Note: Descriptions are shown in the official language in which they were submitted.
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PUMP SYSTEM AND METHODS OF PUMPING WELL FLUIDS
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention is directed to a pumping
system for producing well fluids from petroleum producing
formations penetrated by a well. The present invention
includes the use of dual parallel tubing strings having the
lower portions connected by a crossover flow connection, one
of the tubing strings, i.e., the production tubing string,
forming a flow path for flowing production fluids to the
surface and the other, i.e., the power tubing string, for
providing a conduit for inserting, operating and removing a
rod-activated pump plunger used to lift well fluids from the
well and to move the well fluids up the well to the surface
through the crossover flow connection. A flow control valve
for controlling production flow is also provided. A
lubricating plunger is provided to direct fluid from the
annulus between the power tubing and the rods to an area
between the barrel of the pump and the lubricating plunger
to increase the efficiency of the pump and to assist in ~~and
control.
25
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Description of Related Art
Pumping well fluids from wells penetrating producing
formations has been done for many years. This is particularly
true where heavy viscous oil must be moved to the surface.
Often heavy viscous oils such as produced from California
formations which are relatively close to the earth's surface
contain sand and are difficult to pump. Steam and diluents
have often been used to lower the viscosity of heavy crudes to
improve flow and pumping efficiency; however, sand is still a
major problem.
Heretofore dual tubing strings for a pumping system
for producing petroleum have been suggested. For example,
pumping installations utilizing parallel dual tubing strings
are disclosed in U.S. Patents No. 4,056, 335 to Walter S.
Secrest; 3,802,802 to F. Conrad Greer; and 3,167,019 to
J.W. Harris.
There is still need, however, for a pumping system
having dual production and power tubing strings which permit
ease of operation which has movable parts including the pump
plunger which may be removed from the power tubing string and
replaced in the tubing string without the need for removing
the tubing strings from the well, leaving only the pump barrel
and tubing in place.
SUMMARY OF THE INVENTION
In one aspect, the present invention provides apparatus for
producing well fluids from an oil bearing formation penetrated
by a well including production tubing means forming a
production flow path for production fluids between the earth's
surface and a location in the well suitable for receiving well
production fluids from a pump located in a parallel power
tubing means. Flow control means are preferably located in
the lower portion of the apparatus to permit flow of
production fluids up the production flow path and to prevent
flow of production fluids down the production flow path.
Power tubing means extend down the well in parallel
relationship with the production tubing means to a location in
the well suitable for receiving production fluids into the
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lower portion of the power tubing means from said well. An
insert or tubing-type lubricating plunger is provided, and the
plunger is preferably adapted to be inserted and removed from
the power tubing means while the power tubing means are
located in the well. A standing valve is provided to permit
entry of well fluids from the producing formation into the
lower portion of the power tubing means. A crossover flow
path is formed between the lower portion of the power tubing
means and the flow path of the production tubing means for
flowing production fluids out of the power tubing means and
into the flow path of the production tubing means as the only
flow path for transfer of production fluids to the earth's
surface. Rod means for operating the tubing-type pump are
operatively connected to the pump. Preferably, the means for
operating the pump includes a rod string extending down the
power tubing means and operably connected to the plunger of
the insert or tubing-type pump. The operative elements of the
insert or tubing-type pump are preferably located in the well
below the location of the flow control means. The pump barrel
of the tubing-type pump is a lowest section of the power
tubing string. A valve is provided for flowing lubricating
fluid from the power tubing string into a hollow pull tube
connecting the lower end of the rod string to a lubricating
plunger of the pump. The lubricating plunger has flow ports
for permitting flow of lubricating fluid from inside the
plunger to the annulus between the outside of the plunger and
the inside of the pump barrel. The plunger is used in the
tubing pump to receive fluids from the pull tube to lubricate
the pump, to improve its efficiency and to control sand from
entering the area of between the plunger and barrel.
In a more specific aspect the present invention
provides apparatus for pumping petroleum from a well
penetrating a petroleum producing formation which includes a
downhole assembly located in a well at a position adapted to
receive petroleum fluids from the well. The downhole assembly
includes a parallel anchor having a first passage and a second
passage formed parallel to the central axis of the parallel
anchor. Means are provided for mounting the parallel anchor
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in the well at the desired position and a tubular connecting
pup is connected to the first passage of the parallel anchor
and extends down the well. A flow control means such as a
standing valve, or a sliding valve, which permits flow up the
connecting pup tubing and prevents flow down the connecting
pup tubing is connected in the lower portion of the apparatus,
for example, in or near the connecting pup. A crossover flow
head is connected between the lower end of the connecting pup
tubing below the standing valve and an opening in the pump
barrel to provide a flow path for petroleum from the pump
barrel through the standing valve into the lower portion of
the connecting pup tubing. A production tubing string extends
from the earth's surface down the well and is inserted into
the first passage of the parallel anchor to form, in
combination with the crossover flow head, the connecting pup
tubing and a tubular string, a flow path to the earth's
surface for petroleum. A power tubing string is positioned in
the well parallel to the production tubing string and extends
through the second passage in the parallel anchor. Connecting
means connect the lower end of the power tubing string to the
upper end of the tubular landing nipple. A tubing-type seal
off is inserted into the power tubing and landed in the
tubular landing nipple. Meals are provided to form a flow
path for petroleum between the lower portion of the power
tubing string and the lower portion of the production tubing
string. Means are provided for disconnectably connecting the
plunger of the tubing-type pump in operating position in the
power tubing and the landing nipple for pumping fluid up the
power tubing string to the flow path of the production tubing
string. A lubricating plunger is provided for flowing
lubricating fluid into the annulus formed between the pump
barrel and a pump plunger.
In another aspect, the present invention provides an assembly which
includes parallel power tubing and production tubing strings.
A lubricating plunger is located inside and at the bottom of
the power tubing string. The power tubing string connects to
a bottom hole assembly with a crossover flow head which
connects with the production tubing string. This provides for
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flow of production fluids from the pump to the production
tubing string. A rod string, connected to a pumping unit at
the surface gives the lubricating plunger of the tubing-type
pump an up-and-down motion for pumping the well fluid to the
5 surface through this production tubing string. A "Beard"
valve is connected at the lower end of the rod string. The
"Beard" valve includes a port to permit fluid flow from the
power tubing annulus into the interior of the "Beard" valve.
A hollow pull tube is connected to the lower end of the
"Beard" valve and extends to and is connected to the
lubricating plunger to provide for flow of lubricating fluids
to the plunger. The plunger has ports for flowing the
lubricating fluid out into the annulus between the plunger and
the pump barrel. Thus, diluent or water with a surfactant may
be placed in the power tubing for use in lubrication of the
tubing pump to improve the efficiency thereof and to prevent
sanding up of the pump.
In another aspect, the present invention utilized a tubing insert
plunger. Thus, the plunger of the pump is connected to the
rod string and is inserted inside the power tubing string.
The lowermost section of the power tubing string forms the
barrel of the pump. Generally, only the rod string has to be
pulled to retrieve all moving and wearable pump parts except
for the pump barrel. Thus, the apparatus of the present
invention will save rig time when pump repairs or replacement
is needed. Also because the production flow path is separated
from the pumping rod string, the apparatus of the present
invention will never have a floating rod problem. It will
also eliminate inertia bars and require smaller less expensive
rods. In addition, lubricating fluid may be injected down the
power tubing string through the "Beard" valve and the hollow
pull tube rod and into a lubricating plunger of the pump. The
lubricating plunger is provided with ports to direct the fluid
coming from the hollow pull tube into the area between the
plunger and pump barrel. Increasing the pressure in the
annulus of the power tubing to exceed that of the production
tubing keep sand out of the area between. the plunger and pump
barrel and to increase pump efficiency.
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In one exemplary embodiment, the invention provides
an apparatus for producing well fluids from an oil bearing
formation penetrated by a well. The apparatus comprises a
production tubing string which forms a production flow path
for production fluids. The production tubing string is
configured so that it may be positioned between the earth's
surface and a location in the well suitable for receiving well
production fluids. A power tubing string is also provided and
includes an upper portion and a lower portion. The power
tubing string extends down the well in a generally parallel
relationship with the production tubing string to a location
in the well suitable for receiving production fluids into the
lower portion of the power tubing string. A pumping apparatus
is disposed in the power tubing string to pump well fluids
from the well into the lower portion of the power tubing
string. Further, a crossover flow mechanism is provided
between the lower portion of the power tubing string and the
flow path of the production tubing string to divert the flow
of production fluids out of the power tubing string and into
the flow path of the production tubing string where it may be
transferred to the earth's surface. A lubricant flow path is
also provided and extends from the earth's surface to a
location near the pumping mechanism to allow lubricants to be
introduced into the pumping mechanism. In this way,
lubricants may be provided to the pumping mechanism to
substantially hinder undue wear that may be caused by sand or
other coarse particulate found within the production fluids.
In one particular aspect, the production flow path
has a smaller cross-sectional area than the lower portion of
the power tubing string to increase the velocity of the
production fluids when diverted into the production flow path.
In this way, sand or other coarse particulate within the
production fluids will remain suspended and will not tend to
settle within the tubing strings to hinder operation of the
apparatus.
Two different arrangements of the lubricant flow
path may be provided to supply lubricant to the pumping
mechanism. In one alternative, the lubricant flow path may
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pass through substantially the entire length of the power
tubing string. More specifically, the lubricant flow path
may pass through the crossover flow mechanism. In this
way, the overall size of the power tubing string may be
reduced. In one particularly preferable implementation,
the lubricant flow path will pass through at least one
rod which extends through the power tubing string and
which is used to operate the pumping mechanism.
In the second alternative, the lubricant flow
l0 path may be arranged to bypass the crossover flow
mechanism. For instance, a side tubing string may be
provided to bypass the crossover flow mechanism. The side
tubing string will preferably have a bottom end which is
connected to a lower portion of the power tubing string
near the pumping mechanism so that the lubricant may be
provided to the pumping mechanism.
With both the passthrough and bypass
embodiments just described, a variety of pumping
mechanisms may be employed. For example, the pumping
mechanisms may comprise an insert pump, a progressive
cavity pump, a tubing pump, and the like.
In accordance with another aspect of the
present invention, there is provided an apparatus for
producing well fluids from an oil bearing formation
penetrated by a well, the apparatus comprising:
a production tubing string forming a production
flow path for production fluids, the production tubing
string being adapted to be positioned between the earth's
surface and a location in the well suitable for receiving
well production fluids;
a power tubing string having a lower portion
and an upper portion, the power tubing string being
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adapted to extend down the well in a generally parallel
relationship with the production tubing string to a
location in the well suitable for receiving production
fluids into the lower portion of the power tubing string
from the well;
a pumping apparatus disposed in the power
tubing string which is adapted to pump well fluids from
the well into the lower portion of the power tubing
string; and
l0 a cross-over flow mechanism between the lower
portion of the power tubing string and the flow path of
the production tubing string to divert the flow of
production fluids out of the power tubing string and into
the flow path of the production tubing string for
transfer to the earth's surface.
In accordance with another aspect of the
present invention, there is provided an apparatus for
producing well fluids from an oil bearing formation
penetrated by a well, the apparatus comprising:
a production tubing string forming a production
flow path for production fluids, the production tubing
string being adapted to be positioned between the earth's
surface and a location in the well suitable for receiving
well production fluids;
a power tubing string having a lower portion
and an upper portion, the power tubing string being
adapted to extend down the well in a generally parallel
relationship with the production tubing string to a
location in the well suitable for receiving production
fluids into the lower portion of the power tubing string
from the well;
a pumping apparatus disposed in the power
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tubing string which is adapted to pump well fluids from
the well into the lower portion of the power tubing
string;
a cross-over flow mechanism between the lower
portion of the power tubing string and the flow path of
the production tubing string to divert the flow of
production fluids out of the power tubing string and into
the flow path of the production tubing string for
transfer to the earth's surface; and
a lubricant flow path which is adapted to
extend from the earth's surface to a location near the
pumping mechanism to allow a lubricant to be introduced
to the pumping mechanism.
In accordance with another aspect of the
present invention, there is provided an apparatus for
producing well fluids from an oil bearing formation
penetrated by a well, the apparatus comprising:
a production tubing string forming a production
flow path for production fluids, the production tubing
string being adapted to be positioned between the earth's
surface and a location in the well suitable for receiving
well production fluids;
a power tubing string having a lower portion
and an upper portion, the power tubing string being
adapted to extend down the well in a generally parallel
relationship with the production tubing string to a
location in the well suitable for receiving production
fluids into the lower portion of the power tubing string
from the well;
a pumping apparatus disposed in the power
tubing string which is adapted to pump well fluids from
the well into the lower portion of the power tubing
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string;
a cross-over flow mechanism between the lower
portion of the power tubing string and the flow path of
the production tubing string to divert the flow of
production fluids out of the power tubing string and into
the flow path of the production tubing string for
transfer to the earth's surface; and
a lubricant flow path which is adapted to
extend from the earth's surface to a location near the
pumping mechanism to allow a lubricant to be introduced
to the pumping mechanism, wherein the lubricant flow path
passes through the cross-over flow mechanism.
In accordance with another aspect of the
present invention, there is provided an apparatus for
producing well fluids from an oil bearing formation
penetrated by a well comprising:
a production tubing string forming a production
flow path for production fluids between the earth's
surface and a location in the well suitable for receiving
well production fluids;
a power tubing string extending down said well
in parallel relationship with said production tubing
string to a location in said well suitable for receiving
production fluids into the lower portion of said power
tubing string from said well; said power tubing string
having a pump barrel therein;
a pump plunger in said pump barrel of said
power tubing string in a position for pumping well fluids
from the well into the lower portion of said power tubing
string; and
a cross-over flow means between the lower
portion of said power tubing string and the flow path of
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said production tubing string for flowing production
fluids out of said power tubing string and into said flow
path of said production tubing string for transfer to the
earth's surface.
In accordance with another aspect of the
present invention, there is provided an apparatus for
producing well fluids from an oil bearing formation
penetrated by a well comprising:
a production tubing string forming a production
flow path for production fluids between the earth's
surface and a location in the well suitable for receiving
well production fluids;
flow control means in said apparatus permitting
flow of production fluids up said production flow path
z5 and preventing flow of production fluids down said
production flow path;
a power tubing string extending down said well
in parallel relationship with said production tubing
string to a location in said well suitable for receiving
production fluids into the lower portion of said power
tubing string from said well; said power tubing string
including a pump barrel therein;
a lubricating plunger in said pump barrel of
said power tubing string in a position for pumping well
fluids from the well into the lower portion of said power
tubing string; and
a cross-over flow means between the lower
portion of said power tubing string and the flow path of
said production tubing string for flowing production
fluids out of said power tubing string and into said flow
path of said production tubing string for transfer to the
earth's surface.
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In accordance with another aspect of the
present invention, there is provided a pumping system
comprising:
a pump barrel that is adapted to be placed into
a well casing;
a plunger reciprocatably positioned within the
pump barrel, wherein the plunger has an open top end with
a sharpened edge, a bottom end, and a traveling valve at
the bottom end;
a connector coupled to the plunger below the
top end, wherein the connector is configured to permit
fluids to be moved upwardly through the connector and the
plunger upon each downstroke of the plunger; and
a rod coupled to the connector, wherein the rod
is translatable to reciprocate the plunger within the
pump barrel using an upstroke and a downstroke, and
wherein the top end of the plunger is adapted to direct
particulate into the plunger and away from the pump
barrel upon each upstroke.
In accordance with another aspect of the
present invention, there is provided a method for pumping
fluids from the ground, the method comprising:
placing a pumping system into the ground,
wherein the pumping system comprises a pump barrel, a
plunger reciprocatably positioned within the pump barrel,
wherein the plunger has an open top end with a sharpened
edge, a bottom end, and a traveling valve at the bottom
end, and a connector coupled to the plunger below the top
end; and
reciprocating the plunger within the pump
barrel with an upstroke and a downstroke, and directing
particulate into the plunger through the open top end and
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away from the pump barrel upon each upstroke with the
sharpened edge.
In accordance with another aspect of the
present invention, there is provided a pumping system
comprising;
a pump barrel that is adapted to be placed into
a well casing;
a plunger reciprocatably positioned within the
pump barrel, wherein the plunger has an open top end that
is configured to direct particulate away from the pump
barrel, a bottom end, and a traveling valve at the bottom
end;
a connector coupled to the plunger below the
top end; and
a rod coupled to the connector, wherein the rod is
translatable to reciprocate the plunger within the pump
barrel using an upstroke and a downstroke.
OBJECT OF AN ASPECT OF THE INVENTION
An object of an aspect of the present invention
is to provide a pumping system having parallel power
tubing and production tubing strings in which production
is flowed up the production tubing through a flow control
valve connected at the lower end of the pumping system. A
rod operated insertable and removable pump plunger is
disconnectably connected into the power tubing wherein
the pump plunger may be removed from and inserted into
the power tubing without the need to remove the tubing
string from the well. A hollow pull tube is connected to
the lower end of the rod string by a "Beard" valve and
used to operate the pump plunger and also to provide a
source of lubricating fluid for the lubricating plunger
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of the pump. The plunger has ports for flowing the fluid
into the area between the pump barrel formed by the lower
end of the power tubing and the outside of the plunger
with increased pressure in the pump annulus to inhibit
sand production and to increase pump efficiency. The
increased pressure is accomplished by appropriate surface
mechanism such as a pump. Additional objects and
advantages of aspects of the present invention will
become apparent to those skilled in the art from the
drawings which are made a part of this specification and
the detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagrammatic vertical sectional
view of a well equipped with a pumping system assembled
in accordance with the present invention;
Fig. 2 is an enlarged vertical sectional view
of the portion of the system of Fig. 1 indicated by 100
in Fig. 1;
Fig. 3 is an enlarged vertical sectional view
of the portion of the system of Fig. I indicated at 101
in Fig. 1; and
Fig. 4 is an enlarged vertical sectional view
of the portion of the system of Fig. 3 indicated by 102
in Fig. 3; and
Fig. 5 is a sectional view take at A-A of Fig.
4.
Fig. 6 is a diagrammatic vertical sectional
view of a pumping system having an insert pump and a
lubricant flow path passing directly through a power
tubing string according to the invention.
Fig. 6A is a cross-sectional view of a
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crossover flow head of the pumping system of Fig. 6.
Fig. 7 is a diagrammatic Vertical sectional
view of a pumping system having a tubing pump and a
lubricant flow path passing directly through a power
tubing string according to the invention.
Fig. 7A is a cross-sectional view of a
crossover flow head of the pumping system of Fig. 7.
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Fig. 8 is a diagrammatic vertical sectional view of
a pumping system having a progressive cavity pump and a
lubricant flow path passing directly through a power tubing
string according to the invention.
Fig. 8A is a cross-sectional view of a crossover
flow head of the pumping system of Fig. 8.
Fig. 9 is a diagrammatic vertical sectional view of
a pumping system having an insert pump and a lubricant flow
path which bypasses a crossover flow mechanism to supply a
lubricant to a pump according to the invention.
Fig. 9A is a cross-sectional view of a stinger head
of the pumping system of Fig. 9.
Fig. 9B is a cross-sectional view of a crossover
flow head of the pumping system of Fig. 9.
Fig. 9C is a cross-sectional view of a fluid mixing
head of the pumping system of Fig. 9.
Fig. 10 is diagrammatic vertical sectional view of a
pumping system having a tubing pump and a lubricant flow path
which bypasses a crossover flow mechanism according to the
invention.
Fig. 10A is a cross-sectional view of a stinger head
of the pumping system of Fig. 10._
Fig. lOB is a cross-sectional view of a crossover
flow head of the pumping system of Fig. 10.
Fig. lOC is a cross-sectional view of a fluid mixing
head of the pumping system of Fig. 10.
Fig. 11 is a diagrammatic vertical sectional view of
a pumping system having a progressive cavity pump and a
lubricant flow path which bypasses a crossover flow mechanism
according to the invention.
Fig. 11A is a cross-sectional view of a stinger head
of the pumping system of Fig. 11.
Fig. 11H is a cross-sectional view of a crossover
flow head of the pumping system of Fig. 11.
Fig. 11C is a cross-sectional view of a fluid mixing
head of the pumping system of Fig. 11.
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DETAILED DESCRIPTION OF THE INVENTION
Fig. 1 shows an overall sectional view of a pumping
assembly in accordance with the present invention. A
casing 10 is operably positioned in the well. Parallel power
5 tubing 12 and production tubing 13 strings are positioned in
the casing and connect with the bottom hole assembly which
houses a down hole tubing pump and insert plunger 24 having
lubricating ports 81-84 (see Figs. 4-5). The power tubing 12
and the production tubing 13 provide paths between the surface
10 and a position in a well where well fluids are produced. As
shown in Fig. 1, parallel anchor 15 has a first passage on the
left and a second passage on the right of the anchor. A stab
in tubing member 14 forming the bottom of the tubing string 13
extends through the first passage and is attached to the top
of a connecting pup tubing 16 that screws into the top of a
standing valve nipple 17. A crossover flow head 19 attaches
to the bottom of the standing valve nipple 17 on the left
side. The right side of the crossover flow head 19 is
attached to the bottom of a lock shoe landing nipple 18 and
the top of sealing nipple 20. The power tubing string 12
passes down through the second passage in parallel anchor 15
on the right side and screws into the top of the lock shoe
landing nipple 18. Beneath the cross-over flow head 19 is a
sealing nipple 20. A pump barrel 21, which is preferably the
lowermost section of the power tubing string, is provided
below the sealing nipple 20. When the production tubing
string 13 is installed, the power tubing string 12 and the
bottom hole assembly are already made up together and in place
down hole in the well at a suitable location for recovering
well fluids.
The production tubing string 13 has attached to the
bottom of it a stinger 14 with seals which then stabs into the
passage provided in the left side of the parallel anchor 15.
At the surface the production string 13 is connected to a
conventional flow line which carries well fluids off to a
production tank. A tubing-type insert plunger 24 having
lubricating ports 81-84 is adapted to be inserted and removed
from the power tubing. The lubricating plunger 24 has a
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hollow pull tube 25 that is connected to a rod string 22.
The hollow pull tube 25 is connected to the rod string 22 by
means of a "Beard" valve 26. The rod string 22 protrudes
upward through the inside of the power tubing string 12 to
the surface and is then hung off the bridle and horses head
of a conventional pumping unit. The pumping unit gives the
plunger 24 its up and down motion to pump the well fluids to
the surface. The down hole seal off 28 is also sealed
inside of the top lock shoe landing nipple 18 which holds
the body or outside of the seal off 28 in place and allows
only the plunder 24 to the reciprocate up and down in the
pump barrel 21 to pump the well fluids. The nipple 17
provides a flow control means in the production tubing flow
path. Flow control means, such as a traveling valve or a
sliding sleeve, are fully described in U.S. Patent No.
5,505,258. A standing valve 29 at the lower end of the pump
permits flow of well fluids into the lower portion of the
pump barrel.
Referring again to Fig. 1 which shows the bottom
hole assembly in more detail, the parallel anchor 15, with a
stab in tubing member 14 having a sealing port for stabbing
in, is attached to the top of the connecting pup 16 that
screws into the top of the standing valve nipple 17. The
cross-over flow head 19 attaches to the bottom of the
standing valve nipple 17 on the left side. The right side
of the cross-over flow head 19 is attached to the bottom
lock shoe landing nipple 18 and the top sealing nipple 20.
The power tubing string 12 then passes down through the
parallel anchor 15 on the right side and screws into the top
of the top lock shoe landing nipple 18. Beneath the cross-
over flow head 19 is a sealing nipple 20 which screws into
the top of the pump barrel 21. When the production tubing
string 13 is installed, the power tubing string 12 and th.e
bottom hole assembly are already made up together and in
place down hole. The production tubing string 13 has
attached to the bottom of it a stinger 14 with seals which
then stabs into the left side of the parallel anchor 15.
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Retrieving the bottom hole assembly from the well
should never be necessary unless a hole develops in the power
tubing string 12 from wear by the action of the rod string 22
or if there is sufficient wear of the pump barrel from the
plunger 24. If this should happen, while the insert plunger
is at the surface, simply pull the production tubing string
13, unsealing the stinger 14 with seals out of the parallel
anchor 15. After this apparatus is at the surface, the bottom
hole assembly may be pulled out with the power tubing string
12.
Fig. 2 is an enlarged sectional view of "Beard"
valve 26 shown in Fig. 1 in the circle indicated by the number
100. The valve 26 is connected to the rod string 22. The
"Beard" valve comprises a rod box 41 which is threadedly
connected to an upper mandrel section 42 at its lower end.
The mandrel section has a port 50 to permit flow of a
lubricating fluid into the interior of the valve. A mating
mandrel section 44 is threadedly connected to the upper
mandrel section 42. A hollow pull tube 25 having an interior
flow path 49 is connected to the lower mandrel 44 and to the
top of the lubricating plunger 24. A check valve ball 43 and
spring 47 which seats on seat 46 in mandrel section 44 and 42
permits flow of lubricating fluid downward through port 50
into pull tube 45 when pressure on the fluid in the power
tubing is increased above the pressure in the pump barrel.
The fluid flows to the lubricating plunger 24 inside of pump
barrel 21.
Referring now to Fig. 3 which illustrates the
lubricating plunger 24 and associated elements shown generally
in the circle numbered 101 in Fig. 1. Fig. 3 is an enlarged
vertical sectional view of the pump barrel 21 and the
lubricating plunger 24. Fig. 4 is a more greatly enlarged
vertical section of the mid-portion of the plunger 24 at the
circle 102 of Fig. 3, and Fig. 5 is a sectional view taken at
A-A of Fig. 4.
In Fig. 3 the lubricating plunger 24 is illustrated
in the downstroke portion of the pump cycle. Arrows,
indicated generally as 90, show the flow of well fluids
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through the traveling valve, ball, seat, and cage indicated
generally as 29 up the interior of the plunger 24. As shown
in Fig. 5, the well fluids pass through insert 92 in plunger
connector 91 by means of ports 93-96. At the end of the
downstroke and the beginning of the upstroke well fluids are
raised up the production tubing as the traveling valve 29
closes.
Lubricating fluid 89 flows down hollow pull tube 25
to insert 92 in the plunger connector 91. The lubricating
fluid then passes through ports 81, 82, 83 and 84 into the
area between pump barrel 21-plunger 24 annulus indicated by
the number 85 in Fig. 5. This lubricating fluid lubricates
the plunger and pump barrel in annulus 85 to help prevent
sanding of the pump. The lubricating fluid comes from the
power tubing through the "Beard" valve into the hollow pull
tube. The .lubricating fluid is injected by means of
increasing the pressure on the fluid in the power tubing to a
pressure higher than the pressure in the annulus 85 plus
pressure drop in the "Beard" valve and hollow pull tube.
Thus, the present invention provides apparatus for
producing well fluids from an oil bearing formation penetrated
by a well including production tubing means forming a
production flow path for production fluids between the earth's
surface and a location in the well suitable for receiving well
production fluids from a pump located in a parallel power
tubing means. Flow control means are located in the lower
portion of the apparatus to permit flow of production fluids
up the production flow path and to prevent flow of production
fluids down the production flow path. Power tubing means are
extended down the well in parallel relationship with the
production tubing means to a location in the well suitable for
receiving production fluids into the lower portion of the
power tubing means from said well. ' A tubing-type plunger is
provided and is adapted to be inserted and removed from the
power tubing means while the power tubing means are located in
the well. Means are provided for entry of well fluids from
the well into the lower portion of the power tubing means for
pumping therefrom. A crossover flow path is formed between
CA 02211673 1997-07-28
14
the lower portion of the power tubing means and the flow path
of the production tubing means for flowing production fluids
out of the power tubing means and into the flow path of the
production tubing means as the only flow path for transfer of
production fluids to the earth's surface. Rod means for
operating the tubing-type pump are operatively connected to
the pump. Preferably, the means for operating the pump
includes a rod string extending down the power tubing means
and operably connected to the plunger of the tubing-type pump.
The operative elements of the insert type pump are preferably
located in the well below the location of the flow control
means. A valve is provided for flowing lubricating fluid from
the power tubing string into a hollow pull tube connecting the
lower end of the rod string to a lubricating plunger of the
pump. The lubricating plunger has flow ports for permitting
flow of lubricating fluid from inside the plunger to the
annulus between the outside of the plunger and the inside of
the pump barrel. The plunger is used in the tubing pump to
receive fluids from the pull tube to lubricate the pump and to
improve its efficiency and to control sand from entering the
area of between the plunger and barrel.
Referring now to Figs. 6-8, three pumping system
embodiments will be described which each have a lubricant flow
path which passes directly through the power tubing string to
introduce a lubricant to a pumping mechanism. In this way,
the overall size of the pumping system may be reduced by
allowing the lubricant to flow through an existing tubing
string.
Referring first to Fig. 6, a pumping system 200
having an insert pump 202 will be described. Pumping system
200 comprises a casing 204 having a pair of vents 206, 208 and
a plurality of perforations 210 (or liner slots) which allow
production fluids to pass through casing 204. Casing 204
further includes a flange 212 is secured to a dual well head
flange 214 to hold a power tubing string 216 and a production
tubing string 218 within the well. Production tubing string
218 defines a flow path 220 as indicated by the arrows. Power
tubing string 216 includes an upper portion 222 and a lower,
CA 02211673 1997-07-28
portion 224. Lower portion 224 includes insert pump 202.
Connecting power tubing string 216 to production
tubing string 218 is a crossover flow head 226 (see also Fig.
6A). Conveniently, a tubing release 232 is provided to
5 connect production tubing string 218 to crossover flow head
226. As illustrated in Fig. 6A, the crossover flow head
includes a power tubing string portion 228 and a production
tubing string portion 230. Portion 230 has a smaller cross-
sectional area than portion 228 so that when production fluids
10 are diverted from portion 228 and into portion 230, the rate
of flow of the production fluid will increase. In this way,
sand or other coarse particulate within the production fluids
will remain generally suspended until exiting production
tubing string 218 above the earth's surface.
15 Extending through power tubing string 216 is a rod
234. Rod 2-34 is preferably constructed to be solid and passes
through a stuffing box 236 as is known in the art. Solid rod
234 is connected to a hollow rod 238 by a check valve 240. In
turn, hollow rod 238 is employed to operate insert pump 202.
Insert pump 202 comprises a plunger 242 which moves
in an up and down motion as dictated by hollow rod 238.
Operably attached to hollow rod 238 is a ring traveling valve
244 and a ring standing valve 246. Conveniently, friction
rings 248 are provided to form a seal between the pump barrel
below plunger 242 and power tubing string 216. A sealing unit
250 is further provided to prevent production fluids from
traveling up power tubing string 216 as described in greater
detail hereinafter.
Upon upstroke of hollow rod 238, plunger 242 is
lifted to create a vacuum within the pump barrel below plunger
242. In turn, ring standing valve 246 is lifted by this
vacuum tv allow production fluids to enter into lower portion
of pump barrel below plunger 242 as indicated by arrow 252.
Upon downstroke of the plunger 242, positive pressure is
created within lower portion of the pump barrel below plunger
242, causing ring standing valve 246 to close and causing ring
traveling valve 244 to unseat. In turn, the production fluids
within lower portion of the pump barrel below plunger 242 pass
CA 02211673 1997-07-28
16
through plunger 242 and into crossover flow head 226 as
illustrated by arrows 254. At this point, sealing unit 250
prevents the production fluids from passing further through
power tubing string 216. Hence, the production fluids cross
over from portion 228 and into portion 230, where they travel
through production tubing string 218 until they exit above the
earth's surface.
To provide a lubricant and/or a diluent to
appropriate locations, the lubricant or diluent may be input
into power tubing string 216 through a port 256. As indicated
by arrows 258, the lubricant will lubricate between the up and
down motion of rods 234 and the stationary power tuber string
216. The lubricant will then pass through a hole 260 in check
valve 240 if the lubricant is under sufficient pressure to
unseat spring valve 262. The lubricant then passes through
hollow rod 238 as shown. During its travel, the lubricant may
exit hollow rod 238 in the middle of plunger 242 as shown to
lubricate the surfaces between plunger 242 and pump barrel
201: Some of the lubricant will continue its path through
hollow rod 238 until exiting through a plurality of orifices
264. In this manner, the lubricant will also serve as a
wetting agent to water wet all metal surfaces in pump 202 to
in flowing production fluids into power tubing string 216 as
indicated by arrows 266. In the same manner (using diluent),
the diluent will reduce the viscosity of the production fluids
assisting in the flowing of production fluids into the power
tubing string 216 as indicated by arrows 266.
Hence, by constructing rod 238 to be hollow, a
lubricant and/or diluent may be passed directly through power
tubing string 216 into hollow rod 238 to~supply a
lubricant/diluent to plunger 242 and to supply a
lubricant/diluent to the production fluid to assist. in
removing the production fluid from the well. By passing rod
238 directly through power tubing string 216, the outer
diameter of pumping system 200 may be reduced, while still
providing an effective way to supply the lubricant/diluent to
the suction of the pump. As illustrated by arrow 268,
sufficient space is also provided between casing 204 and
CA 02211673 1997-07-28
17
strings 216 and 218 to allow free gas to escape from the well.
Another particular advantage of pumping system 200
is that insert pump 202 may be pulled from power tubing string
216 while power tubing string 216 remains in the well. In
this way, insert pump 202 may conveniently be repaired or
replaced without having to pull any tubing strings as
described with previous embodiments.
Shown in Figs. 7 and 7A is a pumping system 270
which is similar to pumping system 200 of Fig. 6 except that
pumping system 270 includes a tubing pump 272. Pumping system
270 comprises a casing 274 having vents 276 and 278. A
plurality of perforations 280 are provided in casing 274 to
allow production fluids to pass into casing 274. A casing
flange 282 is attached to a dual well head flange 284 to hold
the two tubing strings 286, 288 in place.
Disposed within casing 274 is a power tubing string
286 and a production tubing string 288. A crossover flow head
290 connects production tubing string 288 to power tubing
string 286. Conveniently, a tubing release 292 is provided to
allow production tubing string 288 to be attached to crossover
flow head 290. Crossover flow head 290 includes a power
tubing string portion 294 and a production tubing string
portion 296 which allow production fluids passing upwardly
through power tubing section 286 to be diverted into
production tubing string 288 in a manner similar to that
previously described with other embodiments.
Passing through power tubing section 286 is a solid
rod 298 which is moved up and down to operate tubing pump 272
as described in greater detail hereinafter. Conveniently, an
on/off tool 300 is provided to allow convenient removal of
solid rod 298. A tubing drain 302~is provided to allow fluids
to be drained from the system during disassembly as is known
in the art.
A hollow rod 304 is attached to solid rod 298 via a
check valve 306. Further down power tubing string 286, hollow
rod 304 is connected to a plunger 308 which is part of tubing
pump 272. Tubing pump 272 further comprises a tubing pump
barrel 310, a traveling valve 312 and a standing valve 314.
CA 02211673 1997-07-28
18
Further, a sealing unit 316 is provided to prevent the flow of
production fluids upwardly through power tubing string 286 so
that the flow may be diverted into production tubing string
288. During operation, hollow rod 304 is lifted to lift
plunger 308. This action causes a vacuum within tubing pump
barrel 310, causing standing valve 314 to lift and production
fluids to enter into tubing pump barrel 310 as indicated by
arrows 318. Upon downstroke of rod 304, standing valve 314 is
seated while traveling valve 312 is lifted to allow the
production fluids within tubing pump barrel 310 to pass
through plunger 308 and into crossover flow~head 290. As
illustrated by arrows 320, the production fluids are then
diverted into production tubing string 288 where they will
exit above the earth's surface. Free gases may travel around
production tubing string 286 as indicated by arrow 322.
A port 324 is provided to allow a lubricant or
diluent to be introduced into power tubing string 286 as
indicated by arrows 326. The introduced lubricant passes
through a hole 328 in check valve 306. When the introduced
lubricant is at a sufficient pressure, spring valve 330 will
release to allow the lubricant to pass through hollow rod 304
as shown. The lubricant will then exit hollow rod 304 in the
middle of plunger 308 as shown by the arrows. Additional
lubricant may pass through the entire length of hollow rod 304
where it will exit through apertures 332 as shown. In this
way, the lubricant or diluent may be supplied to the
production fluids to assist in their removal from the well.
Further, the lubricant introduced near plunger 308 will
provide the necessary lubricant in order to lubricate tubing
pump 272.
Referring now to Figs. 8 and 8A, another embodiment
of a pumping system 340 will be described. Pumping system 340
is similar to pumping system 270 of Fig. 7 except that pumping
system 340 employs a progressive cavity pump 342. For
convenience of discussion, the elements of pumping system 340
which are similar to those in pumping system 270 will be
referred to with identical reference numerals.
Progressive cavity pump 342 comprises a hollow rotor
CA 02211673 1997-07-28
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344 which is connected to hollow rod 304. Hollow rotor 344 in
turn is attached to a stator 346. In this way, when rotor 344
is rotated by rod 304, stator 346 will draw production fluids
from the well, into power tubing string 286 and into crossover
flow head 290. In crossover flow head 290, the production
fluid is diverted from portion 294 to portion 296 to allow
production fluids to be passed through production tubing
string 288 as previously described. Hollow rotor 344 is
connected to a passthrough stinger rod 348 having orifices
332. In this way, a lubricant or diluent may be introduced
into port 324 where it will pass through check valve 306 in a
manner similar to that previously described with system 270.
The lubricant or diluent will then pass through orifices 332
and will be drawn into the suction of the pump 342 in power
tubing string 286. The diluent will serve to dilute the
production fluids to assist in their removal from the well,
while the lubricant will lubricate the rotor and stator to
enhance operation of progressive cavity pump 342.
Figs. 9, 10 and 11 show respective alternative
embodiments of the pumping systems of Figs. 6, 7 and 8. The
embodiments in Figs. 9-11 differ in that the lubricant or
diluent passes from the power tubing string through a stinger
head, around the crossover flow head, and down to a fluid
mixing head at the suction of the pump. In this way, the need
for hollow rods is eliminated since the lubricant is passed
around the cross over flow head.
Referring now to Figs. 9-9C, another embodiment of a
pumping system 350 will be described. For convenience of
discussion, pumping system 350 will be described using similar
reference numerals to describe pumping system 200 of Fig. 6
with the addition of a ""'. Pumping system 350 differs from '
pumping system 200 in that pumping system 350 includes a side
tubing string 352 which allows a lubricant 258' to bypass
portion 228' of crossover head 226'. A stinger head 354 (see
Fig. 9A) allows for the diversion of the lubricant from power
tubing string 216' and into side tubing string 352 as shown.
Sealing unit 250' prevents the flow of lubricant further down
power tubing string 216'.
CA 02211673 1997-07-28
As best illustrated in Fig. 9A, a crossover fluid
path 356 is provided to allow the lubricant to pass from power
tubing string 216' and into side tubing string 352. A check
valve 358 is provided in side tubing string 352 to regulate
5 the flow of lubricant through side tubing string 352. In
particular, check valve 358 includes a spring which allows the
valve to open when a sufficient pressure is applied by the
lubricant. After passing through check valve 358, the
lubricant passes through an adjustable union 360 and through a
10 lumen 362 in crossover flow head 226' (see Fig. 9B). The
lubricant continues through side tubing string 352 and into a
fluid mixing head 364 (see Fig. 9C). In fluid mixing head
364, the lubricant is channeled into power tubing string 216'
in the vicinity of insert pump 202' suction. In this way,
15 when insert pump 202' is operated, sufficient lubricant will
be provided. In operation, plunger 242', traveling valve 244'
and standing valve 246' operate similar to related elements in
insert pump 202 of Fig. 6 to pump production fluids from the
well as indicated by arrows 366.
20 Referring now to Figs. 10-lOC, a further embodiment
of a pumping system 370 will be described. For convenience of
discussion, pumping system 370 will be described using similar
reference numerals to those used previously in describing
pumping system 270 of Fig. 7 followed by a ""'. Pumping
system 370 differs from pumping system 270 of Fig. 7 in that
pumping system 370 includes a side tubing string 372 to bypass
a lubricant around cross over flow head 290'. A stinger head
374 (see Fig. 10A) is provided to divert the flow of the
lubricant as indicated by arrows 326' into side tubing string
372. A check valve 376 is provided within side tubing string
372 to regulate the flow of lubricant through side tubing
string 372 similar to valve 358 of Fig. 9. As best shown in
Fig. 10B, crossover flow head 290' includes a lumen 378
through which side tubing string 372 passes. An adjustable
union 380 is also provided in side tubing string 372. A fluid
mixing head 382 is provided to divert the flow of lubricant
from side tubing string 372 and back into power tubing string
286' as shown. In this way, a lubricant will be provided to
CA 02211673 1997-07-28
21
lubricate tubing pump 270'. Tubing pump 270' includes a
plunger 308', a traveling valve 312' and a standing valve 314'
which operate to pump production fluids from the well and up
through power tubing string 286' similar to the embodiment in
Fig. 7. Further, crossover flow head 290' diverts the flow of
the production fluid from portion 294' to portion 296' where
it will pass through production tubing string 288' similar to
the embodiment of Fig. 7.
Referring now to Figs. 11-11C, still yet another
embodiment of a pumping system 390 will be described. Pumping
system 390 is similar to pumping system 340 of Fig. 8 except
that the lubricant is bypassed around a portion of the power
tubing string. For convenience of discussion, similar
elements will employ the use of similar reference numerals
followed by a "'". -
Pumping system 390 differs from pumping system 340
in that the lubricant bypasses a portion of power tubing
string 286' through a side tubing string 392. In particular,
a stinger head 394 (see Fig. 11A) in combination with sealing
unit 316' diverts the flow of lubricant from power tubing
string 286' and into side tubing string 392 as illustrated by
arrows 326'. A lubricant then passes through a check valve
396 similar to check valve 376 of Fig. 10 which regulates the
flow of lubricant through side tubing string 392. A lumen 398
is provided within crossover flow head 290' to allow side
tubing string 392 to pass through crossover flow head 290'.
An adjustable union 400 is also provided in side tubing string
392. Finally, a fluid mixing head 402 (see Fig. 11C) is
provided to divert the flow of lubricant from side tubing
string 392 back into power tubing string 286' in the vicinity
of progressive cavity pump 342' suction. In this way,
progressive cavity pump 342' will receive sufficient
lubrication for operation.
Upon rotation of rod 298', rotor 344' is rotated
inside stator 346'. In turn, this causes production fluids
within the well to be drawn up into the lower portion of power
tubing string 286'. The production fluids will then be
diverted into production tubing string 288' in a manner
CA 02211673 1997-07-28
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similar to that previously described.
The principles, preferred embodiments and modes of
operation of the present invention have been described in the
foregoing specification. However, the invention which is
intended to be protected is not to be construed as limited to
the particular embodiments disclosed. The embodiments are to
be construed as illustrative rather than restrictive.
Variations and changes may be made by others without departing
from the spirit of the present invention. Accordingly, all
such variations and changes which fall within the spirit and
scope of the present invention is defined in the following
claims are expressly intended to be embraced thereby.
