US 3774685 A
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PATENTEUHHVZ? ms v 3; 774.685
OIL MOP METHOD AND APPARATUS FOR PRODUCING AN OIL WELL An object of the present invention is to-produce crude oil from relatively shallow, i.e., 200 feet to 2,500 feet deep, oil wells. I-Ieretofore, it has not been economically feasible to produce crude oil from certain of these shallow wells because of the very high viscosity, i.e., 50,000 S.U.S., of the oil, the very low oil-water ratio where it is not economically feasible to pump the large quantities of water necessary to produce a suitable quantity of crude oil and in combination the disposition of the pollutants, i.e., salt water brought up with the crude; a combination of two or more of these factors.
Another object of the invention is to provide a method of selective sorption of the oil, consequently mitigating the quality of water brought to the surface of the earth in a mop where whence the mop is cleansed of the oil and paid back down the hole to pick up additional oil.
The quantity and quality, i.e., water-free of the crude oilproduced by this new invention will vary with several factors including, but not limitedto, the size and speed of the mop; viscosity of the oil; efficiency of cleansing the mop; the oil-water ratio; the porosity of the surrounding crude oil-producing geological structure which determines the rate at which the oil will flow to the mop; the mechanical arrangement of the downhold easements.
The mop consists of petrophilic hydrophobic'fibers, such as polypropylene or similar material approximately 3-mils thick by 16 inches wide, by 4 to 16 inches long, interwoven into a l/l6-inch diameter to l-inch diameter wire rope or'rope, weighing approximately 0.0. pounds to L pounds per linear foot and approximately 400 feet to 5,000 feet long, and is of the type shown and described in my .copending U. S. Pat. application Ser. No. 52,448 filed July 6,.1970, entitled AN OIL MOP AND METHOD OF USING SAME.
With the foregoing and other objects in view, the invention will be more fully described hereinafter,and will be more particularly pointed outin the claims appended hereto.
In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views.
FIG. 1 is a side elevational schematic view of an oil well rig constructed in accordance with the present invention having'parts broken away and parts shown in section.
FIG. 2 is an end elevational view of the oil well and rig of FIG. 1.
FIG. 3 is a transverse section taken on the line 3-3 in FIG. 1.
Referring now to FIG. '1 of the drawings, the mop'10 is threaded through a system of sheaves and pulleys to a subterranean oil, or oil and water pool 11 where it will sorb oil. The mop is spliced end to end making it endless and rotativepower is supplied tothe pulley system to cause the mop to' travel continuously as an endless belt, up an eecentrically .mounted tubing stringer 12 through the pulleys and sheaves .and back down a casing 13 to a return idler sheave 14 mounted in a cartridge 15 submerged in or belowthesubterranean oil pool 11. As the mop 10 passes around the idler sheave 14 it is pulled through the oil, or oil and water, where it sorbs oil and tends to reject water. The portion of the endless mop 10 which has sorbed oil is pulled up through the tubing stringer 12 to the surface of the earth where it is guided through a system of squeegee rolls, constructed to pull and cleanse the mop by wringing out, washing out, blowing out, slinging out by centrifugal force, heated, or a combination of any of these methods into a collection pan 16 as produced crude oil. The unladened portion of the mop 10 is trained by a system of guide idler sheaves 17, 18 back to the casing 13 where it is pulled back down to the subterranean oil pool 11 to sorb additional oil and thence in continuous operation.
Referring to the drawings and to follow the path of the continuously operating mop l0 and to understand the function of each component, start where the continuously operating unladened mop 10 enters the casing 13. The approximately 4-inch to 24-inch diameter casing 13 has been implanted in the earth to a subterranean oil or oil and water pool 11. The casing 13 provides an annular space for eccentrically mounting the tubing stringer 12 and an enclosure for the oil ladened mop l0,-space for the unladened mop 10 to travel back to the surface of the earth, and as a guide and a lateral support for the return idler cartridge 15. After reaching the surface of the oil poolthe mop 10 is pulled through a return guide idler 14, mounted in the cartridge 15, to sorb oil for passage to the surface of the earth. The cartridge 15 is a multiple functioning device; i.e., it provides a support for the return guide idler 14, it provides .a means of adjusting the penetration into and/or below the oil pool 11 from'the surface of the earth by raising or lowering the tubing stringer 12, it is equipped with ports 19 that may be used to adjust the degree of sorption saturation of the mop 10 by either withdrawing the cartridge 15 into the casing making a ported valve of the ports between the cartridge 15 and casing 13 or submerging the cartridge .15 into the subterranean water 11 which again will make a ported valve out of the cartridge ports 19 byusing the oil-water interface as the body segment of the ported valve with respect to the oil, the casing also functions as a circular guide and horizontal support for the cartridge 15.
After'the mop 10 has sorbed crude, oil in the cartridge 15 the oil ladened mop 10 travels up the tubing stringer 12 to the earths surface. The tubing stringer 12 is rigidly attached to the cartridge 15 and by raising or lowering the tubing 12 the elevation of the cartridge 15 may be set. The tubing 12 serves as an enclosure for the oil ladened mop 10 to prevent the interchange of oil from the ladened mop to the cleansed mop. If the viscosity of the oil is relativelylow, flexible solid circular disc spacers 20 a few thousandths of an inch smaller in diameter than the tubing are attached to the wire rope, or the rope, to function as pistons in the cylindrical tubing stringer 12. If the discs 20 are installed, the sorbic properties of the mop would function to selectively convey the crude oil from the subterranean oil pool 11 to the vertical tubing 12 and thence most of the force necessary to convey the oil to the surface of the earth would 'be supplied by the discs 20. The sorbic material 21, such as fiberlated polypropylene may be sandwiched between the discs in lieu of interweaving it intothe wire or rope when the discs 20 are used.
As the mop 10 brings the, oil to the surface it leaves the tubing 12 and is guided by guide idlers 22, 23 to a set of squeegee rollers 24, 25 for wringing. The first set of squeegee rollers 24, 25 may be either variable purchase or constant purchase pulleys. One or more sets of the variable purchase squeegee rolls 24, 25 may be used to more evenly divide the power delivered to the oil ladened mop 10 for pulling it to the earths surface, reducing wear, and enhancing the mops life.
Referring to the drawing, roll 24 and roll 25 are mounted to receive power from their respective shafts through an overunning clutch. The shaft of roll 24 is driven in a reverse direction by a chain 26 and sprocket 27 from the shaft 28 of roll 25 and roll 25s shaft is chain and sprocket driven from a drive shaft 29 common to all other squeegee roller drives Roll 24 is bearing mounted on a pivoting frame that is bearing mounted to roll 25 s shaft and is free to rotate around roll 25 circumference to circumference.
When the frame is horizontal, the one point of contact between the mop l and the squeegee rollers 24, 25 provides a minimum, near zero, of power to the traveling mop 10. An outside force is applied to the frame rotating roll 24 in the upward direction so that roll 25 will always pull the mop directly out of the tubing 12. As roll 24 is rotated upward the mop is forced to lay, as it travels upward, first on roll 25 and then on roll 24. As roll 24 is rotated around roll 25 in a clockwise direction the system achieves its maximum purchase of the mop 10. By varying the degree of rotation of roll 24 around roll 25 first in a clockwise direction to increase the purchase and then counterclockwise to decrease its purchase, the degree of purchase may be varied and the amount of power added to the mop 10 therefore controlled. The variable purchase squeegee rolls 24, 25 also serve to wring the mop 10.
- The mop 10 leaves the variable purchase squeegee rollers 24, 25 and enters constant purchase squeegee rolls 30, 31, 32. The constant purchase squeegee rolls consist of the rolls 30, 31, 32. Roll 31 is spring or weight loaded to bear against rolls 30 and 32. The drive to these rolls drive them in unison with each other and in unison with all variable purchase rolls. The constant purchase rolls 30, 31, 32 add an almost constant amount of power to the mop l0 and provide a purchase on the mop 10 to overcome any upsets to the system.
Leaving the constant purchase system the mop 10 enters the guided take-up idler sheave 33 which takes up slack in the mop 10 due to the stretch in the cable or rope caused by the burden of oil on the upward leg of the journey. The idler sheave 33 is weight or spring loaded to position itself according to the stretch in the cable or rope which serves as an indicator to position the degree of purchase of the variable purchase rolls 24, 25 and to trip a clutch mechanism 34 on the drive on overload. This indicating signal could just as easily be obtained from the torque on the constant purchase pulley shafts or the current drawn by the motor, if the drive is electric.
The oil squeezed from the mop 10 by rolls 24, 25 and rolls 30, 31 and 32 is recovered by pan l6, and oil which otherwise would have been too expensive to recover has been saved.
What I claim is:
l. The method of removing oil from a subterranean oil pool comprising a. threading an endless mop of petrophilic hydrophobic fibers through a system of sheaves and pulleys to an oil and water pool,
b. driving the mop continuously through the pulleys and sheaves to raise the oil laden mop to the surface, and
c. removing the oil from the oil laden mop and collecting same while returning the cleansed mop to the subterranean pool to sorb more oil.
2. The method of claim 1 further comprising the step of sinking a casing through the earth to communicate with the oil pool.
3. The method of claim 1 wherein the endless mop of petrophilic hydrophobic fibers comprises a wire rope having polypropylene strips of the order of 3 mils thick by :6 inches wide and 4 to 16 inches long directly attached to said rope.
4. The method of claim 1 wherein the means for driving the mop continuously is a prime mover connected by clutch to drive squeegee rolls in positive driving and squeezing engagement with the mop above the ground for squeezing the oil from the oil laden mop prior to returning the mop to the oil pool.
5. An oil rig for removing oil from a subterranean oil pool comprising a. a casing communicating between ground level and an oil pool,
b. an endless mop of petrophilic hydrophobic fibers secured to a wire rope,
c. a system of sheaves and pulleys associated with said casing and-mop to cause the mop to travel continuously from the oil pool where it sorbs oil up the casing and back down to the oil pool,
d. squeegee means at opposite sides of the mop above ground for driving the mop to raise the oil laden mop to the surface and squeeze the oil therefrom prior to returning it to the oil pool, and
e. oil collecting means positioned above ground and beneath the squeegee means to collect oil brought to the ground leve and squeezed from the mop.
6. An oil rig as claimed in claim 5 wherein the casing has therein an eccentrically mounted tubing through which the oil laden mop is pulled to the surface prior to being subjected to the squeegee action of the driving rolls.
7. An oil rig as claimed in claim 5 wherein said squeegee means are two sets of opposed rolls between which the mop is passed, the first set of rolls being of variable purchase while the second set of rolls are of constant purchase.
8. An oil rig as claimed in claim 7 further comprising a guided take up idler sheave between the constant purchase squeegee rolls and the casing to take up slack in the mop due to the stretch in the wire rope caused by the burden of oil on the upward leg of the journey, and compensating means loaded to position itself according to the stretch in the wire rope which controls the degree of purchase of the variable purchase squeegee rolls and to disengage the drive to said rolls on overload.
9. The method of claim 1 wherein the removal of the oil from the oil laden mop is accomplished by a wringing action.
UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 774,685 Dated November 27, 1973 Inventor(s) HERBERT RHODES It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
The assi'gnee should read: OIL MOP INC.
Signed and sealed this 2nd day of April 19714..
EDWARD M.FLE TCHER,JR. Y I c. MARSHALL DANN Attesting Officer Commissioner of Patents