saturation. This reduces relative permeability to oil in the near-wellbore region. Measured relative-permeability curves show that at the minimum mobile gas saturation of 5%, relative permeability to oil is decreased to about two-thirds of its value at zero gas saturation. With continued production, the zone of mobile gas saturation will expand sufficiently to give a measurable drop in productivity accompanied by an increase in GOR. Almost 700 buildup tests have been run in the Prudhoe Bay field. High-precision gauges are used consistently. The ambiguous interpretations of these tests, however, have generated confusion. One interpreter may claim a well is undamaged while another maintains that the well is damaged. Supposedly undamaged wells have been acidized to give threefold rate increases. We believe this confusion arises from attempts to apply Homer-type buildup analysis methods-or slight modifications thereof-to data from a reservoir that departs significantly from the model implicit in the Homer method. The Prudhoe Bay field has both a gas cap and an underlying aquifer. To provide distance from these contacts, the oil zones are usually perforated in only a portion of the net pay. This complicates a Homer-type analysis. Additionally, the formation is a complex sequence of sand-shales resulting from either braided stream or mouth-bar depositions. The sands are separated by shale stringers of widely varied thickness and of generally unknown permeability and lateral extent. As discussed in Ref. 1, gas-cap pressure support can interact with reservoir heterogeneities to give a bewildering and nonunique variety of distortions of the middle-time region so essential to a Homer-type analysis. No attempt is made to identify a middle-time region in the method described in this paper. Instead, early-time, afterflow-dominated buildup data are analyzed to determine whether productivity decline can be attributed to wellbore damage alone. In this paper we first give some comments on the method. This is followed by examples from buildups taken in the Prudhoe Bay field. The method consistently accounts for well productivity behavior. For some examples, the Homer-type analysis is completely satisfactory. In other examples, the Homer approach gives confusing and inconsistent results. Finally, there are examples from a sequence of tests on the same well that produce impossible results by Homer analysis. It is this very lack of consistency that we hope to eliminate. While we concentrate on tests from Prudhoe Bay, the general problem is not unique to this field. This is illustrated by our first example. JPT P. 311^

Electric Submersible Pumps —Reducing Failures Through Improved Field Procedures In The South Swan Hills Unit

Abstract The Amoco Canada-operated South Swan Hills Unit is currently producing under a combined water, hydrocarbon miscible and dry gas flood. Nearly 85 per cent of the daily production of 6 500 m3 oil and 25 000 m3 water is lifted by 106 submersible pump installations. The average run life of a submersible pump in the Unit has historically been about six months. The adverse conditions contributing to this relatively short operating time include high temperatures, high pressures, the depth of the reservoir, small casing diameter, corrosion, changing gas/oil ratios with the associated problems of gas breakthrough and asphaltene plugging. These combined factors have hampered attempts to lengthen the average run life of a submersible pump installation. Concentrated efforts in the past two years, aimed at improving field operations, are now being seen as having a positive impact on submersible pump performance. This paper describes procedures which were initiated and the resulting advancements which have been made in this area. Introduction The South Swan Hills Unit is located 225 km northwest of Edmonton, Alberta (Fig. 1). The Unit (Fig. 2), formed in 1962 and operated by Amoco Canada Petroleum Company Ltd., consists of 191 production and 60 injection wells. Production is from the Swan Hills formation of the Beaverhill Lake Group, which is a limestone reef complex. Bottomhole temperature is 112 °C at a depth of 2500 mKB. FIGURE 1. Location of the South Swan Hills Unit. (Available in full paper) In 1963, the west side of the Unit was put on a secondary recovery water flood. In 1973, a secondary miscible flood project was initiated in the central portion of the Unit. The enriched gas solvent injection is nearing completion, with all injection wells to be converted to dry gas by August 1982. In 1978, the east portion of the field was placed on waterflood. The number of submersible pump installations peaked at 118 in 1980 and has since been reduced to 106. Previous and present local ions are also shown on Figure 2. History The South Swan Hills Unit currently produces about 6 500 M3/d of oil and 25 000 m3/d of water (Fig. 3). Since the first submersible pump was installed in the Unit in January 1971, production has become increasingly dependent on this form of artificial lift (Fig. 4). Currently, 58 per cent of all production wells utilize submersible pumps, representing 85 per cent of total Unit production. With the exception of the first year of submersible pump operation, the annual failure rate has always been higher than the number of installations (Fig. 5) as a result of the harsh operating environment. During 1980, the 118 locations had experienced 239 failures. Because of the increasing failure rate and the tremendous associated operating cost (approximately $45 000 per changeout), Amoco began an intensified study in early 1980 in an attempt to reduce this failure rate. The study reinforced that the major causes of failure were the result of electrical problems, gas interference (often causing mechanical failures), foreign material and corrosion as well as operational procedures.

Numerical analysis of hydrogen isotope separation characteristics in improved dual temperature exchange reaction system between water and hydrogen gas.

A dual temperature hydrogen isotopic exchange reaction system between water and hydrogen gas is numerically analyzed. The system has two features; high efficiency of isotope exchange reaction and operation under atmospheric pressure. To achieve them, the low temperature section of the system is composed of water mist and hydrogen gas co-current reactor units. For the high temperature section, a multistage-type reactor, in which a bubble plate, superheater and catalyst bed are alternatively arranged, is applied. From a material balance between these reactors, enrichment and decontamination factors for the system are expressed as functions of seven parameters: unit number of the low temperature co-current reactor (X); stage number of the high temperature section (Y); flow ratio of tritium enriched water to decontaminated water (P/W), flow ratio of feed water to hydrogen gas (F/G); reaction temperatures of the low and high temperature sections (T c , T h ); and bubble plate temperature (T b ). Numerical calc...

A Repaid Procedure for Preparing Oxyen-18 Determination in Water Samples

An equipment for the speed δ18O analysis of water samples is described. It used the equilibrium isotopic exchange reaction between water and CO2 gas. Outgasing of samples through capillary without freezing down the samples, together with shaking during the equilibrium time, reduced considerably time for sample preparation. Apparatus is air termostated with hand valves. Measured δ values are not very sensitive to precision of preparation work and reaction conditions, except of temperature. With good temperature control the standard reproducibility of single measurement is better than 0,1‰

Physical Model of the West Willmar Rich Gas Pilot

Abstract A physical model of the West Willmar Frobisher Beds reservoir in southeastern Saskatchewan has been developed by assembling 31 core plugs into a 1.5-metre horizontal pore system. Studies conducted range from simple gas flow through immiscible, miscible and water-and-gas displacements, with results confirmed by compositional simulation n runs wherever practical. The discussion of the data develops new insights into laboratory methods and simulation concepts. The interpretation of results indicates the impact of flow conditions on potential oil recovery from the miscible swept zone in the West Willmar Rich Gas Pilot. Introduction The initial objective of the core flood studies for the Willmar Pilot was simple: to find out how much stock-tank oil could be recovered from the reservoir rock by water flood, gas flood and hydrocarbon miscible flood. As this objective was achieved, it became equally important to develop better insight into the process and its key parameters, not only for the optimization of the West Willmar Pilot, but also for use in designing other gas miscible projects in Western Canada. Subsequent investigations into the effect of the preliminary water flood on miscible flood recovery led to investigations of water-alternating- gas (WAG) flood cycle size, gas-water ratio and effectiveness of chase gas in improving oil recovery and recovering miscible fluid during the latter part of the flood. The attainment of the above objectives was a stepwise process, with each new core flood building upon data previously acquired. The amount of data derived from the experiments- (Figure in full paper) also increased progressively, leading to improvements in equipment and procedures to their current status. Experimental Apparatus and Procedure Apparatus and Procedures The apparatus used in performing the core displacement tests is shown in Figure 1. The novel feature of this apparatus and associated procedures is that inlet injection rate and outlet production rate are equal and constant. These boundary conditions have been found to enhance mechanical reliability and ease of operation. This technique is also useful in avoiding problems with pressure surging that commonly occur with back-pressure control. In situations where two- and three-phase production occurs, the method improves mass and volumetric balances. In situations where the three phases are intimately mixed limits can easily be put on inlet pressure and pressure drop across the core to prevent development of unnecessarily unfavorable reservoir conditions. Where both incompressible and compressible fluid are used in the same test, the procedure provides data equivalent to those obtained in conventional constant injection rate – constant outlet pressure experiments(l). In the case where compressible materials (gases) are injected, the volumes of material injected and collected from the core are determined knowing the pump injection and withdrawal reading, the fluid compressibilities, and the volumes of the fluid injection and collection reservoirs. To measure pressure drop across the core a differential pressure transducer is placed in parallel. High-pressure visual cells permit observation of the phase behaviour of the injected and produced fluids.

Modeling Natural Gas Reservoirs – A Simple Model

Abstract A mathematical model is developed and tested for the production of natural gas with water encroachment and gas entrapment. The model is built on the material and volumetric balance relations, the Schilthuis water drive model, and a gas entrapment mechanism which assumes that the rate of gas entrapment is proportional to the volumetric rate of water influx. This model represents an alternative to the large grid models because of its low computer, maintenance, and manpower costs.

The effect of water and hydrogen gas environments on subcritical crack growth in generator rotor steels

Long-time (approximately WOO days) static and cyclic loading subcritical crack growth tests were conducted with 4 in. (10.16 cm) thick WOL-type compact toughness specimens of NiMoV and NiCrMoV rotor steels exposed to both distilled water and dry hydrogen gas environments. Results show that neither steel is susceptible to environment induced cracking under static loading conditions in the test environments. However, environment did have a significant detrimental effect on the fatigue crack growth performance of both steels. The hydrogen gas environment increased the rate of fatigue crack growth by factors of about 5 and 10 (over that encountered in laboratory air) for the NiCrMoV and NiMoV steels, respectively. A t a low frequency (0.0017 Hz), the water environment increased the rate of fatigue crack growth by a factor of about 2.5 to 3 for both steels. It was also shown that loading frequency has a significant effect on the fatigue crack growth behavior observed in water (increasing growth rate with decreasing frequency) but no effect on the behavior observed in hydrogen gas. The results of these long-time tests were compared to results generated with more conventional short-time tests and recommendations made for predicting long-time subcritical crack growth behavior from short-time tests.

Influence of plasma oncotic pressure on lung water accumulation and gas exchange after experimental lung injury in the pig.

In 18 anaesthetized and artificially ventilated pigs, oleic acid was infused intravenously in order to induce a lung injury characterized by increased lung water content, decreased compliance and a ventilation/perfusion disturbance. After a stabilizing period, half of the animals (group P) underwent repeated plasmapheresis, which halved their plasma oncotic pressure (POP). The rest of the animals were bled and re-transfused with the shed blood, thus serving as a control group. In both groups, care was taken to keep the mean left atrial pressure as constant as possible. During plasmapheresis and "shamapheresis", there was no significant increase in venous admixture (F102 0.21 and 0.6) in either of the groups. At the end of the study, end-inspiratory pressure, dead space/tidal volume ratio and wet/dry lung weight ratio (WW/DW) were significantly higher in group P. Venous admixture and WW/DW correlated significantly with pulmonary arterial pressure and calculated pulmonary capillary pressure, but not with POP or POP minus pulmonary arterial occlusion pressure. It is concluded that reduction of plasma oncotic pressure may increase the lung water content in previously injured lungs, but this extra water accumulation does not necessarily impair oxygenation in the lungs.

Hydrogen safety problems

Consideration of use of hydrogen as a common fuel always raises questions on the matter of safety. The hazardous properties of hydrogen should not disqualify it for widespread use. Hydrogen has been used as a transmissible fuel for 150 yr (mixed with carbon monoxide in water gas) and as a portable fuel in cryogenic form within this generation. The accident experience with hydrogen, other than its use in lighter-than-air craft, has not been inordinately worse than the accident experience with more commonly used fuels. Hydrogen has unique properties which require special treatment to lessen risk: broad combustible range, low energy for ignition, rapid diffusion rate and, as a cryogen, the capability to create high pressures if confined without available relief, and the ability to condense all other gases except helium.

水性ガスによるインドネシア産ラテライトの流動還元について

水性ガスによるインドネシア産ラテライトの流動還元について

Pembina Field Polymer Pilot Flood

Summary A polymer pilot flood using Pusher 700 as carried out in two adjacentfive-spot patterns in the Pembina field to decrease water channeling in a thickconglomerate zone overlying the sand pay. Although a high viscosity wasachieved in the pilot injection water, only temporary improvements in theproducing- and injection-well behavior were observed. Introduction The Pembina field is located in Alberta, Canada, ab out 70 miles southwestof Edmonton (Fig. 1). This large field, which now covers about 500,000 acres, was discovered in 1953 by Mobil Oil Canada, Ltd. The reservoir is astratigraphic trap producing from the Cardium zone at a depth of about 5,000ft. Neither bottom water nor free gas has been found. The field is developed on80- and 160-acre spacing. There are presently about 3,000 active producingwells and 1,400 injection wells. The cumulative production to date is 800million bbl, or about 11 percent of the original oil in place. More than 75percent of the field is under pressure maintenance by waterflooding, miscibleflooding, or gas flooding. The Cardium zone, which is of Cretaceous age, was deposited under varyingconditions and shows a wide range of rock characteristics. The sand is overlainby a conglomerate section that is extremely erratic in deposition and variablein thickness. Permeabilities in the conglomerate can be very high. Pressuremaintenance performance in the field is severely affected by reservoirstratification in the sand, and particularly by the presence of a welldeveloped conglomerate section. Early breakthroughs and high WOR s are typicalproduction characteristics for wells in areas with thick conglomeratesections. Considering that the oil in place in the Pembina field is about 7.4 billionbbl and that about 15 percent of the area is overlain by a well developedconglomerate, some improvement of the vertical sweep efficiency throughreducing the adverse effects of the conglomerate could add large reserves tothis field. However, there have been no successful field tests to achieve thisgoal. The purpose of the pilot was to field test the efficiency of Dow ChemicalU.S.A. Pusher 700 in an area of the Pembina field where the stratification hasseverely affected a waterflood. The viscosity of the Pembina oil is about 1 cp and the flood mobility ratiois less than unity, which is a generally favorable flood situation. Thus, theobjective of the test was not a general performance improvement to correct anadverse mobility-ratio flood, but was to reduce water channeling to bring aboutbetter vertical sweep.