U.S. patent application number 13/990025 was filed with the patent office on 2013-09-26 for liquid lift pumps for gas wells.
This patent application is currently assigned to HANSEN ENERGY SOLUTIONS LLC. The applicant listed for this patent is Henning Hansen. Invention is credited to Henning Hansen.
Application Number | 20130251547 13/990025 |
Document ID | / |
Family ID | 46383796 |
Filed Date | 2013-09-26 |
United States Patent
Application |
20130251547 |
Kind Code |
A1 |
Hansen; Henning |
September 26, 2013 |
Liquid Lift Pumps for Gas Wells
Abstract
A wellbore liquid lift pump includes a pump chamber disposed in
a wellbore at a selected longitudinal position and within a liquid
column therein. The pump chamber has one way valves proximate each
longitudinal end thereof. One of the one way valves is in fluid
communication with the liquid column. The other one way valve is in
fluid communication with a conduit extending from the pump chamber
to the surface. The pump includes means for displacing a volume of
the pump chamber by application of pressure thereto. The pressure
provided by at least one of a gas and a liquid having a density
lower than liquid within the liquid column.
Inventors: |
Hansen; Henning; (Alicante,
ES) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hansen; Henning |
Alicante |
|
ES |
|
|
Assignee: |
HANSEN ENERGY SOLUTIONS LLC
The Woodlands
TX
|
Family ID: |
46383796 |
Appl. No.: |
13/990025 |
Filed: |
November 17, 2011 |
PCT Filed: |
November 17, 2011 |
PCT NO: |
PCT/US2011/061110 |
371 Date: |
May 28, 2013 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61427592 |
Dec 28, 2010 |
|
|
|
61428700 |
Dec 30, 2010 |
|
|
|
Current U.S.
Class: |
417/53 ;
417/300 |
Current CPC
Class: |
F04B 43/10 20130101;
F04F 1/04 20130101; F04B 7/02 20130101; F04B 47/02 20130101; E21B
43/129 20130101 |
Class at
Publication: |
417/53 ;
417/300 |
International
Class: |
F04B 7/02 20060101
F04B007/02 |
Claims
1. A wellbore liquid lift pump, comprising: a pump chamber disposed
in a wellbore at a selected longitudinal position and within a
liquid column therein, the pump chamber having one way valves
proximate each longitudinal end thereof, one of the one way valves
in fluid communication with the liquid column, the other one way
valve in fluid communication with a conduit extending from the pump
chamber to the surface; and means for displacing a volume of the
pump chamber by application of pressure thereto, the pressure
provided by at least one of a gas and a liquid having a density
lower than liquid within the liquid column.
2. The wellbore liquid lift pump of claim 1 wherein the means for
displacing comprises an inflatable bladder.
3. The wellbore liquid lift pump of claim 2 wherein the pressure is
applied through a tube in fluid communication with an interior of
the bladder, the tube extending to the surface.
4. The wellbore liquid lift pump of claim 1 wherein the means for
displacing comprises a steam generator.
5. The wellbore liquid lift pump of claim 4 wherein the steam
generator comprises a least one electrically operated heating
element.
6. A method for lifting liquid out of a wellbore drilled through
subsurface formations, comprising: applying pressure to displace a
volume of a chamber disposed in a liquid column in the wellbore,
the displacing constrained to movement of liquid in the chamber in
a direction toward the surface, the applying pressure comprising at
least one of applying gas pressure and applying liquid pressure,
wherein the liquid has a density less than water in the water
column; and releasing the pressure to enable water in the water
column to enter the chamber.
7. The method of claim 6 wherein the applying pressure comprises
pumping from the surface.
8. The method of claim 7 wherein the pressure is communicated to an
interior of an inflatable bladder disposed in the chamber.
9. The method of claim 6 wherein the applying pressure comprises
heating water in the chamber to cause boiling thereof.
10. The method of claim 8 wherein the releasing pressure comprises
cooling the chamber.
Description
BACKGROUND
[0001] The invention relates generally to the field of downhole
pump for use in hydrocarbon producing wells. More specifically, the
invention relates to a downhole pump based on displacing water in a
chamber where water is trapped using gas pressure, so that the
trapped water is pushed toward the surface, for example from gas
producing wells unable to transport the water to surface by energy
in a hydrocarbon producing, e.g., gas, well.
[0002] Downhole pumps (i.e., pumps disposed in a wellbore drilled
through subsurface formations) used for hydrocarbon production are
typically powered either by an electrical cable extending from the
surface into the wellbore, or by "sucker" rods connected to a
surface drive mechanism. The foregoing types of pumps are typically
complicated, have relatively large surface dimensions and can be
expensive to install, maintain and retrieve.
[0003] There exists a need for pumps having smaller surface
dimensions, that are less costly to install and maintain and that
can also be used to pump oil and water from a wellbore, where the
pump can interface directly with preinstalled tubulars (e.g.,
casing and production tubing in the wellbore.
SUMMARY
[0004] One aspect of the invention is a wellbore liquid lift pump
including a pump chamber disposed in a wellbore at a selected
longitudinal position and within a liquid column therein. The pump
chamber has one way valves proximate each longitudinal end thereof.
One of the one way valves is in fluid communication with the liquid
column. The other one way valve is in fluid communication with a
conduit extending from the pump chamber to the surface. The pump
includes means for displacing a volume of the pump chamber by
application of pressure thereto. The pressure provided by at least
one of a gas and a liquid having a density lower than liquid within
the liquid column.
[0005] A method for lifting liquid out of a wellbore drilled
through subsurface formations according to another aspect of the
invention includes applying pressure to displace a volume of a
chamber disposed in a liquid column in the wellbore. The displacing
is constrained to movement of liquid in the chamber in a direction
toward the surface. The applying pressure includes at least one of
applying gas pressure and applying liquid pressure, wherein the
liquid has a density less than water in the water column. The
pressure is released to enable water in the water column to enter
the chamber.
[0006] Other aspects and advantages of the invention will be
apparent from the description and claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 illustrates a gas well where water trapped therein
prevents the gas from a gas producing zone flowing freely into the
wellbore and then to the surface. The water needs to be removed to
obtain maximum gas production.
[0008] FIG. 2 illustrates a wellbore where a downhole pump system
is placed into the water column. The pump system has a tube
attached between the pump and the surface disposed in a production
tubing in the wellbore.
[0009] FIG. 3 illustrates the construction of the downhole pump,
where a bladder, inflated by gas or fluids, are placed within a
tube area that can be sealed off.
[0010] FIG. 4A illustrates the pump system in "relaxed" mode, where
water will be located outside the outer tube that the pump is
installed within as well as in the area between the pump and the
outer tube.
[0011] FIG. 4B illustrates that gas, alternative lightweight fluid,
(illustrated by red arrows) is pumped in through the center
injection line from surface. This gas or fluid inflates the bladder
from its lower side, pushing water (illustrated by blue arrows)
through the check valves located above the bladder and into the
area between the injection line and the tube that the pump is
installed within. The check valves below the bladder will close due
to increase in pressure of water located between the two check
valve systems.
[0012] FIG. 4C, 4D and 4E illustrates continued inflation of the
bladder, pushing more of the trapped water towards surface.
[0013] FIG. 4F illustrates that gas or lightweight fluid injection
has stopped from surface via the injection line, where a dump valve
function located in the outer tube attached nipple or within the
pump unit releases the pressurized gas or fluid within the bladder
to the area outside the outer tube. Releasing this pressure will
cause bladder to collapse due to higher external than internal
pressure in the bladder. Upper check valves will close, where these
check valves can be spring loaded, while lower check valves will
open so that water can enter into the area above the lower check
valve system.
[0014] FIG. 4G illustrates that bladder is collapsed and that water
has entered the area between the upper and lower check valve
system.
[0015] FIG. 5 illustrates a wellbore where a downhole pump system
having a steam generator is placed into the water column. The pump
system has a tube attached between the pump and the surface.
[0016] FIG. 6 shows a cross section of a semi-stiff, spoolable rod
used to deploy the pump system shown in FIG. 5.
[0017] FIGS. 7A, 7B and 7C illustrate the function of the steam
generator.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates a wellbore drilled through a gas
producing formation 16 in the subsurface. The wellbore may include
a pipe or casing 10 therein, and which may be cemented in place in
the wellbore. Typically, the casing 10 will include perforations 20
or other fluid permeable devices, such as a screen (not shown)
within the axial or longitudinal span of the gas producing
formation 16. Frequently, water 18 may become trapped in the casing
10. The water 18 may enter the casing 10 from the gas producing
formation 16 or other formation that is hydraulically connected to
the interior of the casing 10. Typically, a wellbore will include a
production tubing 14 disposed inside the casing 10 and sealed
against the interior of the casing 10 using a packer 12 or similar
annular seal. The tubing 14 has a smaller diameter than the casing
10 and is used to increase the velocity of the produced gas and
water to help entrain the water and lift it to the surface along
with the produced gas. The water 18 may become trapped in the
casing 10 in certain wellbores because gas entering the casing 10
may not have enough velocity to entrain and lift the water. Trapped
water 18 may exert hydrostatic pressure against the gas producing
formation 16 and thereby reduce or stop the gas from the gas
producing formation 16 flowing freely into the wellbore and then to
the surface. The trapped water 18 needs to be removed to obtain
maximum gas production.
[0019] FIG. 2 shows a wellbore having a downhole pump system 26
according to various aspects of the invention disposed in the water
18 in the casing 10. The pump system 26 may be inserted into the
casing 10 through the tubing 14 by extending a tube 24 into the
interior of the tubing 14. The pump system 26 may be coupled to one
longitudinal end of the tube 24. The pump system 26 may be operated
to displace the water 18 up the tube 24 to the surface, thereby
relieving some of the hydrostatic pressure of the water 18 and
enabling gas from the gas producing formation 16 to move to the
surface.
[0020] FIG. 3 illustrates one example of the downhole pump system
26. In the present example, the pump system 26 may include a pump
chamber 37 that may be sealed to the interior of the tubing 14
proximate its longitudinal ends by annular seals 32, 32A. Each
annular seal 32, 32A may include a check valve 30, 30A or other
type of one way valve, respectively, to enable fluid to enter the
chamber 37 from below and move the fluid out of the pump chamber 37
into the tubing 14 above.
[0021] The pump system 26 may be inserted into the wellbore by
using a spoolable tube such as coiled tubing, segmented (jointed)
tube or other type of conduit used as the tube 24. The tube 24 may
be connected at its longitudinal end to the pump system 26 by a
pressure tight connector 28. The pump system 26 may include a
gas-operated chamber volume displacement element 36. In the present
example, the gas operated chamber volume displacement element 36
may be an elastomer or other type of flexible bladder. Gas pressure
applied from the surface into the interior of the tube 24 may be
used to inflate the bladder and displace the volume inside the pump
chamber 37. As the volume in the pump chamber 37 is displaced,
water in the pump chamber 37 may be moved through the one way valve
30 disposed in the upper annular seal 32. Water and other fluid in
the pump chamber 37 may be prevented from moving downwardly out of
the pump chamber 37 by the lower one way valve 32 in the lower
annular seal 32A.
[0022] The pump system 26 may be installed inside the tubing 14
proximate a longitudinal end thereof, or at any other selected
longitudinal position along the tubing 14 by using a nipple 42
threadedly connected within the tubing 14 using, for example, an
internally threaded connector 38. The nipple 42 may include an
internal feature having smaller diameter than the internal diameter
of the tubing, e.g., a landing shoulder 42A as shown in FIG. 3.
[0023] If required, for example in highly inclined wells, the pump
system 26 can be pumped into the tubing 14 until the pump system 26
lands on the landing shoulder 42A of the nipple 42. Fluid pressure
applied to the surface end of the tubing 14 will act on the pump
chamber 37 by reason of the annular seals 30A, 32A. The one way
valves 30, 32 will seal against such pumping pressure, enabling the
pump system 26 to be moved along the interior of the tubing 14 by
the force exerted on the annular seals 30A, 32A and the pump
chamber 37.
[0024] FIG. 4A illustrates the pump system 26 in "relaxed" mode,
where water will be located within the tubing 14 as well as in the
pump chamber 37.
[0025] FIG. 4B illustrates gas, or alternatively a low density
fluid, e.g., kerosene or other liquid having a specific gravity
less than that of the water 18, being pumped in through the tube 24
from the surface. The gas or low density fluid may inflate the
bladder (chamber volume displacement element 36), thereby pushing
the water (illustrated by the arrows) through the upper one way
valve 30 located above the chamber volume displacement element 36
and into the annular space 29 between the tube 24 and the tubing
14. The one way valve 32 below the pump chamber 37 will close due
to the increase in pressure of the water in the pump chamber 37 as
the chamber volume displacement element 36 is actuated to displace
the volume of the pump chamber 37.
[0026] FIG. 4C shows the chamber displacement element 36 continuing
to expand, so as to move more of the water disposed in the pump
chamber 37 into the annular space 29 between the tube 24 and the
tubing 14. FIGS. 4D and 4E illustrate continued expansion of the
chamber volume displacement element 36, pushing more of the water
out of the chamber 37 and into the annular space 29 toward the
surface.
[0027] FIG. 4F illustrates that gas or low density fluid injection
has stopped, whereupon a dump valve 44 located in the nipple 42 or
within the pump system 26 may release the pressurized gas or fluid
within the volume displacement element 36 (e.g., the bladder) to
the annular space between the tubing 14 and the wellbore casing 10.
Releasing the pressure in the tube 24 will cause the bladder to
collapse due to higher pressure exerted on the bladder. The upper
check valve 30 may close, wherein the upper check valve 30 can be
spring loaded. The lower check valve 32 will open because the
pressure of the water is higher than the pressure in the pump
chamber 37, so that water can enter the pump chamber 37. The
bladder shown in and explained with reference to FIGS. 4A through
4G is only one example of a pressure operated chamber volume
displacement element. Those skilled in the art will readily
recognize that other devices may be used to displace the volume of
the pump chamber 37, for example a piston or bellows operated by
gas or liquid pressure applied to the tube 24. Accordingly, the
invention is not limited in scope to the use of an inflatable
bladder to displace the volume of the pump chamber.
[0028] FIG. 4G illustrates the bladder (pump chamber volume
displacement element 36) collapsed, and that water has entered and
filled the pump chamber 37. The foregoing process explained with
reference to FIGS. 4A through 4G may be repeated to continue to
lift water out of the wellbore.
[0029] FIG. 5 illustrates another example of a downhole pump
system. In the present example, the pump system may be inserted
into the wellbore through the interior of the tubing 14 using a
combination semi-stiff, spoolable rod 50. The semi-stiff spoolable
rod ("spoolable rod") 50 may be made as described, for example in
U.S. Pat. No. 5,184,642 issued to Delacour and incorporated herein
by reference. A cross-section of the spoolable rod 50 is shown in
FIG. 6 and may include embedded within the rod 50 an electrical
cable including insulated electrical conductors 52 and a tube 54,
for example, a stainless steel or other high strength, pressure
resistant tube.
[0030] In the present example, the pump system 26 may be disposed
at the end of the spoolable rod 50, and may be disposed within the
wellbore at a selected position along the interior of the tubing
(14 in FIG. 5) or within the casing (10 in FIG. 5) below the
annular seal (12 in FIG. 2). The present example does not require
that the pump system 26 be seated in a nipple in the tubing 14. The
present example pump system 26 may be merely suspended in the
wellbore at the end of the spoolable rod 50.
[0031] In the present example, and with reference to FIG. 7A, the
chamber volume displacement element may be a steam generator
comprising a housing 58 defining a chamber 66 therein. A one way
valve may be disposed proximate the bottom of the chamber 66, shown
at 68, and another one way valve may be disposed proximate the top
of the chamber 66, as shown at 60. The upper portion of the chamber
66 may be in fluid pressure communication with the tube 54 portion
of the spoolable rod (50 in FIG. 5) through the upper one way valve
60. One or more heating elements 62, e.g., electrical resistance or
electrical induction heating elements may be disposed in or around
the chamber 66 and may be electrically connected to the electrical
conductors 52 in the spoolable rod (50 in FIG. 5). The heating
elements 62 may include a reflector 64 on their exterior to reflect
heat back into the chamber 66.
[0032] Referring to FIG. 7B, when electrical power is applied to
the heating elements 64, water in the chamber 66 may heat to the
boiling point, converting the water into steam. The steam may be at
a higher pressure than the water it was generated from, and thus
cause the upper one way valve 60 to open. The steam may thus travel
upwardly inside the tube 54 in the spoolable rod 50.
[0033] When the steam pressure is relieved by movement thereof
through the upper one way valve 60, the electric current to the
heating elements 64 may be switched off. The gas and steam
remaining in the chamber 66 may then be allowed to cool, thus
reducing the pressure. As the pressure in the chamber 66 falls
below the hydrostatic pressure of the water in the wellbore, and
with reference to FIG. 7C, the water may enter the chamber 66
through the lower one way valve 68, thus at least partially filling
the chamber 66. The foregoing process as explained with reference
to FIGS. 7A, 7B and 7C may be repeated to continue to remove water
from the wellbore.
[0034] FIG. 7A illustrates the function of the downhole pump, or
steam generator, where the pump system contains the following main
components: a fluid intake in the lower end where water will enter
the pump chamber 66; a spring loaded check valve 68 allowing fluid
flow from the intake into the fluid chamber 66; and a sealing
surface in the lower side of the check valve. The fluid chamber,
i.e., steam chamber 66, is surrounded by a housing that contains
heating elements such as for example cables, coils, or similar. A
thermal reflection chamber, being for example a thermos
construction, a heat reflecting material or similar, can be placed
outside the heating elements, but are not crucial for the function
of the system. In the upper section of the fluid chamber, a second
check valve is mounted, preventing fluids to enter the chamber from
the upper side but allowing fluids or steam to escape from the
fluid chamber. The upper section of the chamber is connected to a
tube wherein the fluids, or steam, exerted from the pump system are
pushed to the surface. An electrical cable suspended into the
wellbore from the surface will be coupled to the upper section of
the pump, where after the electrical conductors are coupled to the
heating elements. Those skilled in the art will understand that the
check valves here described can be ball types, piston types, or
other constructions providing same function.
[0035] FIG. 7B illustrates that fluids trapped in the pump chamber
will be heated up by the heating elements, which results in an
increase in pressure ("Pi") within this chamber. When this pressure
eventually exceeds the pressure in the tube ("Pd") connected to the
pump from the surface, the upper check valve will open causing some
of the heated fluids to escape into the tube. When pressure across
this valve is equalized, the valve will close.
[0036] FIG. 7C illustrates that by switching off the heating
elements, the fluids within the fluid chamber will cool down due to
the lower temperature fluids externally ("Pe" on FIG. 3B)
surrounding the pump, resulting in a lower pressure internally in
the fluid chamber than the fluids at the fluid intake in the lower
end of the pump system. This creates a suction effect within the
pump, where cold fluids will enter the fluid chamber via the check
valve mounted in the lower section of the pump system. Repeating
the heating and cooling of the pump by switching on and off the
heating elements, which can be controlled from the surface or built
in as an automatic function in the pump system, will continuously
evacuate water from a wellbore through the attached tube to
surface.
[0037] The pump system can also be equipped with cooling elements
that are electrically powered using the same electrical conductors
52 in the spoolable rod 50 from surface that are used to operate
the one or more heating elements 62.
[0038] Liquid pumps according to the various aspects of the
invention may provide means to lift water and liquids out of a gas
producing wellbore to reduce the hydrostatic pressure on gas
producing formations without the need to retrofit existing wellbore
completion components or without the need for expensive, difficult
to install sucker rod pump systems.
[0039] While the invention has been described with respect to a
limited number of embodiments, those skilled in the art, having
benefit of this disclosure, will appreciate that other embodiments
can be devised which do not depart from the scope of the invention
as disclosed herein. Accordingly, the scope of the invention should
be limited only by the attached claims.
* * * * *