U.S. patent application number 11/122086 was filed with the patent office on 2005-11-10 for pump for evacuation of viscous liquids.
This patent application is currently assigned to SUKHOI NAPHTHA CORPORATION. Invention is credited to Martirosov, Rollan Gurgenovich, Rozin, Vladimir Jurievich, Yamburenko, Nikolay Nikolaevich.
Application Number | 20050249614 11/122086 |
Document ID | / |
Family ID | 35239604 |
Filed Date | 2005-11-10 |
United States Patent
Application |
20050249614 |
Kind Code |
A1 |
Rozin, Vladimir Jurievich ;
et al. |
November 10, 2005 |
Pump for evacuation of viscous liquids
Abstract
A pump for evacuating heavy oil containing mechanical impurities
and embedded in strata is disclosed. The pump includes one or more
tanks, each with a flexible membrane, situated in an external pump
casing. Each flexible membrane divides each tank into two
compartments. The first compartment of each tank is in fluid
communication with a collector cavity. The second compartment of
each tank is in fluid communication with a suction cavity. The
suction cavity includes a suction valve and a forcing valve. The
pump also includes a hydraulic drive connected with the collection
cavity so that operational fluid from the hydraulic drive is forced
against the membrane upon insertion of a hydraulic rod and creates
suction against the membrane upon extraction of the rod. The
external pump casing also includes a change lever for connecting to
external pipes.
Inventors: |
Rozin, Vladimir Jurievich;
(Moscow, RU) ; Martirosov, Rollan Gurgenovich;
(Moscow, RU) ; Yamburenko, Nikolay Nikolaevich;
(Moscow, RU) |
Correspondence
Address: |
HOGAN & HARTSON LLP
IP GROUP, COLUMBIA SQUARE
555 THIRTEENTH STREET, N.W.
WASHINGTON
DC
20004
US
|
Assignee: |
SUKHOI NAPHTHA CORPORATION
|
Family ID: |
35239604 |
Appl. No.: |
11/122086 |
Filed: |
May 5, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60568233 |
May 6, 2004 |
|
|
|
Current U.S.
Class: |
417/394 ;
417/374; 417/390; 417/392 |
Current CPC
Class: |
F04B 15/02 20130101;
F04B 43/067 20130101; F04B 47/08 20130101 |
Class at
Publication: |
417/394 ;
417/374; 417/390; 417/392 |
International
Class: |
F04B 017/00; F04B
035/00 |
Claims
We claim:
1. A pump for evacuating viscous liquid, comprising: an external
pump casing; a sealed collector cavity; a suction cavity, said
suction cavity including a suction valve and a forcing valve; one
or more tanks, each tank including a flexible membrane wherein each
flexible membrane hermetically divides each tank into a first
compartment and a second compartment, wherein the first compartment
of each tank includes openings for fluid communication with said
collector cavity and wherein the second compartment of each tank
includes openings for fluid communication with said suction cavity;
a hydraulic drive connected to the collection cavity, said
hydraulic drive including a rod, a cylinder, and an operational
fluid, said rod including a tail unit and an end portion; wherein
extraction of said end portion from said cylinder creates suction
against said membrane which draws said viscous liquid through said
suction valve, and wherein insertion of said end portion back into
said cylinder displaces said operational fluid, forcing said
operational fluid against said membrane and which forces said
viscous liquid through said forcing valve; and a change lever
mounted on said external pump casing for connecting to external
pipes.
2. The pump of claim 1, further comprising a fastening screw,
wherein said change lever has at least one opening for said
fastening screw and at least one slot for securing the tail unit of
the rod; said tail unit including an annular groove to receive the
fastening screw and including at least one overhang to engage said
at least one slot.
3. The pump of claim 2, further comprising a bearing plate affixed
to said end portion, said bearing plate preventing exit of said rod
from said cylinder.
4. The pump of claim 3, wherein said bearing plate is a multi-lobe
centering cam that allows fluid flow past said bearing plate.
5. The pump of claim 2, further comprising a said sealing base of
said rod where said rod enters said cylinder, said sealing base
including sealing rings and the length of said sealing base
extending equivalent to five times the diameter of said rod.
6. The pump of claim 1, wherein said rod is dimensioned with
respect to said cylinder to allow fluid flow between said rod and
said cylinder.
7. The pump of claim 1, further comprising hydro-pads between each
of said tank and said membrane to ensure said membrane is not
squeezed out through said openings.
8. The pump of claim 1, wherein a geometry of said hydraulic drive
is selected based on the size of said one or more tanks so as to
prevent damage to said membrane due to said membrane being forced
through said openings.
9. The pump of claim 8, wherein said geometry is selected based
further on the dimensions and maximum movement of said rod and
temperature of said operating fluid.
10. The pump of claim 1, further comprising branch pipes connecting
each of said one or more tanks, said branch pipes including
non-welded connections.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Provisional Patent Application No. 60/568,233,
"Pump for Liquid Evacuation," filed May 6, 2004, which is hereby
incorporated by reference.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO A "MICROFICHE APPENDIX"
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present invention relates generally to the pumping of
wells such as oil wells, and in particular to oil pumping equipment
for evacuating heavy oil containing mechanical impurities and
embedded in strata.
[0006] 2. Description of the Related Art
[0007] A plunger-diaphragm pump (PDP) has been previously developed
to facilitate extraction of abrasive-containing, aggressive and
salt-containing bedded liquids such as petroium from steep wells.
Conventional PDPs for evacuation of oil from wells have increased
mean-time-between-repair due to elimination of direct contact
between the pump's mechanical surfaces--such as the hydraulic
plunger and cylinder--and the impurities in the extracted oil.
Statistics show that the prevailing cause of failure in these oil
pumps is plunger wear. Pump repair or scheduled maintenance that
requires removal of the pump from the well greatly reduces the
efficiency and increases the cost of the oil extraction effort.
[0008] Conventional PDPs avoid interaction between a mechanical
plunger pair and the impurity-laden oil by utilizing tanks divided
by flexible membranes. A hydraulic drive (e.g., a plunger in a
cylinder) cycles to force operating liquid against a surface of the
membrane upon a downward stroke and creates suction against the
surface of the membrane upon an upward stroke.
[0009] In conventional PDPs, operating liquid is pushed out to the
tank by a plunger. The plunger, as with all plungers in oil pumps,
has significant length and requires a precision bore diameter to
limit seepage between the plunger and the sidewall of the cylinder.
The plunger is connected to a hollow rod that extends down a cavity
opening from the top of the pump. Any operating liquid that does
seep past the plunger to the above cavity passes through openings
in the hollow rod and flows back through to the hollow plunger. The
bottom of the plunger includes an unloading valve through which the
leaked operating liquid returns to the cavity under the
plunger.
[0010] The existing PDP designs as described above are not optimal.
The length of the plunger contributes to an undesirable increase in
the overall length of the pump. Length becomes a problem in
applications where a well may contain bends or protrusions
preventing an extended straight path for the pump. Conversely,
shortening the travel length of the plunger to decrease the overall
length results in reduced pump capacity. Thus, there remains a need
for a shorter PDP pump that can maintain the same capacity of
current PDP pumps.
[0011] Furthermore, the precise bore required for the plunger to
prevent seepage and the addition of an unloading valve in the
plunger add a significant increased cost to the pump. There is a
need for a more cost effective means to apply hydraulic forces to
the PDP tank membranes. Another disadvantage of the existing PDP is
the possibility of slippage of the rod when it is screwed together
with the rod column and the possibility of an unexpected rod exit
when the pump is being lowered into a well or during transport.
Thus, there is a need for improving the connection of the rod at
the entrance to the pump. Finally, tank assembly methods typically
require connecting tank collector branch pipes by linking branch
pipes in a process that requires expensive welding and accessories
to assure concentricity of the various pipes. There is a need for a
PDP that can utilize less expensive, yet fully effective, branch
pipe connection techniques.
SUMMARY
[0012] Accordingly, the invention is directed to pumping equipment
for evacuating heavy oil containing mechanical impurities and
embedded in strata that improves upon the aforementioned
deficiencies of conventional plunger-diaphragm pumps (PDP).
[0013] The present invention seeks to improve serviceability and
mean-time-between failure of the typical PDP while reducing the
manufacturing cost. In particular, the design of the connection of
the hydraulic rod to the rod column in accordance with the
invention prevents inadvertent exit of the rod. Also, the overall
length of the pump is reduced--and the capacity maintained--by
eliminating use of a plunger, thus allowing use of the pump in
wells with shorter straight-line runs than previously were
possible. The elimination of the plunger also saves production
costs by eliminating plunger materials and avoiding use of
precision boring techniques in the cylinder.
[0014] The production cost of a pump according to the present
invention is reduced due to a change in how the operating fluid is
delivered to the cavity against the tank's flexible membrane. The
operating fluid is displaced from the cylinder by a conditional
rod, eliminating the need for a plunger and the unloading valve
required in typical PDPs. Further cost savings are achieved by
eliminating welded kinked branch pipes and replacing them with
branch pipes without welded seams.
[0015] To achieve these and other advantages and in accordance with
the purpose of the present invention, as embodied and broadly
described, according to the disclosed embodiments, a pump for
evacuating heavy oil containing mechanical impurities and embedded
in strata is disclosed. The pump includes one or more tanks, each
with a flexible membrane, situated in an external pump casing. Each
flexible membrane divides each tank into two compartments. The
first compartment of each tank is in fluid communication with a
collector cavity. The second compartment of each tank is in fluid
communication with a suction cavity. The suction cavity includes a
suction valve and a forcing valve. The pump also includes a
hydraulic drive connected with the collection cavity so that
operational fluid from the hydraulic drive is forced against the
membrane upon insertion of a hydraulic rod and creates suction
against the membrane upon extraction of the rod. The external pump
casing also includes a change lever for connecting to external
pipes.
[0016] According to another embodiment of the invention, the
hydraulic drive includes a hydrocylinder so that the displacement
of the flexible membranes is caused by the change in volume of
operational fluid in the hydrocylinder when a rod is cyclically
inserted into and extracted from the hydrocylinder. According to
another embodiment, the number of tanks in the pump may vary from
as few as one to any suitable larger number.
[0017] According to another embodiment of the invention, the change
lever on the external pump casing has at least one opening for a
fastening screw and at least one slot for securing the tail unit of
the rod. The tail unit of the rod includes an annular groove to
receive the fastening screw and at least one overhang (or cam) to
engage the slot. The fastening screw inserted through the change
lever and into the annular grove prevents inadvertent exiting of
the rod. The engagement of the overhang with the slot prevents
inadvertent rotation of the rod.
[0018] According to a further embodiment of the invention, the
tanks are connected to branch pipes without the use of welded kink
branch pipe connections so as to enable mounting into the pump
casing as a single unit.
[0019] According to another embodiment of the invention, the
geometric properties of the hydraulic drive are selected based on
the size of the tank or set of tanks so as to prevent membrane
damage due to the membrane being forced through openings in the
tanks.
[0020] Additional features and advantages of the invention will be
set forth in the description which follows, and in part will be
apparent from the description, or may be learned by practice of the
invention. The objectives and other advantages of the invention
will be realized and attained by the structure particularly pointed
out in the written description and claims hereof as well as the
appended drawings.
[0021] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory and are intended to provide further explanation of
the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The accompanying drawings are included to provide further
understanding of the invention and are incorporated in and
constitute a part of this specification. The accompanying drawings
illustrate embodiments of the invention and together with the
description serve to explain the principles of the invention. In
the figures:
[0023] FIG. 1 illustrates a cross-sectional view of one embodiment
of the improved plunger-diaphragm pump (PDP) in accordance with the
present invention;
[0024] FIG. 2 illustrates an enlarged view of a portion of the pump
header section showing the entry point of the rod to the pump
housing;
[0025] FIG. 3 illustrates an enlarged view of the pump header
section showing the end portion of the hydraulic rod and sealing
rings at the entrance of the hydraulic drive cavity; and
[0026] FIG. 4 illustrates an enlarged view of a portion of the pump
tail section showing branch pipes without welded seams.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Reference will now be made in detail to the preferred
embodiments of the present invention, examples of which are
illustrated in the accompanying drawings.
[0028] FIG. 1 provides a schematic cross-sectional view of a pump
according to the present invention. As shown in FIG. 1, the pump
includes a two part hydraulic drive, including a header section 1
and a tail section 2. The header section 1 serves as a suction
cavity and is hermetically sealed to the tail section 2, which
serves as a hydraulic drive cavity.
[0029] Inside the header section 1 are an encasement 3 and a
plurality of tanks 4. Each tank 4 is divided into two hermetically
sealed compartments 26 and 27 divided by an elastic membrane 5. The
first compartment 26 of each tank 4 is provided with a hole or set
of holes 28 (FIG. 4) to enable fluid communication with a branch
pipe 8. A plurality of the branch pipes 8 are connected and form,
along with the connected compartment of each tank 4, a collector
cavity 25.
[0030] The second compartment 27 of each tank 4 is provided with a
set of holes to enable fluid communication with the cavity 29
formed by the encasement 3. The encasement 3 forms, along with the
connected compartment of each tank 4, a suction cavity 29. The
tanks 4 serve as a means to secure the flexible membrane 5 and,
thus, to protect the hydraulic drive from contact with the
extracted impurity-laden fluids.
[0031] The encasement 3 has two openings 6, 7 to connect to the
space outside the encasement 3. A suction valve 6 may be located at
the bottom of the encasement 3, as shown in FIG. 1, to allow liquid
to enter the suction cavity 29. A forcing valve 7 may be located at
the top of the encasement 3 to expel the liquid.
[0032] Inside the hydraulic drive cavity of the tail section 2, a
hydrocylinder 9 is connected to a rod 10; and a change lever 12 is
mounted on a casing 11 for connection to external pump and
compressor pipes (not shown). The cavity of the hydrocylinder 9 is
filled with a working medium or operation fluid (for example,
hydraulic oil). Because of the connection between the hydrocylinder
9 and the collection cavity 25 formed by the branch pipes 8 and the
associated compartment of each of the tanks 4, the tanks 4 may be
partially filled with operational fluid as well. The lower portion
of the rod 10, at its downward-most stroke, does not adjoin the
opening to the branch pipe 8. Contact with the opening to the
branch pipe 8 is prevented because the rod 10 is fitted with a tail
unit 15 (FIG. 2) to which the rod column is connected.
[0033] As shown in FIG. 3, the change lever 12 is fitted with a
fastening screws 14 that are screwed into the change lever 12 to
avoid slipping of the rod 10 (shown in FIG. 2) during connection to
the rod column. The tail unit 15 of the rod 10 has an annular
groove, into which the fastening screws 14 can be inserted. Also,
two overhangs (or cams) 17 are included on a bearing flange 16. By
means of the overhangs 17, the tail unit 15 enters the slots on the
face end of the change lever 12. Use of the fastening screws 14 and
the overhangs 17, ensure that the rod 10 (FIG. 2) is securely
locked from unwanted shifts and slipping caused by rotation of the
rod column.
[0034] Returning to FIG. 1, the suction cavity 29 of the header
section 1 is connected to the pressurization cavity of the tail
section 2 by the hydraulic drive, where the hydrocyilinder 9 forms
an annular channel with the external casing through which the
impurity-laden oil flows into lifting pipes (not shown).
[0035] Upon initiation of the pump cycle, the rod 10 is released
from its secured position (in which the tail unit 15 is engaged by
the fastening screws 14). This motion determines the lower point of
movement of the rod 10. During the subsequent upward motion of the
rod 10, a vacuum is created inside the hydrocylinder 9 and the
collector cavity 25 formed by the branch pipes 8 and the tanks 4.
Under this vacuum, the impurity-laden oil that was filling the
header section 2 via the suction valve 6, displaces the membranes 5
and fills up the tanks 4.
[0036] During the downward motion of the rod 10 from the upper
position, the volume of the cavity in the hydrocylinder 9 decreases
due to the insertion of the rod 10. Thus, operational fluid inside
the collector cavity 25 is swept into the tanks 4 and against the
membranes 5. During this process, each of the membranes 5 is
displaced and the impurity-laden oil is forced out of the tanks 4
and passes through the forcing valve 7 (shown in FIG. 1) and
subsequently past the change lever 12 into the external lifting
pipes (not shown). During the pressurization process the suction
valve 6 stops any liquid from flowing back into the well until the
pump cycle repeats.
[0037] While a conventional PDP uses a plunger to force hydraulic
fluid against a membrane, that plunger must be of substantial
length to reduce potential leaks past the plunger into the cylinder
above the plunger. From FIG. 2 it can be seen that an end portion
18 of the rod 10 does not counteract with a surface 19 of the
hydrocylinder 9. Instead a gap exists between the hydrocylinder 9
and the rod 10 allowing fluid flow around the hydrocylinder 9.
Thus, the interior surface of the hydrocylinder 9 and the rod 10 of
the present invention do not work as an adjoining pair, which
allows for less stringent tolerances in the manufacture and
assembly of the hydrocylinder 9 and the rod 10 when compared with
traditional hydraulic plungers. Also the need for an unloading
valve in traditional hydraulic plungers is eliminated.
[0038] As shown in FIG. 2, at the end portion 18, a bearing plate
20 is fitted. The bearing plate 20 can serve as a stopper to
prevent accidental exit of the rod 10 from the hydrocylinder 9. The
bearing plate 20 may be in the form of a multi-lobe centering cam
that allows fluid flow past the bearing plate. The bearing plate 20
can be used as a centering device for the rod 10. However, there is
no need to use the bearing plate 20 as a centering element if the
sealing base of the rod 10 in a box 21 is sufficient (e.g.,
normally between 5-6 diameters of the rod).
[0039] A set of sealing rings 22 is located inside the box 21. The
outer-most ring serves as a wiper. Rubber, fluoroplastic or a
combination of the two is preferably used as a material for the
sealing rings 22. However, any suitable material may be used. Using
a larger number of the sealing rings 22 than shown in FIG. 3, with
at least one of them serving as a wiper ring, may increase
reliability and leakage prevention.
[0040] Filing the pump with operation fluid (for example, oil) can
be performed during or after the pump assembly. After assembly, a
drainage pipeline 24 (FIG. 1), which enables bleed air to be
released during filing, is fitted with a safety valve 23. In case
of overfilling in the event that the hermetic seal is lost, the
valve protects parts of the pump from destruction, enabling further
operation of the pump until the termination of feed.
[0041] During the pump operation, the existence of hydro-pads (not
shown) or other means of stabilization between the tanks 4 and the
membranes 5 is important to ensure the membranes 5 are not squeezed
out through openings in the tanks 4. Such an occurrence would
result in damage or premature wear of the membranes. Using the
proper ratio between volumes of the tanks 4, volume of the branch
pipes 8, and volume of the hydrocylinder 9 can also prevent
membrane damage.
[0042] To avoid the membranes 5 from being squeezed out through
openings in the tanks 4, a working formula is used. The geometry of
the tanks 4 and the hydraulic drive, as well as the amount of
working fluid are related. The necessary data is calculated by the
following formula:
(nV.sub.T+V.sub.cv)>Q.sub.t>V.sub.AM
Q.sub.t=Q.sub.0(1+.beta.pt)
pt=t.sub.max-t.sub.0
V.sub.AM-V.sub.0.sup.-1fH.sub.max, where
[0043] V.sub.AM hydrocylinder cavity volume filled by actuating
medium
[0044] Q.sub.t actuating medium volume under to temperature
[0045] V.sub.T full volume of tank
[0046] n number of tanks
[0047] V.sub.cv tanks collector cavity volume to entry into
hydrocylinder
[0048] V.sub.0 hydrocylinder liquid volume at the most bottom
active position
[0049] Q.sub.0 operating liquid volume under to filling indoors
[0050] t.sub.0 to oil temperature indoors
[0051] .beta. coefficient of oil volume expansivity
[0052] f area of the cylinder
[0053] H.sub.max maximum movement range of the rod
[0054] Additional cost savings in manufacturing of the present pump
may be realized by eliminating welded kinks in the branch pipe 8
that are typically used in PDPs and using non-welded links instead.
FIG. 4 shows the branch pipe 8 connection between the two tanks 4
that utilizes a mechanical fastener. Any suitable mechanical pipe
fastener may be used, including sleeves, collars, and threaded
connections. The capacity of the pump can thus be expanded by
simply connecting additional branch pipe 8 and tank 4 segments.
Also, repairs to damages branch pipes or tanks can be accomplished
by exchanging components between the non-welded links, rather than
replacing an entire set of welded tanks and branch pipes.
[0055] While exemplary embodiments of the invention have been shown
and described herein, it will be obvious to those skilled in the
art that such embodiments are provided by way of example only.
Numerous insubstantial variations, changes, and substitutions will
now be apparent to those skilled in the art without departing from
the scope of the invention disclosed herein by the Applicants.
Accordingly, it is intended that the invention be limited only by
the spirit and scope of the claims, as they will be allowed.
* * * * *