Well Pipe Seal

Abstract

The disclosure is of a seal to be used in a well immediately above a pump and at or below the normal level of the water in the well casing to prevent the movement of water and air downwardly past the seal into the area of the pump. The seal is designed to permit the necessary service connections to be passed through it and then adjusted to tightly seal about these connections before installation of the seal in the well.

Description

SUMMARY OF THE INVENTION

With the development of satisfactory small diameter motors, the popularity of submersible pumps has been increasing rapidly in recent years. These pumps are mounted on the end of the water delivery pipe and lowered into a well usually several feet below the top of the water as the level of the water normally establishes itself by natural hydrostatic pressure. It has been common practice either to provide nothing adjacent the pump or to provide a stabilizing ring which is nothing more that a guide to center the pump in the well. In this arrangement, as the pump turns on and off, the level of the water in the well fluctuates substantially in response to the relationship between the rate at which the pump is withdrawing water from the casing and the rate at which water is flowing into the casing from the surrounding water table. This has a number of undesirable effects.

The purpose of this invention is to provide a seal immediately above the pump and below the normal surface of the water in the casing. The seal forms a barrier between the pump and that portion of the casing which is above the seal. The seal also is designed to permit the passage of various service or utility lines and/or conduits through it and to form a tight seal around these lines before installation. These utility lines include the electric wires to power the pump and a conduit which may be used to measure the static and draw down water levels or to introduce treatment chemicals into the water, such as chlorine for purification or acid for removal of line incrustations. The seal has the added advantage of preventing well contamination from materials which enter the casing above and normally would reach the water if the seal were not present. The use of the seal also reduces corrosion on the inside of the casing and on the pipe.

These and other advantages of the invention will be understood upon reading the following specification and the accompanying drawings.

IN THE DRAWINGS

FIG. 1 is a side elevation view of the invention;

FIG. 2 is a plan view of the invention;

FIG. 3 is a fragmentary, central sectional view of the invention;

FIG. 4 is a fragmentary sectional view of a typical conduit opening before the seal is clamped about the conduit;

FIG. 5 is a view similar to FIG. 4, but showing the relationship of the seal to the conduit after the seal has been clamped;

FIG. 6 is a view similar to FIG. 4 showing a modified form of the seal prior to clamping;

FIG. 7 is a view similar to FIG. 4 showing the effect of the clamping of the plates about the seal;

FIG. 8 illustrates diagrammatically a typical well installation when the present invention is not used;

FIG. 9 is a diagrammatic view similar to FIG. 8, but showing the result of installation of this invention;

FIG. 10 illustrates an alternative method of sealing about one of the service conduits;

FIG. 11 is a sectional elevation view of a modification of this invention;

FIG. 12 is an enlarged fragmentary view of a modification in the construction of the sealing member;

FIG. 13 is a plan view of a further modification of the invention;

FIG. 14 is a fragmentary, enlarged section view taken along the plane XIV--XIV of FIG. 13;

FIG. 15 is an enlarged, fragmentary, exploded view of a further modification of this invention;

FIG. 16 is an enlarged, fragmentary, sectional view of the structure shown in FIG. 15 when the seal has been clamped into sealing relationship.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The seal 10 has a central pipe nipple 11 threaded on both ends, the diameter of which will depend upon the capacity of the pump with which it is to be utilized. Surrounding the nipple 11 are a pair of annular, disklike plates, a lower plate 12 and an upper plate 13. The lower plate 12 is sealed to the nipple 11 by welding at 14. The upper plate 13 is slidable with respect to the nipple 11 so that it may move lengthwise of the nipple. Between the plates 12 and 13 is an annular, sealing member or gasket 15. In the form of the invention shown in FIGS. 1 and 3, this gasket has a diameter substantially greater than that of either of the plates 12 and 13 and also greater than the inside diameter of the well casing 16 (FIG. 3). As a result, when the seal is installed in the casing, the peripheral edge of the seal is forced to compress and turn upwardly and ride along the inside wall of the casing, forming a sealing skirt 17 at this point. To permit this reshaping of the seal or gasket, the upper plate 13 is of lesser diameter than the lower plate 12 to provide clearance for the upturned skirt.

The seal can be made from any suitable flexible material resistant to deterioration in the environment of use. A suitable material for this purpose is a synthetic rubber material of about 60 Durometer sold by Goodyear Tire & Rubber Company under the name Armadillo Chute Lining. This material has been successfully used in both three-sixteenths inch and one-fourth inch thicknesses. This material has proved durable, sufficient body to effectively seal with the casing and a high degree of abrasive resistance which eliminates failure due to wear as the seal is forced down the casing.

At least three holes 20 are provided through the plates 12 and 13 and the gasket 15 (FIG. 2) to receive the bolts 21 (FIG. 1). By tightening the bolts, the plates are made to clamp the gasket 15 and to cause it to deflect as a result of being squeezed. Additional openings or apertures 22 are provided for the electrical conductors for the pump. A service opening 23 is preferably provided for a conduit which may be used for a variety of purposes, such, for example, as to introduce chemicals into the water around the pump.

FIGS. 4 and 5 illustrate one way of forming a seal about the conductors. Before the bolts 21 are tightened, the opening or aperture 22 is of sufficient size to permit the conductor to be passed through as suggested in FIG. 4. Preferably, the conductor or cable has a light friction fit with the gasket 15 and a slight clearance with the holes in the plates 12 and 13. FIG. 5 illustrates the deflection of the gasket 15 when the plates 12 and 13 squeeze it as a result of tightening of the bolts 21. The pressure exerted by the plates causes the gasket to deflect inwardly and form a seal around the conductor 24.

FIGS. 6 and 7 show a modification of this arrangement. In this arrangement, the gasket 15 is so formed that in its natural relaxed position it projects into the aperture 22 to partially restrict it, but being resilient, the conductor 24 can be pushed through it before the plates are clamped. After the plates are clamped, it is caused to squeeze both up and down and inwardly to form a long, tight seal about the conductor as suggested in FIG. 7. Basically the same situation occurs in connection with the aperture 23 for the service conduit.

A modification of this arrangement is shown in FIG. 10 in which a small nipple 25 is secured to one of the plates and provides a threaded mounting for a gland nut 26 to surround either a conductor 24 or a service conduit 27.

FIG. 11 illustrates a modification of this invention in which all of the components of the seal assembly remain the same except the gasket 15a, which in this case is cup-shaped, even before it is inserted in the casing. Thus, the edges of the gasket are turned upwardly to form a flange 30, having an outside diameter slightly greater than that of the casing whereby, when the seal is installed in the casing, the flange 30 is slightly compressed to assure positive sealing pressure and engagement with the walls of the casing. It has been found that the sealing effect against the casing can be materially improved by providing one or more slits 31 extending around the flange and partially through the thickness of the gasket. Preferably, one of these is closely adjacent the top of the flange. These slits are parallel to each other and to the top of the flange. FIG. 12 shows another arrangement wherein the slit 31a opens through the outside face of the flange at the very top of the flange 15b. The purpose of the slits is to give the flange more flexibility so that it may deflect outwardly in the casing to conform to irregularities in the inside wall such as occur at the welded seam in the pipe. Frequently, this seam has a slight depression on the inside of the pipe which will not seal unless the flange of the gasket has a reasonable degree of flexibility to deflect into and occupy the depression formed by the seam. In some cases, the sealing affect can also be improved by chamfering the end of the flange as at 32 to provide a thin, flexible edge at the outside end of the flange which will flex readily against the wall of the casing.

FIG. 13 shows a further modification in which an elongated aperture 40 is provided through the seal assembly. This opening is specifically designed to receive the flat-type, two or three wire electrical conductor to supply energy to the pump. In case it is not used, it is provided with a sealing cap 41 and a flexible, squeezeable seal 42 which are assembled to the lower plate 12 by the screws 43. If opening 40 is to be used, the plate 41 and seal 42 are removed, the wire passed through and when the plates 12 and 13 are squeezed together, a seal will be formed around the wire, basically as illustrated in FIGS. 4-7. In this arrangement, the apertures 22 may either be sealed by bolts passing through them and pulled down tightly or they may be omitted in their entirety. Another possibility is to occupy the apertures 22 with a short length of the conduit 27 heat sealed at the upper end as suggested at 28 in FIG. 10. The same is true of the opening 23.

FIGS. 15 and 16 illustrate a modified arrangement for sealing around the conductors 24 or the conduit 27 or around any wire which is utilized in the slotted opening 40. In this case, the opening in the gasket or seal 15c is enlarged and a grommet 50 is pressed into this opening. The grommet 50 has a central opening just big enough to permit the conductor or conduit to be passed through it. The ends of the grommet are conical in shape and project from both the upper and lower faces of the seal 15c. Thus, when the plates 12 and 13 are clamped down on the seal 15c, the grommet 50 is axially squeezed, resulting in a very pronounced inward deflection forcing the grommet to form a very tight grip and seal around anything passing through its central opening. This arrangement is illustrated in FIG. 16. The tapered ends of the grommet produce forces which result in very tight sealing, both around whatever is passed through the opening and between the grommet and the gasket.

FIGS. 8 and 9 illustrate the application of this invention. FIG. 8 illustrates the conventional arrangement in which the pipe 55 extends down through the casing 16 and has the pump 56 mounted at its lower end and submerged well below the surface 57 of the water. FIG. 9 illustrates the application of this invention. By static pressure, the surface 57 is established by the top 58 of the water table in the surrounding water bearing strata 59. The seal is positioned immediately above the pump as illustrated in FIGS. 3 and 9. In fact, the nipple 11 of the seal forms a coupling between the discharge end of the pump and the pipe 56. The electrical connections for the pump are installed and any other service connection such as a conduit passing through the opening 23 is installed. The bolts 21 are then tightened on the seal to form a water and air tight seal around the wires and the conduit. The pump, seal and pipe are then forced down the well until the pump is fully submerged and the seal is either at or below the surface 57 of the water in the well. In this operation, normally water will pass around the seal up into the area above the seal in the casing, even though this is not illustrated in FIG. 9. However, any water which is in the casing above the seal is automatically trapped and cannot return past the seal into the area occupied by the pump.

In an installation as illustrated in FIG. 8, the pumping action of the pump normally causes the water level within the casing to drop, sometimes to such an extent that the pump itself ends up above the surface of the water and air may enter the pump, interrupting proper pumping action. This occurs when the rate of water flow through the screens from the surrounding water bearing strata 59 is insufficient to adequately supply the pump, at the rate at which it is withdrawing water from the casing. This is a situation which frequently occurs. When the well is fortunate enough to penetrate a thick water bearing strata, the pump may be submerged deeply enough to avoid this problem. However, frequently, the water bearing strata is too thin or shallow to permit sufficient submersion of the pump to prevent draw down which will interfere with pump operation. It is in this situation that the seal overcomes a vexing problem which has never before been solved.

Even in wells having adequate capacity to supply the pump, the water level within the casing drops significantly when the pump is operated and returns to its normal level when the pump stops. Every time the water moves up and down in the casing, it exposes both the wet casing and the wet exterior of the pipe to oxidation resulting in accelerated deterioration of both the casing and the pipe. The seal holds the water level constant, eliminating this condition.

With this seal, when the pump is started, any water which is above the seal cannot be drawn down into the pump area and, therefore, remains static. As a result, the reduced static pressure inside the casing created by the action of the pump, instead of drawing water from above in the casing, draws water from the water table through the screens into the pump and thereby materially increases the rate at which water can be effectively withdrawn from the well. The seal positively prevents air from reaching the pump to interrupt its operation. The seal prevents any water in the area above the seal from fluctuating due to the action of the pump, thus, reducing the corrosive affect of oxidation.

It will seen that any contamination which enters the casing from above will ultimately be deposited in the water in the arrangement shown in FIG. 8. On the other hand, as illustrated in FIG. 9, the seal forms a complete barrier preventing any such contamination from reaching the water which will be lifted by the pump.

It is not usual that well water, either when the well is first brought in or in some cases throughout the life of the well, has to be treated before it is safe and potable. This is frequently done by controlled introduction of a suitable treatment chemical to the water, such as chlorine. By running a tube down the outside of the pipe 55 and passing it through the seal, as shown in FIG. 10, chlorine can be introduced to the water immediately adjacent the pump where it will be most effective. Further, in purging a well, the chlorine can be forced down under pressure and, thus, made to thoroughly dissipate throughout the water in the casing to clean and purify both the water and the mechanical installation before the well is finally put to use. This conduit also permits acid treatment of a well without undue damage to the casing and pipe. In many areas, the delivery capacity of a well is materially restricted by the deposit of lime on the screen and related parts of the well. This can be removed by an acid treatment of the well. However, such acid treatments tend to remove the galvanizing from the inside of the casing and the exterior of the well pipe in areas where the acidified water comes in contact with these members. By providing the seal 10, the acid can be introduced through the conduit 27 under pressure and can be confined to the area of the pump and the screen where its action is required and prevented from attacking the casing and the pipe above the seal. Further, by confining the acid treatment, more rapid and more effective treatment can be accomplished.

By virtue of the existence of the seal, the conduit 27 may be utilized as a means of accurately checking the static and draw down of the water levels to determine the actual delivery capacity of the well. The seal has the incidental benefit of further stabilizing and centering the pump in the well.

It will be recognized that while a preferred embodiment and several modifications of the invention have been illustrated and described, additional modifications may be made within the principal of the invention.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

1. A well seal for submersible pumps installed below water level in a well casing, said seal comprising an upper plate and a lower plate; an annular compressible sealing gasket between said plates; said gasket being circular and having an outside diameter greater than said plates and adapted to become cup-shaped upon insertion in the well casing; a pipe rigidly connected to and forming a watertight seal with one of said plates and extending through said gasket and the other of said plates and projecting both above and below said plates, said pipe being concentric of said plates and gasket; at least one aperture in each of said plates and said gasket, said apertures being aligned for passage therethrough of an energy conductor for the pump; means for moving said plates toward each other to compress said gasket and cause it to migrate into the energy conductor aperture to form a watertight seal about a conductor passing therethrough.

2. A well seal as described in claim 1 wherein said pipe is rigidly connected to the lower of said plates.

3. A well seal as described in claim 1 wherein said aperture in said gasket is larger than the aligned apertures in said plates; a compressible grommet larger than the aligned apertures in said plates seated in said aperture in said gasket having a central opening therethrough smaller than the aligned apertures in said plates.

4. A well seal as described in claim 3 wherein said grommet has an axial length greater than the thickness of said gasket whereby said grommet is compressed both radially and axially as said plates are moved toward each other to increase the sealing effect about a conductor passing therethrough.

5. A well seal as described in claim 4 wherein the ends of said grommet projecting beyond the faces of said gasket are frustoconical in shape with the ends thereof sloped radially inwardly and away from the faces of said gasket.

6. A well seal as described in claim 1 wherein each of said plates and said gasket has a second aperture therethrough, said apertures being aligned to receipt a water treatment conduit therethrough.

7. A seal as described in claim 1 wherein the peripheral edge of said gasket is chamfered downwardly and inwardly to provide a narrow lip adjacent the lower face of said gasket.