US1660818A

US1660818A - Apparatus for recovering oil

Info

Publication number: US1660818A
Application number: US711596A
Authority: US
Inventors: Ranney Leo
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1924-05-07
Filing date: 1924-05-07
Publication date: 1928-02-28
Anticipated expiration: 1945-02-28

Description

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L. RANNEY APPARATUS FOR RECOVERING OIL Feb. 28, 1928.

Patented Feb. 28, 1928.

UNITED STATES PATENT OFFICE.

LEO RANNEY, or JAeKsBoRo, TEXAS, AssIGNoR To STANDARD O'II. DEVELOPMENT GOMPANY, A CORPORATION. or DELAWARE.

APPARATUS FOR Application led Hayj?,

and is trapped or held by the characteris-4 tics and position Of neighboring strata of the earth. The oil bearing sand is found at various depths and invariably lies beneath what is called a cap rock, an essential characteristic of which is its impervious nature causing it to trap and confine beneath it in the porous sand oil, gas and sometimes'water. Usually the oil 1Jsand lies above a similar impervious bed rock which has prevented penetration of the .oil down- Wardly into other strata.

The usual method of oil recovery consists in sinking a,plurality of wells (usually four to six inch casing pipes) to the upper cap rock above the oil bearing sand stratum, setting the casing upon the cap rock, and then drilling a smaller hole through the cap rock into the sand. As before stated, from each well are first' collected the gas and oil which are caused to flow because of the pressure of the free gas or the gas absorbed inthe oil or contained in the pores of the sand.

Among the several serious .problems presented to the operator of such an oil well is the accumulation in the well apparatus of water, paratlin, sand and muck, which pass through the sandinto the well and casing. As a result of this accumulation of bottom settlings, sand and muck, the tubing, work-` ingbarrels, pumps, etc. have'to be periodically pulled and the wells cleaned out, at great labor expense and loss 'of productive time.

A second problem presented is the disposition of the gas delivered into the wells and the oil pipe line fromthe oil bearing sand. Even in an exhausted field there is some gas present, and many methods have been tried in an attempt to save this gas for commer' cial purposes, all of which methods have been more or less unsuccessful. Among the methods that have been tried is'the collection of l this gas in gas-proof oilstorage tanks, but thefgas in. these tanks not only exerts a back 4pressure against the oil, but much gas is lost and also these tanks are a constant source of danger.

RECOVERING OIL.

41924. serial No. 711,596.

A third problem presented is the accumulation of paraiiin in the oil bearingy sand at the point or pointsl of Withdrawal ofthe Oil, and on pumps, valves, working barrels and tubing. As a result of these parain accumulations, the valves and tubing, and the Sand opening or openings are often closed and the flow of Oil into the oil line 'thereby prevented.

Experience shows that when the upper cap .rock is punctured by a well tube, the

oil is caused to. flow into said tube by the pressure of free gas which may havev collected above the oil, but more important, by the continuing pressure of the gas absorbed or held in the oil lor trapped in the pores of the sand, and thepressure ofwhich gas is applied more and more to the oil as the latter is wit-hdrawn from the porous material in which it lies. Another force tending to cause lo'w of the oil tothe surface is the hydrostatic pressure of water be.- neath it. After a time, however, artificial stimuli are necessary to produce a further fiow or to increaseA a weakone. Y When the flow diminishes, the internal pressure is usually accentuated by the application to the well of a suction or vacuum pump. Recovery sometimes has also been increased in 'an abandoned, exhaustedor dying field by 'application of compressed air or water under pressure introduced to the porous sandl through one or more selected wells to in crease the flow from other wells.

TheV object of the present invention is, therefore, to successfully solve the above and other problems presented in the recovery of oil by means of wells by the separation from the oil, before delivery to the earths surface, of gas, water, sand and muck, the gas being separately piped to the surface of the earth Where it is stored, in suitable reservoirs for future commercial use. `By separat-ing the sandl and muck from the oil practically immediately after delivery into the oil line from the oil beari sand, the frequent pulling. of the tubing,

working barrels, pumps, etc., to clean out the oil bearing sands at the oil receivin nipples of the oil line and elsewhere, an the melting of parafn if it has already so accumulated, by periodically flushing with live steam the oil line and its oil receiving nipples. This steam ushing not only solves the parallin problem but also serves as a means for heating the oil bearing sand, particularly adjacent the oilreceiving nipples, which materially reduces the viscosity of the oil and thereby expedites its flow. At the same time the as releasedbythe heated oil becomes an 'a ditional expulsive force t0 drive the oil from the sand.

A further object of the invention is to increase the eectiveness ofsuch artificial` stimuli, as com ressed air and water under pressure, by in]ecting either of these medi ums into the oil bearing sand by means Aof rows of injection nipples which rows are alternately arran ed wlth rows of oil receiving nipples, .t at is a row of injection nipples and then a row of receiving nipples. The oil in the oil bearing sand is, therefore, driven to the right and to the leftby each row of injection nipples and to the two rows of oil receiving nipples at the sides thereof, thereby materially producing or in- -creasin the flow ofoil into the oil line.

Furt ler objects-of the invention are in part obvious and in part will appear more in detail hereinafter.

In the drawin Fig. 1 represents a sectional elevation i ustrating one embodiment of my invention; Fig. 2 is -a s'ectronal plan view on the line 2-2, Fig. 1; Flg. 3 is a vertical section through one of the control valves.

Referring to the drawing, 1 represents a central shaft `extendin downwardly from the surface of the eart 'through the overlying strata to the region of the oil bearing porous material, such as sand, sandstone, v or the like', said material being generally indicated at 2. The depth of the oil bearing sand varies but in any event the shaft is sunk according to the usual methods of mining to a level adjacent the porous sand, either above or belowthe same. In the specific arran ement here shown, said shaft terminates elow the upper cap rock 3, being provided at its bottom with an enlarged laterally extending portion 1 which is formed either entirely wlthin the can rock, or, if it enters the oil sand, is spaced therefrom b impervious material 1". While a mine sha t is here illustrated, it will be understood that in some fields a drift mine may be preferable or necessary.

Extending laterally from the upper end Y portion of shaft rtion 1 and along the upper surface of t e upper cap rock 3, is a branch shaft or tunnel 4, from one or both sides of which extend a plurality of substantially parallel tunnels, four such tunnels being here shown' which extend from the same side of tunnel 4. In the resent embodiment, the first and third o these tunnels', when viewed from leftto right in Fig.

2, are the oil receiving tunnels and are in'- dicated by the reference ,numeralv 5, while the second andv fourth tunnels are the stimuli `injection tunnels andarefindicated by the nipples 8 extend through the upper cap 'rock- 3 down into the oil bearing sand, forming mine walls, the flow through eaghni ple being controlled by its ind1vidual1-vav I the sand around the oil receivin nipples is particularly loose, suitable cylin rical screen members may be associated. with said nipples to prevent the clogging up of the same with the sand particles.

As shown'in Fig. 3, the valves used in the present' installation are. preferably of the well-known gate type and are installed in cross fittings 9. Opposite aims of the crossl fitting receive the ends of pipes forming part of the oil collecting conduit 10. The lower arm of the fitting is connected to a nipple 8. Other suitable valve connections ma be used.

xperience has shown that the oil in the o1l bearing sandis forced into the oil rece1v1ng nipples 8 of the oil pipes 7 by the pressure of free gas which may have colected above the oil, but more important, by the continuing pressure of the gas absorbed or held in the oil or trapped in the pores ofthe sand, and in some instances, by hyvdrostatic pressure. The oil flows throughl pipes 7 into a substantially horizontally dis- .osedplpe 10 arranged in tunnel 4 and is devvere by the latter pipe into the upper lend portion of a separator 11, suitably arranged within the lateral shaft portion 1*. Hori- 'zontally mounted Within the casing of said separator just below the inlet of ipe 10 are one or: more baiing screens 12, vt e purpose of whlch is to agitate the oil fallingthereon and effect the release therefrom of some gas absorbed orheld thereby. The gas delivered into the separator with the oil and the gas" released from ythe oil by the baille screens,

pass from the separator throu kh the gas pi el line 13 and are delivered t ereby to t e earths surface, where the gas is stored in suitable tanks or reservoirs. The saving of this gas for commercial purposes materially increases the financial returns from the oil recovery-operations, and lnasmuch as the gas is sealed from the branch tunnels andthe central shaft at all times, the latter/f are more comfortable and there is Ano vdanger of explosions or otherwise.

The as pipe line 13 is provided, of course, prefers. ly, vadjacent lthe separator, with a suitable valve 14 for controlling the flow of gas therethrough.

` The water, sand and muck delivered into the separator withthe oil fall to the bottom lof the separator, from which they may be upper end portion of a suitable sump 18, the

purpose of the Siphon being' to prevent the passage into the sump of gas from the separator. A by-pass 35 (Fig. 1)' is provided for supplying steam from line 35 to the nipples 8. The oil delivered into the sump passes upwardly through a vertically disposed pipe 19 arranged within the sump and thence into a horizhontally disposed pipe 20 leading to a suitable pump 2,1. Connected to said pump is an oil delivering pipe 22- extending through the central shaft 1 to the earths surface, where the oil is stored in suitable tanks or reservoirs (not shown) As before mentioned, the oil, with its sand, water, muck and gas content,- is forced up intov the'oil pipes and 10 by` the pressure of the gas between the upper and lower cap rocks; sometimes by hydrostatic pressure below the oil, or by the application to the oil bearing sand of artificial stimuli hereinafter described. One or more of these forces produces a ow 'of oil in the pipe line and causes the deliver to the earths surface of the separated gasand oil. By separating the gas from the oil, the former is saved for commercial pur oses, and by separating the water, vsand an 'muck from the oil, the necessity of frequently cleaning out the wells, tubing, working barrels etc., at great expense, is. avoided,l the water, sand and muck being left at the base of the shaft or being otherwise suitably disposed of.

In order to produce a flow of oil into the oil line or to expedite or increase a weak flow, a vacuum may be placed in the oil line, preferably in a manner so that the separator and sump are cutout and are thus notsubjected to the vacuum and need not, therefore, be specially built to withstand it. In the present embodiment, the Vacuum line 23 is connected to the oil pipe just before it reaches the separator 11 and to the oil pipe 20 between pump 21 and sump 18. Pipe 2O is provided between the sump and the point of connection with the vacuum line with a suitable valve 24. andA pipe 10 is provided between the separator 11 and the point of connection of the vacuum line with a suitable valve 25, which valves enable the sump and the separator to be shut ofi1 from the oil line when the vacuum is on. When a vacuum in the line is not necessary, the valve 26 of the vacuum line'will bev closed, and the oil line valves 24 and 25 open.. The pump 21, of course, will be in operation only when necessary to pump oil from the sump or to produce a vacuum in the line. It is to benoted that when the vacuum is on, the valve of' regular oil pump 21 will be bathed in oil, which in a small installation makes an ordinary oil pump suitable for a vacuum pump, thereby obviating the necessity of a regular vacuum pump with valves operated by springs, etc.

If a vacuum. is necessary or desirable in the line and there is considerable sand, muck, and water being delivered with vthe oil into the oil pipes 7 and 10, a suitable collector or reservoir for these .foreign contents can be connected to the oil line.

.In the specific embodiment here shown, a reservoir 27, suitably arranged within the lateral shaft portion 1a, is connected by means of a. pipe 28 with the oil pipe 1,0 justbeforeits connection to the vacuum line 23. The sand, muck and water will be collected in this reservoir and can be periodically withdrawn therefrom through the discharge pipe 29 at the lower end thereof, the passage through said pipe being controlled by al suitable valveA 30. The pipe 28, by means of which thel reservoir is connected to the oil line, will also/be provided with a suitable valve 31 for controlling the flow therethrough. This valve will, of course, be closed and the reservoir thus cut off when it is not needed, such as when a vacuum is not on and the separator 11 therefore in use. One of the advantages of separating the water from the oil before,passing into the pump 21 is that they will not be churned together and the oil thereby emulsified. In a big operation, a separate pump may be installed for the water, as will be readily understood. i

As before stated, experience has shown that the oil will -be forced through the oil receiving nipples 9 into theoil pipes 7 by the pressure of free gas which may have-collected above the oil, but more important, by the ycontinuing pressure of the gas absorbed or held in the oil or trapped in the rvpores of the sand, the pressure of which gas is applied more and more to the oil as the latter is withdrawn from the porousxm'ateally being in `the form of compressed air,`

gas or water under pressure which are injected into the oil bearing sand, the injection of water being particularly advantageous in fields underlain with salt water.

In order to increase the effectiveness of these artificial stimuli, the compressed air,

gas or water is injected into the oil bearing sand at a plurality of points arranged.

in substantially parallel rows, as the movement of a fluid through vsand or other porous material is much more rapid where a large body of the fluid is moved at one time. In the preferred arrangement, the injection rows and the rows of oil receiving nipples are alternately arranged. For example, a horizontally disposed pipe 32 is arranged in each injection tunnel (i, said pipes being provided with a plurality of suitably spaced injection nipples 33 which extend'down through the cap rock 3 into the oil bearing sand, each of said nipples being provided with a suitable valve 33L for controlling the fiow therethrough. Compressed air, gas or water under pressure is supplied to these pipes 32 by a pipe 34 connected thereto, which in turn is suitably connected with a source of compressed air, gas or water at the earths surface, or elsewhere. Thus,'in the arrangement shown in Fig. 2` the rows of injection nipples 33 and the rows of oil receiving nipples 9 are alternately arranged. lVith such an arrangement, the oil in the oil bearing sand will be driven to the right and to the left of each row of injection nipples and to the two rows of oil receiving nipples at the sides thereof. The simultaneous injection of such artificial stimuli at a plurality of points arranged in rows with the rows of oil receiving nipples alternately arranged therewith produces a surprisingly rapid flow of oil which ilow can be still further increasedfif desired, by a vacuum in the oil receiving line.

vIf desired, the injection nipples might be so arranged as to extend through the upper cap rock 3 into the oil bearing sand while the oil receiving nipples might extend up- 4wardly through the lower cap' rock (not shown) into the oil bearing sand, the force of gravity, with such an arrangement, assisting in producing a How of oil into the oil line'. If a large field is to be operated, the injection nipples, if for water, might be arranged at the margin or the edge of the field so as to force the oil inwardly to the central portion of the field, where the oil receiving nipples might be located, but when compressed air or gas is injected, the injection nipples should be placed near the top of the sand structure and the oil receiving nipples nearer to the edge.

In order to melt paraffin accumulations at the oil receiving nipples 9 and elsewhere` and to prevent the further accumulation of paraffin, the oil line with its oil receiving nipples may be periodically flushed out with live steam. v

In the specific embodiment here illustrated, there is arranged within the laterally extending tunnel 4, a steam pipe 35 which is suitably connected to a source of steam supply, located-at the earths surface or elsewhere. Extending from this steam pipe 35 into each of the laterally extending oil tunnels 5 is a branch pipe 36, the rear end of which communicates with the rear end of the oil receiving pipe 7 in that tunnel. The live steam introduced into these oil receiving pipes 7 will flush in turn the oil receiving nipples .as the steam passes through the oil receiving pipes 7 to the oil pipe 10. If desired, the water of condensation in the oil pipe 10 can be separated from the oil before the waterA and the oil are churned together by the pump 21, if it is operating, and especially so if the oil has a tendency to emulsify.A

The flushing of the oil pipes 7 and their oil receiving nipples 8 with live steam not only solves the paraffin problem but also provides a means for heating the oil bearing sand, especially adjacent the oil receiving nipples 8. By so heating the oil` bearing sand, the oil therein is rendered less viscous and its flow through the oil bearing sand materially expedited, moreover, the gas released therefrom becomes an added expulsive force. In order to more thoroughly heat the oil bearing sand, the oil receiving nipples may be provided with suitable heating devices, such as electrical heaters, containers for dry steam, chemicals, etc.

While .I have illustrated in the drawing an arrangement for separating from the oil its foreign content, both fluids and solids and either with or without a vacuum in the line,'it will be understood that the particular conditions at any one field may make a vacuum at all times advisable, so that the separator 11 and sump 18 may be omitted'. Or, on the other hand,'a vacuum may be unnecessary and the vacuum line 23, and pump 21 and reservoir 27 omitted.

Other advantages of the invention will be/ apparent to those skilled in the art to which it relates.

What I claim is:

1. In a mine gallery installation for recovering oil from an oil-bearing stratum, the combination of mine wells, an oil collecting conduit connected to said mine wells, lifting means adjacent the stratum for raising the oil to the earths surface, and means for separating the oil from emulsion-forming substances before the oilenters the lifting means.`

2. In a mine gallery installation for recovering oil froman oil bearing stratum, the combination of mine wells, an oil collecting conduit connected to said mine wells, a separator into which said conduit discharges and arranged adjacent the stratum,

lecting conduit.

separated oil from the separator t0 the earths surface. l

3. An installation according to claim 2 in which a sump 'serving as an oil reservoir is arranged between the separator and the pump.

4. Installation according to claim 2, in which a suction line is connected to the oil collecting' conduit at a point between the mine wells and the separator, and valve means are provided for cut-ting said separator and pump out of circuit with the oil co1- 5. In a mine gallery installation for recovering oil from an oil bearing stratum, the combination of a series of mine wells forming the only inlet for fluids from said stratum to said gallery, an oil collecting conduit connected to said mine wells, a second conduit connected to said mine wells for sup" plying steam thereto, a separator into which said oil collecting conduit discharges and arranged adjacent the stratum, pipes connected to the separator for withdrawilngr respectively gas, oil, and solid or. liquid substancesv contaminating the oil, and a pump and pipe line arranged to forward the separated oil to the earths surface.

6. In the reeoveryof oil from an oil bearing stratum to which access is gained by a mineshaft, and tunnels excavated at an angle thereto, the combination of mine wells, an oil pipe line disposed within said shaft and tunnels and provided with a plurality of oil receiving nipples enteringthe mine wells,

and a live steam supply lineA connected to said oil pipe line for lushing out said line and the oil receiving nipples and mine wells.

7 In the recovery of oil from an oil bearing stratum to which access is gained byv a mine shaft, and tunnels excavated at an angle thereto, the combination of an oil pipe line provided with a plurality of substantially parallel rows of inlet openings for receiving oil from the oil bearing stratum, and

a second pipe line provided with a plurality of substantially parallel rows of discharge openings for introducing a fluid medium into the oil bearing stratum so as to facilitate the flow of oil to said oil receiving openings, the rows of inlet openings and the rows Vof discharge openings being alternately ara second pipe line also disposed within said mine shaft and tunnels and provided with a row of injection nipples for introducing a fluid mediuminto the oil bearing stratum so as to facilitate the flow of oil to said oil receiving nipples.

9. In a mine gallery installation for recovering oil from an oil sand, the combination of a series of mine Wells, an oil collecting conduit connected to said mine wells. a second conduit also connected to said mine wells for supplying steam thereto, a pipe in generally spaced parallel relation to 'the oil collecting pipe and having branches entering the oil sand, and means for supplying a flow stimulating agentto said branches.

10. Installation according to claim 9 in which pipes for collecting oil and pipes for supplying the How stimulating agent are ar ranged respectively in several pairs of generally parallel galleries.

11. In a mine gallery installation for recovering oil from an oil bearing stratum, the combination of a stimulus line, an oil collecting line, a series of openings sealed from the gallery and extending into the stratum, said openings being connected alternately to the stimulus line and the oil collecting line.

In testimony whereof I hereby aflix my signature. y LEO RANN EY.