U.S. patent application number 09/954891 was filed with the patent office on 2002-05-30 for method apparatus for horizontal drilling and oil recovery.
Invention is credited to Billingsley, Robert.
Application Number | 20020062993 09/954891 |
Document ID | / |
Family ID | 26926634 |
Filed Date | 2002-05-30 |
United States Patent
Application |
20020062993 |
Kind Code |
A1 |
Billingsley, Robert |
May 30, 2002 |
Method apparatus for horizontal drilling and oil recovery
Abstract
An oil tool forms holes or perforations which extend
horizontally away from the borehole and into the formation for
recovering additional oil and gas from the formation. The tool
provides a downhole tool capable of drilling horizontally into a
formation and further capable of operating in a relatively small
well bore, such as those having a diameter of less than six inches.
In addition, the tool does not tend to spiral or otherwise deviate
from horizontal during drilling operations. The tool of the present
invention includes a drill capable of drilling or tunneling through
the formation, a magazine or carrier which contains a plurality of
hollow joints or segments, a hydraulic pump and a mechanism for
assembling and disassembling the segments. Once in place, the
assembly mechanism removably attaches a segment from the magazine
to the drill.
Inventors: |
Billingsley, Robert; (Katy,
TX) |
Correspondence
Address: |
Attn. Robert C. Curfiss
BRACEWELL & PATTERSON, L.L.P.
P.O. Box 61389
Houston
TX
77208-1389
US
|
Family ID: |
26926634 |
Appl. No.: |
09/954891 |
Filed: |
September 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60233115 |
Sep 18, 2000 |
|
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Current U.S.
Class: |
175/52 ;
175/77 |
Current CPC
Class: |
E21B 7/04 20130101; E21B
4/18 20130101; E21B 7/06 20130101; E21B 23/001 20200501 |
Class at
Publication: |
175/52 ;
175/77 |
International
Class: |
E21B 019/00 |
Claims
What is claimed is:
1. An apparatus for drilling a horizontal borehole from a vertical
wellbore, comprising: a. a drill bit; b. a plurality of hollow
segments in the vertical wellbore, one of which is attached to the
drill bit; and c. means for driving the drill bit through the
hollow segments.
2. The apparatus of claim 1, wherein the segments are stored in an
unattached manner within the wellbore and are sequentially attached
to one another as the drill bit advancehorizontally.
3. The apparatus of claim 2, further including a magazine of
stacked segments in the wellbore.
4. The apparatus of claim 3, further including a load cell located
at a position in the wellbore at which a horizontal perforation is
desired, wherein each segment in the magazine of stacked segments
drops into the load cell and is attached to the next adjacent
segment as the drill bit horizontally advances.
5. The apparatus of claim 1, further including a drill stem
extending through the segments and attached to the drill bit for
driving the drill.
6. The apparatus of claim 1, wherein the hollow interior of the
segments form a fluid conduit for hydraulic fluid for driving the
drill bit.
7. The apparatus of claim 1, wherein the segments are connected in
a chain and are carried in a loop in the well bore.
8. The apparatus of claim 7, further including a first guide means
near the top of the well bore for supporting and guiding the chain
of segments into the wellbore and a second guide means adjacent a
location in the wellbore where a horizontal perforation is desired
for guiding the segments into the horizontal perforation.
9. The apparatus of claim 8, wherein the first guide means is
axially movable in the wellbore for keeping the chain of segments
in tension.
10. The apparatus of claim 8, wherein the guide means is a
pulley.
11. The apparatus of claim 8, wherein the guide means is a sprocket
gear designed to engage the chain segments.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on the provisional application
Serial No. 60/233,115, filed on Sep. 18, 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention is generally related to drilling and producing
oil from abandoned wells and is specifically directed to horizontal
drilling and perforating such wells.
[0004] 2. Discussion of the Prior Art
[0005] As oil supplies continue to deplete, the ability to recover
additional oil from existing and/or abandoned well sites or
formations becomes of greater importance. One method for recovering
additional oil and gas from a formation is to create holes or
perforations which extend horizontally away from the borehole and
into the formation.
[0006] There are tools in the industry capable forming horizontal
bores or holes. These can generally be categorized as (1) hydraulic
or (2) flexible shaft tools. As shown in U.S. Pat. Nos. 4,317,492
(Summers), 5,439,066 (Gipson) and 5,853,056 (Landers), 5,934,390
(Uthe), hydraulic fluid can be used to create holes or perforations
in oil bearing formations. Typically a hose or tube is passed down
the existing well bore to a point were the horizontal bore is
desired. The hose extends from the surface, where a pump provides
pressurized hydraulic fluid, such as water, to erode the rock or
sand surrounding the downhole end of the hose. While somewhat
effective in forming holes in the strata surrounding the main bore,
this method significantly damages the formation, which may hinder
additional oil or gas production.
[0007] Many tools, such as that shown in U.S. Pat. No. 4,226,288
(Collins), as well as those shown in the '056 and '066 patents,
provides a flexible shaft which extends from the surface, down the
main bore and then turns or bends to extend horizontally into the
formation, traveling generally perpendicular to the main bore.
While these tools may be suitable for use in very large well bores,
they are not suitable for use in wells having smaller bores because
the turning radius of the flexible shaft is too great.
Additionally, those tools which turn the entire shaft to provide
rotation of a drill bit do not typically travel perpendicular to
the well bore. The rotation of the shaft creates a downward
spiraling of the drill bit.
SUMMARY OF THE INVENTION
[0008] The present invention provides a method and apparatus for
forming holes or perforations which extend horizontally away from
the borehole and into the formation for recovering additional oil
and gas from the formation. The present invention provides a
downhole tool capable of drilling horizontally into a formation and
further capable of operating in a relatively small well bore, such
as those having a diameter of less than six inches. In addition,
the tool does not tend to spiral or otherwise deviate from
horizontal during drilling operations. The tool of the present
invention includes a drill capable of drilling or tunneling through
the formation, a magazine or carrier which contains a plurality of
hollow joints or segments, a hydraulic pump and a mechanism for
assembling and disassembling the segments. Once in place, the
assembly mechanism removably attaches a segment from the magazine
to the drill.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an illustration of the vertical bore hole, a
horizontal bore hole and the assembly of the subject invention.
[0010] FIG. 2 is similar to FIG. 1 and shows an alternative
embodiment.
[0011] FIG. 3 is an illustration of a drill bit used in accordance
with the subject invention.
[0012] FIG. 4 shows an alternative embodiment for feeding the
segments of the system in accordance with the subject
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] As shown in FIGS. 1 and 2, the present invention provides a
downhole tool capable of drilling horizontally into a formation and
further capable of operating in a relatively small well bore, such
as those having a diameter of less than six inches. The well bore
10 is perforated at the opening 12 for accommodating a horizontal
drill bit 14. The drill bit is mounted on the front end of a
magazine segment 16. The well bore 10 serves as a storage cell for
a plurality of segments 16, forming a magazine 18. As the bit 14
moves horizontally into the strata, segment 16A will advance out of
the wellbore 10. At this point the next in line segment 16B will
drop into the loading cell 20 and couple to the next ahead segment
16A, permitting the bit 14 to progress further in a horizontal
direction. In addition, the tool does not tend to spiral or
otherwise deviate from horizontal during drilling operations. As
the drill advances into the formation, the assembly mechanism
affixes additional segments, which are fed from the magazine. An
alternative embodiment is shown in FIG. 2 and operates in the same
manner as that shown in FIG. 1.
[0014] Specifically, the tool of the present invention includes a
drill capable of drilling or tunneling through the formation, a
magazine or carrier which contains a plurality of hollow joints or
segments, a hydraulic pump and a mechanism for assembling and
disassembling the segments. Initially, the tool is lowered into the
bore, down to the desired level using known wireline techniques.
Once at its destination, the tool may be removably affixed in the
bore using any suitable method or mechanism to prevent movement of
the tool during operation. Once in place, the assembly mechanism
removably attaches a segment from the magazine to the drill.
Hydraulic fluid from the pump may then be passed through the hollow
segment to the drill to power the bit. The drill the travels out of
the tool through an opening or aperture therein and into the
formation. The pump of the present invention is preferably located
in the tool itself, rather than at the surface. As the drill
advances into the formation, the assembly mechanism affixes
additional segments, which are fed from the magazine, onto the
previously attached or assembled segment. Once the horizontal bore
is formed, the drill may be drawn back into the tool. After
completing a horizontal bore, the tool may be raised or lowered for
further drilling or may simply be rotated to allow an additional
horizontal bore to be formed at the same depth.
[0015] Although any suitable drill may be used, as shown in FIG. 3,
the drill typically incorporates a suitable bit 22 and a plurality
of drive mechanisms such as the drive wheels or axles 24 disposed
on the exterior of the drill to aid in driving or pushing the bit
forward into the formation and to provide stability for the bit
during operation. Hydraulic fluid from a pump turns the bit in the
manner well known to those who are skilled in the art and provides
power to the drive mechanism. The drive mechanism may include
wheels, tracks or any other suitable device. Preferably, a
plurality of tracks are affixed in a spaced manner about the
outside of the bit.
[0016] The segments preferably have a hexagonal or octagonal shape
to add rigidity and prevent bending during drilling. Each segment
has a first, leading end and a second, trailing end. The leading
end of each segment corresponds to the trailing end of the segment
before it. In this way, the segments may be removably joined by the
assembly mechanism and passed into the newly formed horizontal
bore. For example, corresponding first and second ends may be
threaded internally and externally, respectively. Corresponding
ends may have any suitable interlocking arrangement. The segments
have a diameter smaller than that of the hole or bore formed by the
drill bit. Preferably, each segment is approximately three inches
in length and may be formed from any suitable material, but
preferably a metal such as steel. It may be desirable, in certain
instances, to include spacers or support devices at spaced
intervals along the assembled segments. Such spacers provide
support for the segments and prevent bending of the assembled
segments, which may occur due to the smaller diameter of the
segments relative to the horizontal bore. Where spacers are used,
they are typically slotted to allow fluid and cuttings to pass out
of the horizontal bore. The magazine or carrier may be sized
contain any number of segments, preferably, however, the carrier
accommodates enough segments to allow the drill to travel
approximately forty feet from the main bore.
[0017] In a another embodiment, and as shown in FIG. 4, the present
invention is a downhole horizontal drilling tool which includes a
drill, a linked chain drive system and a hydraulic pump. The drill
preferably has a plurality of drive mechanisms 24 positioned
thereon, as previously described. Hydraulic fluid from the pump
drives the drill bit and drive mechanism.
[0018] The linked chain drive system includes at least a pair of
pulleys 32, 34, one of which may be moved axially within the tool,
a linked chain of segments 36, and a drive motor 38. Preferably,
the linked chain is hollow to allow fluid to pass therethrough.
[0019] The last segment in the linked chain is attached to the
drill 14. As the drill travels into the formation, the linked chain
is pulled into the formation as well. As the linked chain travels
into the formation, an upper, axially moveable pulley 32 travels
axially downward, thereby allowing the chain to travel out into the
formation while keeping tension in the chain and controlling the
rate at which it travels. A lower, fixed pulley 34 allows the chain
to turn out of the tool and into the formation. Additional pulleys
may be used to further control the movement of the linked chain.
The motor 38 controls the movement of the upper pulley and may
rotate drill stem 40 inside the linked chain. Alternatively, a pump
may supply a hydraulic fluid through the chain to turn the drill
bit and drive the drive mechanisms in the manner well known. Once
the horizontal bore is formed, the drill and linked chain is drawn
back into the tool.
[0020] While certain embodiments and features have been disclosed
in detail herein, it should be understood the invention includes
all enhancements and modifications within the scope and spirit of
the following claims.
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