U.S. patent application number 10/469112 was filed with the patent office on 2006-10-19 for pumping unit driven by a linear electric motor.
Invention is credited to Xiaoxi Zhou.
Application Number | 20060233650 10/469112 |
Document ID | / |
Family ID | 4681308 |
Filed Date | 2006-10-19 |
United States Patent
Application |
20060233650 |
Kind Code |
A1 |
Zhou; Xiaoxi |
October 19, 2006 |
Pumping unit driven by a linear electric motor
Abstract
The present invention disclose a pumping unit driven by a linear
motor, comprising a guide rail support in the form of a frame
structure, a mover of the linear motor provided with slide blocks,
said slide blocks engages guide slide ways used for said mover and
mounted on inner sides of said guide rail support, six stators of
the linear motor, said stators are mounted on inner sides of said
guide rail support, a chain wheel disposed at the top of said guide
rail support, a chain, said chain is connected to an upper end of
said mover of the linear motor at one end, passes said chain wheel
and is then connected to a pumping slick rod of a wellhead device
at the other end thereof, a counterweight, and a counterweight
chain, said counterweight chain is connected to a lower end of said
mover at one end, passes a bottom chain wheel disposed at the
bottom of the guide rail support and a top chain wheel disposed at
the top of the guide rail support sequentially and is then
connected to said counterweight at the other end thereof. Since the
pumping unit is disposed at a side of the wellhead, it is
convenient for operations and eliminates possibility of occurring
of accident without changing the original wellhead.
Inventors: |
Zhou; Xiaoxi; (Rengiu,
CN) |
Correspondence
Address: |
LEONARD TACHNER, A PROFESSIONAL LAW;CORPORATION
17961 SKY PARK CIRCLE, SUITE 38-E
IRVINE
CA
92614
US
|
Family ID: |
4681308 |
Appl. No.: |
10/469112 |
Filed: |
February 25, 2002 |
PCT Filed: |
February 25, 2002 |
PCT NO: |
PCT/CN02/00111 |
371 Date: |
June 19, 2006 |
Current U.S.
Class: |
417/416 |
Current CPC
Class: |
E21B 43/126 20130101;
F04B 17/042 20130101; F04B 47/02 20130101; F04B 47/14 20130101 |
Class at
Publication: |
417/416 |
International
Class: |
F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 2001 |
CN |
01204055.X |
Claims
1. A pumping unit driven by a linear motor, comprising: a guide
rail support in the form of a frame structure; a mover of the
linear motor provided with slide blocks, said slide blocks engages
guide slide ways used for said mover and mounted on inner sides of
said guide rail support; stators of the linear motor, said stators
are mounted on inner sides of said guide rail support; a chain
wheel disposed at the top of said guide rail support; a chain, said
chain is connected to an upper end of said mover of the linear
motor at one end, passes said chain wheel and is then connected to
a pumping slick rod of a wellhead device at the other end thereof;
a counterweight; and a counterweight chain, said counterweight
chain is connected to a lower end of said mover at one end, passes
a bottom chain wheel disposed at the bottom of the guide rail
support and a top chain wheel disposed at the top of the guide rail
support sequentially and is then connected to said counterweight at
the other end thereof.
2. The pumping unit driven by a linear motor according to the claim
1, wherein said chain wheel, said bottom chain wheel and said top
chain wheel are replaced by pulleys, and said chain and
counterweight chain are replaced by wire ropes accordingly.
3. The pumping unit driven by a linear motor according to the claim
1 or 2, wherein said slide blocks of said mover of the linear motor
used for engaging said slide ways are rollers.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application relates to and claims priority from
PCT/CN02/00111 filed Feb. 25, 2002 and parent Application Serial
No. 01204055.X filed Feb. 26, 2001.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a pumping unit,
more particularly to an oil well pumping unit disposed on the
ground and driven by a linear motor.
BACKGROUND ART
[0003] Presently, most of oil well pumping units are driven by a
rotating motor vie a speed reducer and a conversion device for
converting rotary movement into linear movement, thereby driving
the pumping slick rod and the pumping rod to reciprocate up and
down and driving the downhole oil extraction pump to extract oil.
The pumping unit driven by a rotating motor is large in volume,
complex in structure and high in electrical energy consumption. The
Chinese Utility Model No. 96217 638.9 disclosed a pumping unit
driven by a linear motor. The technical scheme of the Utility Model
is that the linear motor is connected to and drives the pumping rod
and the oil extraction pump, and the speed reducer and the
conversion device for converting rotary movement into linear
movement are omitted, thus eliminating the disadvantages of the
conventional pump unit such as large volume, complex structure and
high energy consumption. This pumping unit is advantageous because
it is driven by a linear motor. The pumping unit comprises a
downhole oil extraction pump, a pumping rod, a driving device, a
headframe and a counterweight. A linear motor is used as the
driving device, stators of the linear motor together with
longitudinal limit posts are fixed on the wellhead device,
positioning blocks are fixed to an upper end and a lower end of the
mover of the linear motor, the mover is slidably against to the
side longitudinal limit posts, buffer springs are fixed to the
wellhead device and the limit posts respectively. The mover of the
motor is hollow inside, and the pumping rod passes through the
center of the mover. The pumping rod together with a clipping seat
is fixed to the mover of the linear motor. The headframe is
provided with pulleys of a weight-balancing device. A wire rope is
connected to the clipping seat and the counterweight at both ends
thereof via the pulleys. Since stators of the linear motor together
with the limit posts are fixed above the wellhead device, many
inevitable disadvantages in the pump unit are as follows:
[0004] 1. Vibration generates while the mover of the linear motor
reciprocates up and down, thus causing the pumping unit to vibrate
with the linear motor. The stators of the linear motor and the
limit posts are fixed to the wellhead device, the mover of the
linear motor causes the wellhead device to vibrate while it moves,
thus causing leakage of crude oil and natural gas from the wellhead
device. Even if the leakage of the crude oil and the natural gas is
not caused by the vibration, it generally occurs, during the
mechanical pumping of the oil. If leakage of the natural gas
occurs, since the linear motor is fixed above the wellhead device,
the leaked natural gas will enter the linear motor directly, thus
causing potential safety hazard. 2. The linear motor is fixed above
the wellhead device so that it occupies a space around the
wellhead, operations such as replacement of the packing set box and
the packing set will become difficult. 3. The linear motor is fixed
above the wellhead device, the vibration of the motor causes the
downhole casing connected to wellhead device to vibrate and deform.
4. The linear motor is fixed above the wellhead device which can
not endure the higher outside pressure. If the linear motor is
fixed above the wellhead, a wellhead device which can endure higher
outside pressure should be designed renewedly to match the linear
motor, this will increase the cost of the pumping unit.
SUMMARY OF THE INVENTION
[0005] Accordingly, an object of the present invention is to move
the linear motor away from the wellhead device so as to resolve the
above problems, i.e. the potential safety hazard occurs when the
natural gas leaks; the linear motor occupies much space around
wellhead because it is fixed above the wellhead device, thus
causing many operations difficult; the linear motor causes the down
hole casing to vibrate. In addition, the wellhead device can endure
higher outside pressure without changing the original wellhead
device in site. The headframe is replaced by a guide rail support
of the linear motor.
[0006] The object is accomplished by providing a pumping unit
driven by a linear motor, comprising a guide rail support, a mover
of the linear motor, stators of the linear motor, a chain, chain
wheel and a counterweight, the guide rail support is in the form of
a frame structure, stators of the linear motor are mounted on inner
sides of the guide rail support, and guide slide-ways used for the
mover of the linear motor are fixed on inner sides of the guide
rail support. The mover of the linear motor is provided with slide
blocks engaging with the guide slide ways. The chain wheel is
disposed on the top of the guide rail support. The chain passes the
chain wheel and is connected to the mover of the linear motor at
one end and connected to a pumping slick rod of the wellhead device
at the other end thereof. A counterweight chain is connected to a
lower end of the mover of the linear motor at one end, passes a
bottom chain wheel disposed at the bottom of the guide rail support
and a top chain wheel disposed at the top of the guide rail support
sequentially, and is then connected to a counterweight at the other
end thereof.
[0007] In another embodiment of the present invention, pulleys can
replace the chain wheels respectively and the chains can be
replaced by wire ropes accordingly.
[0008] The advantages of the present invention are as follows: an
upper end of the mover of the linear motor is connected to one end
of the chain, the chain passes the chain wheel and is connected to
the pumping slick rod at the other end thereof. The wellhead device
and the pumping slick rod are away from the linear motor, and the
linear motor is moved away from the above of the wellhead, when
leakage of the natural gas occurs, the leaked natural gas can not
enter the linear motor directly, thus eliminating the potential
safety hazard. The linear motor is not disposed above the wellhead
device, and the original wellhead device can be used, so that it is
still convenient for a worker to operate around the wellhead by
comparison with the pumping unit driven by a rotating motor in the
prior art. In addition, even if the linear motor generates
vibration during operating, the downhole casing will not be
affected and the wellhead device can endure high pressure. The
structure of the pumping unit driven by a linear motor is also
simplified by replacing the headframe by the guide rail support of
the linear motor.
BRIEF DESCRIPTION OF THE DRAWINGS OF THE INVENTION
[0009] These and/or other advantages of the present invention will
become apparent and more readily appreciated from the following
description of the embodiments, taken in conjunction with the
accompany drawings, in which:
[0010] FIG. 1 is a schematic view of the structure of a pumping
unit driven by a linear motor according to an embodiment of the
present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0011] FIG. 1 shows a structure of the pumping unit driven by a
linear motor according to an embodiment of the present invention. A
wellhead device 1 and a pumping slick rod 2 are necessary for an
oil well, their detailed descriptions are omitted because they are
substantially identical with that in prior art. In FIG. 1,
reference numerical 3 denotes a chain, 4 denotes a chain wheel, 5
denotes a top chain wheel, 6 denotes a counterweight chain, 7
denotes a counterweight, 8 denotes a mover of the linear motor, 9
denote stators of the linear motor, 10 denotes a bottom chain wheel
disposed at bottom of the guide rail support, and 11 denotes a
guide rail support.
[0012] The structure of the present invention is explained in
detail with reference to embodiments taken in conjunction with the
drawing as follows.
Embodiment 1
[0013] The guide rail support 11 of the pumping unit driven by a
linear motor is formed by two channel beams, between the channel
beams are provided with crossbeams, thus forming a frame structure.
The frame structure can be formed by the channel beams and the
crossbeams through welding or screwed connection. In order to
improve stability of the frame structure, the guide rail support
can be formed by flanged beams and steel plates instead of the
channel beams and the crossbeams through welding. Four guide slide
ways formed by angle bars through welding are provided on inner
sides of the guide rail support. The guide slide ways are used for
controlling sliding movement of the mover 8 of the linear motor,
the mover 8 is connected to one end of the counterweight chain 6 at
a lower end thereof, and the counterweight chain 6 passes a bottom
chain wheel 10 disposed at the bottom of the guide rail support and
a top chain wheel 5 disposed at the top of the support sequentially
and is then connected to the counterweight 7 at the other end
thereof. The counterweight 7 should be selected to meet the
requirements of the oil well.
Embodiment 2
[0014] The guide rail support 11 of the pumping unit driven by a
linear motor in the embodiment 2 is substantially identical with
that in the embodiment 1, except for the following aspects: there
are two pulleys 4 at the top of the guide rail support 11, the
diameter of the pulleys is 500 mm, the chain 3 is replaced by a
wire rope 3 whose diameter is 25 mm, and the counterweight chain 6
is also replaced by a counterweight wire rope 6. One end of the
counter weight wire rope 6 is connected to a lower end of the mover
8 of the linear motor, and the other end thereof passes the bottom
chain wheel 10 disposed at bottom of the guide rail support and the
top chain wheel 5 disposed at top of the support sequentially and
is then connected to the counterweight 7. In other words, in the
embodiment 2, the chain and the counterweight chain in the
embodiment 1 are replaced by wire ropes, and the chain wheel, the
bottom chain wheel and the top chain wheel in the embodiment 1 are
replaced by pulleys accordingly. Of course, only the chain and
chain wheel can be replaced by wire rope and pulley respectively,
and the counterweight chain and the bottom and top chain wheels are
not changed, vice versa. In any case, the effect of the present
invention will not be affected.
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