US1661270A - Method of plugging or packing off strata in wells - Google Patents

Description

March 928.

H. M. RYDER ET AL METHOD OF PLUGGING OR PACKING OFF STRATA IN WELLS Filed Jan. 19 27 Patented .Mar. 6, 1928.-

UNITED STATES PATENT 1 OFFICE.

HARRY HOYER RYDER AND EBEON J. BAILEY, F BRADFORD, PENNSYLVANIA, AS-

SIGNORS TO PETROLEUM RECLAMATION CORPORATION,

CORPORATION OF DELAWARE.

or new Yonx, N. Y., A

METHOD or rmresme on racxmc our s'rnA'rA In 'wn'mzs.

Application filed January 19, 1927. Serial No. 161,998.

well wall, which irregular shape may be due to many causes, as for example, cavlng,

shooting, etc. I

The general object of this invention isto provide an inexpensive,- reliable and efiective, method for sealing undesirable strata,

. regardless of the irregularity of the well wall, whereby such strata are rendered nonpermeable to water.

Other objectsand advantages of the Invention will become apparent from the 91- 26 lowing description, taken in connection wlth the accompanying drawing which is a diaammatic sectional view of a plurality of strata throu h which a well has been drilled, one of whic strata is shown as plugged or packed ofi according to the herein described method.

Although the method embodying this invention may be employed in connection with various types of wells, it will be described 85 particularly in connection-with a water intake well 10, such as is ordinarily employed in flooding processes for increasin 'oi recovery. The well 10 is illustrate as drilled from the surface of the ground to an oil bearing stratunr'of sand 11,.through. a

water bearing stratum 12, a porous stratum I 13 and other strata'14, 15 and 16 of various kinds. The well 10"is shown equipped with the usual well casing or tube 18, around I which are arranged suitable packers 19 and 20 of well known forms adapted to prevent water from being lost in the stratum, 15. The casing ortube18 is shown. provided with a plurality'of openings '23 and 24,.the

Q former of which open into the shot hole 22,

and the latter of. which open into the well 10 in thevicinity of the water bearing stra:

turn 12 and at a point above the packer 19. The casing 18 is shown surrounded at its top by the usual plug 26; and provided at a point just below the opening 24 with a suitableseat 27 of the type commonly known as the McGregor seat.

In a well of the type herein shown, which is ordinarily used in flooding processes for increasing oil recovery, water is eithen supplied. from a suitable source above ground or is allowed to pass from the water bearing stratum 12 into the well casing or tube 18, from which it escapes into the shot hole 22, from which it is forced, due to hydrostatic pressure within the well casing or tube 18, intothe oil' bearing stratum 11, I thereby forcing the oil along such stratum to other wells or pumping stations from 7 which the oil is recovered.

Should a well be so formed that communication is aflorded' between an oil bearing stratum and a porous stratum, which may or .may not be located contiguous to the oil bearing stratum, a large portion of the water employed in the above mentioned flooding process may be wasted by reason of its being absorbed in the porous stratum, thus rendering such flooding process more or less ineflicient due to-the impracticability of furnishing a sufficient supply of water to the well to overcome the amount lost through the porous stratum. Such a porous stratum 13 is herein shown contiguous to the oil bearing stratum 11, so that communication between these strata would be aflt'ordedthrough the irregularly 1 shaped .shot hole 22, if the stratum 13 were not sealed. The illustration shown in the 00 drawing furnishes a striking example of a possible condition under which it would be practically impossible to seal oficommunication between the, oil bearing stratum 11 and the porous strata- 13, by such packers of rubber or other material as have heretofore been employed. However,'with the method embodying this invention, communication between the stratum 11 and the stratum 13 may be, effectively closed. In carrying out this method, a pipe 25 is inserted into the well casing or tube 18 from the to thereof; this pipebeing provided at its ower end with a. packer 26, which is adapted to nest upon the seat 27, thereby tem orarily preventing water from the water earing stratum 12 from flowing down through the well casing or tube 18 below the seal afiorded between the seat 27 and the packer 26. With the water from the water bearing stratum 12 shut off from that portion of the well f casing orv tube 18 below the seat 27, such water as may remain within the well casing or tube 18 below the seat 27 drains into the strata 11 and 13 to a level, say in the plane of the bottom of the stratum 16. After the water level within the well casing or tube 18 has thus dropped a suitable sealing material 28, having. a lower specific gravity than the waterwithin the shot hole 22, is introduced into the pipe from any suitable source of supply. The sealing material 28 passes through the pipe 25 and into the wellcasing or tube 18, from which it passes through the openings 23 into the shot hole 22 containing water. Since the sealing material 28 is lighter than the water confined within the shot hole 22, such sealing material rises to the top thereof and displaces the water in the upper portion of the shot hole. In order to facilitate movement of the sealing material down through the pipe 25 and well casing or tube 18, when, for example, a natural head" of water exists in the well and extends a suflicient distance above the oilbearing stratum 11 to interfere with the downward movement of the sealing material, the upper end of the pipe 25 may be closed, for example by means of'a valve 30 and fluid pressure, such as air pressure from a suitable. source, not shown, may be placed in communication with the pipe 25. through a suitable connection 32 which may be provided with a valve 33 adapted to be opened g and closed as-conditions may require. The

fluid pressure thus applied-to the top, of the column of sealingmateria'l'28 serves to force the sealing material down through the pipe 25 and well casing or tube 18 and into the shot hole'22. The sealing material 28 is pref :r-

ably such that it will penetrate the porous strata only to a slight extent, if at all, and is of such a nature that it will efiectiv'ely seal the cavity or space into which it is introduced.

A suitable sealing material may consists of i 85% of a wax distilled residue, known at the refinery as black oil,"-and 15% of what is known at the refinery as dark fueloil. the black oil congealing atj'a temperature of ap-' proximately F. This black oil is diluted with the fuel oil in order to obtain a blend of a consistency which will,flow' down the pipe '25 and well casing or tube 18 without necessitating the use of excessive air pressure to facilitate such moyement.-. In practice, a sufiiclent quantity of sealing material 28 is employed to completely the cavity .to a

point, well below the lower plane of the porousstrata, as for example, in the form around said casing .of

of well shown in the drawing, to a plane coincidentwith the-lower plane of the stratum 16.

After having thus sealed'the porous stratum or strata, a sufiicient period, for example four or five days, is allowed to lapse beore water, pressure is introduced into the well casing or tube 18, which water pressure may be applied by removing the pipe 25 thereby establishing communication between the water bearing stratum 12 and that portion of the well casing or tube 18 below the seat 27, or by connecting the upper end of the well casing 18 to a suitable source of water above ground. Such introduction of water, either from the stratum 12 or from a source above ground, sets up a I pressure within the shot hole 22, with the result that the sealing material 28 is further packed into the upper end of the shot hole 22 and the oil withinthe oil bearing stratum is driven on toward the pumping wells.

If the stratum to be sealed or rendered non-permeable to water is located below the oil bearing stratum, a suitable material heavierthan water orthe solution ordinarily applied in flooding the oil bearing stratum, may .be employed, in which case the process may be carried out substantially as above described.

What is claimed is: Y

1. The method of plugging' the space around a well casing, which consists inintroducing into the well a sealing material in the presence of a displaceable liquid which'has a specific gravity different from that of the sealing material, leaving said sealing material and displaceable liquid undisturbed until thesealing material moves into sealing'position owing to the different specific gravities of said sealing .material and displaoeabl'e' material after 1t is in sealing position.

2.- The method of plugging water pervious strata in wells, which consists in. introducing a sealing material into the well and floating liquid, and applying pressure to thesealing the sealing material into sealing posit-ion, and applying pressure to the sealing mate:

rial after it is 1n sealing position. 3. The method of plugging water perviou strata in a-well, which consists in introducing an oil intothe well and floating said oil into sealing position by a liquid having a specific gravity greater than that of the oi and applymg pressure to the oil? I 4. The method of plugging the space around the casing of a well containing liquid. which consists in introducing into the well casing a sealing material havm a specific gravityless than the liquid wit 'n the well, and applying pressure to" the sealing material to eject it from said easing into the space around said casing.

5. The inethod of luggin a well i the space containing liquid, which consists in introducing into the well casing a sealing material havin a specific gravity less than the liquid wit iin the well,and applying pressure to the sealing material to e ect it from said easing into the space around said casing whereby it will be buoyed into sealing position by said liquid, and applying pressure to the sealing material after it is in sealing position. v

6. The method of sealing predetermined strata in 'wells used-for water flooding in connection withoil and gas recovery, which consists in introducing a sealing material into the well at a selected point, and floating the sealin material into sealing position by as and oil recovery, the

sisting in introducing a sealing material into the space afforded between the well casin and the wall of the well, and floating said sealing material into sealing position at said selected point.

8. For use in wells used for flooding in connection with as and oil recovery, the method of plugging the space around the well easing at a selected point with res ect to a predetermined stratum to be seale off ,from' the gas and oil bearing stratum, consist-ing in introducing a sealing material into the space afl'orded between the well casing and the wall of the well, and floating said sealing material intosealing position at said selected point, and applying pressure tosaid sealing material after it has assumed sealing position.

signatures to this specification.

HARRY MOYER RYDER. LEON J, BAILEY.

In testimony whereof, we have aflixed our

Images