Flow and pressure control packer valve

A packer valve for regulating the fluid flow rate and pressure within a fluid conduit such as a well, includes a housing, and an inflatable packer element mounted on an elongated mandrel. The inside diameter of the housing is formed with an arrangement of annular grooves which circumscribe the inflatable packer element. The inflatable packer element is adapted to adjust an annulus between the housing and the inflatable packer element to provide complete shutoff of fluid flow or to provide a tortuous flow path for fluid flow within the annulus. The tortuous flow path causes a frictional pressure loss. The amount of the pressure loss is controlled by the inflation pressure of the inflatable packer element, by the shape of the annular grooves, and by the length of the inflatable packer element.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to control valves for controlling the flow 
rate and pressure of a fluid. More particularly, the present invention 
relates to a control valve, constructed as a packer valve, adapted to 
control the direction and regulate the flow rate and pressure of a fluid 
flowing in a conduit, such as a well bore. 
2. Description of the Prior Art 
Inflatable packers for directing fluid flow in a fluid conduit are well 
known in the art. Typically, such inflatable packers are utilized in 
downhole applications for sealing a well bore (e.g., oil well or water 
well). As an example, a pair of such packers can be used in the testing of 
a drilled well formation by isolating a length of the formation in 
communication with a testing flow port. 
In general, this type of packer includes an inflatable packer element which 
can be inflated to sealingly engage the inside diameter of the well bore. 
Fluid pressure for inflating the inflatable packer element is typically 
introduced through an operating string placed into the well bore, or by a 
separate pneumatic or hydraulic hose adjacent and external to the 
operating string. Such inflatable packers may also include some means for 
locking the inflatable packer element in an inflated or sealing condition. 
Packers can be a "multi-set packer" which can be deflated and re-inflated 
within a well bore, or a "single set packer" adapted for a single downhole 
inflation. 
In the past, such inflatable packers have been constructed to either 
prevent or to permit fluid flow. Inflatable packers are thus not adapted 
to selectively regulate a fluid flow rate within a well bore. 
It is often desirable to regulate the fluid flow rate or fluid pressures of 
fluids injected into or pumped out of a well. Recharge water wells, for 
instance, may be utilized in Aquifer Storage and Recovery (ASR) programs 
to assist communities during times when water demand peaks. The (ASR) 
process involves storing treated drinking water in suitable underground 
aquifers through recharge wells during low-demand months and recovering 
the water through the same wells during high demand months. 
With such recharge wells, treated water is injected into the wells for 
storage. This injection is typically accomplished at a predetermined flow 
rate and pressure. Flow and pressure regulation is typically achieved 
utilizing a surface mounted flow control valve. 
A variety of flow control valves are well known in the art for controlling 
fluid flow within a conduit. As an example, globe control valves are often 
utilized in high flow applications. Such control valves may include a 
spring actuated, tapered, sealing member that operates in conjunction with 
a contoured orifice. The location of the sealing member with respect to 
the orifice can be adjusted to provide a cross section which achieves a 
desired fluid flow rate and frictional pressure loss. 
A problem with such flow control valves is that they cannot regulate a wide 
range of flows with the large pressure drops inherent in their design. 
Further, their size is such that they cannot fit in a well and allow 
pumping. Moreover, these control valves have a limited operating range 
because typically, a single sealing member and contoured orifice are 
utilized to achieve a large pressure drop. Control is difficult because 
only a small linear movement of the sealing member relative to the 
contoured orifice is required. In addition, with a single orifice valve, 
fluid flow velocities through the control valve are relatively large. Such 
high flow velocities produce hydrodynamic noise and promote cavitation 
within the control valve. Finally, a shortcoming of such prior art control 
valves is that because of their sensitivity, they are difficult to utilize 
with a fluid containing a particulate material (e.g., dirty water). 
The present invention recognizes that a packer valve may be constructed as 
a control valve to direct fluid flow within a conduit and also to regulate 
fluid pressures and flow rates within the conduit. Moreover, such a packer 
valve can be constructed to achieve an infinitely variable frictional 
pressure loss for a fluid flowing through the packer valve. Further, such 
a packer valve can be constructed to achieve a high flow rate with a low 
fluid velocity through the valve. Still further, such a valve can be made 
of a size which permits it to be placed into a well. 
Accordingly, it is an object of the present invention to provide a packer 
valve adapted to direct fluid flow within a fluid conduit such as a well. 
It is another object of the present invention to provide such a packer 
valve that can be placed downhole in a well bore and controllable from the 
surface. 
It is a further object of the present invention to provide such a packer 
valve in which fluid velocities through the valve are low and frictional 
pressure losses through the valve are infinitely variable to control fluid 
flow over a wide range of pressures whether down hole in a well or for 
such control in surface piping systems. 
It is yet another object of the present invention to provide such a packer 
valve that can be used with a variety of fluids including a fluid having 
particulate material therein. 
It is a further object of the present invention to provide a packer valve 
especially adapted for controlling the flow rate and pressure of a fluid 
injected into a well. 
It is yet another object of the present invention to provide a packer valve 
suitable for high flow and high pressure applications that is simple and 
reliable. 
It is yet another object of the present invention to provide a packer valve 
suitable to retrofit existing wells for pumping and injection. 
SUMMARY OF THE INVENTION 
In accordance with the present invention, a packer valve for controlling 
fluid flow and pressure in a fluid conduit such as a well bore is 
provided. In an illustrative embodiment, the packer valve is adapted to 
function as a two way valve for directing fluid flow into the well from 
the surface, or out of the well to the surface. The packer valve can be 
used to direct the flow of an injection fluid from the surface (e.g. 
treated water to be stored within the well) into the well bore and to 
regulate the flow rate and pressure of the injected fluid. The packer 
valve may also direct fluid flow to the surface from a submersible pump 
(or other pumping mechanism) in fluid communication with a pump pipe 
located within the well. 
Generally stated, a packer valve constructed in accordance with the 
invention includes: 
a generally cylindrically shaped housing adapted to fit within a well bore 
in fluid communication therewith and constructed with a length and with an 
inside diameter surface adapted to provide a pre-determined roughness 
factor for friction loss; 
an elongated mandrel mounted within the housing and adapted for fluid 
communication at a downhole end with a pump pipe of the well and at an 
uphole end with an injection fluid source with the mandrel sized to 
minimize uphole flow friction losses; and 
an inflatable packer element, mounted within the housing, circumjacent to 
the mandrel to form an annulus between the outside diameter of the element 
and the inside diameter of the housing, with the annulus in communication 
with the well at the downhole end and the elongated mandrel at the uphole 
end, and with the inflatable packer element adapted to be inflated into 
the annulus to reduce the area of the annulus and thereby provide a flow 
path that achieves a predetermined pressure loss for fluid flow through 
the valve and into the well, as well as to shut off fluid flow into the 
well, allowing fluid flow to the surface. 
INJECTION 
For regulating the flow rate and fluid pressure of an injected fluid the 
housing and packer element are sized and adapted to accomplish four 
things: (1) the inside diameter of the housing of the packer valve is 
formed with a surface to increase the surface roughness thereby increasing 
friction to fluid movement (in an illustrated embodiment this comprises an 
arrangement of parallel spaced annular grooves to provide a series of 
annular orifices); (2) the length of the housing is sized to provide (in 
conjunction with the surface roughness of the inside diameter), an 
adequate total frictional loss to fluid movement as a specific 
differential pressure application may require; (3) the inflatable packer 
element is sized to expand into the annular area between the outside 
diameter of the packer and the inside diameter of the housing (the 
annulus) allowing for a range of flow rates from full flow with little 
frictional loss, through intermediate flows with varying frictional 
losses, to complete restriction of any flow (complete shutoff); (4) the 
housing outside diameter is sized to fit into the well. It should be noted 
here that the sizing and construction of the housing once completed for a 
specific application, cannot be changed in the field; that is, the 
adjustments to flow are controlled only by the varying areas of the 
annulus (effected by the pressure or volume changes of the packer 
element). 
The inside of the housing provides a surface of significant roughness to 
increase frictional pressure losses to fluids. In the application of a 
recharge well with a liquid fluid, this roughness may be accomplished with 
annular grooves that circumscribe the inflatable packer element. If the 
inflation pressure within the inflatable packer element is high enough, 
the packer element expands and contacts the annular grooves and flow 
through the annulus of the valve is blocked, and affords a positive leak 
tight seal. With a lower predetermined inflation pressure, however, the 
inflated packer element only approaches close to the annular grooves, 
thereby providing a tortuous flow path for fluid flow between the 
inflatable packer element and the housing (the annulus). The annular 
grooves increase the friction loss of the flow, and the longer the 
housing, the more grooves there would be, and more friction loss. The 
grooves may be modeled as annular orifices, and the frictional loss 
attributable to each is, in part, a function of the shape of the annular 
grooves. The amount of the frictional pressure is determined by the shape 
of the annular grooves, the length of the housing (i.e. the number of 
grooves) and by the inflation pressure introduced into the packer element 
(which adjusts the annulus area). 
In general, this frictional pressure loss is infinitely variable because 
the inflation pressure of the packer is infinitely variable (which allows 
an infinitely variable annulus area). By adjusting the inflation pressure 
(or inflation volume) to achieve a desired frictional pressure loss, the 
flow rate and pressure of a fluid injected into the well bore can be 
regulated as required. Moreover, because a large surface area is provided 
for pressure regulation by the annular grooves and housing length, low 
fluid velocities and high pressure drops are possible. 
In use, such as for operating a recharge water well, the packer valve can 
be submerged into a well adjacent to a submersible pump of the well. The 
mandrel of the packer valve is connected at one end (downhole) in fluid 
communication with the submersible pump. A check valve located above the 
pump prevents injection fluids from passing into the pump from the 
surface. At an opposite end (uphole) the mandrel of the packer valve is in 
fluid communication with the pump pipe and a surface mounted pump for the 
injection fluid; and also in fluid communication with the top end of the 
housing. In a downhole injection mode, an injection fluid is introduced at 
the surface, and flows through the downhole connecting pipe and through 
the mandrel of the packer valve, and through an outlet orifice of the 
mandrel in flow communication with the annulus. The inflation pressure of 
the inflatable packer element is selected to allow some fluid flow to pass 
to the annulus. This tortuous flow path through the annulus along the 
length of the housing and its grooves provides a frictional pressure loss. 
The frictional pressure loss can be adjusted to provide a desired flow 
rate and pressure of the injection fluid. 
During the injection mode of the packer valve, it is desirable to equalize 
the frictional pressure loss in a linear direction from an uphole end to a 
downhole end of the inflatable packer element. In general, this equal 
pressure distribution can be accomplished by forming the packer element 
with a variable stretch pressure along its length. As an example, for 
providing a variable stretch pressure, the inflatable packer element can 
be formed in segments with each segment having a different stretch 
pressure. An uphole end of the packer element can be formed with a lower 
stretch pressure than a downhole end to counteract the lower differential 
pressure between the injection fluid and the packer inflation pressure. 
The downhole end of the packer element can be formed with a higher stretch 
pressure (than the uphole end), to counteract the larger differential 
pressure between the lower injection fluid pressure, and the packer 
inflation pressure. The element may have several segments, each with a 
stretch pressure designed to provide a linear pressure loss across the 
valve. 
The effect of high differential pressures from end to end of the packer 
valve is to increase the differences in stretch pressures of the element 
segments necessary to produce a linear pressure loss. This effect of the 
pressure differential can also be minimized by forming the inflatable 
packer element with a relatively high stretch pressures relative to the 
fluid pressure. This minimizes the effect of the uphole to downhole 
pressure differential, and in some specific applications may allow the use 
of single segment elements. 
PUMPING 
In an uphole pumping mode, the inflatable packer element is inflated with a 
pressure sufficient to prevent all fluid flow within the annulus. At the 
same time, the submersible pump is allowed to pump water from the well up 
through the check valve and mandrel of the packer valve, through the pump 
pipe, and to the surface. The packer flow control valve can also be 
installed above the bowl assembly of a vertical turbine pump. A check 
valve can be installed at the bottom of the bowl assembly. 
Other objects, advantages, and capabilities of the present invention will 
become more apparent as the description proceeds.

DETAILED DESCRIPTION OF THE INVENTION 
Referring now to FIG. 1, a packer valve constructed in accordance with the 
invention is shown and generally designated as 10. The packer valve 10 is 
shown installed in a recharge water well which is generally designated as 
11. The water well 11 is suitable for use in an Aquifer Storage and 
Recovery (ASR) program in which recharge water is injected into the well 
11 for storage. The packer valve 10 is adapted to direct fluid flow and to 
control the flow rate and pressure of recharge water injected into the 
well 11. 
Such an application for the packer valve, however, is merely exemplary. It 
is to be understood that a packer valve 10 constructed in accordance with 
the invention can be used for controlling the fluid flow rate and pressure 
in other fluid conduits, both downhole and above ground. Moreover, the 
packer valve 10 is adapted for use with a variety of fluids (e.g. oil, 
water, gas) including a dirty or gritty fluid, and fluids of different 
viscosities. Moreover, a pump means may be submersible pumps, turbine 
pumps, or other common means of retrieving water from wells (such as 
airlifting). 
The recharge water well 11 includes a cylindrical well casing or bore 12 
that extends from the ground surface into a desired geological formation. 
Typically, this may be a distance of from several hundred to several 
thousand feet. The well 11 also includes a submerged pump 13 and electric 
motor 14 for pumping water from the formation to the surface. 
The submersible pump 13 is in flow communication with a downhole end of the 
packer valve 10. The packer valve 10 in turn, is in flow communication 
with a pump pipe 15 that extends to the surface. At the surface, the pump 
pipe couples to an elbow 16, a water meter 17, and a water supply conduit 
18. 
A control panel 19 located at the surface functions as a control means to 
control various aspects of the water well 11 such as electrical, pneumatic 
and timing functions. The control panel 19 connects to a power conduit 20. 
The control panel 19 also connects to an electrical conduit 21 which 
connects to a junction box 22. The junction box 22 connects to another 
electrical conduit 23 to the pump motor 14. 
The control panel 19 also includes or is connected to a pneumatic source 
(e.g. compressor) in fluid communication with a pneumatic line 24. The 
pneumatic line 24 in turn connects to the packer valve 10 for supplying an 
inflation gas such as compressed air, or an inert gas to the packer valve 
10. Alternately, in place of an inflation gas, a pressurized inflation 
fluid such as water, oil or other liquid may be used to inflate the packer 
valve 10. Moreover, the inflation gas or fluid need not be supplied 
continuously, as the packer valve 10, may be inflated and maintained in an 
inflated condition using suitable valving (not shown). 
Referring now to FIGS. 2A-2D, the packer valve 10 is shown in detail. The 
packer valve 10, generally stated, includes; a housing 25; an elongated 
mandrel 26 mounted within the housing 25; and an inflatable packer element 
27 mounted circumjacent to the mandrel 26. 
The housing 25 is hollow and generally cylindrical in shape, and may be 
formed of a rigid material such as steel. An outside diameter of the 
housing 25 is sized to fit within the well casing 12 (FIG. 1). The inside 
diameter of the housing 25 is sized with respect to the outside diameter 
of the inflatable packer element 27 such that an annulus 28 is formed 
between the inside diameter of the housing 25 and the outside diameter of 
the inflatable packer element 27. (This annulus is more clearly shown in 
FIG. 5.) 
A downhole end 29 of the housing 25 is open and an uphole end 30 of the 
housing 25 is closed. With the packer valve 10 placed within the well 11 
(FIG. 1), the downhole end 29 of the housing 25 is in flow communication 
with the well 11. This permits an injection fluid to be injected into the 
annulus 28 of the packer valve 10 through the downhole end 29 of the 
housing 25 and into the well casing 11. 
An uphole end 30 of the housing 25 is closed by a connection member 31. The 
connection member 31 functions to connect the packer valve 10 at an uphole 
end to the pump pipe 15 (FIG. 1) which carries water to the surface. The 
connection member 31 also functions to mount an uphole end 32 of the 
mandrel 26 within the housing 25 at an uphole end. 
The uphole end 32 of the mandrel 26 is attached to the connection member 
31. As clearly shown in FIG. 7, the connection member 31 is formed with an 
arrangement of threaded openings for receiving mating capscrews 33. The 
capscrews 33 engage and retain the housing 25. An o-ring 34 (FIG. 2A) 
mounted within a groove seals the connection member 31 with respect to the 
annulus 28 of the packer valve 10. 
As shown in FIGS. 2A and 2B, the inside diameter of the housing 25 in the 
area circumjacent to the inflatable packer element 27, is formed with a 
plurality of annular grooves 35. With the inflatable packer element 27 
partially inflated, the annular grooves 35 provide a tortuous flow path 
for fluid flow within the annulus 28 in a downhole direction. This 
function of the annular grooves 35 is clearly shown in FIG. 3. The flow 
path 36 is between the inflatable packer element 27 and the annular 
grooves 35. This flow path 36 provides a predetermined frictional pressure 
loss for fluid flow. This pressure loss can be adjusted to allow the fluid 
flow rate and fluid pressure of storage water injected through the packer 
valve 10 to the well 11 to be regulated. 
The amount of the frictional pressure loss through the packer valve 10 is a 
function of the annulus 28 remaining after partial inflation of the 
inflatable element 27. This annulus area is selectively controlled by the 
inflation pressure of the element 27 from the surface. In addition, the 
frictional pressure loss is a function of the shape of the annular grooves 
35. This shape is substantially as shown in FIG. 3. Finally, this 
frictional pressure loss is a function of the length of the packer valve 
10 and particularly the inflatable packer element 27. 
As shown in FIG. 3, a downhole edge of each annular groove is heavily 
chamfered 37 to promote fluid flow into each annular groove 35. 
Conversely, an uphole edge of each annular groove 35 is lightly chamfered 
38 to promote fluid retention within the grooves 35 to promote a friction 
loss of fluid flowing out of each annular groove 35. A frictional pressure 
loss is also achieved by the channeling and changing direction of the 
fluid flow within the annular grooves 35. This is indicated by the 
swirling flow paths within the grooves 35 in FIG. 3. 
Referring back again to FIGS. 2A-2D, the mandrel 26 of the packer valve 10 
is mounted within the housing 25 along a longitudinal axis of the housing 
25. The mandrel 26 is hollow and generally cylindrical in shape and is 
adapted to provide a flow conduit for fluid flow pumped from the water 
well 11. As such, a downhole section 39 of the mandrel 26 is connected in 
flow communication with an output of the submersible pump 13 (FIG. 1) for 
the water well 11. 
The mandrel 26 may be formed in separate sections, the uphole section 32 
and the downhole section 39. As previously stated, the uphole section 32 
of the mandrel 26 connects to the connection member 31 of the packer valve 
10. The downhole section 39 of the mandrel 26 connects to the uphole 
section 32 at an upper packer collar 41 (FIG. 2A). Moreover, the upper 
packer collar 41 is located at the upper end of the inflatable packer 
element 27 and connects to the inflatable packer element 27. The downhole 
section 39 of the mandrel 26 connects to the submersible pump 13 (FIG. 1). 
A coupling 42 connects the downhole section 39 of the mandrel 26 with the 
pump 13. A check valve 51 is located between the pump 13 and mandrel 26. 
In addition to providing a conduit for fluid flow from the submersible pump 
13 to the surface, the mandrel 26 is also sized and spaced with respect to 
the housing 25 to allow the annulus 28 formed between the outside diameter 
of the element 27 and the inside diameter of the housing 25 to provide a 
flow path for injection fluid flow (e.g. storage water) as indicated by 
injection arrows 36 into the well 11. The injection flow path into the 
packer valve 10 is from the pump pipe 15 into the uphole section 32 of the 
mandrel 26 (see also FIG. 5). A pumping flow path through the mandrel 26 
is from the pump 13 to the mandrel 26 as indicated by pumping arrows 44 
(see also FIG. 4). 
The uphole section 32 of the mandrel 26 is formed with an elongated opening 
45 (FIG. 2A) in flow communication with the annulus 28. With this 
arrangement, an injection fluid can flow from the interior of the uphole 
section 32 of the mandrel 26 through the elongated opening 45 and into the 
annulus 28. A particulate removing means 50 (FIG. 2A) surrounds the 
opening 45 to catch particulate material, such as sand or grit, that may 
be pumped in a pumping mode. 
The inflatable packer element 27 is mounted to the upper section 32 of the 
mandrel 26 for inflation into the annulus 28. An upper packer collar 41 
and element crimp collar 46 sealingly attaches the inflatable packer 
element 27 to the mandrel 26 and to a packer barb 48. The packer barb 48 
is a generally cylindrical rigid support tube which extends the entire 
length of the inflatable packer element 27. An internal passageway 47 in 
the upper packer collar 41 is formed for introducing an inflation fluid 
from the pneumatic line 24 into an annulus 78 formed between the outside 
diameter of the mandrel 26 and the inside diameter of the packer barb 48. 
There are holes 52 along the length of the barb 48 for introduction of the 
inflation fluid to the inside diameter of the inflatable packer element 27 
for inflation. The internal passageway 47, annulus 78 and holes 52 are in 
flow communication with the pneumatic line 24 (FIG. 1) which in turn is 
connected to a source of a compressed gas. The inflation source may also 
be a liquid. A lower packer collar 49 (FIG. 2C) and element crimp collar 
46 similarly sealingly attaches the inflatable packer element 27 to the 
mandrel 26 and packer barb 48 at a downhole end. 
At the downhole end of the housing 25 a centering plate 80 directs fluid 
flow in the injection mode into the well casing 12. The centering plate 80 
is generally circular in shape and fits within the inside diameter of the 
housing. Orifices 82 are formed in the centering plate 80 for directing 
the injection fluid flow. The centering plate 80 also functions to center 
the location of the mandrel 26 with respect to the housing 25 at the 
downhole end 29. 
The inflatable packer element 27 may be of any suitable length and is 
formed of a resilient material such as vulcanized rubber. The inflatable 
packer element 27 may be formed of several plies of cord or cable 
reinforcement (e.g. 2, 4, 6 or more plies) as is known in the art. 
In an uninflated condition of the inflatable packer element 27, the flow 
path through the annulus 28 of the housing 25 is unrestricted. The 
inflatable packer element 27, however, can be inflated to press against 
the inside diameter of the housing 25 and the annular grooves 35 formed in 
the housing 25. In general, the packer element 27 will have a stretch 
pressure that must be overcome in order to inflate the packer element 27 
to provide a contact force against the inside diameter of the housing 25. 
If the inflation pressure is high enough, the annulus 28 will be sealed, 
and no fluid flow will be permitted through the annulus 28 between the 
inflatable packer element 27 and the housing 25. Between these two 
extremes (completely open vs. completely sealed) however, the inflation 
pressure of the inflatable packer element 27 can be adjusted to achieve a 
desired flow path or size of the annulus 28 to regulate the fluid pressure 
and flow rate through the annulus 28. 
The frictional pressure loss caused by the fluid flow between the 
inflatable packer element 27 and the annular grooves 35 can be used to 
achieve a desired fluid pressure drop and flow rate. This frictional 
pressure loss can be adjusted by adjusting the pressure in the inflatable 
packer element 27 from the surface. In general, since this inflation 
pressure is infinitely variable, the fluid pressure and flow rate within 
the annulus 28 are also infinitely variable. In addition, because a large 
number of annular grooves 35 can be formed with a relatively large surface 
area, relatively large pressure losses and flow rates can be achieved, 
even with relatively small flow velocities. 
In general, it is desirable to provide a pressure drop from an uphole end 
to a downhole end of the packer valve 10 that is approximately the same 
throughout the length of the packer valve (i.e. from end to end of the 
packer valve 10). Since the uphole end of the inflatable packer element 27 
however, is subjected to a higher pressure of the injection fluid, the 
uphole end must have a lower stretch pressure (or be inflated to a higher 
pressure) than the downstream end to achieve the same frictional pressure. 
In order to achieve this desired pressure distribution, the inflatable 
packer element 27 may be constructed in segments (e.g., 2 or more 
segments). The uphole segments can be made with a lower stretch pressure 
relative to the downhole segments. FIG. 6 schematically depicts the use of 
element crimp collars 46 to separate the different segments of the 
inflatable element 27 and secure them to the packer barb 48. The different 
segments of the inflatable packer element 27 may be formed with different 
stretch pressures by techniques which are known in the art, such as by 
varying the thickness of the packer element 27 across its length; varying 
durometer (hardness) of the rubber; varying the numbers of reinforcement 
plies; varying the angle of the cord reinforcements in relation to the 
axis of the element; or a combination of the above. 
As an alternative to element segmentation, in order to overcome this 
unequal uphole to downhole pressure differential, the stretch pressure of 
the inflatable packer element 27 can be made relatively high in comparison 
to the fluid pressure of the injection fluid. The effects of the pressure 
differential will thus be minimized. 
OPERATION 
Referring now to FIGS. 4 and 5, the operation of the packer valve 10 can be 
explained. FIG. 4 shows an uphole pumping mode of the packer valve 10. In 
an uphole pumping mode, water is being pumped from the well 11 to the 
surface. In this mode, the inflatable packer element 27 is inflated with a 
pressure high enough to press against the inside diameter of the housing 
25 and completely seal the annulus 28. This sealing pressure is high 
enough to prevent any flow through the annular grooves 35 in the housing 
25. At the same time, the submersible pump 13 (FIG. 1) is allowed to pump 
water from the well through the mandrel 26 of the packer valve 10, and to 
the surface. Pumping flow direction is shown with arrows 44. 
FIG. 5 shows a downhole injection mode of the packer valve. In a downhole 
injection mode, water is being injected from the surface into the well 11 
for storage. In this mode, water is injected through the pump pipe 15 and 
flows through the opening 45 in the mandrel 26 of the packer valve 10 into 
the annulus 28. A check valve 51 located between the packer valve 10 and 
submersible pump 13 prevents fluid flow into the pump 13 during the 
downhole injection mode. Flow direction during the injection mode is shown 
with arrows 36. 
In the downhole injection mode, the pressure and flow rate of the fluid 
injected into the annulus 28 is controlled by the inflation pressure (or 
inflation volume) of the inflatable packer element 27 which directly 
affects the annular area 28. In this mode, the inflatable packer element 
27 is inflated with a pressure that causes the inflatable packer element 
27 to come close to the inside diameter of the housing 25 thereby reducing 
the annular area 28. This inflation pressure is selected to allow fluid to 
flow between the inflatable packer element 27 and the annular grooves 35. 
This produces a frictional pressure loss as previously explained. The 
pressure loss is also affected by the length of the inflatable packer 
element 27. For a large pressure drop therefore the inflatable packers 
element 27 must be relatively long. 
The amount of the frictional pressure loss can be varied by varying the 
area of the annulus 28. The annulus area can be varied by the inflation 
pressure of the inflatable packer element 27 or the volumetric amount of 
liquid added to the packer element 27. A desired flow rate and pressure 
for the injection fluid into the well can thus be achieved. Since the 
pressure drop is achieved over a relatively large surface area, large 
pressure drops with a low flow velocity can be achieved. In addition, an 
infinitely variable range of fluid pressure and flow rates can be 
achieved. Finally the packer valve can be utilized with a variety of 
fluids including a gritty or dirty fluid. 
DESIGN CONSIDERATION 
As is apparent, the size of the annulus 28 or annular gap is the only 
control element after installation of the packer valve. This annular gap 
is controlled by the outside diameter of the packer, and is a function of 
the pressure inside of the packer, regulated from the surface; or the 
volume inside the packer, again regulated from the surface. The volume and 
inside pressure are related, and are a function of the downhole 
conditions. 
Initial design of the packer valve requires sizing of the mandrel inside 
diameter to allow for adequate flow to the surface without excessive 
friction loss. Initial design of the packer requires sizing of the o.d. of 
the packer and the i.d. of the housing to, similarly, allow for adequate 
flow for injection. And, finally, the outside diameter of the housing 
itself must be sized to fit in the borehole or pipe. Typically, either a 
gas or a liquid is treated as a fluid. 
Thus the invention provides a packer valve that can be used to regulate 
fluid pressure and flow rates in a fluid conduit. While the invention has 
been described in connection with an illustrative embodiment for injecting 
water into a recharge water well, it is to be understood that the 
invention can be used in a variety of other applications and with other 
fluids. As will be apparent then, to those skilled in the art, certain 
changes and modifications can be made without departing from the scope of 
the invention as defined by the following claims.