U.S. patent application number 14/122727 was filed with the patent office on 2014-04-17 for formation penetrating tool.
This patent application is currently assigned to WELLTEC A/S. The applicant listed for this patent is Jorgen Hallundb.ae butted.k, Lars Mangal. Invention is credited to Jorgen Hallundb.ae butted.k, Lars Mangal.
Application Number | 20140102801 14/122727 |
Document ID | / |
Family ID | 46197263 |
Filed Date | 2014-04-17 |
United States Patent
Application |
20140102801 |
Kind Code |
A1 |
Hallundb.ae butted.k; Jorgen ;
et al. |
April 17, 2014 |
FORMATION PENETRATING TOOL
Abstract
The present invention relates to a formation penetrating tool
submersible into a casing in a well for hydraulically penetrating a
formation and having a longitudinal tool axis, comprising a tool
housing, a supply hose, slidable in the tool housing, for supplying
a high pressurised fluid to a nozzle, and the tool housing having
an opening through which the supply hose and the nozzle are led to
penetrate the formation, wherein the formation penetrating tool
further comprises a pump arranged in the tool housing, the pump
being in fluid communication with the supply hose for providing a
jet of fluid out of the nozzle for penetrating the formation.
Furthermore, the invention relates to a downhole system comprising
a formation penetrating tool according to the invention and to a
method for hydraulically penetrating a formation.
Inventors: |
Hallundb.ae butted.k; Jorgen;
(Gr.ae butted.sted, DK) ; Mangal; Lars; (Hellerup,
DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hallundb.ae butted.k; Jorgen
Mangal; Lars |
Gr.ae butted.sted
Hellerup |
|
DK
DK |
|
|
Assignee: |
WELLTEC A/S
Allerod
DK
|
Family ID: |
46197263 |
Appl. No.: |
14/122727 |
Filed: |
May 30, 2012 |
PCT Filed: |
May 30, 2012 |
PCT NO: |
PCT/EP2012/060146 |
371 Date: |
November 27, 2013 |
Current U.S.
Class: |
175/67 ;
175/424 |
Current CPC
Class: |
E21B 43/114 20130101;
E21B 7/061 20130101; E21B 7/18 20130101; E21B 43/26 20130101 |
Class at
Publication: |
175/67 ;
175/424 |
International
Class: |
E21B 7/18 20060101
E21B007/18 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2011 |
EP |
11168240.7 |
Jun 23, 2011 |
EP |
11171170.1 |
Claims
1.-23. (canceled)
24. A formation penetrating tool (1) submersible into a casing (2)
in a well (3) for hydraulically penetrating a formation and having
a longitudinal tool axis, comprising: a tool housing (4), a supply
hose (8), slidable in the tool housing, for supplying a high
pressurised fluid (9) to a nozzle (10), and the tool housing having
an opening (11) through which the supply hose and the nozzle are
led to penetrate the formation, wherein the formation penetrating
tool further comprises a pump (12) arranged in the tool housing,
the pump being in fluid communication with the supply hose for
providing a jet (13) of fluid out of the nozzle for penetrating the
formation.
25. A formation penetrating tool according to claim 24, wherein a
holding unit (14) is arranged for providing a predetermined pushing
force to the supply hose.
26. A formation penetrating tool according to claim 25, wherein the
holding unit comprises a piston (15) circumferenting the supply
hose.
27. A formation penetrating tool according to claim 26, wherein the
piston is arranged in a slidable manner in a piston cylinder in the
tool.
28. A formation penetrating tool according to claim 26, wherein
several annular pistons are provided circumferenting the supply
hose.
29. A formation penetrating tool according to claim 24, further
comprising a casing penetrating unit (5) adapted to provide a hole
(6) in a wall (7) of the casing.
30. A formation penetrating tool according to claim 29, wherein the
casing penetrating unit is arranged in connection with or around
the nozzle.
31. A formation penetrating tool according to claim 30, wherein the
nozzle has a first end (101) connected with the hose and the casing
penetrating unit is a punch provided in a second end (102) of the
nozzle opposite the first end.
32. A formation penetrating tool according to claim 24, wherein the
supply hose is sliding in a fluid channel (20) being in fluid
communication with the pump.
33. A formation penetrating tool according to claim 24, wherein the
tool housing comprises an inlet (21) for the well fluid, the inlet
being in fluid communication with the pump.
34. A formation penetrating tool according to claim 24, further
comprising a moving device (50) for moving at least the supply hose
along the longitudinal tool axis and transverse to the longitudinal
tool axis.
35. A formation penetrating tool according to claim 24, wherein a
fluid control device (24) is arranged in connection with the fluid
reservoir.
36. A downhole system comprising a formation penetrating tool
according to claim 24 and a driving unit (31), such as a downhole
tractor.
37. A downhole system according to claim 36, wherein the driving
unit is a self-propelling unit capable of conveying itself and the
formation penetrating unit forward in the well.
38. A downhole system according to claim 36, wherein the driving
unit comprises wheels arranged (60) on wheel arms (61) projectable
from the tool housing so that the wheel contacts an inner surface
of the well.
39. A method for hydraulically penetrating a formation comprising
the steps of submerging a formation penetrating tool in a casing,
providing an opening in a wall of the casing by means of a casing
penetrating unit, supplying a high pressurised fluid to a nozzle
via a supply hose by means of a pump arranged in the formation
penetrating tool, positioning the nozzle opposite the opening in
the casing, and penetrating the formation by means of a jet of
fluid out of the nozzle, providing a formation bore.
40. A method according to claim 39, further comprising at least one
of the following steps: taking well fluid surrounding the tool in
through a inlet in the tool housing, and pressurising the fluid to
a high pressure before supplying the fluid to the supply hose.
41. A method according to claim 39, wherein the formation
penetrating tool is a wireline tool being submerged into the well
via a wireline.
42. A method according to claim 39, wherein the high pressurised
fluid is well fluid.
43. A method according to claim 39, further comprising at least one
of the following steps: performing a subsequent treatment of the
formation bore by means of acid for creating a larger surface area
of the formation bore, injecting a fluid comprising enzymes into
the formation bore, fracturing the formation by injecting high
pressurised fluid into the formation bore, or perforating the
formation by exploding a charge in connection with the formation
bore.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a formation penetrating
tool submersible into a casing in a well for hydraulically
penetrating a formation and having a longitudinal tool axis,
comprising a tool housing, a supply hose, slidable in the tool
housing, for supplying a high pressurised fluid to a nozzle, and
the tool housing having an opening through which the supply hose
and the nozzle are led to penetrate the formation. Furthermore, the
invention relates to a downhole system comprising a formation
penetrating tool according to the invention and to a method for
hydraulically penetrating a formation.
BACKGROUND ART
[0002] When fracturing the formation in order to provide better
access to the hydrocarbon reservoir, the maximum reservoir contact
is obtained if the fractures are created perpendicularly or
radially from the casing or from the bore hole in a well. When
fracturing, there is always a risk that the fractures are not made
radially from the casing, as the formation cracks at its weakest
spots. In some kinds of formation, the fractures tend to be created
in parallel to the casing or the bore hole even though the
fracturing fluid or perforating charge is directed radially into
the formation.
SUMMARY OF THE INVENTION
[0003] An object of the present invention is to wholly or partly
overcome the above disadvantages and drawbacks of the prior art.
More specifically, it is an object to provide a tool enabling a
more controlled fracturing process.
[0004] The above objects, together with numerous other objects,
advantages and features, which will become evident from the below
description, are accomplished by a solution in accordance with the
present invention by a formation penetrating tool submersible into
a casing in a well for hydraulically penetrating a formation and
having a longitudinal tool axis, comprising: [0005] a tool housing,
[0006] a supply hose slidable in the tool housing for supplying a
high pressurised fluid to a nozzle, and [0007] the tool housing
having an opening for providing access of the supply hose and the
nozzle to the opening in the casing, wherein the formation
penetrating tool further comprises a pump in fluid communication
with the supply hose for providing a jet of fluid out of the nozzle
for penetrating the formation.
[0008] In one aspect, the pump of the downhole penetrating tool may
be arranged in the tool housing, the pump being in fluid
communication with the supply hose for providing a jet of fluid out
of the nozzle for penetrating the formation.
[0009] The nozzle may be connected to an end of the hose so that
the hose ends in the nozzle.
[0010] By having a pump in the tool, fluid from the well can be
used as the pressurised fluid ejected through the nozzle for
penetrating the formation. Thus, the pressurised fluid needs not be
supplied through a long line of tubing extending from surface. This
simplifies the tool as it can be submerged down the well by means
of a wireline only. Not all rigs are equipped with such tubing and
in these cases a special vessel needs to be ordered. Wells can
always be intervened by wireline tools as wireline is always
present, and thus wireline operations are quicker and less
expensive. Having a pump in the tool and not at surface makes it
possible to intervene by means of wireline.
[0011] In another aspect, the formation penetrating tool may be
submersible into a casing in a well by a wireline or by means of
tubing, such as coiled tubing or a drill pipe.
[0012] In one embodiment, a holding unit may be arranged for
providing a predetermined pushing force to the supply hose so that
the supply hose and thereby the nozzle may be kept in a
predetermined position during penetration.
[0013] Thus, the holding unit may be a force generator to prevent
the hose from being forced backwards when jetting fluid for
penetrating the formation.
[0014] In another embodiment, the predetermined pushing force may
be at least equal to or larger than a pressure of the high
pressurised fluid at the nozzle.
[0015] Further, the holding unit may comprise a piston
circumferenting the supply hose.
[0016] Said piston may be an annular piston.
[0017] In one embodiment, the piston may be arranged in a slidable
manner in a piston cylinder in the tool.
[0018] In another embodiment, several annular pistons may be
provided circumferenting the supply hose.
[0019] The formation penetrating tool according to the invention
may further comprise a casing penetrating unit adapted to provide a
hole in a wall of the casing.
[0020] Additionally, the piston may be arranged in a piston housing
in the tool housing.
[0021] In one embodiment, the casing penetrating unit may be
arranged in connection with or around the nozzle.
[0022] In another embodiment, the nozzle may have an annular
opening (orifice) providing a cylindrical jet of fluid.
[0023] Also, the casing penetrating unit may be a punch, a drill
bit or a charge of a perforating gun.
[0024] The nozzle may have a first end connected with the hose and
the casing penetrating unit may be a punch provided in a second end
of the nozzle opposite the first end.
[0025] Moreover, the tool housing may comprise a guiding element
for guiding the supply hose out of the opening in the tool
housing.
[0026] Furthermore, the tool housing may comprise a guiding tube
for guiding the supply hose.
[0027] Also, the supply hose may be sliding in a fluid channel
being in fluid communication with the pump.
[0028] In one embodiment, the supply hose may be armoured.
[0029] The armouring of the supply hose may be a threadingly
arranged in the wall of the hose. The threading may be made of
metal, composite, plastic, or similar material.
[0030] Further, the supply hose may comprise a plastic core such as
a Teflon core, or may be coated with Teflon or other
friction-reducing materials.
[0031] Moreover, the high pressurised fluid may be well fluid.
[0032] In one embodiment, the tool housing may comprise an inlet
for the well fluid, the inlet being in fluid communication with the
pump.
[0033] Having a pump inlet in the tool housing may permit intake of
well fluid surrounding the tool.
[0034] In another embodiment, a filter or screen may be arranged in
connection with the inlet for filtering the well fluid before it
enters the pump.
[0035] The formation penetrating tool according to the present
invention may further comprise a moving device for moving at least
the supply hose along the longitudinal tool axis and transverse to
the longitudinal tool axis.
[0036] Said moving device may be a stroker providing a stroke along
the longitudinal tool axis.
[0037] In another embodiment, the moving device may be a motor
rotating a first part of the tool in relation to a second part of
the tool or moving the supply hose in relation to the formation
along the longitudinal tool axis.
[0038] Further, the first part and second part of the tool may be
connected by means of a shaft.
[0039] Also, the tool may comprise a first part and a second part
and the moving device may move the first part in relation to the
second part to move the supply hose along the longitudinal tool
axis and transverse to the longitudinal tool axis.
[0040] Hereby, a first part of the tool may be moved along the
longitudinal tool axis in relation to a second part of the tool
moving the supply hose in relation to formation along the
longitudinal tool axis. The first part of the tool may comprise the
supply hose, the holding unit and the pump, and the second part of
the tool may comprise the anchoring section.
[0041] The formation penetrating tool may further comprise a
cartridge comprising several geophones to be inserted into the
bores.
[0042] The formation penetrating tool according to the invention
may further comprise a fluid reservoir.
[0043] Also, the fluid reservoir may contain a supply of fluid.
[0044] Furthermore, the fluid may be the pressurised fluid, an
acid, a base, or a mixture of substances.
[0045] In one embodiment, a fluid control device may be arranged in
connection with the fluid reservoir. Hereby, it is obtained that a
fluid communication to the fluid reservoir may be opened or
closed.
[0046] Further, the tool may comprise an anchor section for
pressing the penetrating unit against the wall of the casing or
anchoring the tool to an inner face of the casing.
[0047] In another embodiment, the pump may be powered through a
wireline or a battery.
[0048] In yet another embodiment, the pump may be a centrifugal
pump, a piston pump, or a jet pump.
[0049] Also, the tool may comprise a pressure measuring device.
[0050] Additionally, the tool may comprise an electronic
section.
[0051] Further, the tool may comprise a hydraulic motor or an
electrical motor for driving the pump.
[0052] Moreover, the tool may comprise a position device, such as a
casing collar locator, adapted for positioning the tool in the
casing in an axial and/or a radial direction of the casing.
[0053] Furthermore, the formation penetrating tool may comprise an
inlet being in fluid communication with the pump, enabling a well
fluid to be used as the high pressurised fluid.
[0054] In one embodiment, an additional fluid from a fluid
reservoir may be arranged in the formation penetrating tool via the
supply hose, and the nozzle may be introduced into the penetrated
formation for a subsequent treatment of the penetrated
formation.
[0055] In another embodiment, the subsequent treatment may be an
acid treatment for creating a larger surface area of the penetrated
formation.
[0056] In yet another embodiment, the subsequent treatment may be
an enzyme treatment for cleaning the penetrated formation.
[0057] Moreover, the well fluid may be filtered before entering the
pump.
[0058] The present invention furthermore relates to a downhole
system comprising a formation penetrating tool according to the
invention and a driving unit, such as a downhole tractor.
[0059] Said driving unit may be a self-propelling unit capable of
conveying itself and the formation penetrating unit forward in the
well.
[0060] Also, the driving unit may comprise wheels arranged on wheel
arms projectable from the tool housing so that the wheel contacts
an inner surface of the well.
[0061] Finally, the invention relates to a method for hydraulically
penetrating a formation comprising the steps of [0062] submerging a
formation penetrating tool in a casing, [0063] providing an opening
in a wall of the casing by means of a casing penetrating unit,
[0064] supplying a high pressurised fluid to a nozzle via a supply
hose by means of a pump arranged in the formation penetrating tool,
[0065] positioning the nozzle opposite the opening in the casing,
and [0066] penetrating the formation by means of a jet of fluid out
of the nozzle providing a formation bore.
[0067] The method described above may further comprise at least one
of the following steps: [0068] taking well fluid surrounding the
tool in through a inlet in the tool housing, and [0069]
pressurising the fluid to a high pressure before supplying the
fluid to the supply hose.
[0070] Moreover, the formation penetrating tool may be a wireline
tool being submerged into the well via a wireline.
[0071] Also, the high pressurised fluid may be well fluid.
[0072] Additionally, the method according to the invention may
comprise at least one of the following steps: [0073] performing a
subsequent treatment of the formation bore by means of acid for
creating a larger surface area of the formation bore, [0074]
injecting a fluid comprising enzymes into the formation bore,
[0075] fracturing the formation by injecting high pressurised fluid
into the formation bore, or [0076] perforating the formation by
exploding a charge in connection with the formation bore.
BRIEF DESCRIPTION OF THE DRAWINGS
[0077] The invention and its many advantages will be described in
more detail below with reference to the accompanying schematic
drawings, which for the purpose of illustration show some
non-limiting embodiments and in which
[0078] FIG. 1 shows a formation penetrating tool in a casing,
[0079] FIG. 2 shows a cross-sectional view of the formation
penetrating tool,
[0080] FIG. 3 shows one embodiment of a holding unit,
[0081] FIG. 4A shows a cross-sectional view of another embodiment
of the formation penetrating tool,
[0082] FIG. 4B shows a cross-sectional view of yet another
embodiment of the formation penetrating tool,
[0083] FIG. 5 shows yet another embodiment of the formation
penetrating tool,
[0084] FIG. 6 shows a front view of a nozzle,
[0085] FIG. 7 shows another formation penetrating tool in a first
position in the casing,
[0086] FIG. 8 shows the formation penetrating tool of FIG. 7 in a
second position,
[0087] FIG. 9 shows the formation penetrating tool of FIG. 7 in a
third position, and
[0088] FIGS. 10A-D show cross-sections of different bores in the
formation made by the formation penetrating tool.
[0089] All the figures are highly schematic and not necessarily to
scale, and they show only those parts which are necessary in order
to elucidate the invention, other parts being omitted or merely
suggested.
DETAILED DESCRIPTION OF THE INVENTION
[0090] FIG. 1 shows a formation penetrating tool 1 submerged in a
casing 2 in a well 3. In order to penetrate the formation, the tool
1 has a tool housing 4 in which a casing penetrating unit 5 adapted
to provide a hole 6 in a wall 7 of the casing 2 is arranged.
Subsequently, a nozzle 10 is arranged in an end of a supply hose 8,
slidable within the tool housing 4. The supply hose 8 supplies a
high pressurised fluid 9 to the nozzle 10 which is jetted as a jet
stream out through the hole 6 in order to penetrate the formation,
thereby providing a formation micro-bore substantially radially
from the formation penetrating tool 1. The formation penetrating
tool 1 comprises a pump 12 which is in fluid communication with the
supply hose 8 for providing a jet 13 of fluid out of the nozzle 10
to penetrate the formation creating the micro-bore or formation
bore 32. The formation penetrating tool 1 may penetrate the casing
2 by means of the high pressurised fluid jetted through the nozzle
10, and thus the tool may function without using the casing
penetrating unit 5. However, in the following the function is
explained including the use of a casing penetrating unit 5.
[0091] When fracturing the formation to provide better access to
the hydrocarbon reservoir, there is a risk that the fractures are
not made radially from the casing 2. Thus, by providing a
micro-bore by means of the formation penetrating tool 1, the
fracturing process can be controlled better since a micro-bore acts
as a notch. The fracturing process may be performed by means of
high pressurised fluid pumped down into the casing 2 or by a
perforating gun. In addition, the micro-bore may be used before
performing an acidifying process.
[0092] The tool housing 4 has an opening 11 for providing access of
the supply hose 8 and the nozzle 10 to an opening in the casing 2.
To penetrate the formation, the supply hose 8 is led out through
the opening 11, and fluid 9 is jetted out through the nozzle 10.
The high pressurised fluid jetted into the formation is pressurised
in the pump 12. The pump 12 pumps well fluid in through an inlet 21
and a filter 22 arranged in the inlet 21 and pumps the well fluid
via the supply hose 8 out through the nozzle 10. By using well
fluid to penetrate the formation creating the micro-bore 32, the
reservoir is not further contaminated. In addition, the power
needed for the jetting process is less than if the pump was
arranged at the top of the well and the fluid was pumped down to
the supply hose 8 through a drill pipe or coiled tubing. The pump
12 is arranged in the tool and is driven by an electrical motor 29
which is powered by a wireline through an electronic section 28.
The formation penetrating tool 1 is thus a wireline tool. The
formation penetrating tool 1 is submerged into the well or casing
only through such wireline, e.g. with another form of power supply
line such as an optical fiber, and not through tubing such as
coiled tubing, drill pipe or similar piping.
[0093] The formation penetrating tool 1 comprises an anchoring
section 25 to force the casing penetrating unit 5 against the
casing wall. The tool may have several anchoring sections 25.
[0094] When the jet of fluid 9 hits the formation, the formation
crunches but the force of the jet will also force the supply hose
backwards. Therefore, the tool comprises a holding unit 14 which
holds the supply hose 8 and thus the nozzle 10 close to the
formation. The holding unit 14 provides a predetermined pushing
force to the supply hose so that the supply hose and thereby the
nozzle may be kept in a predetermined position during penetration
so that the jet 13 does not lose its jetting power before reaching
the formation. The predetermined pushing force is substantially
equal to or up to 5% smaller than the pressure of the high
pressurised fluid at the nozzle.
[0095] As can be seen in FIG. 2, the holding unit 14 comprises a
piston 15 arranged around the supply hose 8 so that the hose
penetrates the piston at its centre, the piston thus being an
annular piston. The piston 15 is slidably arranged in a piston
housing 16 in the tool housing 4 so that the hose can extend into
the formation bore as the formation bore is created. The
pressurised fluid 9 from the pump 12 is pumped into a fluid channel
20 which in FIG. 2 functions as the piston housing 16. The fluid
acts upon the piston, forcing the hose out into the formation bore
as it is created by the jet 13. In FIG. 2, the holding unit 14 is
the piston sliding in the piston housing 16. The supply hose 8 is
guided in the formation penetrating tool 1 by a guiding tube 19 and
a guiding element 18 in order to slide without creating substantial
friction.
[0096] In FIG. 2, the casing penetrating device is casing
penetrating unit 5 arranged around the nozzle 10, and the guiding
element 18 is part of the casing penetrating unit 5. In this
embodiment, the nozzle has a first end 101 connected with the
supply hose and a second end 102 opposite the first end being
connected with the casing penetrating unit. In another embodiment,
the casing penetrating unit 5 is arranged in the second part of the
formation penetrating tool 1 and is slided away from opening when
the opening has been made so that the nozzle and the supply hose
can enter the formation.
[0097] The casing penetrating unit is a punch 64 in FIG. 2, but may
also be a drill bit or a charge 33 of a perforating gun forming
part of the tool as shown in FIG. 4A. The punch shown in FIG. 2 is
forced outward towards the casing in order to penetrate the casing
wall, creating a hole 6 in the wall by means of a sliding element
42 slidable arranged in a space 43 in the tool housing 4. The
sliding element 42 comprises an inclined surface 44, and when the
sliding element 42 is forced away from the pump 12 by means of
pressurised fluid in a fluid channel 45 indicated by a dotted line,
the punch is forced out of the opening in the tool housing 4 and
punches a hole in the casing wall.
[0098] In FIG. 4A, the charge 33 is activated by a contact 34
arranged in the piston housing and when the piston slides past the
contact, the side of the piston presses on the contact and the
charge is initiated by the wiring 35, and the charge explodes,
creating an opening in the casing wall.
[0099] The supply hose 8 is armoured by a threading, e.g. made of
metal, embedded in the wall of the hose so that the hose is
self-supporting and will not kink when bending and that the holding
unit can exert pressure from one end or along the hose in order to
provide a holding pressure in the other end of the hose countering
the pressure from the formation when the jet hits the formation.
The supply hose may also comprise a plastic core, such as a Teflon
core, or be coated with Teflon or other friction-reducing materials
in order to supply the pressurised fluid 9 without losing too much
pressure.
[0100] In FIG. 3, the holding unit 14 comprises a first 40 and a
second 41 piston arranged around the supply hose 8 at a distance
from each other, creating a chamber 37 there between. The first
piston is arranged closest to the nozzle. The holding unit 14 also
comprises a fluid channel 38 in fluid communication with the pump
12 or an additional pump providing a pressure on the first piston
40, forcing the hose outward towards the formation and thus holds
the nozzle sufficiently close to the formation in order to crunch
the formation by means of the jet of pressurised fluid 9. The
second piston and the aforementioned piston 15 may be the same
piston.
[0101] As shown in FIG. 5, the formation penetrating tool 1 may
comprise a fluid reservoir 23 containing the fluid 9 if the pump
does not take in well fluid or the reservoir 23 may contain an
additional fluid. The fluid may be any kind of fluid, such as
water, an acid, a base, a mixture of substances. The additional
fluid from the fluid reservoir may also be introduced into the
penetrated formation for a subsequent treatment of the penetrated
formation, so that a second run in order to fracture the formation
using the micro-bore 32 is no longer needed.
[0102] The formation penetrating tool 1 also comprises a fluid
control device 24 arranged in connection with the fluid reservoir
23 so that a fluid communication between the pump 12 and the fluid
reservoir may be open or closed. By having the fluid control device
24, the additional fluid in the fluid reservoir can be mixed with
the well fluid pumped in by means of the pump, and thus the fluid
control device 24 can control the amount of fluid from the
reservoir which is mixed with the well fluid.
[0103] In FIG. 6, the nozzle has an annular orifice providing a
cylindrical jet of fluid. In this way, the fluid creates an annular
micro-bore around a formation centre part which may be brought up
with the tool with a view to analysing the formation so that an
optimal fracturing process can be initiated.
[0104] The formation penetrating tool 1 is powered by wireline 26
or a battery arranged inside the tool. When the formation
penetrating tool 1 comprises a battery, the line 26 can be any line
strong enough to pull the tool out of the well after the
penetrating operation.
[0105] In FIG. 5, the formation penetrating tool 1 comprises a
pressure measuring device 27 for measuring the pressure of the
fluid 9 supplied through the supply hose. The formation penetrating
tool 1 also comprises a position device 30, such as a casing collar
locator, adapted to position the formation penetrating tool 1 in
the casing in an axial and/or a radial direction of the casing 2.
Furthermore, the position is used for finding the formation
micro-bore in the following fracturing process.
[0106] The pump may be a centrifugal pump, a piston pump or a jet
pump.
[0107] FIG. 5 shows a downhole system 100. The downhole system
comprises the formation penetrating tool 1 and a driving unit 31,
such as a downhole tractor. The driving unit is mainly used to
drive and convey the formation penetrating tool 1 and itself
forward in a horizontal part of the well but may also be used as an
anchoring section or a positioning device. The driving unit
comprises wheels 63 arranged on wheel arms 61 projectable from the
tool housing in order for the wheels to contact the inner surface
of the well, casing or borehole.
[0108] In FIG. 7, the formation penetrating tool 1 comprises a
moving device 50 moving a first part 51 of the tool in relation to
a second part 52 of the tool in order to move the supply hose 8
along a longitudinal tool axis or rotating the supply hose 8 in a
direction transverse to the longitudinal tool axis. The first part
and the second part are connected by means of a shaft 53. The
moving device 50 may comprise a stroker providing a stroke along
the longitudinal tool axis so that the first part 51 is moved away
from or closer to the second tool part 52. The moving device 50 may
also comprise a motor for rotation of the first part of the tool in
relation to the second part of the tool or for the first part of
the tool in relation to the second part of the tool along the
longitudinal tool axis and thereby moving the supply hose 8 in
relation to the formation along the longitudinal tool axis. The
orientation could also be performed by means of a swivel or a
relative bearing measurement.
[0109] By having a moving device 50, the first part 51 of the tool
can be moved along the longitudinal tool axis or transverse to the
tool axis in relation to a second part 52 of the tool moving the
supply hose in relation to the formation or the casing along the
longitudinal tool axis or rotating the supply hose along a
direction transverse to the longitudinal tool axis. By being able
to move the supply hose 8, the hole 6 in the casing 2 or the bore
resulting from the high pressurised fluid 9 being jetted into in
the formation can be made larger than just by penetrating the
casing or the formation once. Penetrating the formation once by
jetting fluid 9 through the supply hose 8 out through the nozzle 10
results in a hole 6 in the casing or a bore in the formation having
the cross-section as shown in FIG. 10A. When moving the supply hose
8 by means of the moving device 50, the hole 6 in the casing or the
bore in the formation is enlarged to have the cross-section as
illustrated in FIGS. 10B-D.
[0110] In a first position as shown in FIG. 7, the formation
penetrating tool 1 penetrates the casing 2 or the formation making
a hole or formation bore 32 transverse to the tool axis. In FIG. 8,
the moving device 50 has moved the first part 51 of the tool to a
second position in which the first tool part 51 is moved further
away from the second tool part 52. In this second position, the
formation penetrating tool 1 penetrates the casing 2 or the
formation in a displaced position in relation to the first hole or
formation bore and thus extends the hole or the formation bore,
making the hole or bore larger along the longitudinal tool axis. In
FIG. 9, the formation penetrating tool 1 is shown in its third
position in which the moving device 50 has moved the first part
closer to the second part compared to the first and second
positions. In this third position, the fluid 9 jetted from
formation penetrating tool 1 penetrates the casing 2 or the
formation, extending the hole of the bore even further and
resulting in a hole or bore having a cross-section as shown in FIG.
10D.
[0111] In FIG. 10B, the supply hose 8 has been rotated along a
direction transverse to the longitudinal tool axis making a
longitudinal hole in the casing 2 or a longitudinal bore in the
formation in a plane transverse to the longitudinal tool axis. In
FIG. 10C, the supply hose 8 has been both rotated and moved along
the longitudinal tool axis. In FIG. 10D, the longitudinal bore
extends along the longitudinal tool axis.
[0112] By making longitudinal micro-bores or holes in the
formation, the subsequent fracturing process injecting fracturing
fluid into the formation in the bore or hole can be directed in the
optimal direction, thus orienting the micro well bores to maximise
the effectiveness of the fractures. Fractures tend to orient
themselves in the maximum stress direction, and by orienting the
micro holes in the maximum stress direction, most of the fracture
energy will be used to propagate the fracture.
[0113] The first part 51 of the formation penetrating tool 1
comprises the supply hose 8, the holding unit 14 and the pump 12,
and the second part 52 of the tool 1 comprises the anchoring
section 25. The moving device 50 may be comprised in the first tool
part 51 and attached to the second tool part 52 by means of the
shaft 53 or be comprised in the second tool part 52 and connected
to the first tool part 51.
[0114] After having made a micro-bore or bore in the formation, the
tool may insert a geophone in the bore in order to conduct e.g.
seismic measurements. The formation penetrating tool 1 may comprise
a cartridge comprising several geophones to be inserted into the
bores. In this way, the formation penetrating tool 1 may be used to
upgrade or improve a well to have a seismic system in order to
conduct measurements of the presence of hydrocarbons in the
formation.
[0115] By fluid or well fluid is meant any kind of fluid that may
be present in oil or gas wells downhole, such as natural gas, oil,
oil mud, crude oil, water, etc. By gas is meant any kind of gas
composition present in a well, completion, or open hole, and by oil
is meant any kind of oil composition, such as crude oil, an
oil-containing fluid, etc. Gas, oil, and water fluids may thus all
comprise other elements or substances than gas, oil, and/or water,
respectively.
[0116] By a casing is meant any kind of pipe, tubing, tubular,
liner, string etc. used downhole in relation to oil or natural gas
production.
[0117] Although the invention has been described in the above in
connection with preferred embodiments of the invention, it will be
evident for a person skilled in the art that several modifications
are conceivable without departing from the invention as defined by
the following claims.
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