Note: Descriptions are shown in the official language in which they were submitted.
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MULTI-FUNCTION WELL SERVICING VEHICLE
Field of the Invention
The present invention relates to equipment for completing and servicing
S oil and gas wells , and in particular relates to a multi-function mobile rig
vehicle
capable of carrying out a number of well completing and servicing tasks,
including the insertion of jointed (but not continuous) pipe into said wells.
Background of the Invention and Description of the Prior Art
Typically, when an oil or gas well has been drilled, a number of further
steps are required to complete the well to ready it for production. A logging
operation, a swabbing operation, and an operation involving insertion of pipe
or
tubing into the well, and finally a perforation step to perforate said tubing,
typically are additional steps required to ready a well for production.
The logging step requires the lowering of a logging instrument into the
drilled well. The logging instrument is an elongate cylindrical device that is
typically lowered from a well-servicing vehicle via an electrically-conductive
wireline (referred to in the well completion and servicing industry as an "e-
line")
into the drilled well. The logging device emits gamma rays or the like and is
used
to receive reflected waves from the petroleum formation, such reflected waves
indicating physical properties of rock formation in which the well is drilled
useful
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for determining whether further steps, such as whether fractionation of the
petrochemical formation in which the well lies, would be needed or beneficial.
Information and data from the logging instrument is relayed to the surface of
the
well via the wireline, and the data is "logged" by means of recording
instrumentation, typically situate in the service vehicle at the surface of
the well.
The logging instrument is thereafter brought to the well surface by the
wireline,
which is wound on a winch expressly provided on the service vehicle for this
purpose.
The step of swabbing a well involves the removal of water which may be
in the well, to permit the flow of petroleum from the formation into the well.
Such
swabbing operation involves the lowering, by means of another wireline,
typically
a high strength cable, of a plug which has a valve thereon. The plug is
lowered in
the well, with the water in the well flowing through the valve from the
underside of
the plug to the upperside of the plug, thereby allowing the plug to settle
towards
the bottom of the well. Thereafter, the valve closes when the plug is raised.
In
such manner the raising of the plug allows water above the plug to be removed
from the well when the plug is withdrawn, so as to thereby "underbalance" the
well and permit its later use in oil or gas recovery. The swabbing operation
frequently needs to be carried out a number of times in order that the well be
as
underbalanced as possible.
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After a well is drilled, the well is typically cased with metal tubing or
piping so as to prevent inadvertent closure of the well due to shifting or
collapse
of surrounding strata, and to permit the pumping, in the case of oil, or the
pressurized flow of gas, in the case of natural gas, from the well. This step
is a
further step necessary to complete a well and ready it for production.
In this tubing insertion step, the tubing which is inserted into the well may
be continuous tubing, which is typically used in deeper wells (in excess of
1,500
- 2,000 metres), or in the case of shallow wells, joined pipe is used which
provides slightly higher resistance to fluid flow due to the pipe joints, but
which is
tolerable in shallower wells. Any tubing, regardless of whether continuous or
joined pipe, must be perforated at the lowermost extremity of the well, to
allow oil
or gas to flow into the tubing at the lowermost portion of the well, and
thereafter
flow up and out of the well via the upper tubing.
Accordingly, the final step in completing a well, typically after logging and
swabbing have been carried out, involves the lowering, by means of a
conductive
wireiine, of an explosive charge situated on the lowermost end of the inserted
tubing. Such tubing-conveyed charge is then, when substantially all of the
tubing
been inserted into the well, detonated at the lowermost portion of the well
(i.e. the
producing portion of the well), to permit gas or oil to flow through into the
resulting holes (perforations) in the tubing/casing, and thereby permit the
oil or
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gas, as the case may be, to flow up or be drawn up to the surface of the well
via
the unperforated tubing now above. This procedure is typically known in the
art
as TCP ("tubing conveyed perforation").
Each of the above steps is typically needed to be conducted in order to
bring a drilled well into production.
Mobile rigs for the drilling of wells are well known in the art, such as
those disclosed in US Patents 2,847,098, 3,109,523, 3,670,831, 3,734,210,
3,994,350, 4,371,046, 4,478,291, 5,094,302 and 5,794,723.
Typically, these prior art drilling rigs are relatively large and heavy,
particularly where they are adapted for drilling deeper wells {i.e. wells of
more
than 1500 to 3000m in depth).
In the prior art, due to the size and complexity of the above prior art
drilling rigs, these units are usually only adapted for the drilling of the
well.
Lighter, less complex, "rigless" well servicing equipment, which cannot drill
but
which can carry out one or more steps in the completing of the well, such as
the
logging and/or swabbing operations, are typically employed for these purposes.
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One such example of a prior art "rigless" well service vehicle is the "first
generation" mobile servicing vehicle manufactured by Big Guns Perforating and
Logging Inc. of Calgary, Alberta, Canada, who is also the assignee of this
invention described later herein. Such mobile vehicle essentially consists of
a
double-axle vehicle, the rear bed thereof having a chain-driven winch having a
9/16 inch cable wound thereon for carrying out swabbing operations, and a
further drum having a 5/16 inch conductive wireline wound thereon, used for
lowering a logging instrument for logging operations. Such vehicle further
carried
on the bed thereof computerized equipment for "logging" and analyzing the data
received from the logging instrument via the 5/16 inch conductive wireline.
This prior art vehicle, while useful, was recognized as being more
practical if it could further carry out TCP (tubing conveyed perforation), so
that
the drilling vehicle which possessed a rig or derrick to permit drilling as
well as
insertion of tubing into the well would not need to be manoeuvred back over
the
well to insert the tubing after the logging operations had been done by the
service vehicle. In other words, it was recognized that it would be more
economical if the Big Guns service vehicle could conduct all of the steps of
logging, swabbing, tubing insertion and perforation, so that immediately after
drilling the well the drilling rig could permanently depart from the well site
to other
locations where its valuable services are needed, and leave the task of
completion of the well to a service vehicle.
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Accordingly, to this end, a mast was further added to the first generation
service vehicle made by Big Guns Perforating and Logging Inc., which, by
having
a mast of at least 30 feet in height, could permit the insertion of 30 foot
lengths of
jointed pipe into the well to complete TCP. These "second generation" service
vehicles then properly became a service rig, in that they then possessed a
mast,
pivotably coupled to the bed of the vehicle, which could be raised by
hydraulic
pistons to a substantially vertical or slightly over-vertical position. To
stabilize the
mast/derrick when in a raised position, such vehicles had manual telescoping
stabilizing jacks proximate each of the left, right, front, and back corners
of such
vehicle, to prevent tipping.
Disadvantageously, however, such "second generation" service rig
vehicles needed at least one additional service vehicle having auxiliary
equipment such as hydraulic power tongs for the power handling and threading
of jointed pipe during the TCP operation. This auxiliary equipment was
typically
supplied by another service vehicle having such equipment on the rear bed
thereof, which provided such function when it likewise was backed up to the
well,
typically opposite the service rig vehicle, so that workers could utilize the
service
rig to hold the pipe, and the hydraulic power tongs on the additional service
vehicles to thread the joined pipe together for insertion into the well.
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As an attempt to design a vehicle which could provide a number of well
completion steps, US 6,003,598 teaches a mobile vehicle/carrier 22 having a
collapsible mast or derrick 40 which may be hydraulically raised and lowered
by
means of hydraulic pistons 52. A winch 46 and cable is provided proximate the
crown of the derrick 40 for performing functions such as manipulating joined
pipe
segments if required. A further wireline winch assembly 100 and a drum 102
having a conductive wireline wound thereon allows a logging instrument to be
lowered into the well to permit logging and vertical wells.
The vehicle/carrier 22 disclosed in US 6,003,598 possessed stabilizers
32 at each comer, incorporating a vertically extendible hydraulic jack or
lifter 34
for engaging the ground 21, to level the rig as desired during operation,
thereby
removing some or all of the rig's weight from the front and/or rear axles
26,28. A
platform 47 was further provided, movable from a retracted position to an
operable position by a fastline winch 49 situate proximate the crown of the
derrick 40. Notably, platform 47 was permanently affixed to the derrick 40
(ref.
Fig. 5) at a fixed height, and travelled with the vehicle 22.
Importantly, vehicle 22 of US 6,0003,598 was adapted for injecting
continuous tubing (CT). As such, it possessed a large removable reel 82, part
of
a cartridge assembly 80, on which CT was wound. An injector 70, slidable on
the
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derrick 40 by means of winch 46, was provided, for injecting the continuous
tubing in the well, was also necessary.
While US 6,003,598 discloses that it may be used for manipulating joined
pipe (as opposed to CT) if need be, and indeed discloses winch 46 for such
purpose, disadvantageously vehicle 22 of US 6,003,598 clearly is poorly suited
to
insertion of jointed pipe. In particular, such vehicle 22 for effective use in
inserted jointed (as opposed to continuous pipe) required another service
vehicle
having power tongs to mechanically join pipe segments together, as it clearly
lacked any such equipment. In particular, for shallower wells, where jointed
pipe
instead of CT is typically used, to carry out manipulation of jointed pipe
would
require disengagement of winch 46 with injector 70, as injector 70 was not
needed, in order to allow derrick-mounted winch 46 to handle jointed pipe.
However, all that winch 46 of US 6,003,598 can do is raise and lower jointed
tubing- no power mechanism other than winch 46 is disclosed in US 6,003,598 to
handle jointed pipe, nor could the derrick 40, due to the provision of
slidable
injector 70 on derrick 40, be adapted to provide such power tongs, as they
would
plainly interfere with the injector 70. Particularly, while US 6,003,598
discloses
that such carrier/vehicle 22 may also be used to insert jointed pipe into a
well,
derrick 40 with its sliding injector 70 clearly lacked the ability to provide
upwardly
and downwardly moveable power tools to allow power manipulation of jointed
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pipe, as the injector 70 would necessarily interfere with such devices. At
least
one other service vehicle would be necessary to provide such capability.
Accordingly, the ability to insert jointed pipe in an efficient manner was
not, nor capable of being, provided by vehicle 22 of US 6,003,598.
Accordingly,
vehicle/carrier 22 of US 6,003,598 suffered from the similar shortcoming of
the
second generation Big Guns vehicle, namely the need for other service vehicles
having additional equipment to be present.
In addition, due to the provision of a large cartridge assembly 80 for CT
injection and a sliding injector 70 on vehicle 22 of US 6,003,598, as well as
a
platform 47 which was permanently mounted on vehicle/carrier 22 and
transported with such vehicle 22, vehicle 22 was necessarily large and
cumbersome.
Accordingly, there exists a real need in the industry for a single, multi-
function well servicing vehicle for shallow wells, capable to not only
conducting
logging and swabbing operations, but also effectively and efficiently being
able to
insert joined pipe into the well. Also necessary is the ability to carry out
tubing
conveyed perforation, so as to be able to complete a pre-drilled well and
ready it
for production without the need for any other well servicing vehicles.
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Summary of the Invention
In order to provide a specialized well servicing vehicle capable of
inserting jointed pipe in a pre-drilled well in a mechanized and efficient
manner, but also being able to conduct at least one additional well completion
step, in a first broad embodiment the present invention provides a mobile well
servicing vehicle adapted to conduct insertion of jointed, but not continuous,
pipe into a pre-drilled well, including conducting at least one additional
well-
servicing step selected from the group of well servicing steps consisting of
logging, swabbing, and perforating, such vehicle possessing:
elongate mast means, having a top end and a bottom end, pivotably
coupled to said vehicle proximate said bottom end, pivotable from a first
substantially horizontal position to a second substantially vertical position;
engine means, for providing motive force for said vehicle via a
transmission means;
hydraulic pump means, coupled to said engine means, said engine
means providing operative power to said hydraulic pump means;
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a hydraulic piston member, hydraulically coupled to said hydraulic pump
means, for raising and lowering said mast means from said first position to
said second position, and from said second position to said first position,
respectively;
hydraulically-operated telescoping levelling members situate at
respectively four substantially mutually opposite side corners of said
vehicle,
each hydraulically coupled to said hydraulic pump means;
a first hydraulically-powered winch means, hydraulically coupled to said
hydraulic pump means, situate proximate said top end of said mast means,
for raising and lowering, via a cable member, a hydraulically-operated
grappling means suspended via said cable member from said mast means,
said grappling means adapted to grasp and manipulate said jointed pipe, said
grappling means hydraulically coupled to said pump means;
a second hydraulically-powered winch means, hydraulically coupled to
said hydraulic pump means, having cable means wound thereon to permit
lowering of said jointed pipe via said cable means into said well; and
a third hydraulically-powered winch means, hydraulically coupled to said
hydraulic pump means, having electrically conductive wire line means wound
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thereon, for lowering one or more devices selected from the group of devices
comprising a well-logging device and a well swabbing device, via said wire
line means, into said well.
Advantageously, it was realized by the within inventors that the steps of
well servicing provided by the equipment of this vehicle are sequential steps,
and typically do not overlap in time. Thus if all equipment was to be
hydraulically powered, the hydraulic pressure needed to operate the various
equipment need not be the sum of the required individual equipment
pressures, but need only be the single maximum pressure needed to operate
a single individual equipment. Thus it was realized that considerable weight-
saving and cost saving can be accomplished by being able to use a single
hydraulic pump, and further, one that is powered by the vehicle' s engine and
not by an on-board auxiliary motor. In addition, by providing all equipment be
hydraulic, as opposed to having such equipment powered by mixed means
(e.g. electrical, hydraulic, direct drive from auxiliary internal combustion
motor, or combination thereof), additional cost and weight savings can be
recognized by eliminating the need to provide an electrical generator or
auxiliary internal combustion motor for some of the equipment, such as
winches. Thus by using hydraulic power for each of the implements, and a
single hydraulic pump to supply each of the equipment, namely the power
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tongs, hydraulic pistons, levelling jacks, and first, second and third
winches,
considerable cost and weight savings can be realized.
Accordingly, in a preferred embodiment, such hydraulic pump means
comprises of single hydraulic pump.
In a further preferred embodiment of the present invention, provision is
made for a working platform to be attached to the derrick when the derrick is
positioned in its vertical operative position to provide a platform for
workers to
utilize power tongs to thread jointed pipe together for insertion into the
well.
Accordingly, in such preferred embodiment of the mobile service vehicle
of the present invention,
said mast means is pivotably coupled to said vehicle proximate a
rearmost end of said vehicle;
said vehicle at said rearmost end has attachment means thereon to
permit attachment thereto of said platform member;
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said platform member is adapted to allow a worker access to and to
manually manipulate said hydraulic grasping means immediately above said
well; and
said attachment means adapted to support at least one side of said
platform member so that said platform member is supported in a substantially
raised, horizontal position when said mast means is in said second position.
In the above-preferred embodiment, the attachment means for attaching
the platform to the rear of the rig comprises a plurality of vertically
aligned
apertures on the mast, to allow attachment of the platform member to the rig
at various alternate heights. Removable pins, such as locking cotter pins may
be used to removably attach the platform to the rear of the rig service
vehicle
of the present invention.
Not only is a well servicing vehicle having attachment means for
attaching a platform member thereto disclosed herein, but a well servicing
vehicle of the type described herein further having such platform attached
thereto is further disclosed.
In a further broad aspect of the present invention, a mobile well servicing
vehicle capable of carrying out each of the particular individual operations
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necessary to complete a well, include logging, swabbing, and insertion of
jointed pipe into a well, including the step of perforating the well by
conveying
an explosive charge to a lowermost extremity of the well via the inserted
pipe,
is provided.
Accordingly, in a further aspect of this invention, a mobile well servicing
vehicle is provided, adapted to conduct the individual steps of logging and
swabbing of a pre-drilled well, and in addition the step of the inserting
jointed,
but not continuous, pipe into said well, further including the step of
perforating
the well by conveying an explosive charge to a lowermost extremity of the
well via said inserted jointed pipe. Such vehicle, in such preferred
embodiment, possesses:
elongate mast means, having a top end and a bottom end, pivotably
coupled to said vehicle proximate said bottom end thereof, pivotable from a
first substantially horizontal position to a second substantially vertical
position;
engine means, for providing motive force for said vehicle via a
transmission means;
hydraulic pump means coupled to said engine means, said engine
means providing operative power to said hydraulic pump means;
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a hydraulic piston member for raising said mast means from said first
position to said second position;
hydraulically-operated telescoping levelling members situate at four
substantially mutually opposite side corners of said vehicle;
a first hydraulically-powered winch means, situate proximate said top
end of said mast means, for raising and lowering, via a cable member, a
hydraulically-operated grappling means suspended via said cable member
from said mast means, said grappling means adapted to grasp and
manipulate said jointed pipe;
second hydraulically-powered winch means, situate on a bed of said
vehicle, having cable means one end of which is wound thereon and another
end thereof extending from said mast means, adapted to lower said jointed
pipe via said cable means into said well; and
third hydraulically-powered winch means, situate on said bed of said
vehicle, having electrically conductive wire line means wound thereon, for
lowering a well-logging device and a well swabbing means via said wire line
means into said well;
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wherein said hydraulic pump means supplies all necessary hydraulic
power to each of said telescoping levelling members, said hydraulic piston
member, said hydraulic grasping means, and each of said first, second, and
third hydraulically-powered winch means.
Again, in a preferred refinement, capability is provided in the form of
attachment means at the rear of the vehicle, to affix a platform member to the
rear of such vehicle when the derrick is in the upright vertical position, to
serve as a platform to allow one or more workers to manipulate the hydraulic
power tongs when inserting the jointed pipe into the well or wellhead.
Accordingly, in such further embodiment of the present invention:
said mast means is pivotably coupled to said vehicle proximate a
rearmost end of said vehicle;
said vehicle at said rearmost end having releasably engageable
attachment means thereon to permit releasable attachment thereto of a
raised platform member;
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said raised platform member adapted to allow a worker access to and to
manually manipulate said hydraulic grasping means immediately above said
well; and
said attachment means adapted to support at least one side of said
platform member so that said platform is supported in a substantially
horizontal position when said mast means is in said second position.
Likewise, the above preferred embodiment may, and preferably does,
possess a plurality of substantially vertically-aligned apertures at the rear
of
the vehicle to allow attachment of said platform member to said vehicle at
various alternate heights via said apertures. In this preferred embodiment,
said apertures are located on said mast on exterior side edges thereof, in
vertical, spaced apart, juxtaposed position.
Brief Description of the Drawings
Further advantages and permutations will appear from the following
detailed description of various non-limiting embodiments of the invention,
taken
together with the accompanying drawings, in which:
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FIG. 1 is a perspective view of an embodiment of the mobile multi-
function well servicing and completing vehicle of the present invention, in
the
operative position;
FIG. 2 is a side elevation view of the embodiment shown in Fig. 1,
wherein the second winch is shown being used for injecting jointed pipe into
the
wellhead. The first winch, the cable extending from the first winch, and the
attached hydraulically powered grappling means, has been omitted for clarity;
FIG. 3 is side elevation view similar to Fig. 2, wherein the third winch is
being used for lowering a wireline into the well head for conducting swabbing
operations. Again, for clarity, the first winch, the cable extending from the
first
winch, and the attached hydraulically powered grappling means, have been
omitted for sake of clarity;
FIG. 4 is a side elevation view similar to Fig.'s 2 & 3, showing the derrick
in the collapsed position and the vehicle in its transport position;
FIG. 5 is a schematic side elevation view, of the mobile rig vehicle of the
present invention, in partial cutaway, showing location of the hydraulic pump,
and
schematically connection of the pump to the rear telescoping jacks, the
hydraulic
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cylinders for raising the derrick, and to the first, second, and third winches
(the
connection to the hydraulic pipe grappling means has been omitted for
clarity);
Fig. 6 is a simplified schematic, showing in plan view of the vehicle the
hydraulic connections from the hydraulic pump to respectively each of the
first,
second, and third winches, each of the four telescoping jacks, each of the
hydraulic raising pistons, and the single hydraulically operated pipe-
grappling
means;
Fig. 7A is a rear perspective view of a preferred embodiment of the
mobile rig of the present invention, having attachment means at the rear of
such
vehicle for a platform member, the platform member being shown attached in a
first selected raised position;
Fig. 7B is a rear perspective view of a preferred embodiment of the
mobile rig of the present invention shown in Fig. 7A, showing the same
embodiment of the platform member, but with such platform member attached in
a second selected raised position; and
Fig. 8 is a detailed view of another embodiment of the platform of the
present invention, which is attachable to the mobile rig vehicle of the
present
invention.
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Detailed Description of Some Preferred Embodiments
In all figures, for consistency, identical components are identified with
identical reference numerals.
With reference to Figs. 1-3, an embodiment of the mobile well servicing
vehicle 10 of the present invention is shown. Vehicle 10 is adapted to conduct
insertion of jointed pipe 11 into a well 13, and to further carry out at least
one
additional well-servicing step including logging, swabbing, and/or perforating
of
the inserted tubing 11.
Vehicle 10 possesses an elongate mast or derrick 20, having a top end
and a bottom end 17, which is pivotably coupled to the bed of the vehicle 10
15 proximate a rearmost end 33 of vehicle 10, as shown in Figures 1-3.
Derrick 20 is pivotable from a substantially horizontal transport position,
as shown in each of Figs. 4 & 5, to a substantially vertical operable
position, as
shown in Figs. 1-3, by means of two hydraulic pistons 12 which serve to raise
and lower derrick 20. Because derrick 20 may in some cases be used in a
slightly over-vertical position as shown in Figs. 1-3, in a preferred
embodiment
each of such pistons 12 are of the double-acting type, wherein such pistons 12
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may excert not only a raising force to raise derrick 20 to an over-vertical
position,
but also a retracting force to bring derrick 20 from an over-vertical position
to a
vertical position, and finally to a lowered postion suitable for when the
vehicle 10
need transport derrick 20 and associated additional equipment described below
to another wellsite.
Vehicle 10 possesses an engine 19, coupled to the vehicle transmission
21, for providing the motive force for moving vehicle 10 and transporting
derrick
20.
A conventional hydraulic pump 21 provides pressurized hydraulic fluid to,
inter alia, hydraulic pistons 12 and other additional equipment, as described
below. Such hydraulic pump 21 is any conventional hydraulic pump commonly
available, with suitable pressure and flow capabilities, such as the Sauer
Danfoss
model #A-04-50-02526 05-06-87635 hydraulic pump.
Hydraulic pump 21 is preferably mounted on transmission 21, as shown
in Figure 5, and mechanically coupled to vehicle engine 19 by means of a
splined
power take off shaft (not shown) protruding from vehicle transmission 21.
In preferred embodiment, vehicle 10 maybe a truck of the type made by
Navistar International Corporation of Warrenville, Illinois, model 5600
"Paystar",
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having triple rear axles which are preferable to support weight of derrick 20.
Transmission 21 on such model of truck (see Figure 5) possesses two power
take off shafts (not shown) extending from transmission 21, to which hydraulic
pump 4 may be mechanically coupled to one of said shafts (not shown). In a
preferred embodiment, model #A-04-50-02526 05-06-87635 of hydraulic pump 4
manufactured by Sauer Danfoss is mechanically coupled to one of said splined
pto shafts.
A first hydraulically-powered winch 50 is provided, mounted on proximate
the crown 15 of derrick 20, whose function is explained below.
A second hydraulically-powered winch 14 situated on bed 45 of vehicle
10 is also provided, adapted to raise and lower joined pipe 11 into well 13
and to
hold lengths of inserted pipe 11 during coupling of jointed pipe 11 together.
Second winch 14 has a cable 28, one end of which is wound thereon and
another opposite end extends around shieve 32 located proximate the crown 15
of derrick 20, and finally around a second shieve 44, so as to provide a
mechanical lifting advantage to such winch 14 in a known manner.
First winch 50 is used to raise and lower hydraulically-operated grappling
means in the form of hydraulically-operated power tongs 22, which are used by
workmen, preferably standing on platform 36, to grasp and threadably connect
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lengths of jointed tubing 11 together. Winch 50 is used to raise or lower
power
tongs 22 to the desired height above platform 36 for convenient use by the
workmen. As the height of platform 36 may vary, as described below, due to
varying height of well-head 38 due to various sized blow-out preventers, winch
50 is provided to permit raising or lowering of power tongs 22 to a desired
height
above platform 36 that is convenient for workmen to operate such tongs 22 to
threadably attach the jointed pipe 11 during insertion of such pipe into well
13.
The insertion of lengths of jointed pipe 11 in well 13 involves inserting a
first initial length of jointed pipe 11 into a well-head 38, and thereafter
threadably
attaching a lower end of a further length of pipe 11 to a protruding top end
of
initial pipe 11. The process is repeated until an entire jointed pipe tubing
string is
inserted into well 13, namely until sufficient tubing 11 is lowered to reach
the
bottom of well 13.
When carrying out the pipe joining and insertion operation, cable 28 and
derrick 20 must temporarily lift, or at least hold in position, the length of
continuously jointed tubing 11 that has been inserted in well 13 to that point
in
time. This means that for shallow well depths of 1,500 metres, where jointed
pipe of 2 3/8" diameter is used, cable 28 and derrick 20 need support
approximately 23,OOOIbs of tubing. Requisite safety factors typically mean,
for
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drill depths of 1,500 metres, that derrick 20 must be designed to support at
least
30,OOOIb.
Likewise for jointed pipe of greater diameter, say 2 7/8" for well depths of
1,000 metres, derrick 20 must be designed to support at least 22,OOOIbs.
Due to mechanical advantages incorporated by use of shieves 32 and
44, while cable 28 need support of 30,000 Ibs tension, winch 16 due to various
mechanical advantages provided by shieve 32 and 44 need typically only exert a
force of typically '/4 such maximum tension, typically 7,500 Ibs, which may
even
be reduced further if winch 14 is connected via reduction gearing 27 to a
hydraulic motor 25, as shown schematically in Fig. 6.
A third hydraulically-powered winch 14 has wound thereon conductive
wireline 24, for lowering a well-logging instrument (not shown) into the well
13 to
obtain well data. Such well data from the lowered well-logging instrument is
recorded by logging instruments contained in an operators enclosure 42 resting
on bed 45 of service vehicle 10 (see Fig. 3).
In preferred embodiment, for logging operation, conductive wireline 24
extending from winch 14 is first passed around a portion of shieve 35 and
thence
to shieve 32 on crown 15 of derrick 20, and thereafter downwardly into well
13,
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as shown in Fig. 3, rather than directly to shieve 32 and thereafter
downwardly
into well 13, as shown in Fig. 1. Shieve 35 is coupled to monitoring equipment
such that measured rotation of shieve 35 occurs during lowering of a logging
instrument into well 13, in order that precise measurement of the depth of
such
logging instrument within well 13 is known. Such allows for data received from
the logging instrument (not shown) at the end of conductive wireline 24 to be
precisely correlated to depth measurements determined from the number of
rotations of shieve 35 corresponding to the amount of conductive wireline
"played
out" by winch 14, by data recording instruments provided in operator's
enclosure
l0 42.
In a preferred embodiment of the present invention a single hydraulic
pump 4 (see Fig. 5) is coupled to vehicle transmission 21, namely to a pto
shaft
thereof, and provides pressurized hydraulic fluid to permit operation of each
of
hydraulic pistons 12, power tongs 22, levelling jacks 18, and each of winches
14,
16, and 50. Multi-stage hydraulic pumps, or a plurality of hydraulic pumps,
may
be used depending on whether a single pump can meet the necessary pressure
of volume of hydraulic fluid required to operate individually all of the
aforesaid
hydraulic pistons 12, power tongs 22, levelling jacks 18, and each of winches
14,
16, and 50.
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In the case of winches 14, 16 and 50, each are further provided with a
respective hydraulic motor, namely hydraulic motors 15, 25, and 49 (see Fig.
5)
to receive pressurized hydraulic fluid from pump 4 and convert same into
mechanical force to power each of respective third, second and first winches
14,
16, and 50.
Hydraulic control means, identified schematically as item 80 in Fig. 5 and
6, is provided to allow individual hydraulic control of raising and lowering
of
derrick 20 via pistons 12, levelling of service vehicle 10 by means of
individual
control of levelling jacks 18, operation of power tongs 22, and independent
operation of each of winches 14,16, and 50.
As best seen in Figs. 5 and 6, hydraulic supply lines 46, 47, 48, 49, 51
and 53 extend from hydraulic control means 60 to respectively each of first
winches 50, hydraulic pistons 12, second winch 16, third winch 14, and
levelling
means 18.
Hydraulic control means 60 is further provided a number of individual
controls 101, to control each of hydraulic supply lines 46, 47, 48, 49, 51 and
53,
and may be duplicated so as to provide ease of access to operators at various
points on service vehicle 10. For example, a first set of hydraulic controls
fi0
may be situated within operator's enclosure 42. A duplicate of subset of such
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controls 60 may, in addition or alternatively, be located proximate the rear
most
portion 33 of service vehicle 10 at location designed as item 40 (see Fig. 1
), to
permit service operator 104 to control the various winches 14, 16 and 50 and
the
raising of derrick 20, from a position closer to wellhead 38.
Likewise, an individual set of hydraulic controls 60 may be situated on
derrick 20 at a raised position of the rear most portion 33 of service vehicle
10, to
give workmen standing on platform 36 the ability to control power tongs 22
(see
Fig. 1 ) on an as-needed basis when manipulating and joining jointed pipe 11.
In a preferred embodiment, although mechanical advantages by use of
shieves 32 and 44 may be obtained to lower, hold, and in some cases raise,
lengths of jointed pipe 11 into and out of well 13 by winch 16, frequently
additional mechanical advantage is needed to raise, by such winch means 16,
successive lengths of jointed pipe 11.
Accordingly, in a preferred embodiment as best seen in Fig. 6, hydraulic
motor 25 of winch 16 is coupled to winch 16 by means of reduction gearing, in
order to ensure winch 16 has the mechanical strength to raise what in some
cases may be 23,000 Ib of jointed pipe 11 (see Fig.6). In the preferred
embodiment shown in Fig. 6, planetary reduction gears 27 are interposed
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between hydraulic motor 25 and winch 16, in order to ensure winch 16 has the
mechanical strength to raise, if necessary, such weight of jointed pipe 11.
Hydraulic motors 49 and 47 are likewise provided to power respectively
first winch 50, and third winch 14. However, due to lesser loading on each of
winches 50 and 14 as compared to winch 16, additional reduction gearing is not
typically needed, but may be provided if needed.
A safety guy wire 30, as shown in Fig. 1, is preferably provided, to
prevent derrick 20 going to a substantially over-vertical position and falling
to the
ground and injuring workmen in the event of failure of hydraulic pistons 12
and/or
hydraulic pump 4.
In a preferred embodiment of the well servicing vehicle 10 of the present
invention, releasably engageable attachment means 59 is provided at the rear
most end 33 of service vehicle 10, to permit releasable attachment of a
platform
member 38, to allow a worker at a well site raised access to power tongs 22
immediately above wellhead 38, for the purposes of being able to use such
tongs
22 to threadable engage lengths of jointed pipe 11 when inserting such jointed
pipe 11 into well 13.
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Attachment means 59, in a preferred embodiment, comprises of plurality
of substantially vertically-aligned apertures 61 on derrick 20, preferably in
the
form of a plate member 63 bolted or welded thereto having a series of
vertically-
aligned apertures 61 therein to allow releasable attachment of platform number
36 thereto at various alternate heights, dependent on the height of wellhead
38.
Specifically, by having a number of vertically aligned apertures 61 in
plate member 63, platform member 36 may be removably attached via said
attachment means 59 at a first height above well-head 38, as shown in Fig.7A,
or
may be attached at a second (higher) height above the ground, as shown is Fig.
7B, to accommodate larger (higher) wellheads 38.
It is intended that platform member 36 be coupled to the attachment
means 59 on derrick 20 by hinge members 82 along a side edge 65 thereof. In
order to ensure platform member 36 is capable of being level regardless of the
height at which it is releasibly affixed with the attachment means 59 to
service
vehicle 10, telescoping legs 70 are provided to assist in ensuring the
platform 36
remains horizontal.
In a preferred embodiment, each of telescoping legs 70 may be
individually adjusted, by means of adjustable screw jacks T1, to account for
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uneven terrain around wellhead 38, so that platform 36 is substantially
horizontal
when in the operative position and releasibly attached to vehicle 10.
In the embodiment shown in Figs. 7A and B, platform 36 is of a 'C' shape
to provide a 'C' shaped "catwalk" about an aperture 80 facing forwardly
towards a
front end of vehicle 10, to permit jointed pipe 11 to extend down from mast 20
through platform 36 to wellhead 38.
Alternatively, aperture 80 in plattorm member 36 may face rearward, as
shown in Fig.B, again providing a 'C' shaped platform 36 for workers to
utilize
power tongs 22 about wellhead 38, when inserting jointed pipe 11 into wellhead
38.
Fig 8 shows a detailed perspective view of collapsible releasable
platform member 36. A series of hinge members 82, releasibly attachable to
plate members 63 by means of bolts or locking cotter pins 84, are provided to
permit releasable engagement of platform member 36 with service vehicle 10.
Advantageously, each of telescoping supporting legs 70 are preferably
pivotably collapsible on underside of platform member 36, as shown in Fig. 8,
so
that when such platform member 36 is no longer needed and releasibly detached
from the rear of vehicle 10, supporting legs 70 may be easily collapsed and
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platform 36 may then be easily transported on another vehicle to another well
site. Advantageously, therefore, vehicle 10 need not further transport
platform
member 36 to such other well site.
Releasibly-detachable guardrails 90, releasibly attachable to side edges
92 of platform 36 as shown in Fig. 8, are preferably provided, which in the
installed position provide a safety guard to workman working on such platform
36
when platform 36 is in a raised, operative position.
Advantageously, winches 50 and/or 15 and associated respective cables
34 and 24 may be used to raise platform member 36 to a raised position at
which
it may be affixed to vehicle 10 by attachment means 59 and hinge members 82.
Although the disclosure described and illustrates preferred embodiments
of the invention, it is to be understood that the invention is not limited to
these
particular embodiments. Many variations and modifications will now occur to
those skilled in the art. For definition of the invention, reference is to be
made to
the appended claims.
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