The present invention relates to an electrical connector for use in a well; and, more specifically, to a dis-connectable dielectric grease-packed plug that purposefully preserves pressure within a well bore upon separation of an electrical conductor bundle from a wellhead hanger connection.
Occasionally, but fortunately not often, the production tubing on an oil and gas well will fail or “part” (i.e., separate), due to corrosion problems or other severe well conditions. Most often, the tubing will separate at a threaded connection, like a coupling, or at the wellhead tubing hanger, then fall down the well bore. On a well that includes an electrical submersible pump, or down-hole heater, a power cable is fixed to this production tubing, and attached to a wellhead penetrator, or is used on a “feed-thru” type design. If the production tubing parts or separates, it will drop downward, pulling the power cable with it. This puts a severe strain on the fixed electrical penetrators at the surface wellhead, and often negates their sealing capabilities. High-pressure well fluids can then escape from the wellhead into the atmosphere. Currently, a wellhead penetrator that can maintain a reliable and expected seal upon a separation of a tubing connection, or is purpose-built to handle this catastrophic failure, does not exist. However, Applicants have developed a dis-connectable wellhead hanger connection which, if downward force is applied to the connection, allows a “clean” separation, leaving a reliable seal in the tubing hanger and preventing well fluids from escaping into the atmosphere. In an alternative embodiment disclosed herein, the pin connection is moved into a sealed housing connected to the wellhead adapter, thereby allowing through-wellhead electrical conductors to be retrofitted with pin sockets which maintain the seal on the wellhead assembly. Typically, prior connections were made with cleaned pins inserted in a dry female plug. A new pin structure and method of installation is described covering the male pin with a dielectric grease facilitating the connection process and eliminating all air pockets around the pin thereby insuring a connection unlikely to blow apart upon significant changes of pressure within the wellhead under operation.
This well bore connector comprises a wellhead hanger adapted to seat in a well head; an electrical connector mandrel inserted in the wellhead hanger; a female pin connection socket inserted in the electrical connector mandrel; a mini-mandrel or feed through assembly inserted in the wellhead hanger having one or more electrical conductors sealed within the mandrel and extending from the mandrel; a male pin attached to a stripped end of an electrical conductor extending from the mini-mandrel or feed through assembly inserted into the female pin socket; a dis-connectable connection between the female pin socket and male pin within the wellhead hanger, permitting separation of the mini-mandrel or feed through assembly from the electrical connector mandrel, sealing the well bore to prevent fluids from release upon disconnection.
The well bore connector provides a shoulder within the wellhead hanger to seat the electrical connector mandrel and provides O-rings to seal the electrical connector mandrel in the wellhead hanger to inhibit migration of fluids up the wellhead hanger.
The electrical connector mandrel of the well bore connector is fabricated from polyether ether ketone (PEEK) and provides a shoulder to seat the female pin socket within the mandrel and a snap ring to retain the female pin socket within the mandrel. Additionally, the exterior of the female pin socket provides O-rings to seal against migration of fluids up the interior of the electrical connector mandrel and the interior of the female pin socket provides contact bands to establish a low resistance electrical connection with the male pin.
Moreover, the well bore connector described herein seals the exterior of the mini-mandrel or feed through assembly with O-rings against migration of fluids up the interior of the electrical connector mandrel and the wellhead hanger. The interior of the mini-mandrel or feed through assembly is preferably filed with epoxy around each of the one or more electrical conductors.
The well bore connector can also provide the electrical connector mandrel a stainless-steel collar between the wellhead hanger shoulder and the shoulder on the electrical connector mandrel which inhibits excessive deformation of the electrical connector mandrel in hot, high temperature wells.
Additional features that can be provided by this device include: threads for connection of a wellhead sub assembly to the electrical connector mandrel or an annular space permitting the packing of the wellhead hanger with a dielectric grease on the surface side of the wellhead hanger to inhibit the ingress of water or other contaminants into the electrical connector mandrel.
The wellhead connector can also provide the electrical connector mandrel with threads for connection of a wellhead sub-assembly to the electrical connector mandrel and a wellhead hanger which provides threads for connection of the wellhead sub assembly to the wellhead hanger.
The exterior surface of the male pin of the well bore connector provides a longitudinal slot or groove permitting excess dielectric grease covering the male pin, prior to insertion with the female pin socket, to be extruded.
Applicants also claim a well bore connector assembly connected in a wellhead hanger comprising an electrical connector mandrel inserted in the well-bore connector assembly; a female pin connection socket inserted in the electrical connector mandrel; a mini-mandrel or feed through assembly inserted in the well-bore connector assembly having one or more electrical conductors sealed within the mandrel and extending from the mandrel; a male pin attached to a stripped end of an electrical conductor extending from the mini-mandrel or feed through assembly inserted into the female pin socket; a dis-connectable connection between the female pin socket and male pin, within the well-bore connector assembly permitting separation between the electrical connector mandrel from the mini-mandrel, sealing the well bore and the well-bore connector assembly to prevent fluids from release upon disconnection. This unitary device could be assembled off-site and installed with a compatible wellhead hanger without undue delay. Each of the features of this device replicate the features of the well bore connector previously described herein.
This application also claims a method for installing a dis-connectable electrical connection for use in a wellhead hanger which can comprise the steps of connecting a female pin connector socket to a stripped end of a upper pig tail conductor; inserting the female pin connector socket into an electrical connector mandrel until an upper end of the female pin socket seats against an internal shoulder within the electrical connector mandrel; connecting a male pin connector socket to a stripped end of a lower electrical conductor; and, inserting the male pin connector through a snap ring for insertion in the electrical conductor mandrel until the male pin engages a plurality of contact bands within the female socket end and the snap ring engages in a channel formed within an interior surface of the electrical connector mandrel.
The method of assembly can further comprise the step of covering the male pin with dielectric grease before insertion in the female pin socket to prevent ingress of fluids into the pin connection and inserting the completed assembly into a wellhead hanger. Assembly of the well bore connector assembly is readily accomplished. The assembly would be completed and taken to the wellhead having an appropriate wellhead hanger and inserted in the wellhead hanger and screwed into place by the technician retaining the complete assembly in the wellhead.
Alternatively, a wellhead extension can be connected to a wellhead adapter flange affixed to a wellhead providing an attached pressure-preserving housing, a plurality of feed-through electrical conductors attachable to sockets, contained within an insulative sleeve, joining each electrical conductor to a surface electrical source.
This alternative means for pressure-preserving attachment can be accomplished by a method for installation of the wellhead extension comprising the steps of stripping the exterior insulation from each of the electrical conductors extended from the wellhead mandrel to an exterior of a wellhead adapter flange, then inserting each stripped conductor extending from the wellhead adapter flange into a socket inserting each socket into a polyether ether ketone (PEEK) sleeve enclosed within an exterior pressure-preserving housing and capping the exterior pressure-preserving housing, joining the exterior power supply to the feed-through electrical conductors extending from the wellhead. Claims 1-17 are as provided in the prior approved application except for claim 14 which was cancelled in a prior office response. Drawings of
Upon installation of this assembly, a female pin connection socket 113 of
All of the described embodiments, shown in
Similarly,
Finally,
Dielectric grease, such as Dow Corning Corporation's DC 111, coats the exterior of the insulation of the electric conductor cable 118, to prevent ingress of fluids which might short the electrical connection between the male and female sockets. The same dielectric grease can be used to coat the upper electrical conductor set 111, 111′ as they enter the exterior of the wellhead hanger through the seal subs 307, 407 in
Upon separation of the production tubing from below the wellhead hanger, the mini-mandrel or feed through assembly 105, in each figure would drop away from the electrical connector mandrel 103, 203 as shown more specifically in
Each of the embodiments shown herein is structurally similar. Only changes in the wellhead hanger are made to accommodate the needs of the particular application of this invention. For example,
Similarly, another embodiment can allow connection of the disconnectable assembly to a canned pump coupling as shown in
Alternatively, as shown in
As shown in
Each conductor crimp socket is inserted within PEEK sleeve 1111 which insulates the crimp sockets from the exterior housing 1101 fabricated from either stainless steel or 4130 steel, and which is threaded using threads 1101′ into flange adapter 195 of
Each of the alternative disclosed herein derive from a common structure and are variations of the disclosure made herein. Other alternatives can be fashioned from a similar disclosure without departing from the spirit or intent of this invention.
The accompanying drawings and description referred to herein are illustrative of the invention but not restrictive thereof and together with the description serve only to explain the principles of the invention claimed herein.
This application is a continuation of U.S. application Ser. No. 16/364,770, filed Mar. 26, 2019, which is a continuation-in-part of U.S. application Ser. No. 14/891,253, filed Nov. 13, 2015, now U.S. Pat. No. 10,280,701, which is a U.S. National Stage Application of International Application No. PCT/US14/00092, filed May 14, 2014, which claims priority to U.S. Provisional Application No. 61/823,054, filed May 14, 2013, and U.S. Provisional Application No. 61/863,086, filed Aug. 7, 2013, each of which are incorporated by reference herein as if copied verbatim in their entirety.
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Number | Date | Country | |
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20210230959 A1 | Jul 2021 | US |
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61863086 | Aug 2013 | US | |
61823054 | May 2013 | US |
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Parent | 16364770 | Mar 2019 | US |
Child | 17227987 | US |
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Parent | 14891253 | US | |
Child | 16364770 | US |