Downhole sealing tool

Patent metadata

Field	Value
Publication number	US-2017247971-A1
Application number	US-201515514030-A
Country	US
Kind code	A1
Filing date	Sep 25, 2015
Priority date	Sep 25, 2014
Publication date	Aug 31, 2017
Grant date	—

Abstract

A sealing tool for conveyance within a tubular member within a wellbore extending into a subterranean formation. The sealing tool includes a mandrel and a eutectic sealing material disposed about the mandrel. The eutectic sealing material has a eutectic temperature at which the eutectic sealing material melts. The sealing tool also includes means for heating the eutectic sealing material to at least the eutectic temperature. The eutectic sealing material is transferred onto an inner surface of the tubular member by activating the heating means to heat the eutectic sealing material to at least the eutectic temperature to melt the eutectic sealing material.

First claim

What is claimed is:

1 . An apparatus, comprising:
a sealing tool for conveyance within a tubular member within a wellbore extending into a subterranean formation, wherein the sealing tool comprises:
a mandrel;
a eutectic sealing material disposed about the mandrel, wherein the eutectic sealing material has a eutectic temperature at which the eutectic sealing material melts; and
means for heating the eutectic sealing material to at least the eutectic temperature.

2 . The apparatus of claim 1 wherein the tubular member is a casing member secured within the wellbore.

3 . The apparatus of claim 1 wherein the tubular member is a portion of completion/production tubing installed within the wellbore.

4 . The apparatus of claim 1 wherein the eutectic sealing material comprises an alloy of two or more different metals each having an individual melting temperature that is greater than the eutectic temperature.

5 . The apparatus of claim 1 wherein the eutectic sealing material substantially comprises a bismuth-based alloy.

6 . The apparatus of claim 5 wherein the bismuth-based alloy substantially comprises 58% bismuth and 42% tin, by weight.

7 . The apparatus of claim 1 wherein the mandrel comprises a downhole portion having a first outer diameter that is substantially larger than a second outer diameter of the rest of the mandrel, and wherein a surface transitioning between the first and second outer diameters defines a spreader that urges the eutectic sealing material melted by the heating means radially outward toward an inner surface of the tubular member.

8 . The apparatus of claim 7 wherein the spreader is a substantially frustoconical surface extending axially tapered between the first and second outer diameters and circumferentially extending substantially continuously around the mandrel.

9 . The apparatus of claim 7 wherein the downhole portion of the mandrel comprises a plurality of heat-dissipating features each extending into an outer surface of the downhole portion.

10 . The apparatus of claim 7 wherein the downhole portion of the mandrel comprises a plurality of heat-dissipating features each extending into a cavity that extends into a downhole end of the mandrel.

11 . The apparatus of claim 1 wherein the sealing tool further comprises a sealing member operable to fixedly engage with the tubular member, slidably engage with the mandrel, and form a fluid seal between the tubular member and the mandrel.

12 . The apparatus of claim 1 wherein the heating means comprises an electrical heating coil disposed within the mandrel.

13 . The apparatus of claim 1 wherein the heating means comprises means for activating a heat-generating chemical reaction.

14 . The apparatus of claim 1 wherein the heating means comprises a plurality of heating element probes each contacting the eutectic sealing material.

15 . The apparatus of claim 14 wherein the sealing tool further comprises a brittle material securing the eutectic sealing material around the mandrel.

16 . The apparatus of claim 14 wherein the heating element probes each extend along a longitudinal length of the eutectic sealing material.

17 . The apparatus of claim 16 wherein the heating element probes each extend diagonally and/or helically with respect to a longitudinal axis of the sealing tool.

18 . The apparatus of claim 14 wherein the eutectic sealing material is circumferentially partitioned into a plurality of portions by a corresponding plurality of barriers each extending radially and longitudinally between neighboring ones of the portions of the eutectic sealing material.

19 . The apparatus of claim 18 wherein the heating element probes, the portions of the eutectic sealing material, and the barriers each extend diagonally and/or helically with respect to a longitudinal axis of the sealing tool, and wherein each heating element probe extends within a central region of a corresponding portion of the eutectic sealing material between neighboring ones of the barriers.

20 . The apparatus of claim 1 wherein the sealing tool is operable for conveyance within the tubular member via coiled tubing.

21 . A method, comprising:
conveying a sealing tool within a tubular member within a wellbore extending into a subterranean formation, wherein the sealing tool comprises:
a mandrel;
a eutectic sealing material disposed about the mandrel, wherein the eutectic sealing material has a eutectic temperature at which the eutectic sealing material melts; and
means for heating the eutectic sealing material to at least the eutectic temperature; and
transferring the eutectic sealing material onto an inner surface of the tubular member by activating the heating means to heat the eutectic sealing material to at least the eutectic temperature to melt the eutectic sealing material.

22 . The method of claim 21 wherein conveying the sealing tool within the tubular member comprises conveying the sealing tool via coiled tubing.

23 . The method of claim 21 wherein conveying the sealing tool within the tubular member comprises conveying the sealing tool to a damaged portion of the tubular member, and wherein transferring the eutectic sealing material onto the inner surface of the tubular member comprises covering the damaged portion of the tubular member with the transferred eutectic sealing material.

24 . The method of claim 21 wherein transferring the eutectic sealing material onto the inner surface of the tubular member comprises plugging the tubular member by substantially filling a longitudinal portion of the tubular member.

25 . The method of claim 24 wherein substantially filling the longitudinal portion of the tubular member comprises substantially filling the longitudinal portion with the transferred eutectic sealing material.

26 . The method of claim 21 wherein transferring the eutectic sealing material onto the inner surface of the tubular member comprises axially moving the sealing tool within the tubular member after activating the heating means but before the melted eutectic sealing material transferred onto the inner surface of the tubular member is permitted to completely solidify, such that a feature of the sealing tool spreads the melted eutectic sealing material around the inner surface of the tubular member as the sealing tool moves axially past the melted eutectic sealing material.

27 . The method of claim 26 wherein the transferred eutectic sealing material spread around the inner surface of the tubular member has a thickness ranging between about 5 millimeters and about 25 millimeters.

28 . The method of claim 21 the heating means comprises an electrical coil, and wherein activating the heating means comprises electrically energizing the electrical coil.

29 . The method of claim 21 further comprising, after conveying the sealing tool within the tubular member and before transferring the eutectic sealing material onto the inner surface of the tubular member, engaging a sealing member of the sealing tool with the inner surface of the tubular member to form a fluid seal between the inner surface of the tubular member and the mandrel.

30 . The method of claim 29 wherein transferring the eutectic sealing material onto the inner surface of the tubular member comprises pressurizing the melted eutec

Assignees

• Schlumberger Technology Corp

Inventors

• Rivas Diaz Oscar

Classifications

• E21B33/138

  Plastering the borehole wall; Injecting into the formation · CPC title

• E21B33/12

  Packers; Plugs (used for cementing E21B33/134, E21B33/16) · CPC title

• E21B17/20

  Flexible or articulated drilling pipes {, e.g. flexible or articulated rods, pipes or cables} · CPC title

• E21B29/002

  Cutting, e.g. milling, a pipe with a cutter rotating along the circumference of the pipe · CPC title

• E21B33/13

  Methods or devices for cementing, for plugging holes, crevices or the like · CPC title