External gap assembly
An external gap assembly for a gap sub includes a plurality of non-conductive spacer rings and a plurality of high-strength conductive spacer rings arranged in an alternating pattern about an exterior of the gap sub, a non-conductive external gap seal sleeve disposed beneath the spacer rings that electrically insulates the conductive spacer rings from upper and lower conductive portions of the gap sub, and a plurality of seals disposed between an internal diameter of an upper conductive portion and an interior diameter of a lower conductive portion of the gap sub and the non-conductive external gap seal sleeve. Advantageously, the resistance of the non-conductive gap may be controllably increased, compression and torque on the stack may be controlled, and conductive drilling fluids may be prevented from penetrating the gap sub, thereby enhancing transmission efficiency.
1 . An external gap assembly for a gap sub comprising:
a plurality of non-conductive spacer rings and a plurality of high-strength conductive spacer rings arranged in an alternating pattern about an exterior of the gap sub;
a non-conductive external gap seal sleeve disposed beneath the spacer rings that electrically insulates the conductive spacer rings from an upper conductive portion and a lower conductive portion of the gap sub;
a plurality of interior seals disposed on an internal diameter of the corresponding plurality of non-conductive spacer rings in between the non-conductive spacer rings and a first side of the non-conductive external gap seal sleeve;
a first seal disposed between an internal diameter of the upper conductive portion and the first side of the non-conductive external gap seal sleeve; and
a second seal disposed between an internal diameter of the lower conductive portion and a second side of the non-conductive external gap seal sleeve,
wherein the arrangement of the plurality of interior seals, the first seal, and the second seal prevent all internal fluid pathways between all high-strength conductive spacer rings and both the upper conductive portion and the lower conductive portion.
2 . The external gap assembly of claim 1 , further comprising an interior ceramic torque shoulder ring disposed on an interior between the upper and lower conductive portions of the gap sub.
3 . The external gap assembly of claim 1 , wherein the alternating pattern begins and ends with a non-conductive spacer ring.
4 . The external gap assembly of claim 1 , wherein the alternating pattern comprises 4 non-conductive spacer rings and 3 high-strength conductive spacer rings.
5 . The external gap assembly of claim 1 , wherein the alternating pattern comprises 10 non-conductive spacer rings and 9 high-strength conductive spacer rings.
6 . The external gap assembly of claim 1 , wherein an external gap length can be modified by adding or removing spacer rings to achieve a desired external gap length or target impedance.
7 . The external gap assembly of claim 1 , wherein each of the plurality of non-conductive spacer rings and the plurality of high-strength conductive spacer rings comprise interlocking shapes such that the non-conductive spacer rings cannot deform radially outward.
8 . The external gap assembly of claim 1 , wherein the plurality of non-conductive spacer rings and high-strength conductive spacer rings are put under compression when an upper conductive portion and a lower conductive portion of the gap sub are removably attached to one another that allows for positive control for a stack of the plurality of non-conductive spacer rings and the plurality of high-strength conductive spacer rings that permits optimal sealing at a plurality of sides of each of the plurality of non-conductive spacer rings.
9 . The external gap assembly of claim 1 , wherein the non-conductive spacer rings are composed of polyetheretherketone, non-conductive thermoplastic polymers, thermoset polymers, or combinations thereof.
10 . The external gap assembly of claim 1 , wherein the high-strength conductive spacer rings are composed of non-magnetic stainless steel, non-magnetic metal alloys, ceramics, non-stainless steel, or alloys or combinations thereof.
11 . The external gap assembly of claim 1 , wherein the non-conductive external gap seal sleeve is composed of polyetheretherketone, non-conductive thermoplastic polymers, thermoset polymers, or combinations thereof.
12 . A gap sub comprising:
a tubular comprising an upper conductive portion and a lower conductive portion that are electrically insulated from one another;
an external gap assembly comprising a plurality of non-conductive spacer rings and a plurality of high-strength conductive spacer rings arranged in an alternating pattern about an exterior of the tubular; and
a non-conductive external gap seal sleeve disposed beneath the spacer rings that electrically insulates the conductive spacer rings from the upper conductive portion and the lower conductive portion of the tubular;
a plurality of interior seals disposed on an internal diameter of the corresponding plurality of non-conductive spacer rings in between the non-conductive spacer rings and a first side of the non-conductive external gap seal sleeve;
a first seal disposed between an internal diameter of the upper conductive portion and the first side of the non-conductive external gap seal sleeve; and
a second seal disposed between an internal diameter of the lower conductive portion and a second side of the non-conductive external gap seal sleeve,
wherein the arrangement of the plurality of interior seals, the first seal, and the second seal prevent all internal fluid pathways between all high-strength conductive spacer rings and both the upper conductive portion and the lower conductive portion.
13 . The gap sub of claim 12 , further comprising an interior ceramic torque shoulder ring disposed on an interior between the upper and lower conductive portions of the gab sub.
14 . The gap sub of claim 12 , wherein the alternating pattern begins and ends with a non-conductive spacer ring.
15 . The gap sub of claim 12 , wherein the alternating pattern comprises 4 non-conductive spacer rings and 3 high-strength conductive spacer rings.
16 . The gap sub of claim 12 , wherein the alternating pattern comprises 10 non-conductive spacer rings and 9 high-strength conductive spacer rings.
17 . The gap sub of claim 12 , wherein an external gap length can be modified by adding or removing spacer rings to achieve a desired external gap length or target impedance.
18 . The gap sub of claim 12 , wherein the plurality of non-conductive spacer rings and the plurality of high-strength conductive spacer rings comprise interlocking shapes such that the non-conductive spacer rings cannot deform radially outward.
19 . The gap sub of claim 12 , wherein the plurality of non-conductive spacer rings and high-strength conductive spacer rings are put under compression when an upper conductive portion and a lower conductive portion of the gap sub are removably attached to one another that allows for positive control for a stack of the plurality of non-conductive spacer rings and the plurality of high-strength conductive spacer rings that permits optimal sealing at a plurality of sides of each of the plurality of non-conductive spacer rings.
20 . The gap sub of claim 12 , wherein the non-conductive spacer rings are composed of polyetheretherketone, non-conductive thermoplastic polymer, or combinations thereof.
21 . The gap sub of claim 12 , wherein the high-strength conductive spacer rings are composed of non-magnetic stainless steel, non-magnetic metal alloys, ceramics, non-stainless steel, or alloys, or combinations thereof.
22 . The gap sub of claim 12 , wherein the non-conductive external gap seal sleeve is composed of polyetheretherketone, non-conductive thermoplastic polymers, thermoset polymers, or combinations thereof.