Flex joint incorporating enclosed conductors

• US 4,842,059 A
• Filed: 09/16/1988
• Issued: 06/27/1989
• Est. Priority Date: 09/16/1988
• Status: Expired due to Fees

• Current Assignee: Halliburton Company
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Tomek, Martin L.
• Primary Examiner(s): NOVOSAD, STEPHEN
• Application Number:
  US07/245,234
• Time in Patent Office: 284 Days
• Field of Search: 166/65.1, 166/242, 285/119, 285/166, 285/264, 174/86
• US Class Current: 166/65.1
• CPC Class Codes: E21B 17/05 Swivel joints
• CPC Class Codes: E21B 17/206 with conductors, e.g. electrical, optical
• CPC Class Codes: F16L 27/0853 with spherical hinge

Abstract

A flex joint for an elongate oil tool which permits flexure and bending while yet protecting electrical conductors is disclosed. The duplicated flex joint incorporates a hollow knuckle having a passage therethrough received in a mating and confining socket terminating in a passage. The knuckle and socket form a flex joint. The flex joint is pinned so that rotation in a conic angle is permitted while rotation of the two components relative to one another is forbidden. The passage is periodically closed by means of a transverse plug, an electrical feedthrough permitting electrical conductors to extend through said plug. The passage is further protected from the intrusion of fluids from the well borehole by means of a spring loaded piston compensating pressurized sealed oil system which operates in an annular space on the exterior of the passage.

Claims

1. A downhole elongate oil tool adapted to flex as required in placing the elongate tool in a crooked well borehole wherein electrical signals are transmitted along conductors along the elongate tool, the elongate tool incorporating a flex tool comprising:

(a) a generally spherical knuckle;

(b) a surrounding socket engaging said knuckle with a limited rotational range relative to a defined axis through said knuckle and socket;

(c) a passage through said knuckle opening at an outlet into said socket;

(d) a serially communicated passage through said socket aligned with said knuckle;

(e) means cooperative with said knuckle and said socket;

(1) permitting flexure in a conic angle relative to an axis through said knuckle and socket; and

(2) preventing relative axial rotation betwen said knuckle and said socket; and

(f) means for filling said passages with a pressure isolated oil bath for contacting structural components in said passages, and further wherein said oil bath is pressure isolated by a piston responsive to external fluid pressure in the well borehole to sustain a pressure on said oil bath equal to and in excess of prevailing external pressure.

2. The flex tool of claim 1 wherein said knuckle passage and said socket passage align to receive electrical conductors therethrough.

3. The apparatus of claim 1 wherein the elongate oil tool includes first and second spaced knuckles cooperatively engaged with first and second sockets as described in claim 1 and said first and second knuckles are at opposite ends of an elongate hollow tubular body and said body has a lengthwise passage therethrough wherein said lengthwise passage receives electrical conductors therethrough and said conductors also pass through said knuckles.

4. The apparatus of claim 3 wherein each of said knuckles has a knuckle passage therethrough and said knuckle passage is closed by a plug to provide pressure fluid isolation at said passage, and said plug supports electrical feedthroughs for the electrical conductors.

5. The apparatus of claim 4 including means for filling said passages with a pressure isolated oil bath for contacting structural components in said passages, and further wherein said oil bath is pressure isolated by a piston responsive to external fluid pressure in the well borehole to sustain a pressure on said oil bath equal to and in excess of prevailing external pressure.

6. The apparatus of claim 5 wherein said elongate hollow tubular body encloses an internal sleeve, said sleeve and said body forming an annular space therebetween and said piston is a ring slidably received therein to define spaced and isolated first and second chambers, said first chamber being connected by a passage means to receive well borehole fluid.

7. The apparatus of claim 6 including a coil spring bearing against said piston to bias movement of said piston.

8. The apparatus of claim 3 including means for filling said passages with a pressure isolated oil bath for structural components in said passages, and further wherein said oil bath is pressure isolated by a piston responsive to external fluid pressure in the well borehole to sustain a pressure on said oil bath equal to and in excess of prevailing external pressure.