U.S. patent number 3,814,180 [Application Number 05/285,141] was granted by the patent office on 1974-06-04 for well fishing apparatus.
This patent grant is currently assigned to Cities Service Oil Company. Invention is credited to Don L. Oliver.
United States Patent |
3,814,180 |
Oliver |
June 4, 1974 |
WELL FISHING APPARATUS
Abstract
A fishing tool which can be used for dislodging and collecting
junk from the walls of a well bore. The tool can be located in a
drilling string above a bit, and streams of drilling fluid are
jetted outwardly against the wall of the bore to dislodge junk
which resides in or upon the wall. A junk basket is located on the
tool above the bit, and junk is thus basketed before it falls to
the bottom of the hole.
Inventors: |
Oliver; Don L. (Houston,
TX) |
Assignee: |
Cities Service Oil Company
(Tulsa, OK)
|
Family
ID: |
23092912 |
Appl.
No.: |
05/285,141 |
Filed: |
August 31, 1972 |
Current U.S.
Class: |
166/99;
175/308 |
Current CPC
Class: |
E21B
41/0078 (20130101); E21B 31/03 (20130101); E21B
27/00 (20130101); E21B 34/14 (20130101); E21B
21/103 (20130101) |
Current International
Class: |
E21B
21/10 (20060101); E21B 31/00 (20060101); E21B
27/00 (20060101); E21B 21/00 (20060101); E21B
31/03 (20060101); E21B 34/00 (20060101); E21B
34/14 (20060101); E21B 41/00 (20060101); E21b
031/08 () |
Field of
Search: |
;166/99,311,312,222,223
;175/25,38,60,65,54,72,237,243,308-312,317-320 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; David H.
Attorney, Agent or Firm: Gun; Elton F.
Claims
What is claimed is:
1. A well fishing tool comprising:
a. a tubular body section threadably connectible at the upper end
to a drilling string,
b. a longitudinal fluid passageway in the body section of the tool
leading from the upper end thereof,
c. a fluid channel which extends through the side wall of the body
section from the passageway therein to the outside, and
d. a junk basket which surrounds the tubular body section of the
tool and including a bucket with a bottom that is contiguous with
said body section, said bucket comprising an attached flexible
funnel which leads into the upper end of the bucket and which has
an open upper rim of larger diameter than the body section of the
tool that the bucket surrounds, and whereupon lowering the fishing
tool into a bore hole the funnel of the bucket becomes compressed
and is thus caused to fit tightly into the bore hole.
2. Apparatus as in claim 1 wherein the portion of the body section
surrounded by the basket is inwardly tapered.
3. Apparatus as in claim 1 wherein the lower end of the body
section is threadably connectible to members of a drilling
string.
4. Apparatus as in claim 1 wherein the junk basket is attached to
the tool below the channel through the wall thereof.
5. Apparatus as in claim 1 and further comprising at least one
other channel through the wall of the body section of the tool.
6. Apparatus as in claim 5 wherein at least one of the channels
projects at an inclined angle with respect to the wall of the body
section of the tool.
7. Apparatus as in claim 1 wherein the funnel is rubber.
8. Apparatus as in claim 7 wherein the funnel is reinforced
rubber.
9. Apparatus as in claim 7 wherein the funnel is provided with
metal stays for urging said upper rim of the funnel against the
wall of a bore hole when the funnel is compressed therein.
10. Apparatus as in claim 1 and including a drilling string to
which the upper end of the body section of the tool is
attached.
11. Apparatus as in claim 10 wherein the body section is attached
to the lower end of a drilling string.
12. Apparatus as in claim 11 and further including a member of a
drilling string attached to the lower end of the body section of
the tool.
13. Apparatus as in claim 1 wherein the fluid passageway extends
through the body section of the tool and further comprising:
a. a previously set operable sleeve member inside the body section
which covers the channel through the wall of the body section when
set and which uncovers the channel when operated, and
b. a seal surface in said sleeve member which receives a matching
seal surface on a flow obstructing member emplaced in said sleeve
member.
14. Apparatus as in claim 13 and further comprising at least one
other channel which extends through the side wall of the body
section of the tool, said other channel also being normally covered
by the operable member and uncovered upon operation of the
member.
15. Apparatus as in claim 14 wherein at least one of the channels
projects at an inclined angle with respect to the wall of the
tool.
16. Apparatus as in claim 13 wherein the flow obstructing member is
a plunger emplaced in said sleeve member.
17. Apparatus as in claim 16 wherein the plunger has an outward
projection with a sealing surface which abuts the seal surface of
said sleeve member.
18. Apparatus as in claim 16 wherein the plunger is gravity
actuated.
19. Apparatus as in claim 18 and further comprising means for
retrieving the plunger by wire line.
20. Apparatus as in claim 19 and further comprising a snap ring
which couples the plunger and the sleeve member when the plunger is
employed in the sleeve member.
21. Apparatus as in claim 13 wherein the operable sleeve member is
slidable in the passageway both over and beyond the opening of the
channel in the body section of the tool.
22. Apparatus as in claim 21 and further comprising an internal
recess in the body section of the tool and the sleeve member is
slidable in the recess.
23. Apparatus as in claim 21 and including securing means for
holding the sleeve member in its previously set position over the
channel in the wall of the body section of the tool.
24. Apparatus as in claim 23 wherein the securing means comprises
at least one O-ring fitted into a recess around the outer
circumference of the sleeve.
25. Apparatus as in claim 23 wherein the securing means is a
tensioned spring which urges against the sleeve in an axial
direction.
Description
BACKGROUND OF THE INVENTION
The present invention pertains to the drilling of wells and more
particularly to removal of objects from a well bore which interfere
with or disrupt the drilling operation. More specifically, this
invention pertains to methods of fishing a well for removal of junk
or debris by means of an improved fishing tool.
When a well is being drilled it is not uncommon for the bit to
encounter objects which slow drilling progress and which can also
damage or destroy the bit unless removed from the hole. Examples of
such objects are fragments from the bit itself such as broken
teeth, pieces of cement, large hard fragments of the formation
being drilled which break loose instead of being cut into small
pieces by the bit, and miscellaneous other stone-like or scrap
metal objects. These materials are commonly referred to as "junk"
and are "fished" from the hole by means of a "fishing tool."
Current practices for fishing a well assume that all junk which is
encountered originated at the bottom of the hole. Present fishing
tools therefore amount to coring devices which cut at the outside
of the hole to produce a core wherein the junk is contained and
retrieved when the tool is withdrawn from the well. It has now been
discovered, however, that junk encountered by the bit does not
always originate from the bottom, but may initially reside in the
wall of the well bore, or upon a ledge thereon, and becomes
dislodged during tripping of the drill pipe back and forth through
the hole, so that it is thus knocked loose and falls to the bottom.
Consequently, this dislodged junk does not find its way to the
bottom until sometime after the drill bit has passed the point
where the junk initially resided. When it was previously suspected
that junk was lodged within or resting upon the wall of the bore
hole, drill pipe was sometimes worked up and down in the hole to
knock the junk to the bottom, but this method was not always
effective and was also very time consuming and expensive since it
required subsequent lowering of the string all the way to the
bottom with the bit removed for recovery of the junk with the type
of tool previously mentioned.
A need has thus been recognized for effectively removing junk from
the wall of a well bore, while also obviating the necessity of
fishing it from the bottom once it has been dislodged from the
wall.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide for fishing
of a well so that the aforementioned problems associated with junk
which resides along the sides of the hole are at least
substantially obviated.
Other objects and advantages of the present invention will become
apparent from the following description and the appended
claims.
In accordance with the present invention, a stream of fluid is
jetted in an outward direction from a locus between the top and
bottom of a well bore. The jetted fluid is forcefully impinged
against the wall of the bore hole, thus dislodging junk which
resides or rests on the wall. The dislodged junk is then collected
in a basket on the tool before it falls to the bottom of the
bore.
The invention can be carried out by means of a fishing tool which
comprises a tubular body section threadably connectible at the
upper end to a drilling string, a longitudinal fluid passageway in
the body section of the tool which leads from the upper end
thereof, a fluid channel which extends through the side wall of the
body section from the passageway therein to the outside, and a
basket attached to the tool for catching junk which is dislodged
from the wall of the hole by jetting of the fluid.
Once installed in the string, the tool is lowered into a bore hole
to one or more points where junk is suspect to reside on or in the
wall of the hole. Any suitable fluid, e.g. drilling mud, is then
pumped down the string and forced out of the channel in the body of
the tool to effect outward jetting of the fluid and forceful
impingement thereof against the wall of the hole. Junk is knocked
loose by the momentum of the jetted stream of fluid and removal of
junk is additionally facilitated in softer deposits by the erroding
action of the fluid streams.
Dislodging of junk from the wall of the hole can be facilitated
still further by jetting at least part of the fluid stream at an
angle with respect to the axis of the hole, thus striking the wall
at an upward or downward angle rather than perpendicularly.
Furthermore, the drilling string can be turned during jetting of
the fluid to set up a centrifugal action and, where preferred, the
string can also be moved up and/or down to permit washing of an
elongated section of the hole.
By locating a junk basket on the tool and thus above the bottom of
the hole, junk can be caught before it falls to the bottom, so that
additional steps of retrieval at the lower end of the hole are
obviated. The tool can also be run in with a bit below the basket
so that it is possible to first dislodge and basket the junk and
then proceed to drill before the tool and basket are removed from
the hole to recover the junk.
The tool can also be constructed in such a manner as to permit its
presence in the bore hole at all times without releasing jetted
streams of fluid until such is deemed necessary for the removal of
junk. For instance, the body section of the tool can further
comprise a previously set operable member therein which covers the
channel in the wall of the body section when set and which uncovers
the channel when operated. Circulation of all of the drilling fluid
to a bit carried below the tool can thus be maintained until
diversion of at least a portion of the fluid through the fluid
channels in the tool is desired. In addition, a sealing seat can be
placed in the passageway of the body section of the tool, the
purpose of the seat being to receive a matching sealing surface on
a flow obstructing member emplaced in the passageway. This permits
the passageway in the body section to be shut off below the fluid
jetting locus so that the flow of all fluid being pumped down the
string is diverted through the channel in the wall of the tool and
used at least temporarily for jetting against the wall of the well
bore. Subsequently the obstruction in the passageway can be
displaced and the fluid jetting channels closed so that flow of
fluid past the tool can be resumed, e.g. to a drill bit carried
below the tool.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, partly in section, of one embodiment of the
tool of the present invention.
FIG. 2 is a side view of a weighted dart, or plunger, which can be
used to operate a slidable sleeve which covers the channels in the
wall of the body section of the tool, and also to obstruct flow of
fluid beyond the tool.
FIG. 3 is a side view, partly in section, of a slidable sleeve
which can be used as the present operable member in the tool of
FIG. 1 for covering and uncovering the channels in the wall of the
body section of the tool.
FIG. 4 is a partly fragimentary and partly sectional side view of
another embodiment of the invention wherein the methods of
operating the sleeve are different from that shown in FIG. 1.
FIG. 5 is a sectional view of a slidable sleeve as in FIGS. 1 and 3
but which is held in position by means of a tensioned spring.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIG. 1, a fishing tool is generally represented at 1
and is connected by threads to a drill pipe 2. A basket section of
the tool for catching junk is generally represented at 24, being
attached by threads to the lower end of the tool. A drilling bit 3
is screwed onto the lower end of the basket section. The fishing
tool can thus be made up with the drilling string at the time the
bit is to be lowered in the hole, and does not necessarily perform
the intended function of jetting fluid until there is need to fish
junk from the wall of the hole. The tubular upper body section 4 of
the tool is attached at the upper end to a coupling 5 on the drill
pipe 2. A passageway 6 for drilling fluid runs through the upper
body section 4 and interconnects at the upper and lower ends with
fluid passageways 6a and 6b, which lead, respectively, from the
drill string 2 and into the junk basket 24 and the attached
bit.
Channels 7 are drilled ducts which extend through the wall 8 of the
body section from the passageway 6 to the outside. When the string
is lowered into the bore hole these channels are normally covered
over by an impervious, axially aligned slidable sleeve frictionally
held in place in the passageway 6 by means of O-rings 10 attached
to the sleeve in grooves. When merely drilling in the hole and
fishing is not required, drilling fluid passes through the central
passageway 6c of the sleeve which is aligned with the other
passageways 6, 6a and 6b, thus maintaining a flow of drilling fluid
to the bit since the channels 7 are blocked off by the sleeve which
has been preset in position over the opening of the channels.
In FIG. 1, the sleeve 9 is thus shown in the preset position
whereby the channels 7 are covered over. The passageway 6 in the
vicinity of the sleeve is recessed for a distance in excess of the
sleeve length to permit the sliding thereof when operated and to
provide a chamber which accommodates the thickness of the sleeve
wall, the latter feature tending to preserve the diameter of the
fluid passageway 6 while also forming a shoulder 11 at the top of
the chamber which serves as an upper stop for the sleeve. The upper
edge 24a of the basket section 24 serves as a lower stop for the
sleeve.
For washing the side of a bore hole in order to dislodge and
recover junk in or upon the wall of the hole, channels 7 are
uncovered to at least partly divert flow of fluid out of the
drilling string and into the bore hole through the channels.
Uncovering of the channels by a covering sleeve can be accomplished
in various ways, and two apparatus arrangements intended for this
purpose are shown in the drawings. FIGS. 1-3 illustrate use of a
weighted dart, or plunger, which is dropped into the drilling
string for displacing the sleeve downwardly to uncover the channels
7, and FIG. 4 illustrates use of a sleeve which normally covers the
channels when the sleeve is bottomed, but which can be lifted by
wire line to uncover the channels.
Referring to FIGS. 1-3, the dart 12 is dropped into the drilling
string from the surface when jetting of drilling fluid from
channels 7 is desired for removal of junk from the wall of the
hole. As soon as the dart is dropped, pressurization of the
drilling fluid can be resumed. The momentum of the falling dart may
in itself be sufficient to drive the sleeve downward below the
channels 7, but in any event both dart and sleeve are constructed
so as to form a piston which can be driven downward by pumping
pressure when engaged as shown in the drawing.
More specifically, the sleeve 9 comprises an attached or integral
ring 13 which projects into the central passageway 6c and is
axially aligned therewith. With the sleeve shown, the ring is
machine beveled to provide an upper tapered sealing surface 13b.
The upper part of the dart 12 is provided with a matched bevel 14,
so that when the dart and the sleeve are engaged as in FIG. 1, flow
of fluid past the sleeve is effectively obstructed. Therefore,
elevation of pumping pressure on the drilling fluid will displace
the dart and sleeve downwardly and thus uncover the channels 7 when
dart and sleeve are mated as in FIG. 1.
FIG. 4 illustrates a different arrangement wherein the sleeve is
normally bottomed against the lower stop 24a for covering of the
channels 7. When there is need to divert drilling fluid into the
well hole for dislodging and fishing junk from the wall of the
hole, a wire line tool is lowered which engages a latch 15 on a rod
16 which extends inside the sleeve from one side to the other. The
sleeve is then raised against the upper stop 11 by means of a wire
line tool. A snap ring 17 which extends around the sleeve and is
attached thereto in a groove engages a latching groove 18 in the
wall of the passageway and thus holds the sleeve in an elevated
position. The wire line is then pulled loose from the sleeve and
the latter remains in place by engagement of the snap ring with the
latching groove. Should it become desirable to again cover up
channels 7 once the sleeve has been shifted to uncover them, e.g.
after jetting of fluid against the wall of the well bore and
collection of junk in the basket section, the sleeve can be
relocated over the channels by an action taken at the surface. When
using a sleeve and dart arrangement as shown in FIGS. 1-3, the
lower spindle 19 of the dart is provided with a snap ring 20
attached in a groove so that upon entry of the dart into the sleeve
the snap ring is compressed by the ring 13 into its recess, thus
permitting the bevel 14 on the dart to abut the ring bevel 13b.
However, when the dart is pulled upward through the sleeve,
sufficient resistance is provided by the flat under surface of the
ring to effect upward sliding of the sleeve before the ring 20 is
compressed. Once the sleeve is topped against the upper stop 11,
the snap ring can then be compressed by upward tugging and the dart
withdrawn from the sleeve. Using an arrangement as shown in FIG. 4,
the sleeve can be lowered to again cover the channels by bumping it
downward with a weight on a wire line.
In FIGS. 1 and 4, the sleeve 9 is shown held in a preset position
over the channels 7 by frictional means, i.e. O-rings. FIG. 5
illustrates use of a tensioned spring to hold the sleeve in the
preset position. Using such an arrangement, the sleeve is held up
by spring 23 until displaced by the dart 12. With the dart in place
the sleeve can be held down and channels 7 kept open until the dart
is removed with a wire line.
It will be appreciated that devices other than a sleeve could be
employed as a covering member which could be previously set over
the channels 7 and later operated by an action taken at the surface
to uncover the members, e.g. valves can be installed which
automatically open when pumping pressure is raised above a certain
level. In addition, obstructing members other than a dart of
plunger could be used for shutting off flow of fluid through the
passageway below the channels, e.g. a normally unseated disc or
valve associated with the sleeve which is moved to an open or
closed condition depending upon the position of the sleeve in the
passageway.
It will also be appreciated that the previously described apparatus
inside the body section of the tool for uncovering and recovering
the channels 7, and also the obstruction member such as the plunger
for blocking flow of fluid below the channels, is optional
equipment, since the channels can in some instances be left open
throughout the whole time that the string is in the hole. However,
it will generally be desirable to be able to control flow through
the channels while the string is in the hole so that dislodging and
fishing of junk can be carried out at will with a drilling bit in
place.
One feature necessary for practicing the invention is a means for
basketing junk which is located on the tool above the bit and thus
above the bottom of the hole. In FIG. 1, the basket section of the
tool is generally represented at 24 and is located between the
upper section having the channels 7 therein and the drilling bit 3
at the lower end. The basket surrounds an inwardly tapered lower
tubular body section 25 of smaller diameter than the upper body
section 4 of the tool. The basket shown comprises a bucket 26
having a bottom 27 which is contiguous with the tubular section 25.
A flexible funnel 28 is attached at its lower end to the rim 29 of
the bucket. Through attachment to the bucket the funnel thus
becomes contiguous with the tubular section 25 to form a basket in
which junk is trapped when it is dislodged from the wall of the
bore hole.
The funnel 28, being flexible, can be sized somewhat larger than
the diameter of the body section of the tool and also larger than
the bore hole so that it becomes compressed when lowered into the
hole and thus caused to fit tightly therein. To advantage the
funnel can be made of reinforced rubber and provided with metal
stays 30 to continuously urge the upper rim 31 against the wall of
the hole when compressed. The bucket can be provided with drain
holes 32 to facilitate the gathering of junk therein when the whole
tool is moved upward.
As shown in the drawings, more than one channel 7 can be bored
through the wall of the body section. In addition, one or more of
the channels 7 can be inclined for jetting fluid at an angle
against the wall of the bore hole, and removable nozzles 21 can be
installed in the channels to facilitate regulation of the velocity
at which the streams are jetted against the wall. Velocity of fluid
jetting and the resulting impingement force thereof against the
wall of the hole can also be controlled by regulating the rate at
which fluid is pumped to the tool.
During operation, fluid jets outwardly from the channels 7 as
streams which forcefully impinge against the side wall of the bore
hole. This process is continued until junk is knocked loose and
caught in the basket. During the fishing process the drill string
carrying the tool is preferably rotated and can also be moved up
and down at the same time if such is preferred.
As previously indicated, the tool can be installed in the hole
above a bit prior to drilling, and fishing can be carried out
subsequent to one or more phases of drilling, e.g. when coming out
of the hole to change or replace the type of bit being used. In
such a case, the stream of fluid from the jetting locus above the
bit can be kept shut off during drilling, and then turned on prior
to traversal of the bit in the hole. Therefore, drilling mud which
is ordinarily pumped to the point being drilled can be diverted and
jetted against the wall of the hole from the jetting locus instead
as the string is withdrawn from the hole, thus precleaning the hole
wall prior to subsequent relowering of the string. Although
particular description has been given to location of the fishing
tool directly above the drilling bit, it will be appreciated that
the tool and, hence, the locus for jetting of fluid could be
located higher up in the drilling string when it would be
preferable to do so.
In FIG. 1, the basket section of the tool is shown in a location
above the bit and below the locus for jetting of fluid from the
tool, i.e. channels 7. It will be understood, however, that the
basket section can also be located on the tool above the channels 7
or, for that matter, a basket can be located both above and below
the channels. Whether to locate the basket above and/or below the
jetting locus depends upon the size, weight, shape, etc. of the
suspected or known junk to be fished. Larger, heavier pieces may
not be carried upward by the flow of fluid, and once dislodged will
fall into a basket located below the jetting locus. On the other
hand smaller, lighter pieces of junk can be carried upward and away
from the jets of fluid so that they are suspended and hence never
fall back into a basket located below the jets. In the latter case,
therefore, a basket located above the jets is a suitable adaption
for catching junk which becomes suspended in the jetted fluid, and
baskets can be located both above and below the jets when preferred
for catching relatively light and heavy fractions of junk.
While the present invention has been described with reference to
particular methods, conditions, techniques, materials, apparatus
arrangements and the like, it will nonetheless be understood that
still other embodiments will become apparent which are within the
spirit and scope of the invention defined in the following
claims.
* * * * *