U.S. patent application number 09/247472 was filed with the patent office on 2001-05-24 for oil well separation method and apparatus.
Invention is credited to BARRETT, JAMES, MISZEWSKI, ANTONI, STEVENS, RICHARD.
Application Number | 20010001420 09/247472 |
Document ID | / |
Family ID | 26313077 |
Filed Date | 2001-05-24 |
United States Patent
Application |
20010001420 |
Kind Code |
A1 |
MISZEWSKI, ANTONI ; et
al. |
May 24, 2001 |
OIL WELL SEPARATION METHOD AND APPARATUS
Abstract
The present invention provides separation method and apparatus
for separating components used in downhole well development
activity, whilst in position down the well. Method and apparatus
are characterized in that they do not make use of external
mechanical forces, or internal fluid pressure, applied through the
development apparatus to render the components in a separable
state. The release is achieved through the use of a fusible metal
element.
Inventors: |
MISZEWSKI, ANTONI; (DEVON,
GB) ; BARRETT, JAMES; (DEVON, GB) ; STEVENS,
RICHARD; (HAMPSHIRE, GB) |
Correspondence
Address: |
THE FIRM OF KARL F ROSS
5676 RIVERDALE AVENUE
PO BOX 900
RIVERDALE (BRONX)
NY
10471-0900
US
|
Family ID: |
26313077 |
Appl. No.: |
09/247472 |
Filed: |
February 8, 1999 |
Current U.S.
Class: |
166/376 ;
166/377; 166/65.1 |
Current CPC
Class: |
E21B 17/06 20130101 |
Class at
Publication: |
166/376 ;
166/377; 166/65.1 |
International
Class: |
E21B 017/06 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 9, 1998 |
GB |
9802633.9 |
Nov 14, 1998 |
GB |
9824933.7 |
Claims
Claims:
1. Separation apparatus operable to separate components positioned
down a well, said apparatus including a substantially cylindrical
body section able to withstand loads in tension, compression and
torsion; and electrically operable release means operable to
separate parts of said body section, said release means being
operable independently of any supply of fluid under pressure to
said or through said body and independently of any tension,
compression or torsion loads applied to said body section,
characterized in that the release means comprises a fusible metal
component.
2. Apparatus as claimed in claim 1, characterised in that the
apparatus is adapted to be connected to an end of a coiled tube and
comprises a throughbore through said body section to allow fluid
under pressure to be conveyed through said apparatus.
3. Apparatus as claimed in claim 2 when constructed and arranged to
receive fluid under pressure from the environment surrounding said
apparatus, when submerged down a well, to cause said parts to
undergo relative displacement.
4. Apparatus as claimed in claim 1, characterised in that the
apparatus is adapted to be connected to a wireline.
5. Apparatus according to any previous claim wherein the metal
includes tin and/or bismuth.
6. Separation apparatus when constructed arranged and operable
substantially as herein before described with reference to, and as
illustrated in, the accompanying drawings.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a separation method and apparatus,
and has been devised, in particular, to provide a method of, and
apparatus for, separating components situated down a drilled
well.
BACKGROUND
[0002] In the development of oil wells, and in intervention
operations, coiled tubing is used extensively to deploy a variety
of tools down the well, and it is now becoming commonplace to run
single or multi-cored armoured electrical cable within such
tubing.
[0003] As the depth of wells increase, along with the complexity of
the wells and the varying configurations of the various tools, the
danger of a tool becoming stuck somewhere in a well becomes
greater. The consequences of a tool becoming stuck in a well are
potentially costly and may include loss of, or damage to, the
downhole tool, the coiled tubing, and/or the well itself.
[0004] Thus, in the event of a tool becoming stuck in a well, it is
desirable to be able to separate the tool from the tubing, in a
controlled way, using a purpose built release mechanism.
[0005] Release mechanisms exist in various forms, operated
variously by pressure applied through the coiled tubing, or by
direct pull. However such existing mechanisms tend to restrict the
scope of operations of the equipment. For example, in the case of
direct pull operated release, the design maximum loads expected in
normal execution of a job must fall below the separation load of
the release mechanism by a considerable safety margin, to avoid
unwanted release. In the case of a pressure operated release,
operations which involve pumping a fluid through the coiled tubing
(e.g. lifting or killing the well) must be closely monitored to
ensure that the differential pressure created in the tube, by
pumping, does not reach that at which disconnection will occur.
This increases the time taken for the pumping operation.
[0006] It is an object of the present invention to provide a
separation method and apparatus which will address the aforegoing
problems or which will at least provide a useful choice.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the invention, there is provided
separation apparatus operable to separate components positioned
down a well, said apparatus including a substantially cylindrical
body section able to withstand loads in tension, compression and
torsion; and electrically operable release means operable to
separate parts of said body section, said release means being
operable independently of any supply of fluid under pressure to
said or through said body and independently of any tension,
compression or torsion loads applied to said body section,
characterized in that the release means comprises a fusible metal
component.
[0008] The invention also provides apparatus adapted to be
connected to an end of a coiled tube and comprises a through-bore
through said body section to allow fluid under pressure to be
conveyed through said apparatus.
[0009] The apparatus is preferably constructed and arranged to
receive fluid under pressure from the environment surrounding, said
apparatus, when submerged down a well, to cause said parts to
undergo relative displacement.
[0010] The invention also provides apparatus adapted to be
connected to a wireline.
[0011] The invention also provides apparatus wherein the metal
includes tin and/or bismuth.
[0012] Preferably said release means includes a release catch
operable by the melting of the fusible metal element, after which
parts of said body section may be displaced with respect to one
another to effect separation. Whilst some form of mechanical
biasing means may be provided to displace the parts of said body
section with respect to one another, the apparatus is preferably
constructed and arranged to receive fluid under pressure from the
environment surrounding said apparatus, when submerged down a well,
to cause said parts to undergo relative displacement.
[0013] Preferably said apparatus is as hereinafter described.
[0014] Many variations in the way the present invention might be
performed will present themselves to those skilled in the art. The
description which follows is intended only as an illustration and
the absence of particular alternatives or variants should in no way
be applied to limit the scope of the invention. Such description of
specific elements as follows should also be interpreted as
including equivalents whether existing now or in the future. The
scope of the invention should be determined solely by the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] One form of apparatus embodying the invention will now be
described with reference to the accompanying drawings in which:
[0016] FIG. 1 shows a vertical section through separation apparatus
according to the invention, in an assembled state;
[0017] FIG. 2 shows a similar view to FIG. 1 but with the apparatus
in a state of partial release; and
[0018] FIG. 3 shows a similar view to FIGS. 1 and 2 but with the
apparatus in a state of full release.
[0019] FIG. 4 shows a further embodiment of the apparatus of the
invention adapted for use with wire based systems.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
[0020] Referring to FIGS. 1 to 3 of the drawings, the present
invention provides separation apparatus 5 having a generally
cylindrical body section 6. The upper end 7 of the body section is
configured for attachment to a tool (not shown) above, or to the
lower end of coiled tubing (not shown) of the type used in well
development. The lower end 8 of the body section is configured for
engagement with an industry standard fishing neck, shown in outline
by reference numeral 9.
[0021] In the form shown the body section is composed of three
principal parts, an upper adapter 10, a release mandrel 11, and an
outer sleeve 12. Release means, generally designated 13, retain the
parts together during normal well development operations, but allow
separation of the componentry mounted on the lower end 8 from that
engaging upper end 7 in a manner which will be described
hereinafter.
[0022] The components 10, 11 and 12 are splined together to permit
torsional loads to be applied through the apparatus, the components
10 and 11 also being interconnected in such a way as to allow
tension and compression forces to be applied therethrough.
[0023] The upper adapter 10 is, itself, a generally cylindrical
member having a through-bore 14 through which, in use, fluid may be
passed under pressure for use in well development procedures. Such
procedures may comprise, for example, powering a drill motor,
lifting or killing the well. The upper adapter extends for
substantially the entire length of the body section and engages the
inner surface of the release mandrel at its lower end.
[0024] The outer surface of the upper adapter is stepped at 15 to
receive the outer sleeve 12 and ensure the outer surface of the
apparatus presents a relatively smooth cylindrical surface. The
upper adapter 10 is further stepped at 16 so as to, in combination
with the inner surface of the sleeve 12, define a drain chamber 17
above the release means 13. A further chamber 18 is defined between
the outer sleeve and the upper adapter below the release means.
Finally, the outer adapter includes a plurality of blind holes 19
which contribute to the release function as described below.
[0025] The outer sleeve 12 is a simple cylindrical member engaging
the upper adapter 10 at its upper end, and sliding over the upper
end of the release mandrel 11 at its lower end. Radial vent holes
20 place the chamber 18 in communication with the atmosphere
surrounding the apparatus.
[0026] The release mandrel 11 includes, at its lower end, the
adaptation 8 configured to engage the industry standard neck 9.
Extending upwardly therefrom, and passing through the chamber 18,
are a plurality of sprung fingers 21 having a series of peripheral
threads 22 about the upper edges thereof, which threads 22 engage
corresponding peripheral threads 23 extending about the outer
surface of the upper adapter. It will be appreciated that these
inter engaged threads permit tension and compression forces to be
applied through the apparatus. The fingers 21 are sprung so as to
engage threads 22 with threads 23. The threads are normally secured
against disengagement by the release means 13. However, when the
release means 13 is operated, and the security removed, a minor
tension force applied to the upper adaptor will cause threads 22 to
ride over threads 23.
[0027] The release means 13 comprises a ball cage 25 having a
series of radial holes 26 therein which align with the holes 19 and
serve, in combination with ball retaining ring 28, to locate and
retain ball bearings 27 which provide a locking function. The
components are sized so that ball bearings 27 will be expelled from
holes 19 upon axial movement of the ball retaining ring 28.
[0028] A fusible metal assembly 29 is retained axially, between the
ball retaining ring 28 and the ball cage 25. The fusible metal
assembly consists of a ring 30 of cast, low melting point metal,
surrounded by a jacket 31 of heat insulating material. An
electrical heating element 32 is embedded in the metal ring 30
whilst a drain port 33 is provided through the upper edge of the
insulating jacket 31 so as to place the metal ring 30 in
communication with the drain chamber 17.
[0029] The material of the fusible metal assembly may be a
relatively pure metal or an alloy. If it is an alloy, it is
preferably such that it has a relatively well-defined melting
point, such as a near eutectic alloy, rather than one which has a
relatively broad temperature range between beginning to soften and
fully liquid, such as a solder. Convenient materials for the metal
include tin, bismuth, and various alloys thereof.
[0030] Finally the release means 13 includes a release sleeve 35
which fits over the outside of the sprung fingers 21 of the release
mandrel, and thus normally serves to retain the threads 22 in
engagement with the threads 23. The release sleeve 35 is capable of
axial movement and a hydraulic seal is formed between the release
sleeve, the outer sleeve, and the fingers such that the release
sleeve may act as a piston. It will be seen that the lower edge of
the release sleeve forms part of the upper boundary of chamber
18.
[0031] The release operation of the apparatus will now be
described.
[0032] The apparatus is assembled at ground level. For this reason,
the sealed drain chamber 17 is at atmospheric pressure. As the
apparatus enters a well, the pressure surrounding the apparatus
increases with depth. Fluid or gas under pressure from the well
enters chamber 18 through vent holes 20 and this fluid or gas
causes an upwards force on the release sleeve 35 which is resisted
by the ball cage 25.
[0033] Referring now to FIGS. 2 & 3, if it is required to
operate the release, an electrical current is passed through the
element 32 embedded in the fusible metal assembly. This causes the
metal ring 30 to melt and the molten metal to flow into drain
chamber 17 through drain port 33.
[0034] As the metal ring 30 melts and collapses, the release sleeve
35, under the bias of the pressure in chamber 18, displaces the
ball retaining ring 28 axially and allows the ball bearings 27 to
release from holes 19. This then permits the ball cage 25 to move
axially until the release sleeve clears the sprung fingers 21 as
shown in FIG. 3. As the release sleeve 3 5 clears the fingers 21,
the security restraint maintaining threads 22 in contact with
threads 23 is removed. In this situation, application of a
relatively minor tensile load to the upper adaptor 10 will cause
threads 22 to ride over threads 23 and, in turn, permit the upper
adapter to be drawn away.
[0035] When the upper adaptor is pulled clear, unimpeded access is
permitted to an industry standard fishing neck in the downhole half
of the tool.
[0036] It will thus be appreciated that the invention provides a
form of separation apparatus which permits all usual well
development activity to proceed without risk of separation, yet
permits easy separation when required.
[0037] FIG. 4 shows a further embodiment of the apparatus 105
adapted for use with wire line based systems. The corresponding
parts of the apparatus are essentially the same as in the
embodiment described in FIGS. 1 to 3 and the same identifying
numerals have been used. In this embodiment, the upper end 7 of the
body section is configured for attachment to a wire line connecting
tool 101 by means of a central rod 102, and the connecting means
101 is secured to the suspending wire 103. In all other respects,
the apparatus operates in the same way as described for the
previous embodiment.
* * * * *