US 1842098 A
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mm. m, W32. WA D 4 mmww PROCESS FOR OBTAINING HYDROCARBONS FROM PRODUCING SANDS Filed Nov. 15, 1928 3 Sheets-Sheet l F. A. HOWARD Jan. 19, 1932. 1,842,098
PROCESS FOR OBTAINING HYDHOCARBONS FROM PRODUCING SANDS Filed Nov. 15, 1928 3 Sheets$heet 2 W I Q W Q 33x 1 1w 8 mm F. A. HOWARD Jim. w, H932.
PROCESS FOR OBTAINING HYDROCARBONS FROM PRODUCING SANDS Filed Nov. 15, 1928 3 Sheets-Sheet 3 vNDO l mvu WWZNQQO @51 MA/ @btowwg,
Patented den. 1%, lEE
UNlTED FRANK A. HOWARD, OF ELIZABETH, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY, A CORPORATION OF DELAWARE PROCESS FOR OBTAINING HYDROOARBONS FROM PRODUCING- SANDS Application filed November 15, 1928. Serial No. 319,523.
The present invention relates to the art of obtaining valuable hydrocarbons from the earth and more specifically comprises an 1mproved system for the recovery of volatile hydrocarbons from producingsandsby application of high vacuum. My invent on w1ll be fully understood from the following description and the drawings which lllnstrate a suitable means for accompllsh'mg my improved method.
In the drawings, Fig. 1 is a sectional view broken so as to show the earths surface and the producing sands and the neighborlng strata with mine tunnels, ventilation tunnels, and the pipe system for the collection of hydrocarbons;
Fig. 2 is a plan view taken in sectlon along line H-H of Fig. 1; and
Fig. 3 is a semi-diagrammatic view in sec tion of a portion of the piping which may be substituted for that illustrated in Flg. 1 and Fig. 2; and
Fig. 4 is a section elevation of an out-cropping producing stratum to which my method is applied, showing the ground surface and a tunnel driven directly into the stratum.
In. a copending application, Serial No. 296,006, filed July 2a, 1928 in the name of Warren K. Lewis, a method for obtaining volatile hydrocarbons from producing sands by application of high vacuum is disclosed. My present method is an improvement of the above noted process and has for one of its objects a more complete utilization of the high vacuum by greatly increasing the area of thesand upon which the vacuum is effective and decreasing the frictional losses caused by passage of gas through thick strata of sand and long pipes while under low pressure. Other objects and advantages of the present method will be apparent to those skilled in the art.
Referring to the drawings, Fig. 1 and Fig. 2, reference character 1 denotes a shaft extending from the ground surface to a point above or below the producing sands, shown generally at A. Cap rocks B and B are shown above and below the sands. The shaft is lined with concrete 2 and is divided into two parts by a partition 3, the working shaft denoted by numeral 4 and the air shaft by 5.
The lower end of shaft 1 is shown below cap rock B but it should be understood that if desired the shaft may be terminated just above cap rock B. From the lower end of the shaft, two sets of tunnels, 6 and 7, are mined parallel to the producing sand but separated therefrom by the cap rook. Tunnels 6 are mine tunnels and connected into the working shaft 41, while tunnels 7, which run parallel to tunnels 6, are provided for ventilation. A single tunnel may be made if desired and separated into the two parts by a partition. Tunnels 7 are connected with the ventilation shaft 5 and a fan 6 is provided to force fresh air into shaft 5. At intervals of about 100 feet, air passages 8 are bored to connect tunnels 6 and 7 so that air passes out of the mine by shaft 4, as will be understood.
In the plan view, Fig. 2, the parallel arrangement of the tunnels is best shown and they are constructed so as to form a net work of passages below or above the producin sand which is thus divided into areas G, pre erably square and each enclosing about acres. Where it is necessary for tunnels 6 and 7 to cross, tunnel 7 will be overor undercast, as indicated at D.
lfn each of the tunnels 6, a main collection manifold 9 is provided extending the length of the tunnel and at short intervals along its length collection pipes 10 extend slantwise into the various areas of sand bounded by the tunnels, as will be understood. Pipes 10 are sealed into the cap rock as at 11 and the sand around each pipe is reamed out as at 12 into a cavity which exposes a large area of the sand.
The manifold pipes 9 are preferably laid on a slight inclination and at the lowest point a separation tank 13 is provided, into which the manifolds drain. A vacuum pump 1 withdraws vapor from tank 13 and after passage through cooler 15, the mixture of gas and liquid condensate is discharged into a second separator tank 16. Gas from tank 16 then passes up through line 17 to the earths surface and may there be treated for the extraction'of gasoline by any suitable system. The system shown comprises a compressor 18, cooler 19, and condensate separation drum 20 from which gas is withdrawn by line 21 and liquid to storage (not shown) by line 22.
Two liquid pumps, 23 and 24, are provided to force liquid from-drums l3 and 16 respectively to earths surface by lines 25 and 26 to storage (not shown).
In Fig. 3 a modification of the collection method is shown. Collection pipes 10, sealed into the rock at 11 are fitted with ejector nozzles 27, the collection pipe entering the nozzle at the side at about the point of minimum cross sectional area, as will be understood. High pressure gas is fed to the nozzles by supply pipe 28 and the flow is controlled by a valve 29. Steam may be used as the high pressure medium, if desired, but preferably gas from the gasoline recovery system is compressed to a suitable pressure and returned to the mine by pipe lines (not shown).
In Fig. 4, my method is applied to an outcropping stratum A, bounded as before by cap rocks B and B. Shaft 1 and tunnels 6 may be omitted in this case and a large, long cavity 12 is driven directly into the stratum A. It will be understood that this method is to be applied to an oil sand relatively free of gas, either so by nature or by long application of vacuum according to present practice. If gas is present in moderate or large quantities, a tunnel may be dug above or below the stratum A, as in Fig. 1. Cavity 12 may go back into the sand for a considerable distance and many such cavities may be provided at short intervals, horizontally and vertically if the stratum be large, although only one is shown in Fig. 4. The opening of cavity 12 is closed by a material ll -impervious to oil and gas, such as cement, and a pipe 10 is sealed in for removal'ofvapor. Pipe 10 com-- municates with separator drum 13, vacuum pump 14, cooler 15 and condensate drum 16, as shown in Figs. 1 and 2.
I have observed that it has been impossible.
, heretofore to maintain a high vacuum on any considerable body of sands. This is due to the frictional loss caused by passage of vapor through a relatively thick stratum of sand,'
and because of the fact that the area of exposed sand is relatively small. The production of volatile vapors is also greatly restricted. By my method, however, it is possible to greatly increase the area through which vapor is passed and to also greatly reduce the thickness of the layer through which it passes. It is therefore capable of producing vapors from the sand at a rate which is much greater than is heretofore obtained. Vacuua of 29 to 29.5 inches of mercury are maintained on large areas with large yields of vapors. It is highly desirable to prevent all leakage of air or other gas into the producing stratum, particularly in the neighborhood of the vapor i cs 10. Old oil wells and out-cropping shoul preferablybe sealed.
It is desirable to automatically control the ventilating fan 6 by the analysis of the gas in the mine, whereby the concentration of methane and the like may be kept below the dangerous limit. The tunnels'may also be constructed in anysuitable manner and need not be made strictly according to the description, although that method is preferred.
My invention is not to be limited by any theory of the operation of my process nor by any illustrative example, but only by the following claims in which I wish to claim all novelty inherent in the invention.
1. Process for obtaining hydrocarbon vapor from a stratum containing the same, comprising forming mine galleries adjacent the stratum, removing large amounts of solid material from the stratum ata plurality of points, whereby extended areas are laid open to the influence of reduced pressure, inserting pipes to tap said extended areas, flowing a stream of high pressure gas in a generally downward direction adjacent the point of outlet of such pipes and in communication therewith, whereby a high vacuum is produced in said extended areas, withdrawing the hydrocarbon vapor with the high pressure gas, and recovering condensable constituents from the mixture.
2. Process for obtaining hydrocarbon vapor from a stratum containing the same, comprising forming mine galleries adjacent the stratum, removing large amountsof solid material from the stratum at a plurality of points, whereby a corresponding plurality of extended areas are laid open, inserting pipes to tap said extended areas, flowing a stream of high pressure gas adjacent the point of outlet of such pipes and in communication therewith, whereby a high vacuum is produced in said extended areas, withdrawing the hydrocarbon vapor with the high pressure gas, recovering condensable constituents from the mixture, compressing the residual gas, and returning at least a portion of the same to the stratum as said stream of high pressure gas.
3. Process according to claim 2, in which the high pressure gas is caused to produce a vacuum in the extended areas of about 29-29.5 inches of mercury.