US1812305A - Recovery of oil from the earth by mining operations - Google Patents

Description

L. RANNEY 1,812,305

RECOVERY OF OIL FROM THE EARTH BY MINING OPERATIONS `lune 30, 1931.

3 sheets-sheet 1 @Qu bUbQO MDN WHW/FN m A/V//Qn L. RANNEY June` 30, 19.31.

RECOVERY OF OIL FROM THE EARTH BY MINING OPERATIONS 3 Sheets-Sheet 2 EXF1/L S/ON Filed Aug. 5' 1925 E o RANNEY 5140014150@ i.. RANNEY June 3o, 1931.A

`RECOVERY OF OIL FROM THE EARTH B Y MINING OPERATIONS 3 Sheets-Sheet 5 Filed Aug. 5' 1925 QSSSQN NOON RSU NNOJ LGR/miv anne/nto@ NNUONN RY MOON RSU NHO- l l r l l l l @n WKO Patented June 30, 19.31

`UNrraD y STATES LEO RAN'NEY, OF GBEENWICH, CONNECTICUT, ASSIGNOB TO STANDARD COMPANY, A CORPORATION OF' DELAWARE PATENT OFFICE DEVELOPHEN T RECOVERY OF OIL FROM THE EARTH BY IINING OPERATIONS Application med August 5, 1926. Serial No. 127,233.

This invention relates to the recovery of oil from the earth by mining operations including the formation 'fof' a vwork-ing area, adjacent to but spaced from an oil-bearing stratum or oil sand, from which area expulsive Y nection with the accompanying drawings,

in which Fig. 1 is a fragmentary dlagrammatic v ertical section through an instal ation in which a shaft and mine gallery or tunnel are pro- 17 vided; U

Fig. 2 is a plan view of an oil recovery s stem, the plane of the view being taken online II-II, Fig. 1;

Fig. 3 is a partial vertical sectlon through an alternative form of installation comprlsinv chambers formed in the oil sand;

2Fig. 4 is a complete plan view correspondin to Fig. 3; and

Fig. 5 is a vertical section showing the c'method of tapping gas sands to secure a suppl of expulsion agent. l

Iteferring to Figs. 1 and 2, reference numeral 1 denotes a mine shaft passing throu h an upper ca -rock 2 and an oil sand 3. T c shaft is sea ed from the oil sand by a concrete wall 4, or other suitable means. A mine gallery or tunnel 5 is driven from the bottom of the shaft 1 through the lower cap-rock 6, or other impervious stratum underlying the oil sand. 'Ihe allery is preferably extended along each e ge of the track to be worked, for instance a forty-acre unit, in the general manner shown in Fig. 2. A suitable number of more or less centrally located wells, for instance the iive wells designated 7 8, 9, 10, and 11, are drilled from the earth surface to tap the oil sand.

A pi e 12 is laid horizontally throughout the alltery 5 and has branch nipples 13 sealed 5 in t e lower cap-rock 6 by sealing material 14. Each of the nipples has a valve 15 of the gate type. Holes or mine wells are drilled through the nipples into the oil sand, the drill being inserted through the outer end of the cross fitting 16 provided at the base of each nipple. In my Patent N o. 1,634,236 granted June 28, 1927, ofwhich the present application is a continuation in part, I have described in detail the formation and operation of mine wells of the type referred to.

' A suction pump 17 is connected to the pipe 12 and forwards the iiuid entering that pipe through a connecting pipe 18 to the surface storage tank 19. A pipe 20, connected to aA source of the expulsion agent (gas, air, water, etc.), is connected to the pipe 18. valved by-pass 21 is provided for carrying the expulsion agent around the suction pump In the operation of the installation described I prefer to proceed as follows: First strong suction is applied to the pipe 12 and the nipples connected to it. In this way there is soon formed an unexcavated drainage tunnel (area from which oil has been largely exhausted) extending entirely around the tract being worked. Since the mine wells tap the bottom of the sand at numerous closely spaced points, the evacuation of oil is rapid and quite complete for a considerable distance from the. gallery. The oil collected is forwarded to the storage tank 19. The iow of oil from the mine wells may be controlled, and heat may be applied, as described in Serial No.,14,448 above referred to, but in most fields this expedient will not be necessary for the purposes of the present invention.

When the unexcavated drainage tunnel has been established around the tract to be worked, an expulsion agent, for example air or a special gas which breaks the surface tension of oil adhering to the sand grains is forced through pipes 20, 18 and 12 and nipples 13 into the oil sand 3. A wall of air is thus formed around the tract, enclosing the oil and forcing it along lines converging towards the center. The nipples should be placed suiiiciently close together to ensure that the air or gas injected from each overlaps with that injected through the adjacent tween the tract being worked and those ad-v jacent it. Differences in porosity of the sand at various points of the tract may require that valves in different mine wells be partially closed to` admit less air. means by which to control the direction of the wave of air or gas in the sand, so that it may reach all points.

During the forcing in of the air some oil is likely- 'to drain into the mine wells. This oil may) be collected in one or more tanks 20 and su sequently forwarded to the main collecting tank 19. v Separate pipe systems for withdrawing oil and introduclng the expulsion agent may be provided, but this is gen- 'erally unnecssary.

The four outer wells, 7, 8, 9 and 10, first receive the oil as it is forced inwardly from the boundaries of the tract. When air begins to be discharged from these wells they are closed and the central well 11 is used for the withdrawal of oil. However, variations in the porosity of the sand might alter the arrangement of producing wells.

By applying-the expulsion agent in the manner described I' secure a very complete recovery of the oil. The expulsion agent operates upon a body 'of oil which is continuo'usly becoming denser and which is continuouslyy filling any voided streaks of sand-and,

therefore, is effectively displaced by the agent. This method eliminates any by-passing of oil, such as occurs when applying air on a lengthening or a stationary line of attack. I operate witli a constantly shortening line of attack upon the oil sand.

For best results the mine wells should bel drilled entirely around the producing area, but some of the advantages of the invention may be obtained with other arrangements. For example, an expulsion agent introduced through mine wells on two or three sides of the area will permit a high recovery of oil from the sand.

According to Figs. 3 and 4, there is illustrated a mine allery or a tunnel 21 of the -type above re erred to, connected with a chamber 22 formed in the oil sand itself.v

The chamber is walled with concrete Vor the like 23 so as vto seal .it from the oil sand.

Holes 24 are drilled from the chamber in a generall horizontal direction along two or more si es of the tract to be worked. I prefer to form one of the chambers at each of .the four corners of the tract, as shown in Fig. 4, the holes 24 extending from each chamber approximately half-way along thesides of the tract.

The holes 24 are conveniently formed by 55 inserting a drill through the nipple 25 sealed This givesv inthe wall of the chamber 22.4 The nipple is connectedwith a fitting 26, havinl a gate valve 27 and end closure 28.adapte to permit assage of the drill. Additional sections of rill stem are added as the drill penetrates. the sand, and it is practical to form horizontal openings of the required lengtln After removal ofthe drill the expulsion agent is suppliedthro- ughpipes 29 and 30 to the header 31, from which it passes into the nipples and thence into the open holes extending through thesand. Suction ma be prelimmarily applied to pipe 29 to with raw oil draining into the open holes 24.

Mine wells may be provided in the tunnel vif desired. VVhere it 1s more enonomical to sink shaftsifor the construction of the several chambers'the gallery may be omitted. In my application Serial No. 100,531,` filed April 8, 1926, a general method of operating with the use of chambers inthe sand is described and claimed. The utilization of this processherein is in the supplying of an expulsion agent continuously along the bottom of the sand and with a continuously shortening line of attack upon the oil sand.

Test pipes 32 (Fig. 1), each carrying a tluidvgauge 33 and a pressure gauge 34, are

preferably provided rat numerous levels in t on the first mentioned side reading higher than those on the other sides. The pressure under which the expulsion agent is supplied will be modified so as to equalize this difference and secure a substantially uniform advance toward the center of the tract. The amount of pressure necessary will vary greatly with conditions. A pressure of lbs. per square inch maintained adjacent the gallery will be adequate for the average oil sand. Test pipes should be placed at least every-300 or 400 yards throughout the extent of the galleries. The use of these pipes is described and claimed in my application vSerial No. 116,857 filed June 18, 1926.

While air 'has been chiefly mentioned as an expulsion agent, others may be more suitable under certain' conditions. -Gas and water may be convenietly used. Where one or more gas sands are adjacent the oil sand, it is convenient to secure the gas in the general manner shown in Fig. 5. In this figure a gas line 35 taps the as sand 36and is connected to a pipe 37 which delivers into the nip les 38. Assuming that there is also an un erlying gas sand 39, this may be connected with the pipe 37 by a pipe 40. Valves 41V and 41 and pressure gauges 42 and 42 are provided on the gas lines 35 and 40, respectively.

It is sometimesdesirable to ream out an opening about the inlet ends of the gas lines, as shown at 43 and 43', Fig. 5. A better flow of gas is obtained in this way. Flow of oil may be expedited also by reaming chambers 44 at the inlet of each mine well. g

I prefer to operate from beneath the4 oil sand in most cases, but where difficulty of tunneling or other causes makes this inadvisable, my method can be operated from a working area adjacent the upper surface of the oil sand. The preliminary formation of an unexcavated drainage tunnel is generally desirable, since a substantial amount of oil can be recovered as an incident to this operation. However, the expulsion agent may be forced into the sand' without preliminary withdrawal of oil, and all the oil may be driven tothe central collecting openings or oil wells'.

It will be understood that the number of mine wells may be varied greatly, the only requirement being that they be sufficiently close together to permit the formation of an effective wall of the expulsion agent introduced through them. In working a square forty-acre tract of a thick, highly consolidated oil sand, I prefer to make about 132 mine wells' on each side, the wells usually being equally spaced along the sides.

Various changes and alternative. arrangements may be made within the scope of the appended claims, in which itis my lntention to claim al1 novelty inherent in the invention, as broadly as the prior art permits.

I claim:

1. In the recovery of oil from an oil-bearing stratum, the improvement which comprises forming a mine gallery along the margin of the tract to be worked, the galler bel ing adjacent said stratum but spaced t erethe center of'said area, and withdrawing the n oil from said well.

4. Method according to claim 3, in which the oil-expelling agent is gas obtained from a stratum adjacent the oil sand.

' 5. Method'according to claim 3, in which the oil-expelling agent is supplied under pressure regulated in accordance with conditions in the sand, as indicated by test devices inserted therein.

' LEO RANNEY.

from by material substantially impervious to fluid, tapping said stratum from the gallery by a large number of closely spaced openings, drilling a surface well to the stratum within the area defined by the gallery, and introducin a fluid oil-expelling agent through said c osely spaced openings, thereby forming a fiuid barrier moving inwardly from the margin of the tract to force the oil there-v in throuirh the surface well.

2. Method of recovering oil from a selected areaof an oil-bearing stratum, comprisingl forming a mine gallery adjacent to but below or above said area, said gallery extending about the margin of the area, forming a large number of closely spaced openings from the gallery into the olcaring stratum, drilling a surface well within said area, withdrawing oil from said openings to form an unexcavabed drainage tunnel, then forcing an ex-

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