U.S. patent number 3,722,603 [Application Number 05/181,067] was granted by the patent office on 1973-03-27 for well drilling apparatus.
Invention is credited to Cicero C. Brown.
United States Patent |
3,722,603 |
Brown |
March 27, 1973 |
WELL DRILLING APPARATUS
Abstract
A fluid pressure-operated snubber device for use in drilling
wells, generally in place of rotary table and drawworks systems
commonly employed for rotary drilling. The device comprises a
stationary lower snubbing member and rotatable and vertically
reciprocable upper snubbing member operable for rotating drill pipe
for drilling a well and for running the drill pipe into and out of
the well. Each of the snubbing members includes a set of
pipe-gripping wedges movable into and out of pipe-gripping
engagement by fluid pressure-operated means and a set of cam
actuated shoes for applying torsional forces to the pipe string for
rotating the same in drilling and in making-up and breaking-out the
sections of the pipe string when running into and out of the
well.
Inventors: |
Brown; Cicero C. (Houston,
TX) |
Family
ID: |
22662771 |
Appl.
No.: |
05/181,067 |
Filed: |
September 16, 1971 |
Current U.S.
Class: |
173/159;
81/57.16; 173/149; 81/57.18; 173/164 |
Current CPC
Class: |
E21B
19/10 (20130101); E21B 19/08 (20130101); E21B
19/16 (20130101) |
Current International
Class: |
E21B
19/16 (20060101); E21B 19/08 (20060101); E21B
19/10 (20060101); E21B 19/00 (20060101); E21b
019/16 () |
Field of
Search: |
;173/149,152,159,164
;81/57.16,57.18 ;175/85 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Purser; Ernest R.
Claims
I claim:
1. A well drilling snubber, comprising:
a. a supporting base;
b. a stationary lower snubbing member mounted on said base;
c. an upper snubbing member disposed on said base above said lower
snubbing member for rotation and vertical reciprocation relative to
the latter;
d. fluid pressure-operated means on said base for reciprocating and
rotating said upper snubbing member;
e. each of said snubbing members including:
i. a tubular body having a vertical through-bore to receive a
pipe;
ii. a frusto-conical bushing mounted in said bore for limited
angular movement therein relative to said body;
iii. a set of pipe-gripping wedges mounted in said bushing for
reciprocative movement into and out of pipe-gripping position;
iv. fluid pressure-actuated means for reciprocating said
wedges;
v. a torsion-transmitting member mounted to said bushing below said
wedges; and
vi. pipe-gripping members mounted in said torsion-transmitting
member for radial movement into and out of pipe-engaging position
in response to said angular movement of said bushing relative to
said body.
2. A well drilling snubber according to claim 1, wherein said fluid
pressure-operated means comprises:
a. a plurality of hydraulic jack means vertically disposed on said
base;
b. a crosshead plate reciprocable by said jack means and rotatably
supporting said upper snubbing member; and
c. reversible hydraulic motor means mounted on said crosshead plate
and having rotary drive connections to said upper snubbing
member.
3. A well drilling snubber according to claim 2 including:
a. a second crosshead plate non-movably secured to said jack means;
and
b. means fixedly supporting said lower snubbing member on said
second crosshead plate.
4. A well drilling snubber according to claim 1 wherein said
torsion-transmitting member comprises:
a. an annular cam plate having a plurality of radial slots therein
to slidably receive said pipe-gripping members;
b. sets of angularly spaced, oppositely facing cam elements on the
opposing surfaces of said body and said cam plate cooperating with
the inner ends of said pipe-gripping members to effect said radial
movements thereof.
5. A well drilling snubber according to claim 1, including: a cam
sleeve connected to said means for reciprocating said wedges and
forming a rotatable connection between said bushing and said body
operable in response to movement of said wedges to pipe-releasing
position to move said pipe-gripping member out of pipe-engaging
position.
Description
BACKGROUND OF THE INVENTION
In conventional rotary drilling, a power-driven rotary table
operating through a so-called "Kelley joint" connected to the upper
end of the drill pipe string is employed for rotating the drill
string and high-powered drawworks systems, including derricks with
multiple-strand, cable-connected crown and travelling blocks, are
employed for running the drill string into and out of the well and
for otherwise performing drilling and pipe handling operations.
Conventionally, the rotary table and the drawworks and the power
units for driving and operating the same constitute massive,
relatively complicated and expensive structures, particularly those
designed for deep drilling.
The present invention is directed to a relatively simple, compact
structure comprising fluid pressure-operated, preferably hydraulic,
elements for performing both the drilling and pipe-running
functions of more conventional rotary rigs.
In accordance with the present invention, an improved form of
hydraulic snubbing device is provided comprising a stationary lower
snubbing member or head and an upper snubbing member or head which
is both vertically reciprocable and rotatable relative to the lower
head, the snubbing heads cooperating with a pipe string to perform
the rotary drilling functions and the running of the pipe string
into and out of the well. Each of the snubbing heads includes sets
of vertically reciprocable pipe-gripping wedges or slips and
angularly rockable, cam-actuated gripping shoes for applying
torsional forces to the pipe string for use both in rotating the
pipe string for drilling and when making and breaking the threaded
pipe joints as when adding joints to the drilling string and when
running the string into and out of the well.
All the principal elements of the device are designed for fluid
pressure, preferably hydraulic pressure, operation.
The structure in accordance with this invention is thus very
compact, low in cost, easily transportable, simple in operation,
and readily adaptable for drilling to any desired depth. The
structure requires only a relatively simple, low capacity derrick
or mast in conjunction therewith, since the major functions of such
derrick or mast will be to support relatively low weight elements
such as the mud swivel and hose and at most, only a few sections of
pipe, since the main load of the pipe string both in drilling and
in running into and out of the well will be taken by the snubber
heads, as will appear hereinafter.
Other and more specific objects and advantages of this invention
will become more readily apparent from the following detailed
description when read in conjunction with the accompanying drawing
which illustrates one useful embodiment in accordance with this
invention.
In the drawing:
FIG. 1 is a view partly in elevation and partly in section of the
snubber device showing the upper snubbing member in gripping
engagement with the drilling string and the lower snubbing member
in released position;
FIG. 2 is a view similar to FIG. 1 but showing both snubbing
members in gripping engagement with the drilling string;
FIGS. 3 and 4 are cross-sectional views taken respectively on lines
3--3 and 4--4 of FIG. 1;
FIGS. 5, 6 and 7 are cross-sectional views taken respectively on
lines 5--5, 6--6 and 7--7 of FIG. 2;
FIG. 8 is a detail view taken on line 8--8 of FIG. 1;
FIG. 9 is a cross-sectional view taken on line 9--9 of FIG. 1;
and
FIG. 10 is a cross-sectional view taken on line 10--10 of FIG.
1.
Referring to the drawing, the snubber device is shown mounted on a
base plate 10 which is generally U-shaped (FIG. 9) and is
ordinarily appropriately mounted on a longitudinally slotted skid S
enabling the structure to be moved laterally into place about the
upper end of a well W. A plurality of hydraulic jacks, designated
generally by the letters J, four in number in the illustrative
embodiment, are mounted in upright position on base plate 10 and
spaced to define the corners of a square. Each of the jacks
comprises a cylinder 11 and a suitably sealed piston 12 slidably
mounted for reciprocation in the cylinders between pressure fluid
connections 13 and 14 which serve alternately as inlet and
discharge conduits for the pressure fluid employed for
reciprocating the pistons. The pistons are connected to elongate
piston rods 15 which extend upwardly through stuffing boxes 16. The
upper ends of the piston rods are suitably connected to a
transverse crosshead plate 17 which supports an upper snubbing
head, designated generally by the letter H.sub.1, for vertical
reciprocating with the crosshead plate.
A lower crosshead plate 18 extends transversely between the
cylinders 11 at a suitable elevation above base plate 10 and is
fixedly secured to the cylinders. Crosshead plate 18 supports a
stationary lower snubbing head, designated generally by the letter
H.sub.2.
A top plate 19 is supported above crosshead plate 17 on the upper
end of a ring-shaped wall 20 which is seated about a peripheral
shoulder 21 on plate 17 and has its upper end secured by bolts 22
to the rim of top plate 19.
The snubbing heads H.sub.1 and H.sub.2 are generally similar in
construction, the same or corresponding parts bearing the same
numerals. Snubbing head H.sub.1 includes additional structure for
positively rotating the same and the parts therefor will be
appropriately designated as the description proceeds.
Each snubbing head comprises a tubular housing 23 carrying on its
lower end an off-set flange 24 which is received in the upper end
of a housing extension 23a and secured thereto by bolts 24a. In the
case of upper snubbing head H.sub.1, the housing is mounted for
rotation in coaxial openings 25 and 26 in top plates 19 and in
crosshead plate 17, respectively. In the case of lower snubbing
head H.sub.2, the housing extends through a central opening 27a in
lower crosshead plate 18 and is fixedly secured thereto by means of
a bolted flange 28. A rotary bushing 29, having a downwardly and
inwardly tapering frusto-conical bore 30, is mounted in housing 23
for relative rotation on bearings 27 and is provided about its
exterior with an annular groove 31 adapted to receive the inner
ends of guide pins 32 (FIG. 5) which are screwed through the wall
of housing 23 to effectively guide relative rotation between the
latter and bushing 29. The lower end of the latter carries a
downwardly extending annular flange 33 keyed to a cooperating
upwardly extending annular flange 34, which is secured to an
annular cam plate 35 disposed concentrically inside housing
extension 23a to define a generally annular space 35a therebetween.
Cam plate 35 has a central bore 36 and a plurality of
equi-angularly spaced slots 37 (four illustrated as in FIG. 4)
extending radially entirely through the plate.
A shoe 38, generally rectangular in cross-section, is slidably
mounted in each slot 37 for limited radial movement therein and
carries a series of cam rollers 39 rollably mounted about a
vertical shaft 40 supported from the inner or rearward end of shoe
38 to project into annular space 35a. The opposite ends of shaft 40
extend above and below rollers 39 into annular space 35a and carry
small rollers 41 which limit outer or forward movement of shoe 38
by engagement of rollers 41 with the inner periphery of plate 35.
The outer end of each shoe 38 has mounted therein a plurality of
vertically extending pipe-gripping teeth or dies 42.
The inner wall of housing extension 23a is formed with a plurality
of inwardly projecting drive cams 43 (FIGS. 4 and 6), spaced on
90.degree. centers by relief grooves 44. The cams cooperate with
rollers 39 in response to relative angular rotation between plate
35 and housing 23, 23a to advance or project shoes 38 inwardly of
bore 36 and to allow retraction of the shoes when rollers 39 move
off of cams 43 into relief grooves 44.
As best seen in FIGS. 1 and 10, each snubbing head is provided with
a second set of angularly spaced cams 45 which project from the
inner periphery of cam plate 35 adjacent its upper and lower edges
in alignment with the roller-carrying ends of shafts 40. These cams
also are on 90.degree. spacing and are offset 45.degree. relative
to cams 43 and engagement with rollers 41 to effect positive
retraction of shoes 38 from pipe-gripping position at certain
stages of operation, as will appear subsequently.
Both of the snubbing heads H.sub.1 and H.sub.2 are fitted with
generally similar power-operated slip lifter devices, designated
generally by the numerals 50. Each of the latter comprises a
downwardly and inwardly tapering frusto-conical slip bowl 51 seated
in bore 30 of rotary bushing 29 and secured thereto through an
overhanging bolt flange 52 by means of bolts 53. A plurality of
pipe-gripping wedges or slips 54 are longitudinally slidably
mounted in slip bowl 51 and keyed thereto by longitudinally
extending dove-tail keys 55, as best seen in FIGS. 3 and 5. The
upper ends of the slips carry hanger arms 56 which project through
pockets 57a in a hanger ring 57 and are slidably supported for
limited angular movement on the upper edges of the hanger ring
pockets by means of hanger bolts 56a. Hanger ring 57 is mounted for
rotation in an overhanging lift ring by means of bearing-supported
trunnions 58a. The lift ring is secured to the upper ends of
pistons 59 mounted in cylinders 60 for reciprocation in response to
fluid pressure supplied to the cylinders through spaced apart
pressure fluid conduits 61,61 which serve alternately as supply and
exhaust conduits in the known manner.
Returning now to the afore-mentioned additional structure for
effecting positive rotation of snubbing head H.sub.1, housing 23 of
the latter is provided opposite off-set flange 24 with an outwardly
extending annular flange 65 which is suitably connected by bolts 66
to the hub 67 of a ring gear 68 positioned horizontally in the
space between top plate 19 and upper crosshead plate 17 and
supported for rotation on bearings 69 between the latter and flange
65 and bearings 70 disposed above flange 65 between housing 23 and
the bore 71 of top plate 19. A plurality of reversible hydraulic
motors 72 are mounted on top plate 19 with their shafts 73
extending downwardly through the top plate and carrying pinions 74
which are in mesh with teeth 75 of ring gear 68 for effecting
reversible rotation of upper snubbing head H.sub.1. Motors 72 are
connected by conduits 76 and 77 to pressure fluid supply and
exhaust manifolds 78 and 79 which are, in turn, connected by
conduits 80 and 80a to suitable pressure fluid supply and discharge
sources.
In connection with the operation of the slips 54 and shoes 38, each
of the snubbing heads is provided with a cam sleeve 81 pendently
secured to hanger ring 57 and having an internal diameter to
closely surround the exterior of housing 23 and so as to be
slidable over and about the latter. Cam sleeve 81 is provided on
opposite sides thereof with windows 82 shaped, as best seen in FIG.
8, with opposed downwardly sloping cam surfaces 83,83 terminating
in spaced relation to provide a vertical slot 84 therebetween which
opens to the lower edge of the sleeve. The cam sleeve cooperates
with rollers 85 mounted on headed shafts 86 extending radially
outwardly from housing 23 adjacent its upper end. The lower edge of
sleeve 81 carries an outwardly extending annular flange 87 provided
with vertical openings 88 to allow passage of rollers 85
therethrough as may be required during operation of the device, as
will be described hereinafter.
In operation, FIG. 1 illustrates the positions of the parts at the
beginning of a drilling-ahead sequence. It will be noted that slips
54 in upper snubbing head H.sub.1 are in the lowered or set
position gripping drill pipe P which extends through both snubbing
heads into well bore W, and the slips in lower head H.sub.2 are
raised and retracted in completely inactive position so far as
drilling is concerned. Also upper head H.sub.1 will be in its
elevated position as determined by the upward extension of piston
rods 15 from cylinders 11 of jacks J. Lowering of upper slips 54
will simultaneously lower its attached cam sleeve 81 producing
relative upward movement of rollers 85 through slots 84 to inactive
or neutral center positions in windows 82 indicated at 85a, as seen
in FIG. 8.
Initiation of rotation of housing 23, 23a of the upper head by
motors 72 will produce an initial angular movement of the housing
relative to cam plate 35 which will move drive cams 43 behind
rollers 39 to project shoes 38 inwardly to force dies 42 into
torsion-applying pipe-gripping position, whereupon continued
rotation of the upper head by the hydraulic motors will rotate the
drill pipe. At the same time, fluid pressure may be directed to
jacks J to control "weight-on-bit" to any extent desired to assure
optimum drilling rate and to allow downward movement of the upper
snubbing head to conform with the advance of the drill.
It will be understood, although not shown, that drilling fluids may
be circulated down through the drill pipe and bit and up through
the well bore in a conventional manner as the drilling proceeds to
perform the functions ordinarily required of such fluid.
As slips 54 in lower head H.sub.2 are raised to release their grip
on the drill pipe, the associated cam sleeve 81, being attached to
lift ring 57, will be moved upward relative to lower housing 23,
23a. Teeth 42 of shoes 38 in the lower head H.sub.2 will still be
in engagement with the drill pipe. However, by reason of this
engagement, initial angular movement by the upper snubbing head
will be transmitted through the drill pipe to cam plate 35 in the
lower snubbing head causing the cam plate to rotate retractor cams
45 into engagement with the roller carrying ends of the related
shaft 40 (FIG. 10) to effect positive retraction of shoes 38 from
engagement with pipe P thereby freeing the pipe for rotation by the
upper snubbing head.
When the end of a drilling stroke is reached, and it is necessary
to add a new section of drill pipe, the slips in the lower head
will be set below the drill pipe box B, in the position as seen in
FIG. 2 and the mud line connection to the upper end of the drill
pipe will be released. Thereupon the upper set of slips will be
raised and released and the upper snubbing head raised to receive
the new section of drill pipe which will be lowered through the
bore of the upper snubbing head and its threaded pin stabbed into
the box member of a coupling C. Thereupon, the upper slips will be
lowered and set and right-hand rotation of the upper head begun
while the slips in the lower head remain in gripping position to
serve as a back-up wrench while the threading operation takes
place. Some pressure fluid may be released from jacks J to
accomodate the downward movement of the upper head as the threads
are made up. The setting of the upper slips and the initial
rotation of the upper head will act through upper cams 43 to move
upper shoes 38 into torque-applying engagement with the pipe.
This sequence of operations as heretofore described is repeated as
the drilling proceeds to continue the addition of sections of pipe
to the drilling string to correspond to the increased well
depth.
FIG. 2 also illustrates the relative positions of the snubbing
heads at a stage in the process of breaking down the pipe string,
as when withdrawing it from the well for changing bit or other
purposes requiring removal of the pipe from the well. As shown,
both sets of slips 54 and torque shoes 38 will be set to grip the
pipe on opposite sides of coupling C. Thereupon, upper head H.sub.1
may be rotated in the direction to unscrew the upper section of the
pipe string while the lower head H.sub.2 holds back against the
lower pipe section. Pressure fluid will be applied to jacks J to
raise upper head H.sub.1 sufficiently to accommodate the
unthreading operation. The upper slips may then be released to
allow the now unthreaded pipe section to be withdrawn from the
upper head.
The upper head will then be lowered about the upper end of the pipe
section left projecting above the lower head and the upper slips
will again be set; the lower slips released and the pipe string
raised to bring the next coupling up above the lower head in
position for repetition of the previously described unscrewing of
the thus elevated pipe section.
Elevation of cam sleeves 81 with their respective lift rings 57 in
effecting release of the related slips 54 will produce camming
action between cam surfaces 83 and rollers 85 to produce the
limited relative angular movement of cam plate 35 required to cause
retractor cams 45, by acting against the ends of shafts 40, to
effect retraction of shoes 38 sufficient to retract teeth 42 from
engagement with pipe P. This provides assurance that any time slips
54 are released, the torsion-applying teeth 42 also will be
positively released.
The well drilling apparatus heretofore described provides a highly
efficient, low-cost, rotary drilling unit capable of drilling to
depths of 10,000 feet or more by reason of the fact that the entire
load of the drilling string in drilling and in running the pipe in
and out of the well is carried on hydraulic jacks. Thus, only a
light load capacity derrick or mast is required as the maximum
loads to which they may be subjected will be the weight of a joint
or stand of pipe and the mud hose and swivel. The need for
conventional massive crown and travelling blocks and Kelley joints
is likewise eliminated.
Also, since the jacks are operated by hydraulic pressure, the power
requirements for running and operating the drill string may be met
by relatively small compact power units as compared with the
engines required for more conventional rotary drilling rigs. The
whole rig may be skid-mounted for easy overland transportation by
trucks and is readily adaptable for use in marine drilling.
The apparatus herein described may also be used for running casing,
when required, by appropriate changes in the dimensions of the
pipe-gripping elements to accommodate the different casing
dimensions.
The entire system for drilling and handling pipe is designed for
operation by a set of remote automated controls; requires an
absolute minimum of manual labor; and operates with a maximum
degree of speed and efficiency.
The numerous other advantages of the apparatus herein disclosed
will be readily apparent to those skilled in the art. It will be
understood that numerous changes and modifications may be made in
the details of the illustrative embodiment within the scope of the
appended claims but without departing from the spirit of this
invention.
* * * * *