U.S. patent application number 10/240920 was filed with the patent office on 2003-09-11 for method and device for testing a well.
Invention is credited to Sollesnes, Odd.
Application Number | 20030168214 10/240920 |
Document ID | / |
Family ID | 19910995 |
Filed Date | 2003-09-11 |
United States Patent
Application |
20030168214 |
Kind Code |
A1 |
Sollesnes, Odd |
September 11, 2003 |
Method and device for testing a well
Abstract
A method and a device for testing of a well, such as in a well
liner, a newly drilled hole, and the like, is disclosed. The method
is characterised in that a plug is directed down into the well,
that the plug is fixed towards the wall of the well the sealing
means of the plug is activated to seal against the wall of the
well, and after the testing has ceased the sealing function is
removed by disintegrating the plug. Preferably a plug of a
disintegratable material is used, such as a ceramic material, glass
or the like.
Inventors: |
Sollesnes, Odd; (Hanby,
NO) |
Correspondence
Address: |
CARELLA, BYRNE, BAIN, GILFILLAN, CECCHI,
STEWART & OLSTEIN
6 BECKER FARM ROAD
ROSELAND
NJ
07068
US
|
Family ID: |
19910995 |
Appl. No.: |
10/240920 |
Filed: |
April 30, 2003 |
PCT Filed: |
April 6, 2001 |
PCT NO: |
PCT/NO01/00151 |
Current U.S.
Class: |
166/250.08 ;
166/376 |
Current CPC
Class: |
E21B 33/1204 20130101;
E21B 29/00 20130101; E21B 47/117 20200501 |
Class at
Publication: |
166/250.08 ;
166/376 |
International
Class: |
E21B 047/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 7, 2000 |
NO |
20001801 |
Claims
1. Method for testing of a well, such as in a well liner, a newly
drilled hole, and the like, characterised in that a plug is
directed into the hole, that the plug is fixed against the wall of
the well, that the sealing means of the plug are activated to form
a seal with the wall of the well, and after the test is completed,
the sealing function is removed by disintegrating the plug.
2. Method according to claim 1, characterised in that a plug made
from a material which can disintegrate is used.
3. Method according to claims 1-2, characterised in that a chemical
material is used, such as a cold or warm moulded material, such as
compression moulded, sintered or melt cast material.
4. Method according to claims 1-3, characterised in that the plug
is comprised of glass which disintegrates when exposed to pressure,
such as impact pressure from a fluid, at detonation of a smaller
explosive charge/ignition system with time delay, or by means of a
drill bit.
5. Method according to claims 1-4, characterised in that the plug
is disintegrated when exposed to pressure such as impact pressure
from a fluid, or at detonation of an explosive charge/ignition
system.
6. Method according to claims 1-5, characterised in that a plug
which is pre-programmed to be disintegrated with a given time
delay, is applied.
7. Method according to one of the preceding claims, characterised
in that the test is carried out at a pressure which is lower than
the disintegration pressure, whereupon the pressure is increased so
that the plug is destroyed.
8. Method according to claims 1-3, characterised in that a test
plug (40), which is fitted in advance to a section (41) (a liner
section) which shall be placed in the well, is used.
9. Device for testing of a well, such as in a well liner, a newly
drilled hole, and the like, characterised in that a plug which is
arranged to be fixed against a well- or liner wall is used, that
the plug comprises sealing means which are arranged to seal with
the wall of the well, with the plug being comprised of a material
which can disintegrate.
10. Device according to claim 9, characterised in that the plug is
comprised of a ceramic material, such as a cold- or hot moulded
material, such as compression moulded, sintered or melt cast
material.
11. Device according to one of the claims 9-10, characterised in
that the plug is comprised of glass which can be crushed and is
arranged to be disintegrated when exposed to pressure such as
impact pressure from a fluid, at detonation of an explosive
charge/ignition system, preferably with a time delay, or by means
of an external crushing appliance such as a drill bit.
12. Device according to one of the claims 9-11, characterised in
that the plug is comprised of an integrated part comprising means
for being fixed to a string, and the means, such as mutually
displaceable slips for securing the plug against the inner wall of
the liner or well wall, implements such as gasket elements arranged
to be placed against a liner wall or well wall, and implements for
the disintegration, such as an explosive charge with an ignition
system with delayed action.
13. Device according to claims 9-12, characterised in that the plug
is arranged to be disintegrated by exposure to pressure, such as
impact pressure from a fluid, or is comprised of an explosive
charge/ignition system which can be detonated.
14. Device according to claims 9-13, characterised in that a plug
which is pre-programmed to disintegrate with a given timed delay,
is used.
15. Device according to claims 1-3, characterised in that the test
plug (40) is an integral part of a section (41) (a liner section)
for placing in a well.
Description
[0001] The present invention relates to a method and a device as
disclosed in the introduction to the subsequent claims 1 and 9
respectively.
[0002] Furthermore, the invention is concerned with a method and a
device for testing of wells, production pipes and the like during
drilling, testing, logging and production of hydrocarbons, both
from land based sites and offshore.
[0003] Today, leak tests are carried out with the aid of plugs
when, for example, a well liner or a production pipe shall be
pressure tested. The plug is driven down into the hole and fixed.
It is also tested before the real test itself to determine whether
it is leak-proof, and must as a rule be adjusted or replaced. When
the test has been completed, the plug must be brought up from the
hole by means of a special tool. There is a chance that this will
fail, and a larger operation with a fishing tool to bring the plug
up must be initiated.
[0004] There is indeed a known solution where the whole, or parts
of, the plug is manufactured from rubber, and where a section
comprises a chemical which dissolves the rubber plug when the test
is completed and one wishes to remove the plug.
[0005] It is an object of the invention to provide a new type of
plug that completely eliminates the above mentioned problems, i.e.
a plug for which it is absolutely not necessary to pick up the
remains when it is destroyed down in the hole.
[0006] Furthermore, it is an object of the invention to provide a
plug type that does not represent any fouling of the hole.
[0007] The method according to the invention is characterised in
that a plug is conducted down in the well, that the plug is fixed
against the wall of the well, that the sealing means of the plug
are activated to make a seal with the wall of the well, and after
the test has been completed, the sealing function is removed by the
plug being disintegrated.
[0008] Further features of the method are disclosed in the
dependent method claims.
[0009] The device according to the invention is characterised by a
plug which is arranged to be fixed against the wall of the well or
liner, that the plug is comprised of sealing means which are
arranged to make a seal with the wall of the well, with the plug
being comprised of a material which can disintegrate.
[0010] Further features of the invented device are disclosed in the
dependent claims 10-15.
[0011] Provided now is a plug of a material which can disintegrate
or be crushed by an applied pressure, such as impact pressure from
a fluid, by detonation of a small explosive charge/ignition system
with time lag, or by means of a drill bit. The plug material which
can disintegrate or be crushed, is preferably made from a ceramic
material, from glass, or from another material which can be
crushed. Crushed means also that it shall be possible to pulverize
the material into an unproblematic material consisting of small
particles. Furthermore, the material must consist of a material
which is resistant to corroding fluid and gas environments.
Furthermore, the material must be so durable that the plug can
remain in the well as a permanent plug. Furthermore, the plug can
be manufactured in all possible dimensions for the operations where
previously conventional plugs were used.
[0012] Preferably a ceramic material is used, such as a cold or hot
moulded sintered material, such as compression moulded material, or
melt cast material.
[0013] The plugs can be conducted down through a pre-fabricated
casing (liner) of a tube or a wire and be fixed at a desired depth.
The plug is removed by disintegration.
[0014] The plug according to the invention can be pre-fabricated in
a "pop joint" which is fitted to the string at a correct depth, and
then the whole assembly is conducted down into the hole.
[0015] Alternatively, the plug can be driven down in the liner pipe
on a pipe or a wire, and then be fixed at a desired depth. The
plugs are removed as described above. The setting of plugs will
never take more than one run.
[0016] The invention shall now be explained further with reference
to the subsequent figures in which:
[0017] FIG. 1 shows an application of the device according to the
invention in connection with a drilling hole which is served from a
semi-sub platform.
[0018] FIG. 2 shows a cross-section of a plug according to the
invention.
[0019] FIG. 3 shows a test plug fitted to a liner section.
[0020] FIG. 4 shows a test plug which is inserted after the liner
is fitted.
[0021] FIG. 5 shows a plug construction for a casing, and which is
arranged for disintegration by direct mechanical means.
[0022] Initially, reference is made to FIG. 1. Here, a floating
platform (a semi-sub) 10, the surface of the sea 12 and the bottom
of the sea 14, are shown. The platform comprises of a drilling rig
16. A well 18 is drilled into the bed formation 20 and it runs
downwards in an arc shape. The well hole comprises of a liner 22 (a
casing). A plug 24 is placed a distance down into the well. The
plug 24 functions such that it completely closes the passage
through the liner/well hole. Thus, it is possible to carry out a
test of the well. Such a test can mean that the space above the
plug is pressurised. If the space can keep the pressure, it is
considered that the liner is impervious, i.e. no leaks will occur
from any of the areas of the liner pipe and out into the
surrounding formation. The plug 24 can be directed down by being
fitted to the end of an operating string which is then directed
down and is positioned by the string comprising a mechanism which
can activate the securing mechanism of the plug against the wall,
and set the seals against the wall of the liner so that a tight
seal is formed.
[0023] An example of such a plug is shown in FIG. 2. The plug 30 is
an assembled construction of the plug body of the crushable
material 32 itself, and upper 34, middle 36 and lower slips
constructions which are used to set the plug against the pipe
wall/liner 40, and to maintain the necessary seal with the
wall/liner. The slips are wedge-formed elements which are forced
against the wall.
[0024] Indicated schematically at 42, is an explosive charge 42
which is incorporated into the crushable material. This can be
activated by remote control, and will then be blown up so that the
material (especially glass) is pulverised, and opens the fluid
channel. The plug can have a cylindrical shape or have any shape
adapted to the channel in which it shall function. Furthermore, it
can be divided into sections. Instead of its own explosive charge,
one can also carry out the crushing by means of pressure or other
methods as described above.
[0025] Such a plug can also be fitted into an independent
production pipe, or inside a liner, to test if this is
leak-proof.
[0026] FIG. 3 shows an alternative embodiment of a test plug 40
fully fitted in a liner-section 41. This comprises gaskets 44 and
means for connection to the pressure activator 46. The test plug 40
is a pre-fabricated unit which is activated and destroyed with the
aid of pressurising. The plug is fitted into a so-called pop joint,
shown by 42. It is simple to fit, in that it is inserted in the
string at a desired depth, and the operation is as normal with
re-fill for each tenth joint. When the liner pipes (liners)
including the liner-section with the test plug, is placed in the
well, it can be tested as under normal operation.
[0027] 1. In order to activate and destroy the plug, this occurs by
increasing the pressure by +20/30 bar above the test pressure, at
which pressure the plug is destroyed. The pressure can be gradually
increased upwards to the explosion pressure.
[0028] 2. A time delay is achieved by the pressure being increased
up to about 50 bar below the test pressure and being maintained at
this level for a pre-determined time (including the testing
period), for example, for 30 minutes. Thereafter, the plug is
destroyed, for example, by increasing the pressure again.
[0029] With this solution according to the invention, one achieves
that it is unnecessary to use any "fishing" operations to bring up
the plug. One saves one run. With respect to earlier practices, one
can programme the operation, or regulate the inherent properties of
the plug, for a given time delay. And furthermore, it is simple to
adapt to different conditions.
[0030] The mentioned time delay can also arise in that above the
plug, from where the pressure is exerted, is a throttle valve,
which ensures that the effect of the pressure (the increase) for
direct contact with the plug must occur over a given time, before
the explosion pressure is reached.
[0031] FIG. 4 shows a test plug 50, with gaskets/slips 54 which can
be placed in the well after the liner (liner) 56 is fitted. The
test plug 50 can be driven down either on a pipe or a coil tubing,
and be placed at a desired depth by pressurising. The destruction
is initiated by means of pressure over time, or immediately.
[0032] The plug is fitted on a running tool and placed in the well
at the desired depth. The plug 54 is set by increasing the pressure
inside the tube, something which will activate the gaskets and
slips 54. The string and the tool are pulled up and the testing can
start. After the test the plug can be destroyed in two ways
depending on which release/destruction method has been chosen in
advance.
[0033] 1. Immediate destruction, to activate and destroy the plug,
occurs by increasing the pressure by +20/30 bar above the test
pressure, at which pressure the plug is destroyed.
[0034] 2. A time delay is achieved by the pressure being increased
up to about 50 bar below the test pressure and maintained at this
level for a given time (including the test time), for example for
30 minutes. The plug is thereafter destroyed, for example, by the
pressure being increased again.
[0035] FIG. 5 shows a plug 60 which is arranged for disintegration
by direct mechanical means. The plug 60 comprises a float so that
it can be used for casing functions. It can be delivered as a
separate plug including a tool to lower it down. The plug is
destroyed by placing a drill bit in the well (where the drill bit
shall be used for the drilling itself) and then gently striking the
top of the plug with the drill bit so that it is destroyed.
[0036] 1. The plug is easy to use and it is delivered fully
pressure tested fitted onto a pop joint. The pop joint is placed in
the string at a desired depth and the operation is normal with
refill for each tenth joint. When the casing is placed and
cemented, the plug is destroyed by simply driving down the drill
bit and striking the plug so that it is crushed.
[0037] 2. The plug is fitted onto the moving tool and fed down into
the well to a desired depth. The plug is placed by increasing the
pressure inside the pipe, and the gaskets and slips 64 are
activated so that the plug is fixed. Then the string and the tool
can be removed.
[0038] The cementing and testing can then start. When these
operations are completed, the plug can be destroyed in the same way
as above.
[0039] There are many ways in which the plug can be directed down
and fitted/placed. Furthermore, there are many areas within such
activities that have a need for such sealing plugs. The present
invention can be used within all of these.
[0040] The abovementioned description, with reference to the
figures, relates to a preferred embodiment of the invention only,
and is not to be considered as limiting for the present invention.
Thus, the invention can be altered and modified from the framework
disclosed in the subsequent claims.
* * * * *