U.S. patent application number 14/211677 was filed with the patent office on 2014-09-18 for prevention of wireline damage at a downhole window.
This patent application is currently assigned to Saudi Arabian Oil Company. The applicant listed for this patent is Saudi Arabian Oil Company. Invention is credited to Mohannad A. ABDELAZIZ, Brian A. ROTH.
Application Number | 20140262334 14/211677 |
Document ID | / |
Family ID | 50543690 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140262334 |
Kind Code |
A1 |
ABDELAZIZ; Mohannad A. ; et
al. |
September 18, 2014 |
PREVENTION OF WIRELINE DAMAGE AT A DOWNHOLE WINDOW
Abstract
A bottom hole assembly (BHA) which is transported via a wireline
through downhole and lateral wellbores and thence through a
wellbore window aperture, the BHA carrying with it a blocking tool
which is adapted to engage the edge of a lateral wellbore window
and prevent the wireline from contacting and abrading against that
edge of the window, the blocking tool being detachable from the BHA
which proceeds axially distally through the wellbore window while
the wireline slides through the blocking tool. Upon withdrawal of
the BHA the blocking tool is reattached thereto and is removed with
it.
Inventors: |
ABDELAZIZ; Mohannad A.;
(Dhahran, SA) ; ROTH; Brian A.; (Dhahran,
SA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Saudi Arabian Oil Company |
Dhahran |
|
SA |
|
|
Assignee: |
Saudi Arabian Oil Company
Dhahran
SA
|
Family ID: |
50543690 |
Appl. No.: |
14/211677 |
Filed: |
March 14, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61784784 |
Mar 14, 2013 |
|
|
|
Current U.S.
Class: |
166/378 ;
166/206 |
Current CPC
Class: |
E21B 41/0035 20130101;
E21B 23/14 20130101 |
Class at
Publication: |
166/378 ;
166/206 |
International
Class: |
E21B 23/14 20060101
E21B023/14 |
Claims
1. A method of reducing potential damage to a wireline having a BHA
coupled to its distal end when said wireline is axially extended
through and past edges of a window opening that extends from the
outer to the inner side of the wall of a lateral wellbore, the BHA
having a proximal and distal ends, the wireline and BHA having
outer diameter less than that of said window, the method comprising
the steps: a. removably coupling a blocking tool to the proximal
end of said BHA, b. coupling said BHA to the distal end of said
wireline, c. directing said wireline and BHA to said window in said
lateral wellbore, d. directing said blocking tool to expand to a
diameter greater than the diameter of said window, e. de-coupling
said blocking tool from said BHA and allowing said wireline and BHA
to axially enter and traverse said window and enter said wellbore
while said blocking tool prevents said wireline and BHA from
contacting said edges of said window f. subsequently withdrawing
said wireline and BHA outward through said window while said
blocking tool continues to prevent said wireline and BHA from
contacting said edges of said window, and g. re-coupling said BHA
to the proximal end of said blocking tool as said wireline and BHA
are withdrawn through said window.
2. The method of claim 2 where said blocking tool has a body part
and a plurality of arms with proximal ends pivotally coupled to
said body part and distal ends, the arms having a closed position
and said arms being movable to an extended position where said
distal ends thereof are radially outward of said body part to
define a diameter of said blocking tool greater than the diameter
of said window, whereby said blocking tool is barred from entering
into said window.
3. The method of claim 2 where said blocking tool comprises a drive
mechanism to move said arms to said extended position and to
subsequently withdraw said arms to said closed position.
4. The method of claim 2 where said drive mechanism further
comprises spring elements biasing said arms toward said open
position thereof, and said drive mechanism restrains said arms in
said retracted position until directed to allow said spring
elements to drive said arms to said open position.
5. The method of claim 1 where said BHA contains wellbore logging
sensors that are capable of measuring and/or monitoring properties
selected from the group consisting of resistivity, conductivity,
formation pressure, acoustics, radioactivity, electromagnetic and
nuclear magnetic resonance of strata and their contained liquids
being investigated and/or monitored.
6. A method of reducing the risk of potential damage to a wireline
when it is axially extended through and past edges of a window
opening that extends from the outer to the inner side of the wall
of a lateral wellbore, the window opening being larger than the
diameter of said wireline, the method comprising the steps: a.
providing a blocking mechanism that has width greater than the size
of the window opening, b. positioning said blocking mechanism
adjacent said outer side of said lateral wellbore adjacent said
window, said blocking mechanism being barred from entering and
traversing said window because of its diameter being larger than
said window opening, and c. with said blocking mechanism blocking
said wireline from engaging said edges of said window as said
wireline is directed to enter and pass through said window, and as
said wireline is subsequently withdrawn out of said window.
7. A bottom hole assembly (BHA) connectable to a wireline cable,
the BHA having outer diameter D1 adapted to pass through a wellbore
inner pipe of predetermined inner diameter Dp, the BHA comprising:
a. a cylindrical housing having a proximal end connectable to said
wireline and a distal end, and a maximum outer diameter D1 less
than Dp, and b. a blocking tool comprising: i. a body part having a
central axis and a distal end releasably coupled to said proximal
end of said housing, ii. a maximum outer diameter D2 less than Dp,
iii. a central bore through which said wireline cable is axially
slidable, iv. a blocking part carried by said body part and movable
from a closed position where said blocking part extends radially
outward of said central axis a distance less than Dp, and has an
open position where it extends radially outward a distance greater
than Dp, and v. a drive mechanism adapted to move said blocking
part from said closed position to said open position, and further
adapted to cause separation of said blocking tool from said
cylindrical body while allowing said cable to remain slidable
through said blocking tool when said cylindrical housing moves
axially distally away from said blocking tool.
8. A bottom hole assembly (BHA) connectable to a wireline cable,
and operable to pass through a downhole wellbore contiguous with a
lateral wellbore both having diameter DP, the lateral wellbore
having a lateral window aperture of maximum diameter Dw, the BHA
comprising: a. a cylindrical housing having a proximal end
connectable to a wireline and a distal end, and a maximum outer
diameter D1 less than Dp, and b. a blocking tool comprising: i. a
body part having a central axis and a distal end releasably coupled
to said proximal end of said housing, ii. a maximum outer diameter
D2 less than Dp, iii. a central bore through which said wireline
cable is axially slidable, iv. a blocking part carried by said body
part and movable from a closed position where said blocking part
extends radially outward of said central axis a distance less than
Dp, and has an open position where it extends radially outward a
distance greater than Dw, and v. a drive mechanism adapted to move
said blocking part from said closed position to said open position,
and further adapted to cause separation of said blocking tool from
said cylindrical body while allowing said cable to remain slidable
through said blocking tool when said cylindrical housing moves
axially distally away from said blocking tool.
9. The BHA according to claim 8 where said blocking part comprises
a pair of arms having proximal ends pivotally coupled to said body
part and distal ends said arms being movable to a position where
said distal ends thereof are radially outward of said body
part.
10. A BHA according to claim 9 where said pair of arms are spring
biased toward said open position and are restrained by said drive
mechanism in said closed position until said BHA begins to enter
said wellbore window.
11. The BHA according to claim 8 where said blocking part comprises
a plurality of arms having proximal ends pivotally coupled to said
body part and distal ends said arms being movable to a position
where said distal ends thereof are radially outward of said body
part.
12. A BHA according to claim 8 where said BHA contains wellbore
logging sensors are capable of measuring and/or monitoring
properties selected from the group consisting of resistivity,
conductivity, formation pressure, acoustics, radioactivity,
electromagnetic and nuclear magnetic resonance of strata and their
contained liquids being investigated and/or monitored.
13. A method operable with a BHA as defined in claim 8 that is
entering a lateral wellbore window, comprising the steps to prevent
said wireline from engaging any edge of said lateral wellbore
window: a. directing said drive mechanism of said blocking tool to
move said blocking part to said open position to have diameter
greater than Dw of said window and to engage the edge of said
window and thereby block entry of said blocking tool through said
window, and b. separating said blocking tool from said BHA while
allowing said cable to remain slidable through said blocking tool
and maintaining said cable spaced from engaging said window edge,
as said BHA moves axially distally away from said blocking tool.
Description
RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
Provisional Patent Application No. 61/784,784 filed on 14 Mar.
2013, the disclosure of which is incorporated herein by reference
in its entirety.
FIELD OF THE INVENTION
[0002] This invention is in the field of oil and gas drilling
apparatus and procedures for well logging at different elevations
along the depth of the wellbore in order to determine and monitor
the characteristics of the strata that are being encountered and
traversed.
BACKGROUND AND PRIOR ART
[0003] Basic downhole wellbore systems often include lateral
wellbores at different depths. For investigation, monitoring or
other well logging operations it is known to employ a logging tool
or bottom hole assembly (BHA) which has the capacity to measure
and/or monitor any, all or any combination of resistivity,
conductivity, formation pressure, electrical, acoustic,
radioactive, electromagnetic, nuclear magnetic resonance and other
properties of the strata such as rock, sand, mud, oil, gas and
shale and their contained fluids.
[0004] U.S. Pat. No. 6,131,659 entitled "Downhole Well Corrosion
Monitoring Apparatus and Method", incorporated herein by reference,
discloses an array of transducers and associated microprocessors
insertable into a wellbore.
[0005] U.S. Pat. No. 6,725,925 entitled "Downhole Cathodic
Protection Cable System, incorporated herein by reference,
discloses some of the basic concepts in downhole drilling
operation.
[0006] A further disclosure entitled "Technical Paper:
High-performance Wellbore Departure and Drilling System for
Accessing New Target", incorporated herein by reference (available
at the website http://slb.com/resources/technical
papers/drilling/138001.aspx), discloses application of wellbore
departure in downhole drilling systems. The paper asserts that
conventional wellbore departure and drilling systems generally
require the operator to make multiple downhole trips to achieve a
specific objective, including a window milling bottom hole assembly
(BHA) that is run in hole to create an exit path in the existing
casing and drill sufficient rathole for the next drilling assembly,
and that in the subsequent trip, a directional drilling BHA is run
to extend the rathole and drill laterally to the target. The paper
discusses the possibility of single trip operation with good
downhole dynamics control and overall BHA drillability. The paper
surmises that a re-entry system should be able to mill a window in
the existing casing sufficiently large enough for obstruction free
entry of the BHA and new liners, and that once the BHA has exited
the casing, the new system would be required to drill a full gauge
lateral wellbore to the target with good directional control and
minimal vibration. Technological/operational issues analyzed
include dynamic simulation of the BHA to study the nature and
magnitude of the vibrations, controlling vibrations and feed rate
to reduce premature cutter damage during window milling operations,
utilizing the latest force balance software for selection of
shapes, sizes, number and location of cutters for maximizing
on-bottom time, exploring hybrid cutting structures on bit/mill to
maintain gauge. The discussed system, over several phases, involved
milling of a window in the existing casing and drilling a lateral
to various depths. The first phase was run on a conventional rotary
BHA in soft and medium formations, the second phase included
testing on a positive displacement motor with bent sub or bent
housing, and the third phase included a push-the-bit type rotary
steerable system. The paper concludes that a functional single-trip
system for milling a window and drilling a lateral borehole is
commercially feasible, and that a versatile system will contribute
substantially to the technology required to efficiently and
economically mill a window in the existing casing and then drill an
extended length lateral wellbore to the target formation without
tripping for equipment/bit change out.
[0007] Wirelines and slicklines are tools inserted in to a well for
both workover and logging efforts, and are similar devices. A
slickline is used to place and recover wellbore equipment, such as
plugs, gauges and valves. These are single-strand non-electric
cables lowered into oil and gas wells from the surface. Slicklines
can also be used for adjustment of downhole valves and sleeves, and
to repair tubing within the wellbore. A wireline is an electrical
cable used to lower tools into, transmit data about the conditions
of the well bore, and conduct logging. Wirelines can be single
strands or multi-strands. A wireline can be used for well
intervention and formation evaluation operations. Wireline logs can
be used to measure formation properties in a well through
electrical lines. These measurements can be used to help
geologists, drillers and engineers make real-time decisions about
drilling operations, and can include resistivity, conductivity and
formation pressure, as well as sonic properties and wellbore
dimensions. A logging tool, known in the industry as a sonde, is
located at the bottom of the wireline. The tool is lowered by the
wireline to a certain depth, and measurements are taken
continuously on the ascent. When producing wells require remedial
work to sustain, restore or enhance production, this is referred to
in the industry as workover operations. A well-servicing unit is
used to winch items in and out of the wellbore. The line used to
raise and lower equipment can be braided steel wireline or a single
strand slickline. Workover operations can include well clean-up,
setting plugs, production logging and perforation through
explosives.
[0008] Wirelines can also be used for core drilling operations, in
which the objective is to retrieve a core sample. In core drilling,
a core drill string includes a series of connected long hollow
tubes, known as a rod string, with a barrel at the end connected to
a cutting bit at the bottom of the hole. To remove the core, the
entire core barrel including each connected tube is removed. With
wireline core drilling, the barrel can be removed without removing
the rod string. An overshot is lowered on the end of a wireline,
and the overshot attaches to the back of the inner tube disengages
itself from the barrel as the core barrel inner tube and the
wireline is pulled back.
[0009] To access a lateral wellbore such a BHA is attached to a
wireline cable and transported downward in the main wellbore, then
turned in a lateral direction and into the lateral wellbore, and
then directed to exit the lateral wellbore through a window or
aperture milled in a wall thereof and then into a strata of
interest.
[0010] Unfortunately the milled window in a lateral casing wall
often has sharp edges that may abrade or break a wireline cable
that traverses against such edges. Tension on such cable as well as
repeating the operation for multiple runs of a BHA are two factors
that increase abrasive friction or other damage to a wireline
cable.
[0011] Use of wireline cable and slicklines to transport the
logging tool has been preferred for various reasons including ease,
accuracy and economy; however, the risk of abrading or damaging the
cable at the lateral window has been a major problem causing time
delays, expense and even shutdown of the entire apparatus when a
cable must be repaired or replaced.
OBJECTS AND SUMMARY OF THE PRESENT INVENTION
[0012] A first object of the present invention is to provide
apparatus that allows safe and efficient use of wireline cable to
transport a BHA through a milled window in a lateral wellbore and
provides similarly for safe and efficient use of slicklines.
[0013] Another object is to provide a tool attached to a BHA which
engages the wellbore window and prevents the wireline from
contacting the edge of the window as the BHA travels through said
window and moves axially distally beyond said window.
[0014] A further object is for the tool as described above to be
attached to and carried by the BHA as it passes through downhole
and lateral wellbores approaching said lateral wellbore window. In
a preferred embodiment of the present invention the tool will have
a diameter no greater than the BHA to which it is removably
attached. Alternatively, this tool may be standalone from the BHA
and still function with a wellbore window to improve safe and
efficient use of wirelines and slicklines.
[0015] A still further object is for said tool as described above
to separate from said BHA when said BHA enters said window, and as
the tool engages the window to maintain said wireline from
contacting the edge of the window.
[0016] A further object is for said tool as defined above to be
reconnected to said BHA when the BHA is withdrawn back out through
said window and thence outward of said lateral and downhole
wellbores.
[0017] An additional object is for said tool is described above to
engage said edge of the window by having a part of said tool move
to positions radially outward of the central axis of the BHA to
thus have a diameter greater than the opening of the window.
[0018] Another object is for said tool as described above to
comprise a pair of pivotal arms which are spring biased or
otherwise directed to their open position where they span a space
greater than the opening of said window. Optionally, the tool could
have two pairs of arms or some number more than two arms.
[0019] It is thus another object to provide a tool which can
protect the wireline from damage by a sharp edge of the wellbore
window, which tool is transported to the window by the BHA itself
and is removed by the BHA when it is retracted.
[0020] Various exemplary embodiments of the present invention are
described below:
1. A bottom hole assembly (BHA) connectable to a wireline cable,
the BHA having outer diameter D1 adapted to pass through a wellbore
inner pipe of predetermined inner diameter Dp, the BHA comprising:
[0021] a. a cylindrical housing having a proximal end connectable
to said wireline and a distal end, and a maximum outer diameter D1
less Dp, and [0022] b. a blocking tool comprising: [0023] i. a body
part having a central axis and a distal end releasably coupled to
said proximal end of said housing, [0024] ii. a maximum outer
diameter D2 less than Dp, [0025] iii. a central bore through which
said wireline cable is axially slidable, [0026] iv. a blocking part
carried by said body part and movable from a closed position where
said blocking part extends radially outward of said central axis a
distance less than Dp, and has an open position where it extends
radially outward a distance greater than Dp, and [0027] v. a drive
mechanism adapted to move said blocking part from said closed
position to said open position, and further adapted to cause
separation of said blocking tool from said cylindrical body while
allowing said cable to remain slidable through said blocking tool
when said cylindrical housing moves axially distally away from said
blocking tool. 2. A bottom hole assembly (BHA) connectable to a
wireline cable, and operable to pass through a downhole wellbore
contiguous with a lateral wellbore both having diameter Dp (or the
lateral wellbore may have a diameter less than the diameter of the
mainbore), the lateral wellbore having a lateral window aperture of
maximum diameter Dw, the BHA comprising: [0028] a. a cylindrical
housing having a proximal end connectable to a wireline and a
distal end, and a maximum outer diameter D1 less than Dp, and
[0029] b. a blocking tool comprising: [0030] i. a body part having
a central axis and a distal end releasably coupled to said proximal
end of said housing, [0031] ii. a maximum outer diameter D2 less
than Dp, [0032] iii. a central bore through which said wireline
cable is axially slidable, [0033] iv. a blocking part carried by
said body part and movable from a closed position where said
blocking part extends radially outward of said central axis a
distance less than Dp, and has an open position where it extends
radially outward a distance greater than Dw, and [0034] v. a drive
mechanism adapted to move said blocking part from said closed
position to said open position, and further adapted to cause
separation of said blocking tool from said cylindrical body while
allowing said cable to remain slidable through said blocking tool
when said cylindrical housing moves axially distally away from said
blocking tool. 3. A method operable with a BHA as defined in
example 2 above that is entering a lateral wellbore window,
comprising the steps to prevent said wireline from engaging any
edge of said lateral wellbore window: [0035] a. directing said
drive mechanism of said blocking tool to move said blocking part to
said open position to have diameter greater than said window and to
engage the edge of said window and thereby block entry of said
blocking tool through said window, and [0036] b. separating said
blocking tool from said BHA while allowing said cable to remain
slidable through said blocking tool and maintaining said cable
spaced from engaging said window edge, as said BHA moves axially
distally away from said blocking tool. 4. A BHA according to
example 1 above where said blocking part comprises a pair of arms
having proximal ends pivotally coupled to said body part and distal
ends, said arms being movable to a position where said distal ends
thereof are radially outward of said body part. 5. A BHA according
to example 4 above where said pair of arms are spring biased toward
said open position and are restrained by said drive mechanism in
said closed position until said BHA begins to enter said wellbore
window. 6. A BHA according to example 5 above where said BHA
contains wellbore logging sensors selected from the group
consisting of resistivity, conductivity, formation pressure,
electrical, acoustics, radioactive, electromagnetic, nuclear
magnetic resonance and other properties of strata and their
contained liquids being investigated and/or monitored. 7. A BHA
according to example 1 above where said blocking part comprises a
plurality of arms having proximal ends pivotally coupled to said
body part and distal ends, said arms being movable to a position
where said distal ends thereof are radially outward of said body
part.
[0037] Further method embodiments of the present invention are
exemplified as follows:
1. A method of reducing potential damage to a wireline having a BHA
coupled to its distal end when said wireline is axially extended
through and past edges of a window opening that extends from the
outer to the inner side of the wall of a lateral wellbore, the BHA
having a proximal and distal ends, the wireline and BHA having
outer diameter less than that of said window, the method comprising
the steps: [0038] a. removably coupling a blocking tool to the
proximal end of said BHA, [0039] b. coupling said BHA to the distal
end of said wireline, [0040] c. directing said wireline and BHA to
said window in said lateral wellbore, [0041] d. directing said
blocking tool to expand to a diameter greater than the diameter of
said window, [0042] e. de-coupling said blocking tool from said BHA
and allowing said wireline and BHA to axially enter and traverse
said window and enter said wellbore while said blocking tool
prevents said wireline and BHA from contacting said edges of said
window [0043] f. subsequently withdrawing said wireline and BHA
outward through said window while said blocking tool continues to
prevent said wireline and BHA from contacting said edges of said
window, and [0044] g. re-coupling said BHA to the proximal end of
said blocking tool as said wireline and BHA are withdrawn through
said window. 2. The method of claim 2 where said blocking tool has
a body part and a plurality of arms with proximal ends pivotally
coupled to said body part and distal ends, the arms having a closed
position and said arms being movable to an extended position where
said distal ends thereof are radially outward of said body part to
define a diameter of said blocking tool greater than the diameter
of said window, whereby said blocking tool is barred from entering
into said window. 3. The method of claim 2 where said blocking tool
comprises a drive mechanism to move said arms to said extended
position and to subsequently withdraw said arms to said closed
position. 4. The method of claim 2 where said drive mechanism
further comprises spring elements biasing said arms toward said
open position thereof, and said drive mechanism restrains said arms
in said retracted position until directed to allow said spring
elements to drive said arms to said open position. 5. The method of
claim 1 where said BHA contains wellbore logging sensors that are
capable of measuring and/or monitoring properties selected from the
group consisting of resistivity, conductivity, formation pressure,
acoustics, radioactivity, electromagnetic and nuclear magnetic
resonance of strata and their contained liquids being investigated
and/or monitored. 6. A method of reducing the risk of potential
damage to a wireline when it is axially extended through and past
edges of a window opening that extends from the outer to the inner
side of the wall of a lateral wellbore, the window opening being
larger than the diameter of said wireline, the method comprising
the steps: [0045] a. providing a blocking mechanism that has width
greater than the size of the window opening, [0046] b. positioning
said blocking mechanism adjacent said outer side of said lateral
wellbore adjacent said window, said blocking mechanism being barred
from entering and traversing said window because of its diameter
being larger than said window opening, and [0047] c. with said
blocking mechanism blocking said wireline from engaging said edges
of said window as said wireline is directed to enter and pass
through said window, and as said wireline is subsequently withdrawn
out of said window.
[0048] These and other objects will be evident from the drawings
and description herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is a schematic fragmentary side elevation view
partially in section of a prior art well casing, downhole pipe and
wellhead penetrator,
[0050] FIG. 2 is an enlarged detail of a portion of the prior art
structure in FIG. 1,
[0051] FIG. 3A is a schematic fragmentary side elevation view of a
BHA at the distal end of a wireline in a downhole well casing
approaching a lateral wellbore,
[0052] FIG. 3B is a view similar to FIG. 3A showing the BHA in the
lateral well bore and inserted through a lateral window,
[0053] FIG. 3C is a detailed top plan view of the lateral window
opening in the lateral wellbore of FIG. 3B,
[0054] FIG. 3D is a fragmentary side elevation view in section of
the lateral window of FIG. 3C,
[0055] FIG. 4A is similar to FIG. 3A but shows the BHA with the
blocking tool coupled to the distal and of the BHA,
[0056] FIG. 4B is similar to FIG. 3B but shows the BHA having
passed through the lateral window and the blocking tool in gauging
the inner edge of the lateral window,
[0057] FIG. 5A is an enlarged side elevation view of the BHA
showing the blocking mechanism with arms in closed condition,
[0058] FIG. 5B is similar to FIG. 5A but shows the blocking
mechanism with the arms extended transversely and engaging the
edges of the inside wall of the lateral window as the BHA begins
entry and traverse of the lateral window, and
[0059] FIG. 5C is similar to FIG. 5B but shows the blocking member
separated from the BHA and the BHA moved distally away from the
blocking member.
[0060] FIG. 5D is similar to FIG. 5C but employs two pairs of
arms.
[0061] FIG. 5E is similar to FIG. 5A but illustrates employs longer
arms.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0062] For convenience and clarity in describing these embodiments,
similar elements or components appearing in different Figures will
have the same reference numbers.
[0063] FIGS. 1, 2, 3A-3D, 4A and 4B illustrate a conventional
downhole wellbore 10 whose downhole outer pipe casing 11 inner
casing 12 leads to lateral wellbore 13. Near the top of wellbore 10
is a wellhead penetrator 14 into which is inserted either wireline
16 seen in FIG. 1 or coiled cable 17 seen in FIG. 2.
[0064] At the distal end 20 of wireline 16, seen in FIG. 3A, is
attached a bottom hole assembly (BHA) 22 which includes selective
sensors or at least one sensor for detecting and/or measuring and
reporting the existence and characteristics of strata in the
vicinity of a lateral wellbore 13 that will be entered by the BHA
22. At the distal or lead end of the BHA 22 is a steering probe 24
which is used to guide the BHA along a selective path including
turn 25, then into lateral wellbore 13. FIG. 3B shows the BHA
having passed through lateral window 26 of lateral wellbore 13 and
into area 28.
[0065] FIG. 3C provides an enlarged illustration of lateral window
26 in lateral wellbore 13, this window being an opening milled or
otherwise cut in the wall of lateral wellbore 13. While window 26
appears as an oval opening, its proximal edge 27 is necessarily a
friction point or knife edge against which wireline 16 rubs when it
traverses window 26 and moves distally into area 28. It is this
knife edge friction point where wirelines become damaged and may
even break when they are moved axially back-and-forth during strata
examination, with expensive and time-consuming consequences. Thus,
a need has existed for a system that has wireline benefits of ease
of use, speed and relatively low cost, and also avoids or reduces
damage or risk of damage to wirelines. The present invention
achieves these objectives as illustrated in FIGS. 4A, 4B, 5A, 5B
and 5C described below. Window 26 may have a vertical as well as
horizontal orientation.
[0066] FIG. 4A is similar to FIG. 3A showing a downhole outer pipe
casing 11, inner pipe 12, lateral wellbore 13, wireline 16 and BHA
22 with its steering probe 24. The rear or proximal end segment is
blocking tool 30 where later separates from the remainder of BHA 22
as further described below. The BHA is shown descending before it
turns to approach lateral window 26 and passes the window's sharp
edged 27.
[0067] FIG. 4B shows BHA 22 having traveled to and through lateral
window 26 with a blocking tool 30 separated from the remainder of
BHA 22 and now situated at the inner edge of window 26. Wireline 16
has moved axially through blocking tool 30 as BHA 22 is directed
axially into area or zone 28.
[0068] An object of this invention is to protect a wireline from
damage at the friction point 27 where it must pass, this procedure
occurring deep underground.
[0069] The new blocking tool 30 shown in FIGS. 4B and 5A-5C has a
pair of arms 32 that spring out when released. When these arms
engage the edges 29 of window/aperture 26 in lateral wellbore 13,
tool 30 is situated at window 26 but blocked from proceeding
through the window. While so situated tool 30 serves as a guide or
bushing and may include rollers through which cable 16 moves easily
axially without encountering sharp edge 27 of window 26. Arms 32
and associated mechanism not shown in tool 30 position, orient and
maintain this tool in the lateral wellbore window 26, and safely
guide wireline 16. BHA 22 is thus transported axially into zone 28
with no risk of damage to cable 16 from friction, abrasion or
cutting by edge 27. Furthermore, the bushing characteristic of tool
30 facilitates ease, speed and safety of repeated back-and-forth
transitions of cable 16.
[0070] The specific construction of blocking tool 30 may vary, but
the one illustrated herein has arms 32 in closed compact position
shown in FIG. 5A, the arms being biased by springs 34 to pivot in
the directions of arrows 33 to open positions shown in FIG. 5B.
Release element 36 activated by electronic signals in wireline
cable 16 releases arms 32 to spring to their open position, seen in
FIG. 5B, just when the BHA 22 has arrived in the mid-window
location. Feet 38 of arms 32 are now spaced apart a distance
greater than the width of opening 26, which bars tool 30 from
continuing through window 26. However, with this movement of arms
32 to their open end blocking position, blocking tool 30 separates
from the main body of BHA 22, the main body then proceeding in the
direction of arrow 40 its investigation and monitoring functions,
as seen in FIG. 5C. Separation may be achieved by many different
mechanisms, one device illustrated schematically herein is element
39 that engages mating element 39A and is activated by release
element 36.
[0071] FIG. 5D illustrates a variation of the blocking tool, having
more than two arms, such as a second pair of opposite arms, one
being shown as arm 33 and its foot or roller wheel 33A, the
opposite arm not seen. FIG. 5E illustrates a still further
variation of the blocking tool where the arms 40 are not confined
to be stored internal of the housing and thus can be longer and
more effective in some situations.
[0072] When BHA 22 is withdrawn back up the wellbore, cable 16 is
pulled in the direction of arrow 42 as seen in FIG. 5C, until BHA
22 returns to its position of FIG. 5B, and then proceeds backwards
and upwards into the wellbore. During retraction of cable 16 the
tension in the cable pulls BHA 22 rearward where it reconnects with
blocking tool 30. Blocking tool 30 either returns to its closed
position of FIG. 5A, or alternatively its arms 32 resiliently close
enough to fit within downhole pipe 12 as BHA 22 is withdrawn. For
arms 32 as illustrated, the feet 38 are formed as rollers to
facilitate movement of the feet when they engage edges 29 of window
26, and when they later ride against the inner wall surfaces of
pipe 12 when BHA is retracted. Other forms of blocking tools are
possible, but the device presently shown effectively achieves the
goal of facilitating passage of cable 16 past sharp edge 27 while
eliminating frictional contact therewith and risk of abrasion or
other damage to the cable, and does so by attachment of an
auxiliary blocking element at the distal end of the BHA that
conforms generally to the small diameter dimensions required for
ready passage of the BHA within the downhole pipe and the lateral
borehole.
[0073] Thus, in this embodiment the BHA carries its own blocking in
cable guidance tool all the way down to the lower depths of the
wellbore. This tool traverses the extremely narrow diameter of the
inner downhole pipe and then opens to a substantially larger
diameter in its blocking mode. In this particular case the blocking
tool's arms 32 are carried totally within the outer circumferential
dimension of the cylindrical BHA. The location of the cable
generally along the central axis of BHA 22 is maintained, as seen
in FIG. 5C, when blocking tool 30 separates from the main body of
BHA 22.
[0074] In the claims herein the bottom hole assembly or BHA for
investigation, monitoring or other well logging operations is
presumed to include at least one sensor to investigate, measure and
or monitor resistivity, conductivity, formation pressure,
electrical, acoustic, radioactive, electromagnetic, nuclear
magnetic resonance and other properties of the strata and their
contained fluids in an area of interest. In embodiments of this
invention a selected BHA would have outer dimensions appropriate
for being transported through the bore of a downhole and lateral
wellbore.
[0075] While the invention has been described in conjunction with
several embodiments, it is to be understood that many alternatives,
modifications, and variations will be apparent to those skilled in
the art in light of the foregoing description. Accordingly, this
invention is intended to embrace all such alternatives,
modifications, and variations which fall within the spirit and
scope of the appended claims.
* * * * *
References