US3714384A

US3714384A - Subsea electric connector system and procedure for use

Info

Publication number: US3714384A
Application number: US00201635A
Authority: US
Inventors: J Burkhardt; R Koerner; T Childers; D Tidwell
Original assignee: Exxon Production Research Co
Current assignee: ExxonMobil Upstream Research Co
Priority date: 1971-11-24
Filing date: 1971-11-24
Publication date: 1973-01-30
Anticipated expiration: 1990-01-30

Abstract

METHOD AND APPARATUS FOR CONNECTING AND DISCONNECTING REPLACEABLE ELECTRICALLY OPERATED EQUIPMENT TO AND FROM RESPECTIVELY, A SOURCE OF ELECTRICAL POWER, PARTIENLARLY AT REMOTE UNDERWATER LOCATIONS. THE ELECTRICAL CONNECTION APPARATUS INCLUDES AT LEAST TWO CONNECTOR UNITS. EACH CONNECTOR UNIT COMPRISES TWO HALVES CAPABLE OF BEING REPEATEDLY MADE UP TO AND SEPARATED FROM EACH OTHER. ONE-HALF INCLUDES A PRONG HAVING METAL SPIKES FORMED ON ONE END AND THE OTHER HALF INCLUDES A PRONG HAVING A CUP FORMED ON ONE END CONTAINING A MALLEABLE METAL. ONE-HALF OF THE CONNECTOR UNIT IS ISSTALLED PERMANENTLY SUBSEA AND IS CONNECTED TO SWITCH MEANS WHICH IS CAPABBLE OF CONTROLLING FLOW OF ELECTRICAL POWER FROM THE ELECTRICAL ENERGY SOURCE TO THAT HALF. THE OTHER HALF

OF THE CONNECTOR IS MOVABLE AND CONNECTED TO ELECTRICALLY OPERATED, REPLACEABLE EQUIPMENT. AN ELECTRICAL CONNECTION IS MADE WHEN THE PRONGS ARE LOCKED TOGETHER SO THAT THE SPINKES PENETRATE AND ARE EMBEDDED IN THE MALLEABLE METAL. THE MOVABLE HALVES OF THE CONNECTOR UNITS ARE COVERED WITH A NON-CONDUCTIVE LIQUID, SUCH AS OIL, PRIOR TO MAKING UP THE CONNECTION. AS THE CONNECTION IS MADE UP THE OIL FORCES WATER FROM ABOUT THE PERMANENTLY INSTALLED CONNECTOR HALVES AND WHEN MADE UP THE CONNECTION IS SURROUNDED WITH OIL. MEANS ACTUATE THE SWITCH MEANS TO CUT OFF ELECTRIC POWER TO THE CONNECTION UNITS BEFORE THE CONNECTOR HALVES CAN BE DISCONNECTED.

Description

SUBSEA ELECTRIC CONNECTOR SYSTEM AND PROCEDURE FOR USE Filed NOV. 24, 1971 Jan. 30, 1973 J URKH R T ETAL 3 Sheets-Sheet l FIG.

ATTORNEY.

mm 5 1 R 3 mu w s G 4 iii 7 m G fi M m F 1 m MEN .E 5 F Wmne S A mum A J.T.DR; M 3 Y J 7 A B s 1: 5

Jan. 30, 1973 BURKHARDT ET AL 3,714,384

SUBSEA ELECTRIC CONNECTOR SYSTEM AND PROCEDURE FOR USE Filed Nov. 24,. 1971 s Sheets-Sheet 2 F'IG.6.

H l EH I Joseph A-Burkhordi, Thomas W.Chi|ders,

Danny R. Tidwell,

Roger J Koerner INVENTORS.

JOHN S- SCHNEIDER,

ATTORNEY.

Jan. 30, 1973 A, BURKHARDT ET AL 3,714,384

SUBSEA ELECTRIC CONNECTOR SYSTEM AND PROCEDURE FOR USE 3 Sheets-Sheet 3 Filed Nov. 24, 1971 S m HJ e wuE MO TKN R yr ne "9 00 DR JOHN S SCHNEIDER,

ATTORNEY.

nited States Patent Office 3,714,384 Patented Jan. 30, 1973 US. Cl. 200-51 R 14 Claims ABSTRACT OF THE DISCLOSURE Method and apparatus for connecting and disconnecting replaceable electrically operated equipment to and from, respectively, a source of electrical power, particularly at remote underwater locations. The electrical connection apparatus includes at least two connector units. Each connector unit comprises two halves capable of being repeatedly made up to and separated from each other. One-half includes a prong having metal spikes formed on one end and the other half includes a prong having a cup formed on one end containing a malleable metal. One-half of the connector unit is installed permanently subsea and is connected to switch means which is capable of controlling flow of electrical power from the electrical energy source to that half. The other half of the connector is movable and connected to electrically operated, replaceable equipment. An electrical connection is made when the prongs are locked together so that the spikes penetrate and are embedded in the malleable metal. The movable halves of the connector units are covered with a non-conductive liquid, such as oil, prior to making up the connection. As the connection is made up the oil forces water from about the permanently installed connector halves and when made up the connection is surrounded with oil. Means actuate the switch means to cut off electric power to the connection units before the connector halves can be disconnected.

BACKGROUND OF THE INVENTION The present invention concerns electrical connector systems for use in underwater locations.

In submerged oil and/or gas production systems the reliable transmission of high power electric energy to replaceable subsea electrically operable equipment packaged in modules is directly related to the dependability of the electric connector system. If a high power electric connector can be repeatedly made up and separated while in a submerged environment, apparatus that requires electric power, such as hydraulic pump motors, can be readily maintained as failures occur. The mechanical, high power electric connector and connection procedure of the present invention provides a solution to the problem of making reliable electrical connections underwater. That solution permits efficient maintenance of electrically operated equipment under water by providing (1) a connector that can be made up and broken at any depth subsea and in an electrically non-conductive environment, (2) a metal-to-metal connection with low power regulation characteristics, (3) a means for recovering the portion of the connector that is subject to degradation, and (4) application through the use of special purpose manipulators or divers.

SUMMARY OF THE INVENTION Broadly, the invention involves an electrical connection apparatus capable of being repeatedly made up and broken comprising an electric connector unit capable of transmitting electric power having two mateable parts,

one part having a head portion provided with a plurality of rows of sharp pyramid shaped spikes separated by sloped unidirectional valleys and the other part having a prong provided with a head formed in the shape of a cup. The cup contains a malleable metal. Pins extend through the metal and the cup and the cup is shaped to retain the metal in the cup. Spikes are embedded in the malleable metal when the one part and the other part are mated together. In more detail, the apparatus involves mounting at least two connector units together, the parts thereof when mated being surrounded with nonconductive liquid. One part of each connector unit is connected to permanently installed switch means and the other part thereof is connected to electrically operated replaceable equipment. Means are provided for actuating the switch means to cut olf power to the one-half of each connector unit when in one position and to permit flow of electric power to the one-half of the connector unit when in another position. The switch actuator means prevents disconnection of the connector unit halves when the switch actuator means is in the other position.

The invention also includes a method for making an electrical connection in a water environment, in which the components of the electrical connection comprises at least two connector units, each of which comprises two engageable-separable metal parts, a first part being connected to permanently arranged subsea electric power control means and a second part being connected to replaceable electric operated equipment, which comprises the steps of covering the second parts of said electric connector units with non-conductive liquid at the waters surface; lowering the second parts together with the replaceable electric operated equipment through the water to adjacent the first parts of the electric connector units while maintaining the second parts covered with nonconductive liquid; engaging the first and second parts of each connector unit, the non-conductive liquid, forcing water from said first parts as the first and second parts are brought into engagement and the non-conductive liquid remaining about said engaged first and second parts.

The method also contemplates replacing electric operated equipment and includes the step of cutting ofi power to the first parts of the electric connector units prior to disengaging the second parts connected to electric operated equipment to be replaced, the power cut off being required before disengagement of the parts can be made.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 show plan and side views, respectively, of one of the connectors of the present invention;

FIGS. 3 and 4 show side and plan views, respectively, of the other connector of the present invention;

FIG. 3A shows a side view of a modification of the connector of FIG. 3;

FIG. 5 illustrates three sets of the connectors of FIGS. 1-2 and FIGS. 3-4 mounted in flanges and in the process of being made up;

FIG. 6 is a view showing one set of the connectors of FIG. 5 and the associated flanges in made-up position;

FIG. 7 illustrates the upper connector shown in FIG. 5 and their associated flange arranged on a mounting -fixture prior to making up the connector;

FIG. 8 is a side view of one of the connectors mounted on an electric switch housing together with apparatus for cutting off the switches preparatory to release of the connector flanges from each other; and

FIG. 9 is a view taken on lines 99 of FIG. -8.

DETAILED DESCRIPTION OF THE INVENTION In FIGS. 1 and 2 there is shown the permanent or unrecoverable male half or part 10 of a connector unit. It

constitutes a prong 11 constructed of a durable, strong, corrosion resistant material such as stainless steel. The head of the prong 12 is machined so as to expose several rows of sharp, pyramid shaped spikes 13 separated by sloped, unidirectional valleys 14. Electrical insulation 15 is bonded to the prong.

FIGS. 3 and 4 shows the recoverable or removable female half or part of the connector unit. It constitutes a prong 21 having an exposed end thereof machined into the form of a cup 22. Pins 23 are installed in the cup as shown and both pins 23 and the cup area are heated and tinned with a suitable metal. Thereafter, a malleable highly conductive metal, such as lead or copper, is melted and poured into the cup over the support pins 23. The malleable metal is allowed to fuse with the tinned metal and a weld bond is created between the soft metal pad indicated at 24 and the steel cup 22 The bottom 25 of the cup is grooved, as shown, for purposes of retaining the metal 24. Pins 23, as well as the retaining shape of cup 22, provide vertical and lateral support for the soft metal slug 24. FIG. 3A shows a modified female half 20'. It is similar to female half 20 except cup 22, machined on the end of prong 21', has sloped inner side walls instead of grooves for retaining soft metal slug 24' and for providing, along with pins 23', vertical and lateral support for slug 24'.

Referring to FIG. 5, there is shown an arrangement of three connectors designated as lower prongs 11a, 11b and 110 and upper prongs 21a, 21b and 210. Each of the lower prongs 11a, 11b and 11c is potted into a flange by potting material 32 and connected to an electrical conductor 33. Each of the

upper prongs

21a, 21b, and 21c is installed in an insulated bore, indicated at 34, in a flange 31 and maintained in place by a stop ring 35 and a coil spring 36. Each cup 22 is urged downwardly by spring 36. As shown also in FIG. 6, flange 31, which may suitably form a part of or be connected to removable electrically operable equipment, such as for example a removable pump module, has a protruding wall 37 which forms a cavity 38 in which cups 22 are located. A locking shoulder 39 is located on the lower external. end of wall 37. Flange 31 fits over flange 30 with the interior surface 40 of wall 37 slidable downwardly on the exterior surface 41 of upper portion 42 of flange 30. An external shoulder 43 is located at the lower end of portion 42. Drain grooves 44 extend along surface 41 from shoulder 43 to the upper end of flange 30. An external locking shoulder 45 is located on flange 30 below shoulder 43. As shown in FIG. 6 when the lower end surface 46 of wall 37 engages shoulder 43, the connection is made up. A coupling or split clamp 47 engages locking

shoulders

39 and 45 and locks flanges'30 and 31 together.

FIG. 7 shows flange 31 (associated with a desired module) resting on a mounting fixture 50 which is attached to the carriage of a submergible manipulator maintenance system, not shown, that is capable of installing flange 31 (and module) on receiving flange 30 located on the subsea system. Mounting fixture 50 includes sleeve 51 provided with a seal 52 which engages surface 40 of wall 37. An air vent tube 55 extends through fixture 50 into the upper end of cavity 38. A purge oil storage tank 56 is connected into cavity 38 by a conduit or hose 57 which extends through mounting fixture 50 and contains a valve 53 and a releasable connection 54.

As seen in FIGS. 8 and 9, removable flange-module 31 is locked to flange 30 by split clamp 47 which is tightened and loosened (dotted lines shown in FIG. 8) by coupling bolts 70. Flange 39 is mounted on a fixed subsurface unit or housing 71 which contains three

electrical cutout switches

72a, 72b and 720, a junction box 73 and support structure '74 for the switches. Conductors 33a, b and c are connected to the switches as shown. Each switch connects into junction box 73 and a conductor 76 connects junction box 73 to an electrical power source, not shown. All of the equipment in subsurface unit 71 is immersed in a non-conductive liquid such as oil. A switch actuator rod 80, having a hex end 81, is connected to switch relay 72b and by mechanical linkages 82 to cut-out switches 72a and 720 as shown. A switch interlock safety yolk 83 is connected to switch actuator rod 80 external of unit housing 71.

In operation of the electrical connector system flangernodule 31 is placed on fixture 50 as seen in FIG. 7. With valve 53 open oil 60 is drained or pumped into cavity 38. Air indicated at 61 is scavenged from the cavity through open tube 55. When oil exits from tube SS-outlet tube 63, valve 53 is closed or the fill port is otherwise plugged off, the oil fill tube or conduit 57 is removed by disconnecting connection 54 and an oil filled pressure compensation bellows 62, indicated in dashed lines, is attached to the outlet tube 63 of valve 59. This arrangement equates the cavity oil volume with the increasing ambient pressure as the manipulator maintenance equipment, not shown, descends into the ocean. Flange-module 31 and fixture 50 are then deployed to a subsea work station where they confront a failed module as, for example, a failed pump module that is connected by flange 31 to flange 30 of the permanent subsea system. The failed module is identical to the one carried down from the surface. A special purpose end effector, not shown, on the manipulator maintenance system is positioned over bolt 81. A socket wrench in the end effector rotates bolt 81 and rod 80 as indicated by the arrowed line in FIG. 8 and the dash-dot lines 83. As rod 80 is rotated, the switch relay 72b is opened and through iinkages 82

relay switches

72a and 72c are opened and power from the electrical power source to conductors 33a, 33b and 330 is removed. Rotation of bolt 81 also displaces attached interlock safety yolk 83 from its position in front of one of the upper flange bolts 70. Movement of the yolk in this manner allows the manipulator end effector to attach to the upper flange bolts 70 after disengaging from lower bolt 81, unbolt flange 31 and remove the module-flange. Yolk 83 prevents accidental disconnect of the module when the electric power is applied to the connector. Separating the connector hot in a seawater environment would cause a dangerous and unwarranted short circuit condition in the electric powered distribution system.

After removing the failed module, the manipulator maintenance system end effector latches onto the new module-flange 31 located on the carriage and installs it in place of the defective module in a reverse sequence to that recited above. As seen in FIGS. 5 and 6 particularly, as the new module-flange 31 is lowered onto flange 30, the oil in cavity 38 urges seawater from around prongs 11. The sloping configuration of the spikes 13 of prongs 11 facilitates such purging as do the drain grooves 44 located around the periphery of flange 30. In this manner the two connectors are mated under a zero power transfer condition and also brought together and maintained in a dielectric oil environment. Suflicient axial load is applied to

flanges

30 and 31 by the flange clamp 47 as it is bolted down by flange bolts 70 on locking

shoulders

39 and 45 to embed the spikes 13 of prongs 11 into the soft metal pads 24 of prongs 21. This action effects a metalto-metal connection which has a relatively large contact area that affords resistance to fusion of the connectors as well as very low contact resistance which provides low loss power transmission. As makeup force is exerted on the connector halves 10 and 20, the coil load spring 36 is compressed and serves to provide mating force to hold the two connecting halves together over time and thereby ensure a reliable long-term electrical connection that is protected from metal creep. Spring 36 also allows loose machim'ng tolerances to be specified in the manufacture of the assembly. As seen in FIG. 6, the remain ing oil volume indicated at 69' permanent-1y surrounds the electrical connectors and allows continuous power transmission across the connector in a nonconductive oil environment.

Although the connection procedure as herein described uses remotely operable mechanical manipulators, such procedure can also be carried out by divers where water depths permit use of divers. Also, although only oil is mentioned as the non-conductive liquid which surrounds the connection, other dielectric liquids having a specific gravity lighter than the environment water may be used instead. Three sets of

individual connectors

10, 20 are shown and described herein as the preferred embodiment of the invention. However, two connectors or more than three connectors might be used in other type applications.

Changes and modifications may be made in the specific illustrative embodiments of the invention shown and/or described herein without departing from the scope of the invention as defined in the appended claims.

Having fully described the nature, apparatus, method and advantages of our invention, we claim:

1. An electrical connection comprising:

an electric connector unit capable of transmitting electric power having two mateable parts, one of said parts having a prong provided with a plurality of rows of sharp pyramid shaped spikes separated by sloped unidirectional valleys, and the other of said parts having a prong provided with a cup containing a malleable metal.

2. An electrical connection as recited in claim 1 in which said other part also having pins extending through said metal and said cup, said cup being shaped to retain said metal in said cup.

3. Electrical connection apparatus comprising:

at least two electric connector units, each connector unit being capable of transmitting electric power and having two mateable parts, one of said parts having a prong provided with metal spikes formed on one end and the other of said parts having a prong provided with a cup containing malleable metal formed on one end, said spikes being embedded in said malleable metal and said engaged parts being surrounded by non-conductive liquid when said one part and said other part are mated together.

4. Electrical connection apparatus as recited in claim 3 in which said one part includes a prong having a head on said one end thereof provided with a plurality of rows of sharp pyramid shaped spikes separated by sloped unidirectional valleys, said head being surrounded by electrical insulation.

5. Electrical connection apparatus as recited in claim 3 in which said other part includes a prong having a head on one end thereof in the shape of a cup, said cup containing a malleable metal and pins extending through said metal and said cup, said cup being shaped to retain said metal in said cup.

6. Apparatus as recited in claim 3 in which said one part includes a prong having a head on one end thereof provided with a plurality of rows of sharp pyramid shaped spikes separated by sloped unidirectional valleys and surrounded by electrical insulation and said other part includes a prong having a head on one end thereof in the shape of a cup, said cup containing a malleable metal and pins extending through said metal and said cup, said cup being shaped to retain said metal in said cup.

7. Electrical connection apparatus as recited in claim 6:

including a first flange having a bore therethrough;

said spiked prong being immovably arranged in said first flange bore;

a second flange having an insulated bore therethrough;

said cupped prong being immovably arranged in said insulated bore of said second flange;

means biasing said cupped prong in a direction toward said spiked prong; and

stop means arranged on said cupped prong for limiting movement of said cupped prong in said direction to wards said spiked prong.

8. Electrical connection apparatus as recited in claim 7 including said first flange having an external locking shoulder and drain grooves on the external wall thereof;

said second flange forming a cavity, the internal wall of which is adapted to fit over the external wall of said first flange, said second flange having an external locking shoulder; and

clamp means engageable with said locking shoulder for locking said shoulders together.

9. Electrical connection apparatus as recited in claim 8 including:

electrical connectors, each having one end connected to one of said spiked prongs;

electric switch means connected to said first flange;

the other end of each of said conductors being connected to said switch means;

a switch actuator means connected to said switch means and movable from one position in which said switch means prevents flow of electric power to said conductors and another position in which said switch means permits flow of electric power to said conductors;

safety means connected to said switch actuator means having one position which permits release of said clamp means and another position which prevents release of said clamp means;

said switch actuator means being moved by said safety means from said one position of said actuator to said other position of said actuator and vice versa when said safety means is moved from said one position of said safety means to the other position of said safety means and vice versa; and

a source of electric power connected to said swtich means.

10. Electrical connection apparatus as recited in claim 3 including:

a first flange having a bore therethrough;

said spiked prong being immovably arranged in said first flange bore;

a second flange having an insulated bore therethrough;

means biasing said cupped prong in a direction toward said spiked prong;

stop means arranged on said cupped prong for limiting movement of said cupped prong in said direction toward said spiked prong;

said first flange having an external locking shoulder and drain grooves on the external wall thereof;

clamp means engageable with said locking shoulders for locking said shoulders together.

11. Apparatus as recited in claim 10 including electrical conductors, each having one end connected to one of said spiked prongs;

electric switch means connected to said first flange;

the other end of each of said conductors being connected to said switch means;

said switch actuator means being moved by said safety means from said one position of said actuator to said other position of said actuator and vice versa when said safety means is moved from said one position of said safety means .to the other position of said safety means and vice versa; and

a source of electric power connected to said switch means. 12. A method for making an electrical connection in a water environment, in which the components of said electrical connection comprise at least two connector units, each of which comprises two engageable-separable metal parts, a first part being connected to permanently arranged subsea electric power control means and a second part being connected to replaceable electric operated equipment, which comprises the steps of:

covering said second parts of said electric connector units with non-conductive liquid at the waters surface; lowering said second parts together with said replaceable electric operated equipment through the water to adjacent said first parts of said electric connector units while maintaining said second parts covered with said non-conductive liquid; engaging said first and second parts of each connector unit, said non-conductive liquid forcing water from said first parts as said first and second parts are brought into engagement and said non-conductive liquid remaining about said engaged first and second parts.

8. 13. A method as recited in claim 12 including the step of cutting off power to said first parts of said electric connector units prior to disengaging other second parts from' said first parts, said other second parts being connected to electric operated equipment to be replaced, said power cut References Cited UNITED STATES PATENTS 2,490,020 12/1949 Enzler 200-166 BH 2,858,518 10/1958 Chrystie et a1. 339-96 3,522,576 8/1970 Cairns 339-96 3,602,873

8/1971 Childers 339-117 R DAVID SMITH, JR., Primary Examiner U.S. Cl. X.R.