US2843052A

US2843052A - Fluid expansible passage seal

Info

Publication number: US2843052A
Application number: US475618A
Authority: US
Inventors: Orrin E Andrus
Original assignee: AO Smith Corp
Current assignee: AO Smith Corp
Priority date: 1954-12-16
Filing date: 1954-12-16
Publication date: 1958-07-15
Anticipated expiration: 1975-07-15

Description

July 15 1958 o. E. ANDRUs FLUID ExPANsIBLE PASSAGE SEAL Filed Dec. 16, 1954 INVENTOR. Orrin E.Andrus BY @MQW , 5 RAN.

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ATTORNEYS.

United States Patent O f' FLUID EXPANSIBLE PASSAGE SEAL rrin E. Andrus, Milwaukee, Wis., assigner to A. 0. Smith Corporation, Milwaukee, Wis., a corporation of New York Application December 16, 1954, Serial No. 475,618

4 Claims. (Cl. 10S- 202) This invention relates to a seal for closing the passage about an object within a casing and more particularly to such a seal between a submersible motor-pump unit and the well casing.

In the past, when the well casing has been employed as the discharge pipe, the seal between the pump and the well casing has involved mechanically-actuated expansible devices or an expansible member connected by tubing to a fluid source above the well. The seals of the prior art are quite complicated and consequently are often expensive.

An expansible seal is disclosed in Patent No. 2,623,473 issued to Pankratz on December 30, 1952, for a Swab for Tapered Casing or Tubing. The disclosure of Patent No. 2,623,473 employs mechanically-actuated valves to inflate a packer with a gas which is normally confined in a chamber lowered into the well with the swab. Mechanically-actuated valves are also employed to deflate the packer. The gas is admitted to the tube or drained from the tube by jarring the mechanism to thereby actuate valves by remote means.

According to the present invention, admission and escape of the gas to and from an expansive sealing tube is controlled by a heat-disruptable seal disposed within outlet passages leading from a gas chamber disposed adjacent the seal. One of the outlet passages permits the gas to expand into the sealing tube and thereby to inflate the tube, while a second outlet passage allows the gas to escape to the exterior of the chamber and thereby to deflate the tube.

As applied to a submersible motor-pump assembly, an expansible doughnut-shaped member or tube encircles the motor-pump and is lowered into the well therewith. A gas chamber is secured to the assembly or associated equipment. The chamber is provided with a pair of outlet passages, each being closed by a heat-disruptable material. An electric heating element is disposed adjacent the heat-disruptable material in each passage and is connected by an electrical cable to a source of current outside the well. The energization of the heating element from the source of current is controlled externally of the well.

After the submersible motor-pump assembly is lowered into the well casing to the desired depth, the rst or tube expanding passage is opened by energization of the first heating element. The gas expands and inates the tube to seal the submersible motor-pump assembly within the well casing. The water is pumped upwardly above the seal and trapped within the well casing which acts as the discharge tubing. When the pump is to be removed, as for repair or replacement, the second passage is opened by energization of the second heating element. The gas escapes from the tube and the tube deflates allowing the motor-pump to 'be removed from the well casing.

An object of the present invention is to provide a passage seal which is remotely controlled and also which is positive in action and low in `cost of construction.

The drawing furnished herewith illustrates the best n 2,843,052 Patented July 15, 1958 mode presently contemplated for carrying out the invention.

In the drawing:

Figure 1 is an elevational view of a well pump and motor unit supported within a well casing;

Fig. 2 is an enlarged View, in cross section, of a preferred embodiment of the sealing and releasing system;

Fig. 3 is a View taken on line 3--3 of Fig. 2; and

Fig. 4 is an enlarged sectional view of a sealed joint employed in the illustrated embodiment of the invention.

Referring to Figure l, there is illustrated a submersible motor-pump unit of the conventional deep-well variety having a submersible motor 1 connected below and in spaced vertical relation to a pump 2 with a screened water inlet 3 therebetween. The motor-pump unit is supported within a well casing 4 with the water inlet 3 below the level of the well liquid 5, and with a power line 6 for the motor 1 extending upwardly along a groove in the motor-pump housing and out of the well casing to a conventional starting and operating switch 7 which is connected to the alternating current supply lines 8. To support the motorpump unit in position, a cable 9 is secured to an eyelet 1t) which is secured to the motorpump unit and to an eyelet 11 which is attached to a. casing head 12 closing the top of the well casing 4. The eyelet 11 has a shank 13 which is welded to the casing head 12 as at 14.

The casing head 12 is secured as by bolts 15 to a casing flange 16 at the top of the casing 4 with an O-ring seal 17 therebetween to prevent leakage of the well liquid. A discharge pipe 18 is secured within a ferrule 19 on the casing head 12 and has a conventional control valve 20 to open and close the pipe 18.

To employ the well casing 4 above the motor-pump `unit as a liquid conduit, a generally doughnut-shaped expansible member or tube 21 encircles an annular extension 22 of the motor-pump housing and when inflated prevents the ow of liquid between the motor-pump unit and the well casing. The water 5 is pumped upwardly and out of the discharge pipe 18 with the well casing 4 replacing the conventional tubing connecting a discharge pipe to an outlet of the pump. Further, the pump unit has a check valve, not shown in the drawing, which allows the flow of liquid through the pump 2 only in an upward or outlet direction.

The annular extension 22 is formed integrally with the housing of the motor pump and is centrally indented as at 23 to accommodate the doughnut-shaped tube 21.

The doughnut-shaped tube 21 is constructed of a ilexible material to allow expansion and contraction of the tube. A suitable material for tube Z1 is a reinforced impervious rubber of a composition similar to that used in inner tubes of automobile tires. The rubber being impervious to gases remains inflated until positively released.

Referring in particular to Fig. 2, the tube 21 is provided with a stem 24 to eifect an inflation and deflation of the tube Z1. The stem 24 extends through an aperture in the annular extension 22 and is connected into cornmunication with a gas chamber 25 by a conduit 26 to effect the inflation of the tube 21.

As more clearly shown in Fig. 4, the conduit 26 passes through a threaded cap Z7 and is sealed within the stem 24 by threading the cap upon an enlarged threaded portion 28 of the stem 24. The' adjacent edges of the openings in the cap 27 and the stem 24 through which the conduit 26 passes are chamfered as at 29 and 3i), respectively, to provide a recess adjacent the conduit 26. A ring seal 31 having an axial half-moon cross-section is disposed within the recess, as shown, and when the cap 27 is threaded onto the enlarged portion 28, the ring seal 31 tightly seals the conduit 26 within the stem 24.

As more clearly shown in Figs. 2 and 3, the gas chamber 2S is secured to the top of the pump 2 by a threaded portion 32 extending from the chamber and threaded into a` correspondingly threaded aperture in the pump 2. The chamber 25 is provided with a recessed side 33 in alignment with the indented portion 23 of the annular extension 22 to maintain a passage of constant cross-section past the chamber. A pair of spaced tubular extensions or

outlets

34 and 35 are formed integrally with the chamber to form a pair of outlet passages. A fluid 36 is confined under high pressure within the chamber. Nitrogen or argon, which are inert gases, are desirable as the confined fluid although other fluids may be employed.

The conduit 26 is sealed within the outlet 34 in the same manner as the conduit is sealed within the stem 24. The outer end of the outlet 34 is threaded to receive a correspondingly threaded cap 37 through which the conduit 26 passes into the outlet. The outlet 34 and cap 37 are chamfered as at 38 and 39, respectively, to receive a ring seal 40 and tightly seal the conduit within the outlet 34 when the cap 37 is threaded onto the outlet 34. Therefore, when the tube is unobstructed, the confined fluid 36 within the chamber 25 is free to expand into the doughnut-shaped tube 21.

The opening in a tip 41 of the conduit 26 extending within the outlet 34 is of a substantially reduced diameter and is sealed by a plug 42 of heat-disruptable material to allow remote control of the inflation lof the sealing tube, as hereinafter described. The tip 41 is formed in any suitable manner such as swaging.

The second outlet 35 accommodates a discharge conduit 43 which communicates with the well above the chamber. The conduit 43 is sealed in place in the same manner as the conduit 26 by a ring seal 44 forced into position by a cap 45 which threads onto the outlet 35.

The opening in a tip 46 of the second conduit 43 is also reduced in diameter and plugged with a heat-disruptable material 47 to effect a remote control of the deflation of the sealing tube, as hereinafter described.

A heating coil 48 is wound around and in close proximity to the first outlet 34 and similarly a heating coil 49 is wound around and in close proximity to the second outlet 35. When each of the heating coils 48 and 49 is energized, the associated heat-disruptable plugs 42 and 47 are heated and are disrupted to open the respective conduit.

A heat-disruptable plug is defined as one that allows an opening of the passage in response to a predetermined rise in temperature either as a result of fusion, combustion or disintegration of the plug or as a result of a loosening of the plug from the tube so as to allow the pressure of the confined gas to force or push the plug from its closing position. For example, a suitable plug is a low temperature solder disposed within the reduced openings of the

conduits

26 and 43. The solder is fused to the walls of the tubes and forms a positive sealing of the tubes. When the solder is heated, it softens or melts and allows the pressure of the confined gas to push or blow it into the larger diameter portion of its respective tube.

The electric leads 50 and 51 for the coils are disposed within a shield 52 which also houses the main motor power line 6.

As shown in the drawing, the coils have a common return lead 53 which is permanently connected to the line 54 of the supply lines 8. Each of the

coils

48 and 49 also has an associated

lead

55 and 56 which is connected to a contact 57 and 58, respectively, of an associated switch 59. The switch 59 is connected to a line 60 of the supply lines 8. To energize the coil 48 the switch 59 is closed into engagement with the contact 57 and to energize the coil 49, the switch 59 is closed into engagement with the contact 58.

The operation of the above described embodiment of the invention is as follows:

The submersible motor-pump unit is lowered into the well and secured at a predetermined elevation by the cable 9. The switch 59 is then closed into engagement with the contact 57 and the heating coil 48 is energized. The heat-disruptable material 42 is disrupted and opens the passage to the sealing tube 21. The confined fluid 36 expands and infiates the sealing tube 21 and thereby seals the motor-pump unit to the well casing 4, as shown in Figure 1. During operation, the pump 2 forces water into the well casing above it. The sealing tube 21 prevents the pumped water from returning to its original level. The check valve within the pump, not shown in the drawing, serves to prevent the pumped water from returning from the casing to its original level when the pump is not operating. Therefore, the well casing 4 above the seal 21 serves as the conventional tubing from the pump to the discharge pipe 18.

When the motor-pump unit is to be removed from the well, the heating coil 49 is energized by closing the switch 59 into engagement with contacts 58. The heat generated by the coil 49 disrupts material 47 and thereby opens the outlet passage 35. The confined fluid 36 escapes from the chamber 25 and the sealing tube 21, allowing the collapse of the sealing tube and removal of the motor-pump unit.

To re-use the apparatus, the

tubes

26 and 43 are again sealed. and the gas 36 is replaced whereby the apparatus is again adapted to seal a motor-pump unit within a well casing.

Any suitable means may be employed to replace the gas 36 such as a fitting which permits the filling of the chamber through the discharge passage 35 and then permits the sealing of the conduit 43 within the discharge passage 35.

Although` the seal is described as applied to a pump having a check valve, the seal is equally applicable to a pump without such a valve. If a check valve is not used, then the well liquid must first fill the well casing at each pumping before water can be drawn from the well.

The presently disclosed seal is particularly adapted for an inaccessibly disposed seal which is to remain intact for a number of years. This is because no mechanically actuated mechanism is employed in the structure of the controlled seal. Although a mechanical valve or similar seal is suitable for general application, when a seal is to be opened only at some remote future time, there is a substantial danger that the mechanical variety seal will leak prior to that time or that it will freeze shut. With a relatively inaccessible seal, it is particularly important that the preceding be prevented.

The present invention provides a positive acting and low-cost construction for a remotely controlled seal.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

l. Sealing apparatus for closing the passage between a submersible motor-pump unit and a well casing, which comprises an expansible member disposed between the motor-pump unit and the well casing, a chamber disposed adjacent to the motor-pump unit and having an outlet passage connecting the chamber into communication with the expansible member, said chamber being adapted to hold a pressurized'fiuid therein, a heat-disruptable material disposed within said passage to close the passage, an electrically energized heating element disposed adjacent the heat-disruptable material to effect a disruption of said material and a consequent inflation of said expansible member, a source of current connected to the heating element to control the energization of the heating element, and control means for said source of current disposed at the upper end of the well casing to selectively energize said heating element.

2. Sealing apparatus for closing the passage between a motor-pump unit and a well casing, which comprises an expansible member disposed between the motor-pump unit and the well casing, a chamber disposed adjacent to the motor-pump unit and having an outlet passage connecting the chamber into communication with the expansible member, said chamber being adapted to conne a pressurized uid therein, a heat-disruptable material disposed within said passage to close the passage, an electrical heating element secured adjacent the heat-disruptable material to eiect an opening of the passage, a second outlet passage connecting the chamber and the well uid into communication, a heat-disruptable material disposed within the second outlet passage to close the second passage, a second electrical heating element secured adjacent the heat-disruptable material in the second passage to eifect an opening of the second passage and :a consequent deflation of the expansible member, a source of current connected in circuit with the first and second named electrical heating elements, and control means for said source of current disposed at the upper end of the well casing to selectively energize the rst and second named heating elements.

3. A control apparatus for closing the passage between a submersible motor-pump unit and a well casing by an inilatable member, which comprises a chamber -attached to the motor-pump unit and inserted into the well casing with the motor-pump unit, a tube connected between the chamber and the inflatable member to provide a passage between the chamber and the inflatable member, a heatdisruptable plug closing the tube between the chamber and the inflatable member, a pressurized uid conined within the chamber under sucient pressure to elect an inflation of the inatable member upon opening the tube to thereby seal the motor-pump unit and the well casing, an electrical heating element secured adjacent the plug, and a remote manual control disposed adjacent the upper end of the well casing and connecting the heating element in circuit with a source of power.

4. A remotely controlled sealing device for closing the passage between a submersible motor-pump unit and a well casing by an expansible doughnut-shaped member surrounding the motor-pump unit, which comprises a chamber secured to the motor-pump unit and lowered into the well casing therewith, a pressurized uid conned within said chamber, a first tube connected in communication with said expansible member and said chamber to etect an ination of the member by said pressurized fluid, a second tube communicating with the exterior of the chamber and the chamber to effect a deation of the eX- pansible member, a heat-disruptable plug in said rst tube, a heat-disruptable plug in said second tube, an electrical heating means secured adjacent said first and second heat-disruptable plugs to rst effect an opening of said first tube and an ination of the expansible member and to secondly effect an opening of said second tube and a deflation of the expansible member, a source of power, and manually operated means disposed adjacent the upper end of the well casing and connecting the source of power and the electrical heating means to permit selective energization of the heating means and consequent individual control of the opening of said first tube and said second tube.

References Cited in the le of this patent UNITED STATES PATENTS 2,207,001 Dillon Oct. 1l, 1937 2,245,144 Grith Jan. 27, 1940 2,269,189 Downs` Jan. 6, 1942 2,458,270 Humason Jan. 4, 1949 2,702,993 Harris Mar. 1, 1955