U.S. patent application number 11/508108 was filed with the patent office on 2008-02-28 for method for increasing bit load.
Invention is credited to Benton F. Baugh.
Application Number | 20080050180 11/508108 |
Document ID | / |
Family ID | 39113613 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080050180 |
Kind Code |
A1 |
Baugh; Benton F. |
February 28, 2008 |
Method for increasing bit load
Abstract
A circulation system in which a drilling fluid flows from the
surface, through a pipe, through a motor and a drill bit, and
returns to the surface through the annular area between the outside
diameter of the pipe and the internal diameter of the hole being
drilled, to urge the drilling system forward by providing a seal
which engages the internal diameter of the hole being drilled,
providing a booster pump to pump the drilling fluids between the
seal and the outer diameter of the drilling system such that the
pressure downstream of the booster pump is higher than the pressure
upstream of the booster pump by a differential pressure giving a
force generally proportionate to the area within the diameter of
the sealing engagement with the internal diameter of the bore times
the differential pressure to urge the drilling system forward.
Inventors: |
Baugh; Benton F.; (Houston,
TX) |
Correspondence
Address: |
Benton F. Baugh
14626 Oak Bend
Houston
TX
77079
US
|
Family ID: |
39113613 |
Appl. No.: |
11/508108 |
Filed: |
August 23, 2006 |
Current U.S.
Class: |
405/184 |
Current CPC
Class: |
E21B 21/08 20130101;
E21B 7/046 20130101 |
Class at
Publication: |
405/184 |
International
Class: |
E03F 3/06 20060101
E03F003/06 |
Claims
1. In a circulation system in a hole in which a fluid flows from a
starting location, through a pipe within said hole, through a
motor, and returns to said starting location through the annular
area between the outside diameter of said pipe and the internal
diameter of said hole, the method of urging said motor further from
said starting location, comprising providing a seal which sealingly
engages said internal diameter of said hole, providing a booster
pump to pump said fluids between said seal and the outer diameter
of said pipe such that the pressure downstream of said booster pump
is higher than the pressure upstream of said booster pump by a
differential pressure, such that a force generally proportionate to
the area within the diameter of said sealing engagement with said
internal diameter of said hole times said differential pressure
urges said motor forward.
2. The invention of claim 1, wherein fluid leaving the distal end
of said pipe removes material from the end of said hole and
increases the length of said hole from said starting location.
3. The invention of claim 1, wherein said motor rotates a drilling
bit which removes material from the end of said hole and increases
the length of said hole from said starting location.
4. The invention of claim 3, wherein urging said motor further from
said starting location increases load on said drilling bit at the
distal end of said hole from said starting location.
5. The invention of claim 1, wherein said motor is urged forward in
a generally horizontal direction.
6. The invention of claim 1, wherein said seal is a pressure
energized cup type seal.
7. The invention of claim 5, wherein said pressure energized cup
type seal has a connection to said motor which keeps said energized
cup type seal from being turned inside out during retrieval from
the hole.
8. The invention of claim 1, wherein booster pump is a turbine
style pump.
9. The invention of claim 8, wherein the rotating section of said
turbine type booster pump is rotated by said motor.
10. In a circulation system in which a drilling fluid flows from
the surface, through a pipe, through a drilling system comprising a
motor and a drill bit, and returns to said surface through the
annular area between the outside diameter of said pipe and the
internal diameter of the hole being drilled, the method of urging
said drilling system forward, comprising providing a seal which
sealingly engages said internal diameter of said hole being drilled
at a location between said drilling bit and said surface, providing
a booster pump to pump said drilling fluids between said seal and
the outer diameter of said drilling system such that the pressure
downstream of said booster pump is higher than the pressure
upstream of said booster pump by a differential pressure, such that
a force generally proportionate to the area within the diameter of
said sealing engagement with said internal diameter of said bore
times said differential pressure urges said drilling system
forward.
11. The invention of claim 10, wherein urging said drilling system
forward increases the load on the area to be drilled.
12. The invention of claim 11, wherein the area to be drilled is
formations within the earth.
13. The invention of claim 10, wherein said drilling system is
urged forward in a generally horizontal direction.
14. The invention of claim 10, wherein said seal is a pressure
energized cup type seal.
15. The invention of claim 14, wherein said pressure energized cup
type seal has a connection to said drilling system on the end
distal from said bit which keeps said energized cup type seal from
being turned inside out during retrieval from the hole.
16. The invention of claim 10, wherein booster pump is a turbine
style pump.
17. The invention of claim 16, wherein the rotating section of said
turbine type booster pump is rotated by said motor.
18. In a circulation system in which a drilling fluid flows from
the surface, through a pipe, through a drilling system comprising a
motor and a drill bit, and returns to said surface through the
annular area between the outside diameter of said pipe and the
internal diameter of said hole being drilled, the method of
increasing the load on said drilling bit on the formations to be
drilled to improve the drilling operations, comprising providing a
seal which sealingly engages said internal diameter of said hole
being drilled at a location between said drilling bit and said
surface, providing a booster pump to pump said drilling fluids
between said seal and the outer diameter of said drilling system
such that the pressure downstream of said booster pump is higher
than the pressure upstream of said booster pump by a differential
pressure, such that a force generally proportionate to the area
within the diameter of said sealing engagement with said internal
diameter of said bore times said differential pressure urges said
drilling system forward.
19. The invention of claim 18, wherein said load is increased on
said drill bit by urging said drilling system forward.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] N/A
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] N/A
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISK
[0003] N/A
BACKGROUND OF THE INVENTION
[0004] The field of this invention of that of moving pipe into a
generally horizontal hole and drilling at the end of the hole. The
distance at which the pipe can be pushed into a generally
horizontal hole is limited by the forces available and the column
buckling characteristics of the pipe.
[0005] Pipes are used to push in horizontal directions for
activities such as drilling in oil and gas wells as holes are
drilled horizontally thru shallow but wide pockets or reservoirs of
oil or gas. Once the wells are drilled, cleanout or secondary
production operations can be enhanced by a smaller string of tubing
being inserted into the horizontal runs. The use of the smaller but
faster strings has been limited due to the limited load which can
be put on a bit at the end of the tubing.
[0006] A variety of other pipes exist in which improved "bit load"
can be useful includes sewage systems, water lines, and
pipelines.
[0007] Especially in the case of thin wall pipe such as coiled
tubing which can be unreeled into a pipe, column buckling strength
is low. As the pipe is not actually assured of being straight in
the first place, column buckling resulting in a spiral
configuration in the well will cause high friction with the wall of
the hole. This friction will limit and/or stop forward movement of
the pipe, and eliminate or limit the available end loading
available to a drilling bit at the end of the tubing.
[0008] When the generally horizontal hole begins with a vertical
hole such as in an oil or gas well, the transmission of force
around the curve between vertical and horizontal further limits the
forces available in the generally horizontal section.
BRIEF SUMMARY OF THE INVENTION
[0009] The object of this invention is to provide a method which
will provide a forward motive force for tools and pipes which are
in generally horizontal holes.
[0010] A second object of the present invention is to provide a
motive force which will increase the load on a drill bit while the
drill bit is drilling.
[0011] A third object of the present invention is to provide a
method of providing lower pressures at the drilling bit to enhance
drilling penetration rate.
[0012] A fourth object of the present invention is to provide means
to move the jetting head of a pipeline blockage remediation system
forward while pumping into the internal string of pipe and taking
returns up the larger annulus rather than pumping down the annulus
and having to take the returns back up the smaller internal
diameter of the internal string.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0013] Figure no. 1 is a section of the earth showing a well being
drilled with the system of this invention being in place.
[0014] Figure no. 2 is a closer view of a portion of FIG. 1 showing
the general area of the drilling system without the benefits of the
present invention for comparison.
[0015] Figure no. 3 is a closer view of a portion of FIG. 1 showing
the general area of the drilling system with the benefits of the
present invention for comparison.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIG. 1 shows a drilling system 1 in a well bore 3. The
drilling system generally comprises a drill bit 5, a booster pump
7, a sealing cup 9, and a drill motor 12. A drilling and
circulating string 14 is used to push the drilling system along
well bore 3 and provide hydraulic power for drill motor 12.
Drilling system will often also include directional control systems
16 which require control cables 18.
[0017] A relatively vertical casing 20 is shown with a whipstock
device 22 shown to divert the drilling operations from vertical to
more horizontal as is well known in the art. The figure illustrates
that a window 24 has been milled in the side of the casing 20 off
whipstock 22 to start the diversion of the string from near
vertical to near to horizontal, or in some cases fully horizontal.
For clarity on the drawing the turn to horizontal is shown to be
almost within the size of the casing, whereas in reality the turn
to horizontal can take hundreds of feet.
[0018] Numerous flow arrows 26 shown that the fluids flow down from
the surface 28 thru the internal diameter of the smaller string 14,
thru the drilling system, and back up the annular area within the
internal hole of the bore being drilled to the surface 28.
[0019] Referring now to FIG. 2, drilling system is shown 1 in a
well bore 3 which does not have the means of the present invention.
The figure shows the drill bit 5, a mud motor 12, drilling and
circulating string 14, and flow arrows 26.
[0020] For purpose of discussion of this figure we will presume
that the operations are occurring at a depth of about 1000 feet,
such that the ambient or non-flowing pressure is 1,000 p.s.i. at
locations P1, P2, P3, and P4. This would reflect that the pressure
gradient of the drilling fluid system to be about 1/2 p.s.i. per
foot which is a relatively light weight drilling fluid.
[0021] When a sample flow is started, the annulus pressure P1 still
approximates 1000 p.s.i. P2 is also 1000 p.s.i. as it is the same
space and there is minimal flow loss up the large annulus area. The
reason for identifying the pressure in these two similar places
will be understood in figure no. 3. P3 is inside the bit and
reflects the flow loss across the jet nozzles 30, increasing to
1300 p.s.i. or a 300 p.s.i. differential. Pressure P4 is 1400
p.s.i. or a 100 p.s.i. differential to hydraulically provide the
power to drive the motor to turn the bit.
[0022] Referring now to figure no. 3, drilling system has a booster
pump 7 in the annulus above the drilling bit 5 and a flexible cup
seal 9 to seal on the formation hole or I.D. of the pipe the unit
is passing thru. Booster pump 7 is shown with bearing and seal sets
40 and 42, rotating turbine blades 44, stationary turbine blades
46, lower centralizer ring 48, upper centralizer ring 50, upper
connection 52, and hoses 54. Lower and upper centralizer rings 48
and 50 keep the sealing cup 9 generally centralized so that it will
remain in sealing contact with the well bore 3. Upper connection 52
prevents the sealing cup 9 from being turned backward and inside
out when the system is pulled out of the hole.
[0023] The rotating blades 44 of the turbine type booster pump is
spun on the same shaft as the drilling bit 5 and in combination
with the stationary blades 46, it produces a pumping differential,
in this sample case about 20 p.s.i. P1 remains at 1,000 p.s.i., but
P2 is reduced to 980 p.s.i. Inside the drill bit 5 with the same
300 p.s.i. differential across the jets 30 the pressure is reduced
to 1,280 p.s.i. The motor is taking an extra 100 p.s.i. to power
the rotating blades 32, so the pressure is increased by 100 p.s.i.
but reduced by the 20 p.s.i. from the booster pump 7, giving a net
pressure of 1480 p.s.i.
[0024] The 980 p.s.i. at P2 above the bit is a relative vacuum in
comparison to the expected 1000 p.s.i., so in a sense, the system
works by vacuuming the bit towards the end of the hole.
[0025] If we presume we are drilling a 65/8'' diameter hole, the
seal engagement between the bore and the cup seal provides an area
of the 34.471 sq. in. The 20 p.s.i. differential from the booster
pump across this area yields a force on the bit of 34.471*20=689.4
lbs.
[0026] This is 689.4 lbs of bit force for drilling at a location
where otherwise zero force might be available.
[0027] The example given is a nominal set of values which will be
achieved as desired. As larger bores are encountered, less of a
pressure differential will be desired to prevent overloading the
bits. A 20 p.s.i. differential in a 20'' bore will provide a 10,000
lb. load on the bit. In smaller bores, a longer impeller will be
desired to provide higher differentials for loading.
[0028] It is understood in the art that reducing the head pressure
on the formation at the point of drilling will often speed the
drilling rate. This is called underbalanced drilling. Complex
systems of percolating some nitrogen in the annulus of drilling
wells is sometimes used to implement this principle. This system
literally reduces the head pressure specifically on the drilling
area by 20 p.s.i. in this case. When properly balanced, it will
allow an overbalance in the bore of the hole away from the drill
bit and an under balance in the area of the bit to optimize
drilling.
[0029] Remediation of a blockage in a pipeline requires that access
to the blockage is achieved with a small circulating string of pipe
within the pipeline, usually coiled tubing. Pushing a string of
coiled tubing into a horizontal pipeline is typically hindered by
the difficulty in pushing coiled for significant distances. Pushing
coiled tubing is generally limited to about one mile before the
coiled tubing buckles into a helical pattern and friction locks in
the pipeline. One solution is to place a sealing cup on the end of
the pipeline and pressuring the backside of the cup. This has the
limitation of the returns having to come back the smaller bore of
the I.D. of the coiled tubing.
[0030] The present invention offers the advantage of the high
pressure pumping down the I.D. of the coiled tubing and the return
back up the much larger annulus area. It can also offer higher
pressures to power the drill motor to provide the motive force for
the end of the coiled tubing of a relative vacuum.
[0031] The particular embodiments disclosed above are illustrative
only, as the invention may be modified and practiced in different
but equivalent manners apparent to those skilled in the art having
the benefit of the teachings herein. Furthermore, no limitations
are intended to the details of construction or design herein shown,
other than as described in the claims below. It is therefore
evident that the particular embodiments disclosed above may be
altered or modified and all such variations are considered within
the scope and spirit of the invention. Accordingly, the protection
sought herein is as set forth in the claims below.
* * * * *