Gas Volume Ratio Research Articles

混合ガス (天然ガス+CO2) による鉄鉱石の還元について

In the previous reports (ib., Tetsu-to-Hagane Vol.41, 1955, p.5-11; Vol.41, 1955, p.1149-4155), the authors reported the experiment on the reduction process of iron are by natural gas, and it was recognized that the reduction power of the gas was very strong when its decomposition was found. Then it was found that its decomposition was increased with increase of the reducing degree of iron are too.Then, the authors examined the reformation of natural gas by CO2 gas and the reduction of iron are by its reformed gas.Results obtained were as follow;(1) The reforming ratio was varied from 60 to 90% by the reducing degree of iron sand pellets which were fixed in the reforming furnace.(2) Using the unreduced iron sand pellets, the reforming ratio at 850°C was greater than at 900, 950°C.(3) Using completly reduced pellets, the reforming ratio was 90% of more.(4) When the volume ratio (CH4: CO2) of mixed gas was about 1: 1, reforming ratio was greatest and the reduction of iron are by reforming mixed gas was rapid, and the degree of reduction reached 90-100%.

Flow Resistance of Gas-oil Mixtures through Vertical Pipes

The resistance to flow of mixtures of gas and oil in passing up through theflow tubing of oil wells operated by gas-lift or by natural flow is a factor inoil-recovery technic that has received but little attention. Yet accuratedesign of a tubing installation for a particular set of conditions, whereoperation is by either of these methods, is impossible without quantitativedata on the pressure loss suffered by the oil-gas mixture in its passagethrough the well tubing to the surface. Because of lack of such information, petroleum production technologists have been compelled to approach this problemby "cut-and-try" methods, which, doubtless in many cases, has resultedin the installation and use of tubing too large or too small for most efficientutilization of the expansive force of the gas used in lifting the oil.Impressed with the necessity for information of this character, the authorshave conducted a series of tests with large-scale apparatus in the petroleumengineering laboratories of the University of California, designed to beproductive of data that would.afford a means of attacking the problem offlow-tubing design on a more scientific basis. Mechanics of Expulsion of Gas-Oil Mixtures in Naturally Flowing and Gas-LiftWells When oil is lifted from a well by the expansive force of compressed natural gasor air, the fluids enter the lower end of the eduction tube under elevatedpressure, with the gas partly in solution, but largely distributed in the formof occluded bubbles within the oil mass. As discharged from deep wells, afterreaching the surface, there will normally be at least 60 times as much gas, byvolume, as of oil; and in many cases the ratio of gas volume to that of the oilwill have a value as great as 1000 or more. On entering the lower end of theeduction tube, however, a relatively smaller volume of gas will be found in theoil-gas mixture, on account of compression of the gas in accordance with theelevated pressure necessary.

Effect of Back Pressure on Wells in Brock Field

Various estimates have been made as to the percentage of oil left in a fieldafter the wells have become so small that it is no longer practical to producethem. Engineers have given the matter much study and can substantiate theirfigures by data taken from fields from the Appalachians to California. Theaverage oil sand has a porosity of about 20 per cent., which gives a capacityper acre-foot of approximately 1500 bbl. The sand thickness in Oklahoma poolsaverages 20 ft. With 20 per cent. porosity and a 20-ft. sand thickness, thecapacity per acre is 30,000 bbl., yet these pools will seldom yield more than5000 bbl. to the acre. These figures support the theory that at least 50 per cent. of the oilremains in a sand after all known methods to recover it have been used.Certainly we can never recover all the oil, unless in years to come oil becomesso rare and yet so necessary that the price will justify sinking shafts intothe abandoned fields and regular mining methods of drifting and stoping.However, with improved methods of production and conservation of the naturalagencies of expulsion, we should be able to increase recovery. It is with thisin mind that this paper, relating to the effect of back pressure on wells, ispresented. Except in the fields where production is caused by hydrostatic pressure, thechief agency for getting oil out of the sand into the hole is the gas thatoccurs with the oil. After the pressure has declined, probably gravity also isa factor, but not an important one. With a given amount of oil in a sand and agiven amount of gas occurring with the oil, the ratio of gas volume per barrelof oil is the key to the ultimate recovery from that sand. Our efforts shouldbe along lines that will lower this ratio and make the gas, the agency given usby nature, do its work better and yield more of the oil, of which it is apart. AIME 070–64