U.S. patent number 3,709,292 [Application Number 05/132,361] was granted by the patent office on 1973-01-09 for power fluid conditioning unit.
This patent grant is currently assigned to Armco Steel Corporation. Invention is credited to Harold H. Palmour.
United States Patent |
3,709,292 |
Palmour |
January 9, 1973 |
POWER FLUID CONDITIONING UNIT
Abstract
A one well, self contained, wide producing range, hydraulic
pumping system comprising a power fluid conditioning unit to
condition produced water, oil, or a mixture of oil and water, from
the produced well fluids and exhausted power fluid so that it will
be suitable for use as power fluid to economically pump a well
which produces medium to large volumes from average to greater
depths of lift.
Inventors: |
Palmour; Harold H. (Humble,
TX) |
Assignee: |
Armco Steel Corporation
(Middletown, OH)
|
Family
ID: |
22453663 |
Appl.
No.: |
05/132,361 |
Filed: |
April 8, 1971 |
Current U.S.
Class: |
166/68;
166/105.5; 417/80 |
Current CPC
Class: |
E21B
43/129 (20130101); E21B 43/00 (20130101) |
Current International
Class: |
E21B
43/12 (20060101); E21B 43/00 (20060101); E21b
043/00 () |
Field of
Search: |
;166/68,105.4,105.5,105.6 ;417/77,79-83 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Leppink; James A.
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. In a downwell engine and pump unit which utilizes power fluid
for pumping well fluid, such as oil, gas and water, from a well to
a flow line, a one well, self contained, hydraulic pumping system
comprising a power fluid conditioning unit to condition produced
fluid from the produced well fluid and well exhausted power fluid
so that it will be suitable for use as power fluid, which
comprises:
a. a pressurized separator-accumulator tank which communicates with
said well for receiving the exhausted power fluid and produced well
fluid, the gravity separation of water from oil and gas taking
place in said tank, said tank having at least two main outlets
therein, a first outlet communicating with said flow line, the
volume of oil, gas and water produced by said well being
substantially discharged therethrough, and a second outlet in the
lower section of said tank for release of gravity separated water,
oil, or mixture of oil and water;
b. a back pressure valve disposed between said flow line and said
tank for controlling the pressure in said tank;
c. at least one cyclone, centrifugal separator for conditioning
fluid from said separator-accumulator tank by removing suspended
solids therefrom, said cyclone separator having an inlet which
communicates with said second outlet of said tank for receiving
fluid from the lower section of said tank at an optimum pressure so
as to give a desired pressure drop across said cyclone separator
for the requirements of a particular well, a first outlet connected
with said flow line for passage of suspended solids separated by
said cyclone separator with some fluid into said flow line, and a
second outlet for the discharge of conditioned fluid;
d. power driven pump means, the inlet thereof communicating with
said second outlet of said cyclone separator and the outlet thereof
communicating with said downwell pump in said well and providing
condition, high pressure fluid to be used as power fluid; and
e. means to control the speed of said downwell pump by adjusting
power fluid flow thereto from said power driven pump means so as to
maintain the desired strokes permitted on said downwell pump.
2. The downwell engine and pump according to claim 1, wherein said
means to control the speed of said downwell pump comprise by-pass
means communicating between said inlet of said cyclone separator
and the outlet of said power driven pump means, and valve means
associated with said by-pass means which controls the speed of said
downwell pump by passing back to said cyclone separator a quantity
of clean fluid, the amount of said fluid being by-passed
controlling the amount of fluid sent to said well.
3. The downwell engine and pump according to claim 1, wherein said
cyclone, centrifugal separator comprises an inverted conical
section, said first outlet being located at the apex thereof, said
inlet being positioned in the side wall in the upper region of said
cyclone separator and being adapted to direct the inlet flow of
fluid to be conditioned substantially tangentially to the inner
surface of said side wall, and said second outlet being located in
the upper end of said cyclone separator, whereby pressurized fluid
to be conditioned enters said inlet and rotation thereof develops
high centrifugal forces in said cyclone separator, drawing
suspended solids outward toward the side wall and downward in an
accelerating spiral along the side wall to said apex and moving
conditioned fluid inward and upward to said second outlet as a
spiraling vortex, and the underflow of suspended solids separated
by said cyclone separator are discharged with some fluid through
said first outlet into said flow line.
4. The downwell engine and pump according to claim 1, wherein means
are provided for discharging chemicals into the suction of said
pump means so that the clean fluid passing therethrough acquires
lubricating, non-corrosive and other desired qualities.
5. The downwell engine and pump according to claim 4, wherein said
chemical discharge means comprises a chemical pump.
6. The downwell engine and pump according to claim 1, wherein said
power fluid conditioning unit is mounted upon a skid.
7. The downwell engine and pump according to claim 1, wherein a
check valve is positioned between the apex of said cyclone
separator and said flow line to preclude a back flow of solids from
said flow line to said cyclone separator when said power fluid
conditioning unit is shut down.
8. The downwell engine and pump according to claim 7, wherein said
pump means comprises an electric motor driven pump.
9. The downwell engine and pump according to claim 8, wherein a
hydramotor valve, which is open when the electricity is on and
which closes automatically when the electricity is off, is
positioned between said check valve and the apex of said cyclone
separator so as to prevent said cyclone separator from losing fluid
if an electrical failure occurs and stops said pump means and said
well continues to produce gas.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hydraulic pumping systems, and more
particularly, to a hydraulic pumping system which is economically
applicable for the average to greater depth wells which are
producing only moderate to large volumes of well fluids.
2. Description of the Prior Art
It is becoming increasingly rare when the plans for the producing
phase of oil fields do not include a water flood. Often water
injection is begun immediately as a means of maintaining bottom
hole pressures and thereby extending the flowing life of the field.
In any case, as a well of this type goes on the pump, it can be
assumed that large quantities of water will have to be produced
with the oil and that the total volumes to be pumped will gradually
increase as the percentage of water increases.
Hydraulic downwell pumps disposed at the lower ends of wells are
especially suited to these installations, as their capacity may be
controlled by varying their speed, and this being affected by
simply adjusting power fluid flow. An additional advantage of
hydraulic pumps is being able to retrieve a free type hydraulic
pump by circulating it out of the well. Such retrieval becomes even
more important when inspection or repair is necessary due to the
adverse environment which is often encountered.
The oil industry today is also concerned with deeper drilling, off
shore development and continued activity in the formation of large
secondary recovery projects. With each of these trends, when
artificial lift is required, it will be desirable to have a lift
system capable of lifting greater volumes, and in many instances
from greater depths of lift, requiring subsurface production units
which develop more downhole horsepower within the confines of
dimensional limitations of the tubing or casing string to provide
the required energy to lift the well fluids to the surface.
Accordingly, the development of sub-surface production units which
have increased producing capabilities also requires larger volumes
of power fluid to be directed to these units in order to provide
the additional energy required.
While water has heretofore been utilized as a power fluid, its use
has been in multiple well installations where central power plants,
treating facilities, tankage and controls are at one location,
requiring high pressure power fluid lines out to each well to
conduct the power fluid to that well. Its use has also been in
"closed power fluid systems", wherein the power fluid is kept
separated from the well fluids and thereby requires a separate
string of pipe to return the exhaust or spent power fluid back to
the surface and a return line from the well back to the central
station. In addition to the power fluid, high pressure distribution
lines to the wells and the return power fluid lines back to the
central station, another string of pipe or production tubing is
necessary from the surface to the bottom of the well. A flow line
from the well to the tank battery or central station is, of course,
necessary for all methods of artificial lift. The power water used
in these multi-well installations is supplied from a source other
than the producing well and is stored for use in a tank at
atmospheric pressure near the surface power pump.
While the prior art has successfully used both power water and
power oil as hydraulic fluid to operate sub-surface hydraulic
pumps, such use has been with multi-well installations or in closed
power fluid systems where the power fluid is kept separated from
the well fluids, and not with a one-well, self contained unit that
has universal application to produce solid free power fluid.
SUMMARY OF THE INVENTION
The present invention provides a one well, self contained,
hydraulic pumping installation for a pumping system of the type
having a downwell pump which utilizes produced water, oil, or a
mixture of oil and water, as the power fluid for pumping well
fluids. The pumping installation comprises a power fluid
conditioning unit to condition produced water, oil, or a mixture of
oil and water, which is always under pressure above atmosphere,
from the produced well fluids and exhausted power fluid so that it
will be suitable for use as power fluid. Briefly, the produced well
fluids and exhausted power fluid from the well, which include oil,
gas and water, enters a pressurized, separator-accumulator tank
where water is separated from the oil and gas by gravity
separation. Water, oil, or a mixture of oil and water, from the
pressurized tank is then forced into the inlet of at least one
cyclone separator, wherein solids are separated therefrom. The
conditioned fluid discharged from the cyclone separator then
proceeds into the suction manifold of a pressure pump, wherein, if
necessary, appropriate chemicals are injected into the suction of
the pressure pump by a chemical pump and high pressure conditioned
fluid is discharged from the power fluid outlet of the pressure
pump and down the well to operate a sub-surface production unit,
such as a downwell hydraulic pump.
The volume of oil, gas and water a well is producing is discharged
from the separator-accumulator tank into a flow line which leads to
further processing units. Solids separated by the cyclone separator
are discharged with some fluid directly into the flow line and join
the production of the well.
The power fluid conditioning unit of the present invention provides
a one-well synergetic lift system which is safe, flexible and an
economical method of producing an oil well. Since the power fluid
conditioning unit of the present invention combines the spent power
fluid with the fluid at the bottom of the hole and then separates
conditioned power fluid in the power fluid conditioning unit, it
saves the surface piping as well as a string of tubing from the
bottom of a hole, which are required, for example, with existing
closed central systems serving many wells. The power fluid
conditioning unit of the present invention keeps the power fluid
under pressure at all times and thus it is not exposed to air where
it can pick up oxygen and be more corrosive, as is the case with
other closed water power systems. It eliminates the cost associated
with a sucker rod pumping system. In addition, it eliminates (1)
the inventory of power oil, (2) the power oil tank, (3) high
pressure power oil lines, (4) fire hazards, and (5) additional
treating facilities necessary at the central battery of the usual
closed central system. The power fluid conditioning unit of the
present invention may be tailored to fit the requirements of a well
with a maximum flexibility for producing rates or well changes and
it may be quickly installed because it does not entail a major
construction job at the lease.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic flow diagram showing a one well, self
contained, hydraulic pumping system according to the present
invention.
FIG. 2 is a perspective view showing the skid mounted power fluid
conditioning unit of the present invention.
FIG. 3 is a cross sectional view through an exemplary
separator-accumulator tank which forms a part of the power fluid
conditioning unit of the present invention.
FIG. 4 is a cross sectional view taken on the lines 4 -- 4 of FIG.
3.
FIG. 5 is a perspective cross sectional view showing an exemplary
cyclone separator which forms a part of the power fluid
conditioning unit of the present invention.
FIG. 6 is a graphical summary (maximum pump displacement vs. pump
setting depth) of the results of a testing program on the power
fluid conditioning unit of the present invention as utilized with a
variety of downwell hydraulic pumps at differing pump setting
depths.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning first to the schematic view of FIG. 1, it will be seen that
a typical well 10 is provided with a standard wellhead control 12
communicating with a sub-surface production unit, such as the
downwell pump 14, which utilizes water, oil, or a mixture of oil
and water, as the power fluid, for pumping the well. The power
fluid intake is illustrated at 16 and the produced well fluids and
exhausted power fluid are illustrated at 18.
The present invention provides a one well, self contained,
hydraulic pumping installation comprising a power fluid
conditioning unit 20 to condition produced fluid from the produced
well fluids and exhausted power fluid so that it will be suitable
for use as power fluid. The conditioning unit 20 includes a
pressurized separator-accumulator tank 22, including a back
pressure valve 24 for controlling the pressure therein, a cyclone
centrifugal separator 26, power driven pump means 28, and means for
controlling the speed of the downwell pump 14 in the well 10, by
controlling the power fluid flow, such as the valve means 30 which
by-passes a quantity of clean power fluid back to the intake of the
cyclone separator 26. Additionally, means 66, such as a chemical
pump, may be provided for discharging chemicals into the suction of
the pump means 28, such as an electric motor driven multi-plex
plunger pump 60, so that the clean power fluid passing therethrough
acquires lubricating, non-corrosive and other desired power fluid
qualities. If necessary, a gas eliminator 31 may also be provided
between the cyclone separator 26 and the pump means 28.
The produced well fluids and the exhausted power fluid 18 are
pumped from the well 10 into the pressurized separator-accumulator
tank 22, which is designed basically as a free-water knockout,
wherein the gravity separation of water from oil and gas takes
place. The separator-accumulator tank, as best seen in FIGS. 3 and
4, is provided with at least two main outlets therein, a first
outlet 34 communicating with the flow line 36, which leads to the
lease treating facilities and tank battery (not shown), the volume
of oil, gas and water produced by the well 10 being discharged
therethrough, and a second outlet 38 in the lower section of the
tank 22 for release of desired quantities of gravity separator
water, oil, or mixture of oil and water, to be conditioned for use
as power fluid. In FIGS. 3 and 4, the separation of the produced
well fluids and the exhausted power fluid in the tank 22 into gas,
oil and water is indicated by the numerals 40, 42 and 44,
respectively.
A back pressure valve 24 is positioned between the flow line 36 and
the tank 22 for controlling the pressure in the tank 22.
At least one cyclone, centrifugal separator 26 communicates with
the second outlet 38 in the lower section of the tank 22 so that
the cyclone separator 26 will receive fluid from the lower section
of the tank 22 at an optimum pressure (controlled by the back
pressure valve 24) to give a desired pressure drop there across for
the requirements of a particular well.
As can best be seen from FIG. 5, the cyclone separator 26 is
provided with an inverted conical section 48, which may, as
desired, include an upper vertical side wall 46 of circular cross
section. The apex 50 of the conical section 48 is connected with
the flow line 36 for passage of liquids and solids from the cyclone
separator 26. An inlet 52 on the side wall of the cyclone separator
26 communicates with the second outlet 38 of the tank 22. The inlet
52 is adapted to direct the inlet flow of fluid to be conditioned
from the tank 22 substantially tangentially to the inner surface of
the cyclone separator 26. An outlet 54 for conditioned fluid from
the cyclone separator 26 is provided in the upper end thereof. In
operation, pressurized fluid to be cleaned enters the inlet 52 and
rotation thereof, as indicated by the arrows 56, develops high
centrifugal forces in the cyclone separator 26, drawing suspended
solids outward toward the wall of the conical section 48 and
downward in an accelerating spiral along the wall to the solids
discharge point at the apex 50 and moving conditioned water inward
and upward to the outlet 54 as a spiraling vortex. The collected
solids separated by the cyclone separator 26 are discharged with
some fluid through the hydromotor valve 51 and the check valve 53
into the flow line 36, and join the production of the well 10
leading to the tank battery (not shown). As more fluid goes with
the collected solids, finer size separation is possible.
It should be noted that the check valve 53 prevents a back flow of
collected solids from the flow line 36 into the cyclone separator
26 when the conditioning unit 20 is not in operation. Additionally,
it should also be noted that the hydromotor valve 51, which is open
when the electricity is on and closes automatically when the
electricity is off, prevents the cyclone separator 26 from losing
its fluid if the well 10 continues to produce gas when an electric
failure occurs and stops the pump means 28. The hydromotor 51 is,
of course, an optional piece of equipment and unnecessary when the
conditioning unit 20 is utilized on certain wells.
Clean fluid which is discharged from the outlet 54 of the cyclone
separator 26 proceeds through the gas eliminator 31 into the
suction manifold 62 of the power driven pump means 28, such as the
electric motor 58 and the multi-plex plunger pump 60. The outlet 64
of the pump 60 communicates through the desurger 65, which reduces
the flow during the peak flow and adds to the minimum flow, with
the power fluid intake 16 of the downwell pump 14 in the well 10,
and, as long as the average pressure remains the same and the pump
cycles remain constant over a period of time, provides
substantially a constant volume of clean, high pressure fluid to be
delivered to the downwell engine of the downwell pump 14.
At this point it should be noted that the downwell pump 14
discharging into the pressurized separator-accumulator tank 22 as
the result of the horsepower created by the surface pump means 28
supplies the pressure that is used to make all of the components of
the power fluid conditioning unit 20 of this invention function.
Accordingly, it is unnecessary to use an auxilliary power source
such as a centrifugal pump to charge the cyclone separator 26 and
the pump 28.
It should also be noted that it is extremely desirable to treat the
clean, high pressure power fluid so that it will acquire
lubricating, non-corrosive and other desired power fluid qualities.
Accordingly, means 66, such as a chemical pump, may be provided for
discharging desired chemicals into the suction manifold 62 of the
pump 60.
The capacity of the downwell pump 14 may be controlled by varying
its speed, and this may be affected by any suitable means for
controlling the power fluid flow to the intake 16 from the outlet
64 of the pump 60. For example, the power fluid flow may be varied
by varying the speed of the pump 60 which can be done in a
controlled manner; for instance when using an internal combustion
engine, or it can be accomplished by a constant speed prime mover
with a variable speed drive.
Exemplary means for controlling the power fluid flow to the
downwell pump 14 from the pump 60 is shown in FIGS. 1 and 2.
Suitable by-pass means 68 communicate between valve means 30 and
the inlet 52 of the cyclone separator 26. The valve means 30
controls the speed of the downwell pump 14 by passing back to the
inlet 52 of the cyclone separator 26 a quantity of clean fluid, the
amount of the fluid being by-passed controlling the amount of fluid
sent to the well 10 so as to maintain the desired strokes per
minute on the downwell pump 14.
As shown in FIG. 2, the power fluid conditioning unit 20 is
preferably mounted upon a suitable skid 70 so that it is compact
and may be positioned as desired with respect to a well.
FIG. 6 is a graphical summary of the results of a testing program
on the power fluid conditioning unit 20 of the present invention as
utilized with a variety of downwell hydraulic pumps at differing
pump setting depths. As can be seen, maximum pump displacement vs.
pump setting depth is shown. Such data is based upon 50 percent
water-cut production, 5 1/2 inches casing, and a maximum well head
operating pressure of 2500 p.s.i.
While certain preferred embodiments of the invention have been
specifically illustrated and described, it is understood that the
invention is not limited thereto, as many variations will be
apparent to those skilled in the art, and the invention is to be
given its broadest interpretation within the terms of the following
claims.
* * * * *