Canadian Patents Database / Patent 2676833 Summary

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(12) Patent Application: (11) CA 2676833
(54) English Title: APPARATUS FOR PUMPING FLUIDS FROM A WELL
(54) French Title: APPAREIL POUR LE POMPAGE DE LIQUIDES HORS D'UN PUITS
(51) International Patent Classification (IPC):
  • F04B 47/00 (2006.01)
  • E21B 47/12 (2006.01)
(72) Inventors :
  • LIKNES, ALVIN (Canada)
(73) Owners :
  • LIKNES, ALVIN (Canada)
(71) Applicants :
  • LIKNES, ALVIN (Canada)
(74) Agent: SEABY & ASSOCIATES
(74) Associate agent:
(45) Issued:
(22) Filed Date: 2009-08-27
(41) Open to Public Inspection: 2010-03-22
(30) Availability of licence: N/A
(30) Language of filing: English

(30) Application Priority Data:
Application No. Country/Territory Date
12/235,002 United States of America 2008-09-22

English Abstract




An apparatus for pumping fluids from a well having a production tubing
extending from a wellhead of the well downhole to a downhole location. A pump
having
a pump barrel connected to a bottom of the production tubing, and a plunger
reciprocable
within the pump barrel for lifting fluid from the bottom of the well up
through the
production tubing and to the wellhead as the plunger upstrokes, and for
filling the barrel
below the plunger as the plunger upstrokes. A sealed housing attached to the
wellhead
with the production tubing in fluid communication with the interior of the
sealed housing.
A cable drum positioned within the interior of the sealed housing. A prime
mover
operably connected to the cable drum for rotating the cable drum and a cable
wound on
the cable drum for winding and unwinding by rotating the cable drum. The cable

extending downwardly through the production tubing and attached to the
plunger.
Controls for operating the prime mover for rotating the cable drum to
reciprocate the
plunger within the pump barrel.


Note: Claims are shown in the official language in which they were submitted.



CLAIMS


What is claimed is:


1. An apparatus for pumping fluids from a well, comprising in combination:
a production tubing extending from a wellhead of the well downhole to a
downhole location;

a pump having a pump barrel connected to a bottom of said production tubing,
and a. plunger reciprocable within said pump barrel for lifting fluid from the
bottom of the
well up through said production tubing and to the wellhead as the plunger
upstrokes, and
for filling the barrel below the plunger as the plunger upstrokes;

a sealed housing, said sealed housing attached to the wellhead with said
production tubing in fluid communication with the interior of said sealed
housing;
a cable drum positioned within said interior of said sealed housing;

a prime mover operably connected to said cable drum for rotating said cable
drum;

a cable wound on said cable drum for winding and unwinding by rotating said
cable drum, said cable extending downwardly through said production tubing and

attached to said plunger; and

controls for operating said prime mover for rotating said cable drum to
reciprocate
said plunger within said pump barrel.






2. The apparatus of claim 1, wherein said prime mover is positioned within
said
interior of said sealed housing.

3. The apparatus of claim 1, wherein said prime mover is a hydraulic motor.
4. The apparatus of claim 1, further comprising a flowline connected in fluid
communication with said interior of said housing for receiving fluid from said
production

tubing during reciprocation of said plunger.

5. The apparatus of claim 1, wherein said controls include a programmable
logic
controller programmed for the operation of said prime mover for rotating said
cable
drum.

6. The apparatus of claim 5, further comprising means to determine the angular

position of said cable drum and outputting a signal to said programmable logic
controller.
7. The apparatus of claim 5, further comprising means to determine elongation
of
said cable.

8. The apparatus of claim 1, wherein said production tubing is a continuous,
non-
segmented length of coiled tubing.



16



9. The apparatus of claim 1, further comprising means to determine fluid
production
from the well.



17

Note: Descriptions are shown in the official language in which they were submitted.


CA 02676833 2009-08-27

Apparatus For Pumping Fluids From A Well
FILED OF THE INVENTION

[001] The present invention relates generally to the pumping of fluid from a
well, and
more particularly, relating to an apparatus for mounting to the wellhead of a
low
producing oil and/or gas well for use in producing hydrocarbons from the well.
BACKGROUND OF THE INVENTION

[002] When an oil and/or gas well no longer produces hydrocarbons naturally,
artificial
lift systems are commonly used to continue hydrocarbon production from the
well. Artificial lift systems include some sort of mechanical device that is
inserted into the well to lift fluid from the bottom of the well to the
surface.

[003] One of the most commonly used systems for artificial lift in oil
production is a
combination of a pumpjack (also know as horse head pump, a beam pump, and
sucker rod pump), and piston pump installed in downhole in the wellbore. A
pumpjack is the above ground drive for reciprocating the plunger of the piston
pump. The pumpjack is connected to the plunger of the piston pump through a
series of sucker rods connected end-to-end from the pumpjack to the plunger.

The pumpjack converts rotary motion of a prime mover, such as an electric
motor
or a combustion engine, into a vertical reciprocating motion to drive the
sucker
rods up and down. The piston pump is connected to the end of a production
string, which includes numerous separate segments of rigid pipe connected end-
to-end that is lowered into the wellbore of the well to position the pump at a

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CA 02676833 2009-08-27

location where well fluid will be drawn in by the piston pump. The production
string is typically secured at the wellhead by a tubing hanger which supports
the
production string in the wellbore.

[004] The pumpjack system has many drawbacks including the diameter of the
sucker
rods being limited by well conditions, and as load is imposed on the sucker
rods
during the upstroke of the plunger, the rods stretch due to their elasticity.
With
relatively new sucker rods, this stretch is taken up at the beginning of the
down
stroke of the plunger. However, with older sucker rods the continuous
stretching
and relaxing of the rods results in fatigue and plastic deformation and
permanent
elongation. The amount of elongate of the sucker rods is indefinite and
uncertain,
but in deep wells it may become so great that nearly the entire stroke of the
plunger is taken up in stretching and releasing of the sucker rods, which
greatly
reduces the efficiency of the pump system. Additionally, installation of rigid
segments of production tubing is time consuming, dangerous, and expensive.
Also, because this conventional pumping system generally has large dimensions
and relatively high weights, it needs a robust foundation and therefore a
relatively
high capital investment. Furthermore, the labor intensity involved in carrying
out
periodic parameter adjustments, balance adjustments and costs of operation are
relatively high.

[005] Another problem with hydrocarbon production is the environmental impact
of
producing the hydrocarbons. The seal between the polished rod (upper most

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CA 02676833 2009-08-27

sucker rod) and the wellhead in pumpjack systems has a tendency to leak,
resulting in higher environmental impact and lost of usable oil. To reduce
this
impact, pumpjack systems need to be frequently inspected to ensure leaking is
not
occurring.

SUMMARY OF THE INVENTION

1006] In general, in one aspect, an apparatus for pumping fluids from a well
is provided.
The apparatus includes a production tubing extending from a wellhead of the
well
downhole to a downhole location. A pump having a pump barrel connected to a
bottom of the production tubing, and a plunger reciprocable within the pump
barrel for lifting fluid from the bottom of the well up through the production
tubing and to the wellhead as the plunger upstrokes, and for filling the
barrel
below the plunger as the plunger upstrokes. A sealed housing attached to the
wellhead with the production tubing in fluid communication with the interior
of
the sealed housing. A cable drum positioned within the interior of the sealed
housing. A prime mover operably connected to the cable drum for rotating the
cable drum and a cable wound on the cable drum for winding and unwinding by
rotating the cable drum. The cable extending downwardly through the production
tubing and attached to the plunger. Controls for operating the prime mover for
rotating the cable drum to reciprocate the plunger within the pump barrel.

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CA 02676833 2009-08-27

[007] The prime mover can be positioned within the interior of the sealed
housing. The
prime mover can be a hydraulic motor. A flowline can be connected in fluid
communication with the interior of the housing for receiving fluid from the
production tubing during reciprocation of the plunger. The controls can
include a

programmable logic controller programmed for the operation of the prime mover
for rotating the cable drum. A means to determine the angular position of the
cable drum and outputting a signal to the programmable logic controller can be
provided. A means to determine elongation of the cable can be provided. The
production tubing can be a continuous, non-segmented length of coiled tubing.
A
means to determine fluid production from the well can be provided.

[008] There has thus been outlined, rather broadly, the more important
features of the
invention in order that the detailed description thereof that follows may be
better
understood and in order that the present contribution to the art may be better
appreciated.

[009] Numerous objects, features and advantages of the present invention will
be
readily apparent to those of ordinary skill in the art upon a reading of the
following detailed description of presently preferred, but nonetheless
illustrative,
embodiments of the present invention when taken in conjunction with the
accompanying drawings. The invention is capable of other embodiments and of
being practiced and carried out in various ways. Also, it is to be understood
that

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CA 02676833 2009-08-27

the phraseology and terminology employed herein are for the purpose of
descriptions and should not be regarded as limiting.

[0010] As such, those skilled in the art will appreciate that the conception,
upon which
this disclosure is based, may readily be utilized as a basis for the designing
of
other structures, methods and systems for carrying out the several purposes of
the
present invention. It is important, therefore, that the claims be regarded as
including such equivalent constructions insofar as they do not depart from the
spirit and scope of the present invention.

[0011] For a better understanding of the invention, its operating advantages
and the
specific objects attained by its uses, reference should be had to the
accompanying
drawings and descriptive matter in which there is illustrated preferred
embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings, which are included to provide further
understanding
of the invention and are incorporated in and constitute a part of this
specification,
illustrate preferred embodiments of the invention and together with the
description serve to explain the principles of the invention, in which:



CA 02676833 2009-08-27

[0013] Figure 1 is a front elevation diagram of the apparatus for pumping
fluids from a
well constructed in accordance with the principles of the present invention,
and
installed on a typical oil well;

[0014] Figure 2 is a side elevation diagram of FIG. 1;
[0015] Figure 3 is an enlarged detail view of FIG. 1;

[0016] Figure 4 is a schematic diagram of a control system of the apparatus;
and
[0017] Figure 5 is a front elevation diagram of the apparatus for pumping
fluids from a
well with an alternative flowline connection arrangement.

DETAILED DESCRIPTION OF THE INVENTION

[0018] Referring to FIGS. 1-4 of the drawings, reference numeral 10 generally
designates
the apparatus for pumping fluid from a well in accordance with the principals
of
the present invention. As shown in the Figures of the drawings, there is
broadly
disclosed an oil and/or gas well 12 that has the usual borehole, or well-bore
14
having casing 16, formed into the Earth. The borehole 14 extends from the
surface, down through a hydrocarbon producing formation 18 from which fluid
flows through casing perforations 20 into the casing annulus 22. While
specific
discussion is made herein with respect to an oil and/or gas well, the pumping
apparatus 10 of the present invention can be utilized to pump fluids from
other

6


CA 02676833 2009-08-27

types of wells, such as a water well. Well 12 has a conventional wellhead 24
attached to the surface end of the well casing 16 and including a blowout
preventer (BOP) 25. The wellhead 24 configuration can include different
components suited for the requirements and/or operation conditions of each
particular well.

[0019] The pumping apparatus 10 includes a production tube 26 extending from
the
wellhead 24 down the well casing 16 to a downhole position. The production
tube 26 can be retained or secured to the wellhead 24 by a conventional tubing
hanger (not shown), which is well known in the art. The production tubing 26
can
be a length of coiled tubing for specific advantages over segmented sections
of
rigid tubing, including being capable of being run into the well without
killing the
well.

[0020] A pump 30 is connected to the bottom 28 of the production tubing 26,
and is
operable to pump formation fluid from casing 16 into and upwardly through the
production tubing to the wellhead 24. Pump 30 can be a conventional down-hole
reciprocating piston pump having a pump barre132, a piston 34 received within
the pump barrel for reciprocation therein, a connecting rod 36 extending
upwardly
from the piston, a standing ball check valve 38, and a traveling ball check
valve
(not shown). The pump barrel 32 can be connected to the bottom 28 of the
production tubing 26 with the connecting rod 36 extending upwardly in the
production tubing. Broadly, in operation, when the piston 34 is pulled
upwardly

7


CA 02676833 2009-08-27

the traveling valve, positioned across a flow passage through the piston,
closes
and the standing valve 38 opens due to a drop in pressure below the piston in
the
pump barre132. Consequently, the pump barre132 fills with formation fluid as
the piston 34 is raised and lifts the formation fluid that is above the piston
upward
through the production tubing 26. When the piston 34 travels downwardly, the
traveling valve opens, and the standing valve 38 closes due to an increase in
pressure below the piston in the pump barre132. The formation fluid in the
pump
barre132, which was drawn during the upstroke of the piston, flows up through
the traveling valve in the piston. Once the piston 34 reaches the end of its
downward stroke, it begins its upward stroke, repeating the process to pump
fluid.

[0021] The connecting rod 36 is connected to the end of a cable 48 that is
wound on a
winch/cable drum 46 that is mounted within a housing 40 attached to the
wellhead
24. Cable 48 is wound off the cable drum 46 past a cable guide 52 then down
and
into the top of the wellhead 24 and production tubing 26. The cable guide 52
is
to provide an appropriate fleet angle for the cable 48 to wrap properly and to
eliminate the need for an expensive level wind or other tool. Housing 40 is
connected to the wellhead 24 with the production tubing 26 in fluid
communication with the interior 42 of the housing. The housing 40 is sealed
and
pressure rated at a pressure rating higher than the shut-in pressure of the
well 12,
and the working pressure of a production pipeline when production is being
produced into a pipeline. Housing 40 may have a removable, sealable hatch 44
to
permit access to the interior 42.

8


CA 02676833 2009-08-27

[00221 An important aspect of the pumping apparatus 10 of the present
invention is the
sealing of the cable 48 and cable drum 46 within the well environment by being
positioned and contained within the housing 40. Undoubtedly, during operation,
formation fluid will accumulate on the cable 48, and with the cable being

contained within the well environment, the formation fluid is prevented from
impacting the ambient environment. Additionally, expensive and leak prone
seals
that otherwise would be required to seal the cable with wellhead are
eliminated,
and thus reducing operating expense, and the likely environmental impact due
to
seal leakage or failure, among other advantages.

[0023] A prime mover, such as hydraulic motor 50 is operatively coupled to the
cable
drum 46 for rotating the cable drum to wind and unwind the cable 48 thereon.
An
intermediate drive (not shown), such as a transmission or gear box, can be
connected between the cable drum 46 and the hydraulic motor 50 as desired or
may be required. The intermediate drive could be a variable speed drive to
more
accurately control the rotation of the cable drum 46. Alternatively, the
hydraulic
motor could be replaced with an electric motor or a combustion engine. A winch
break (not shown) can be provided to help control the winding of the cable 48
under load.

[0024] The hydraulic motor 50 can also be positioned and supported within the
interior
42 of the housing 40, or alternatively, can be positioned and supported
exterior to
9


CA 02676833 2009-08-27

the housing with its drive shaft extending into the interior of the housing. A
shaft
seal (not shown) would seal the drive shaft with the wall of the housing 40 to
prevent leaking of formation fluid from the housing. The hydraulic motor 50 is
connected to a hydraulic circuit comprising a hydraulic pump 54, hydraulic
fluid
lines 55 and 56, a valve 58, and a hydraulic fluid reservoir 60 containing a
quantity of hydraulic fluid. The hydraulic pump 54 is operated to circulate
hydraulic fluid within the hydraulic circuit to operate the hydraulic motor 50
driving the cable drum 46. Valve 58 is operated to direct the flow of
hydraulic
fluid to the hydraulic motor 50 to either operate the hydraulic motor in a
forward
or reverse direction in order to either wind or unwind the cable 48 onto and
from
the cable drum 46.

[0025] With reference back to FIG. 1, the wellhead 24 can be provided with a
flowline
connections 70 and 71 for fluid and/or gas flow. Appropriate pipelines 72 and
73
are connected to the flowline connections 70 and 71 respectively for conveying
fluid and/or gas to collection tanks, separators, and/or production pipelines.
Flowline connection 70 can be provided with a one-way check valve 74, a valve
76, and fluid flow switch 66. Similarly, flowline connection 71 can be
provided
with a one-way check valve 75, a valve 77, and a fluid flow switch 67. While
only
two flowline connections are illustrated the wellhead 24 may be configured to
have as many as required by the operating conditions of the well 12. As shown
in
FIG. 5, alternatively or in addition to, the housing 40 can be provided with a



CA 02676833 2009-08-27

flowline connection, such as flowline connection 70 in fluid communication
with
the interior of the housing.

[0026] Numerous different control methods and apparatuses can be employed to
control
the operation of the hydraulic motor 50 to affect the reciprocation of the
piston 34
of the pump 30 through the winding of the cable 48. An exemplary control, can
include a rotary position encoder 62, a fluid pressure sensor 64, a fluid flow

switch 66, valve 58, and a programmable logic controller (PLC) 68. The rotary
position encoder 62 can be operatively coupled to the drive shaft of the
hydraulic
motor 50 to determine the angular position of the shaft and ultimately the
angular
position of the cable drum 48. A rotary position encoder, also called a shaft
encoder, is an electro-mechanical device used to convert the angular position
of a
shaft or axle to an analog or digital code, making it an angle transducer.
These
devices are routinely used in industrial controls and robotics, and are
readily
available and are easily implemented into control logic. The fluid pressure
sensor
64 can be installed on hydraulic fluid line 56 to measure the pressure of the
hydraulic fluid in the fluid line to determine the load on the hydraulic motor
50.
The fluid flow switch 66 can be installed in flowline 68 connected to wellhead
24
for sensing pumped fluid flow through the flowline from the wellhead. The
rotary
position encoder 62, the fluid pressure sensor 64, the fluid flow switch 66,
the
valve 58, a winch brake (if provided), and pump 54 are each operatively
coupled
to the PLC 68.

~1


CA 02676833 2009-08-27

[0027:1 After initial installation, operation of one cycle of the pumping
apparatus 10 that
is installed on well 12 is as follows. When the piston 34 is at the bottom of
its
stroke in the pump barrel 32 as indicated by the rotary position encoder 62,
the
PLC 68 operates valve 58 to direct hydraulic fluid to the hydraulic motor 50
to
wind the cable 48 onto the cable drum 46 to raise piston upward. The position
of
piston 34 along its stroke is continuously measured by the rotary position
encoder
62 and reported to the PLC 68. As the piston 34 is raised fluid pressure
sensor 64
continuously monitors the fluid pressure within the hydraulic line and reports
this
to the PLC 68. The PLC 68 uses this pressure signal to monitor load on the
piston
and cable 48. The piston 34 is determined to be at the top of its stroke as
indicated
by the rotary position encoder 62. As a fail-safe, an abnormal increase in
hydraulic line pressure as measured by the pressure sensor 64 can be used to
indicate the piston 34 is being pulled upward against the top of the pump
barrel

32. Once it is determined the piston 34 is at the top of its stroke, the PLC
68
commands valve 58 to reverse fluid flow to the hydraulic motor 50 to unwind
the
cable 48 from the cable drum 46 to lower the piston. The piston 34 will reset
to
the bottom of its stroke under gravitational force of the weight of the piston
and
the weight of the cable 34 acting on the piston. Once the piston 34 is
determined
to be at the bottom of its stroke, the cycle repeats to produce formation
fluid up
through the production tubing 26 into the wellhead 24 and through the flowline
connection 70.

12


CA 02676833 2009-08-27

[0028] The PLC 68 can be programmed to determine an estimation of elongation
of the
cable 48 in real-time as a result of the load of the column of formation fluid
using
Hooke's Law of elasticity. The elongate of the cable is directly proportional
to
the tensile force and the length of the cable and inversely proportional to
the
cross-sectional area of the cable and the modulus of elasticity of the
material of
the cable. Tensile force on the cable can be calculated by determining the
hydrostatic head of the column of formation fluid and knowing the diameter of
the piston and the diameter of the cable. The length of the cable between the
cable drum 46 and the connecting rod 36 can be easily determined from the
rotary
position encoder 62 and other known constants of the well geometry, such as
well
depth. The cross-sectional area of the cable and the modulus of elasticity of
the
material of the cable are also known. The elongate of the cable 48 can be used
to
more accurately determine the position of the piston 34 along its stroke.

[0029] Output from the fluid flow switch 66 can be used by the PLC 68 to
determine if
formation fluid is being produced by operation of the pumping apparatus 10. To
prevent dry running of the pumping apparatus 10, the PLC 68 will cause the
pumping apparatus to operate in a shut-down mode for a predetermined period of
time upon the sensing of no fluid being produced by the fluid flow switch 66.

13


CA 02676833 2009-08-27

[0030] A number of embodiments of the present invention have been described.
Nevertheless, it will be understood that various modifications may be made
without departing from the spirit and scope of the invention. Accordingly,
other
embodiments are within the scope of the following claims.

14

A single figure which represents the drawing illustrating the invention.

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Admin Status

Title Date
Forecasted Issue Date Unavailable
(22) Filed 2009-08-27
(41) Open to Public Inspection 2010-03-22
Dead Application 2013-08-27

Abandonment History

Abandonment Date Reason Reinstatement Date
2012-08-27 FAILURE TO PAY APPLICATION MAINTENANCE FEE

Payment History

Fee Type Anniversary Year Due Date Amount Paid Paid Date
Filing $200.00 2009-08-27
Maintenance Fee - Application - New Act 2 2011-08-29 $50.00 2011-07-26
Current owners on record shown in alphabetical order.
Current Owners on Record
LIKNES, ALVIN
Past owners on record shown in alphabetical order.
Past Owners on Record
None
Past Owners that do not appear in the "Owners on Record" listing will appear in other documentation within the application.

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Representative Drawing 2010-03-15 1 10
Cover Page 2010-03-15 2 47
Abstract 2009-08-27 1 26
Description 2009-08-27 14 457
Claims 2009-08-27 3 53
Drawings 2009-08-27 5 89
Assignment 2009-08-27 2 61