U.S. patent application number 17/550131 was filed with the patent office on 2022-06-16 for high pressure pump with separate clean and dirty fluid circuits.
The applicant listed for this patent is Proserv Gilmore Valve LLC. Invention is credited to Ryan BLUDAU.
Application Number | 20220186723 17/550131 |
Document ID | / |
Family ID | 1000006127603 |
Filed Date | 2022-06-16 |
United States Patent
Application |
20220186723 |
Kind Code |
A1 |
BLUDAU; Ryan |
June 16, 2022 |
HIGH PRESSURE PUMP WITH SEPARATE CLEAN AND DIRTY FLUID CIRCUITS
Abstract
Implementations described herein relate to apparatus and methods
for using a membrane pump to establish fracking pressure. Apparatus
described herein includes, in place of mechanical pumps such as
piston and impeller pumps, one or more membrane pumps are employed
in a fluid circuit to increase the pressure of the fracking fluid.
In operation of this system, a clean fluid circuit is used to
pressurize clean fluid, transfer that pressure into the dirty
fluid, and then return the clean fluid to a storage, and a dirty
fluid circuit flows the dirty fluid from a storage, to the membrane
pump to be pressurized, and then into a well bore to pressurize a
formation penetrated by the well bore.
Inventors: |
BLUDAU; Ryan; (Katy,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Proserv Gilmore Valve LLC |
Houston |
TX |
US |
|
|
Family ID: |
1000006127603 |
Appl. No.: |
17/550131 |
Filed: |
December 14, 2021 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
63162863 |
Mar 18, 2021 |
|
|
|
63125535 |
Dec 15, 2020 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 43/0733 20130101;
E21B 43/267 20130101; F04B 53/16 20130101; F04B 47/00 20130101 |
International
Class: |
F04B 43/073 20060101
F04B043/073; F04B 53/16 20060101 F04B053/16; F04B 47/00 20060101
F04B047/00; E21B 43/267 20060101 E21B043/267 |
Claims
1. A fracking fluid pressurization system, comprising; a dirty
fluid inlet line connected to a dirty fluid source at a first
pressure; a dirty fluid outlet line connectable to a well bore; a
clean fluid inlet line connected to a clean fluid source at a
second pressure greater than the first pressure; a clean fluid
return line maintainable at a pressure less than the first
pressure; a membrane pump comprising; a body having a hollow
interior; and a membrane within the hollow interior of the body,
dividing the hollow interior into a first volume and a second
volume, the first and second fluid volumes isolated from one
another by the membrane; a dirty fluid inlet in fluid communication
with the dirty fluid inlet line and the first volume; a dirty fluid
inlet check valve fluidly interposed between dirty fluid inlet line
and the dirty fluid inlet; a dirty fluid outlet in fluid
communication with the first volume and the dirty fluid outlet
line; a dirty fluid outlet check valve fluidly interposed between
dirty fluid outlet line and the dirty fluid outlet; a clean fluid
inlet in fluid communication with the second volume; an inlet user
position selectable valve fluidly interposed between the clean
fluid inlet line and the clean fluid inlet; a clean fluid outlet in
fluid communication with the second volume; and an outlet user
position selectable valve fluidly interposed between the clean
fluid outlet and the clean fluid outlet line.
2. The fracking fluid pressurization system in claim 1, further
comprising a dirty fluid pump the output of which is at the first
pressure.
3. The fracking fluid pressurization system in claim 1, wherein the
dirty fluid pump mixes the proppant with a fluid.
4. The fracking fluid pressurization system in claim 2, further
comprising a clean fluid pump the output of which is at the second
pressure.
5. The fracking fluid pressurization system in claim 1, wherein the
clean fluid outlet is in fluid communication with a fluid tank and
the clean fluid inlet is in fluid communication with the fluid
tank.
6. The fracking fluid pressurization system in claim 5, further
comprising a fluid chiller interposed between the clean fluid
outlet and the fluid tank.
7. The fracking fluid pressurization system in claim 5, further
comprising a pressure regulator interposed between the clean fluid
pump and the inlet user position selectable valve.
8. A method for establishing a fracking pressure in a dirty fluid
including a proppant therein, comprising providing a membrane pump
comprising; a body having a hollow interior; and a membrane within
the hollow interior of the body, dividing the hollow interior into
a first volume and a second volume, the first and second fluid
volumes isolated from one another by the membrane; providing a
dirty fluid inlet in fluid communication with the dirty fluid inlet
line and the first volume; providing a dirty fluid inlet check
valve fluidly interposed between dirty fluid inlet line and the
dirty fluid inlet; providing a dirty fluid outlet in fluid
communication with the first volume and the dirty fluid outlet
line; providing a dirty fluid outlet check valve fluidly interposed
between dirty fluid outlet line and the dirty fluid outlet;
providing a clean fluid inlet in fluid communication with the
second volume; providing an inlet user position selectable valve
fluidly interposed between the clean fluid inlet line and the clean
fluid inlet; providing a clean fluid outlet in fluid communication
with the second volume; and providing an outlet user position
selectable valve fluidly interposed between the clean fluid outlet
and the clean fluid outlet line, preparing a dirty fluid comprising
water, chemistry, proppant, from a water, chemistry, and proppant
source, pumping, using a low-pressure pump, the dirty fluid into
the first volume of the membrane pump; and pumping, a clean fluid
from a clean fluid source, using a high-pressure pump to pump the
clean fluid into the second volume of the membrane pump, wherein;
the clean fluid in the membrane pump pushing the dirty fluid in the
membrane pump out of the membrane pump toward a well bore.
9. The method for establishing a fracking pressure in a dirty fluid
including a proppant therein in claim 8, further comprising a dirty
fluid pump the output of which is at the first pressure.
10. The method for establishing a fracking pressure in a dirty
fluid including a proppant therein in claim 8, wherein the dirty
fluid pump mixes the proppant with a fluid.
11. The method for establishing a fracking pressure in a dirty
fluid including a proppant therein 9, further comprising a clean
fluid pump the output of which is at the second pressure.
12. The method for establishing a fracking pressure in a dirty
fluid including a proppant therein in claim 8, wherein the clean
fluid outlet is in fluid communication with a fluid tank and the
clean fluid inlet is in fluid communication with the fluid
tank.
13. The method for establishing a fracking pressure in a dirty
fluid including a proppant therein in claim 12, further comprising
a fluid chiller interposed between the clean fluid outlet and the
fluid tank.
14. The method for establishing a fracking pressure in a dirty
fluid including a proppant therein in claim 12, further comprising
a pressure regulator interposed between the clean fluid pump and
the inlet user position selectable valve.
15. A method of providing a dirty fluid therein a dirty fluid
including a proppant therein to a well bore deadheaded to a
formation to be fractured, comprising: providing a pump housing
having a membrane therein separating the interior of the pressure
vessel into a first fluid side and a second fluid side, the housing
having an internal housing volume therein; providing a dirty fluid
inlet in fluid communication with the dirty fluid inlet line and
the first fluid side; and providing a dirty fluid inlet check valve
fluidly interposed between dirty fluid inlet line and the dirty
fluid inlet; providing a dirty fluid outlet in fluid communication
with the first fluid side and the dirty fluid outlet line;
providing a dirty fluid outlet check valve fluidly interposed
between dirty fluid outlet line and the dirty fluid outlet;
providing a clean fluid inlet in fluid communication with the
second fluid side; providing an inlet user position selectable
valve fluidly interposed between the clean fluid inlet line and the
clean fluid inlet; providing a clean fluid outlet in fluid
communication with the second fluid side; and providing an outlet
user position selectable valve fluidly interposed between the clean
fluid outlet and the clean fluid outlet line, preparing a dirty
fluid comprising water, chemistry, proppant, from a water,
chemistry, and proppant source, pumping, using a low-pressure pump,
the dirty fluid into the first fluid side of the membrane pump to
establish a full internal housing volume of dirty fluid within the
housing, pumping, a clean fluid from a clean fluid source, using a
high-pressure pump to pump the clean fluid into the second fluid
side of the membrane pump, wherein; the clean fluid in the membrane
pump pushes the full internal housing volume of dirty fluid in the
housing out of the housing toward the well bore.
16. The method of providing a dirty fluid including a proppant
therein to a well bore deadheaded to a formation to be fractured of
claim 15, wherein after pumping the clean fluid in the housing to
push the full internal housing volume of dirty fluid in the housing
out of the housing toward the well bore refilling the first fluid
side of the housing with dirty fluid.
17. The method of providing a dirty fluid including a proppant
therein to a well bore deadheaded to a formation to be fractured of
claim 15, further comprising providing a dirty fluid pump
outputting dirty fluid at a first pressure, wherein; the refilling
of the first fluid side of the housing with the dirty fluid is
provided by opening the outlet user position selectable valve to
expose the clean fluid in the second fluid side of the housing to a
pressure lower than the first pressure, whereby the pressure in the
dirty fluid in the first fluid side is reduced to a pressure less
than the first pressure and the dirty inlet check valve opens to
allow dirty fluid from the dirty fluid pump to enter the first
fluid side.
18. The method of providing a dirty fluid including a proppant
therein to a well bore deadheaded to a formation to be fractured of
claim 17, further comprising providing a clean fluid pump
outputting dirty fluid at a second pressure, wherein; the refilling
of the second fluid side of the housing with the clean fluid is
provided by opening the inlet user position selectable valve to
expose the dirty fluid in the first fluid side of the housing to a
pressure greater than the first pressure, whereby the pressure in
the dirty fluid in the first fluid side is increased to a pressure
sufficient to close the dirty inlet check valve and open the dirty
fluid outlet check valve.
19. The method of providing a dirty fluid including a proppant
therein to a well bore deadheaded to a formation to be fractured of
claim 18, whereby the pressure in the dirty fluid in the first
fluid side is increased to a pressure sufficient to close the dirty
inlet check valve and thereafter open the dirty fluid outlet check
valve.
20. The method of providing a dirty fluid including a proppant
therein to a well bore deadheaded to a formation to be fractured of
claim 18, further comprising providing a dirty fluid outlet
manifold fluidly connecting between the dirty fluid outlet check
valve and a well bore.
21. A drilling mud pump, comprising: a drilling mud fluid inlet
line connected to a drilling mud source at a first pressure; a mud
outlet line connectable to a borehole; a clean fluid inlet line
connected to a clean fluid source at a second pressure greater than
the first pressure; a clean fluid return line maintainable at a
pressure less than the first pressure; a membrane pump comprising;
a body having a hollow interior; and a membrane within the hollow
interior of the body, dividing the hollow interior into a first
volume and a second volume, the first and second fluid volumes
isolated from one another by the membrane; a drilling mud inlet in
fluid communication with the drilling mud inlet line and the first
volume; a drilling mud inlet check valve fluidly interposed between
drilling mud inlet line and the drilling mud inlet; a drilling mud
outlet in fluid communication with the first volume and the
drilling mud outlet line; a drilling mud outlet check valve fluidly
interposed between drilling mud outlet line and the drilling mud
outlet; a clean fluid inlet in fluid communication with the second
volume; an inlet user position selectable valve fluidly interposed
between the clean fluid inlet line and the clean fluid inlet; a
clean fluid outlet in fluid communication with the second volume;
and an outlet user position selectable valve fluidly interposed
between the clean fluid outlet and the clean fluid outlet line.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. provisional patent
application Ser. No. 63/162,863, filed Mar. 18, 2021 and U.S.
provisional patent application Ser. No. 63/125,535, filed Dec. 15,
2020, each of which are herein incorporated by reference.
BACKGROUND
Field
[0002] Embodiments of the present invention generally relate to
apparatus and methods of pressurizing fluid having abrasive solids
therein. More particularly, the present invention relates to the
pumping of fluids having abrasive solids therein using a pressure
transfer technique to pressurize the solids containing fluid across
a membrane.
Description of the Related Art
[0003] Fracking is a known technique to recover hydrocarbons such
as oil and gas from formations where the formation architecture
will otherwise not allow commercially feasible recovery of the
hydrocarbons. During fracking, fluid having a proppant carried
therein, for example sand or an engineered solid, is compressed to
a high pressure, for example up to 15,000 psi, and the fluid and
proppant is injected through a fracking unit through a borehole to
the target formation. The pressurized fluid cause cracking or
fracturing of the formation, and the proppant becomes wedged in the
cracks, maintaining the cracks to space apart the formation when
the fluid under pressure is removed. The hydrocarbons can then flow
from the formation through these open cracks.
[0004] One issue encountered during fracking is the cost of the
maintenance, and replacement of, the mechanical pumps used to
pressurize the fracking fluid. For example, piston pumps and rotary
vane type pumps are commonly employed to pressurize a dirty fluid,
i.e., a solids laden fluid, such as a fracking fluid. However, the
lifetime of these components is very short because of the excessive
wear thereof caused by the erosion of the surfaces thereof by the
proppant in the fracking fluid.
SUMMARY
[0005] A fracking fluid pressurization system, includes a dirty
fluid inlet line connected to a dirty fluid source at a first
pressure, a dirty fluid outlet line connectable to a well bore, a
clean fluid inlet line connected to a clean fluid source at a
second pressure greater than the first pressure, a clean fluid
return line maintainable at a pressure less than the first
pressure, a pump comprising, a body having a hollow interior, and a
membrane within the hollow interior of the body, dividing the
hollow interior into a first volume and a second volume, the first
and second fluid volumes isolated from one another by the membrane,
a dirty fluid inlet in fluid communication with the dirty fluid
inlet line and the first volume, a dirty fluid inlet check valve
fluidly interposed between dirty fluid inlet line and the dirty
fluid inlet, a dirty fluid outlet in fluid communication with the
first volume and the dirty fluid outlet line, a dirty fluid outlet
check valve fluidly interposed between dirty fluid outlet line and
the dirty fluid outlet, a clean fluid inlet in fluid communication
with the second volume, an inlet user position selectable valve
fluidly interposed between the clean fluid inlet line and the clean
fluid inlet, a clean fluid outlet in fluid communication with the
second volume, and an outlet user position selectable valve fluidly
interposed between the clean fluid outlet and the clean fluid
outlet line.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] So that the manner in which the above recited features of
the present disclosure can be understood in detail, a more
particular description of the disclosure, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only exemplary embodiments
and are therefore not to be considered limiting of its scope, may
admit to other equally effective embodiments.
[0007] FIG. 1 illustrates a schematic view of a fracking circuit
featuring a membrane pump.
[0008] FIG. 2 illustrates a sectional view of a membrane pump of
the fracking circuit of FIG. 1 at a resting state.
[0009] FIG. 3 illustrates a sectional view of a membrane pump of
the fracking circuit of FIG. 1 at a state in which the first volume
is being filled.
[0010] FIG. 4 illustrates a sectional perspective view of a
membrane pump of the fracking circuit of FIG. 1 at a state in which
the first volume is full.
[0011] FIG. 5 illustrates a sectional view of a membrane pump of
the fracking circuit of FIG. 1 at a state in which the second
volume is being filled
[0012] FIG. 6 illustrates a sectional view of a membrane pump of
the fracking circuit of FIG. 1 at a state in which the second
volume is being filled and the first volume is being emptied.
[0013] FIG. 7 illustrates a sectional view of a membrane pump of
the fracking circuit of FIG. 1 at a state in which the second
volume is full and the first volume is empty.
[0014] FIG. 8 illustrates a schematic view of a drilling mud
fracking circuit featuring a membrane pump.
[0015] FIG. 9 illustrates a mobile fracking pump system.
[0016] To facilitate understanding, identical reference numerals
have been used, where possible, to designate identical elements
that are common to the figures. It is contemplated that elements
and features of one embodiment may be beneficially incorporated in
other embodiments without further recitation.
DETAILED DESCRIPTION
[0017] Herein, in place of mechanical pumps such as piston and
impeller pumps, one or more membrane pumps are employed in a fluid
circuit to increase the pressure of a dirty fluid, for example the
fracking fluid, for injection into a subterranean formation. As
used herein, a dirty fluid is a fluid that contains solids and
particulates that are known to cause wear of or on, or degrade,
mechanical pumps, for example wear or degradation of piston pump
surfaces, When this wear or degradation occurs, the isolation
between the high and low pressure regions of the pumps, separated
by seals, may fail and prevent the pump from achieving the desired
outlet pressure of the fluid from the pump. By using a membrane
pump, a clean fluid, for example water without solids purposely
added thereto, is pressurized using a traditional mechanical
pumping apparatus, and this fluid is used to pressurize the dirty,
proppant containing, fracking fluid, without intermingling of the
two fluids, i.e., without commingling of the dirty and clean
fluids. As a result, the only moving part of the pump in contact
with the dirty fluid is the membrane, and movement thereof, caused
by differential pressure thereacross, is used to pressurize the
dirty fracking fluid. Multiple membrane pumps can be employed to
service a fracking unit, and by the provision of check valves on
the inlets and outlets of each of the dirty fluid and clean fluid
into the pump, the dirty fracking fluid is pressurized using a
minimum of moving pump parts exposed to the dirty fracking fluid.
In operation of this system, a clean fluid circuit is used to
pressurize clean fluid, i.e., a fluid such as water that has not
had a proppant added thereinto, and transfer that pressure into the
dirty fluid in the pump, and then return the clean fluid to a
storage. A dirty fluid circuit is configured to transfer or flow
the dirty fluid, i.e., a fluid such as water to which proppants and
chemicals such as surfactants are added, from a fluid storage to
the membrane pump to be pressurized, and then into a well bore to
pressurize a subterranean formation penetrated by the well bore.
Valves in the fracking fluid circuit are used to isolate the dirty
fluid being pressurized from communication with the well bore until
the pressure thereof is raised to a level above the pressure in the
wellbore. Thus, the pressure in the well bore can be raised in
stepwise fashion using one or more pumps. Once the fracturing of
the formation is completed, the dirty fluid is allowed to flow out
of the well bore and is collected for recycling or other
disposition thereof.
[0018] A fracking fluid circuit 100 utilizing membrane pumps 110 to
pressurize a fracking fluid is shown in FIG. 1. During operation of
the fluid circuit to pressurize the fracking fluid, the fluid
circuit components are located in close proximity to a fracking
unit over a wellhead or well bore. The fracking unit includes an
injection unit 101which is located adjacent to or over a well bore
or wellhead of a well bore extending to a formation to be
fractured. The injection unit 101 is fluidly connected to a piping
connected to a ball or gate valve 103. The ball or gate valve 103
isolates flow into, or out of, the well bore and flowing through
the injection unit 101. In FIG. 1, three injection units 101 are
shown with each connected to the fracking fluid circuit 100 through
a ball or gate valve 103 associated with, and dedicated to, each
injection unit 101. A fluid flow line 90 from each of the one or
more ball or gate valve(s) 103 leads to a common flow line or
manifold 92 attached to a first fracture relief valve 105. The
first fracture relief valve 105 allows emergency pressure relief to
occur during an upset or other deleterious event during a fracking
operation. The first fracture relief valve 105 is positioned
between the manifold 92 leading to the one or more ball or gate
valve(s) 103 and a first check valve 107 leading to one or more
membrane pump(s) 110 through a high pressure dirty fluid line 94.
The check valves in the fluid circuit 100 only open if there is a
pressure differential between the fluid ports of the check valve
sufficiently great to cause the check valves poppet or seal to move
off of a seat thereof. Each of the check valves herein, unless
otherwise specified, generally include a seat, a poppet which can
move against the seat to seal off an opening through the seat and
thus close the check valve, or move away from the seat to allow
fluid to pass through the opening, and a biasing element, typically
a spring, which if the pressure is the same or nearly the same on
the inlet and outlet sides of the check valve, pushes the poppet
against the seat to keep the check valve closed and will maintain
the check valve in this closed position until the pressure
difference between the inlet which ports fluid to the portion of
the poppet exposed within the circumference of the seat and the and
the outlet is sufficient to overcome the force of the spring
biasing the poppet against the seat. When the pressure on the valve
inlet causes the pressure on the inlet side of the poppet to exceed
the spring force, the poppet moves away from the seat and fluid can
flow through the check valve. If there is one and only one membrane
pump in the fracking circuit, the inlet to the first check valve
107 is connected through the high pressure dirty fluid manifold 94
to a dirty fluid outlet check valve 108, here membrane pump 108a,
connected to the dirty fluid outlet of a membrane pump 110. If
there are multiple membrane pumps 110, as shown in FIG. 1 six
membrane pumps 110a-f, the first check valve 107 is fluidly
connected through the high pressure dirty fluid manifold 94 to
multiple dirty fluid outlet check valves 108, here outlet check
valves 108a-f, each membrane pump 110a-f having one dirty fluid
outlet check valve 108 corresponding thereto connected between that
membrane pump 110 and the high pressure dirty fluid manifold 94
connected to the first check valve 107. Although six membrane pumps
110a-f are illustrated, a lesser or greater number may be used
based on user need.
[0019] Each of the one or more membrane pumps 110a-f includes a
housing providing a pressure vessel capable of securely holding
therein fluid at pressures of up to 15,000 or more psi, and a
flexible, stretchable membrane 98 (FIG. 2), of a rubber or rubber
like material) disposed therein and separating the dirty fluid
volume 50 of the membrane pump 110 from the clean fluid volume 52
thereof. Each membrane pump 110a-f includes a dirty fluid inlet 54,
which is controlled to be in an open or closed position by a
corresponding one of the dirty fluid inlet check valves 109
(109a-f), a dirty fluid outlet 56, which is controlled to be in an
open or closed position by a corresponding one of the dirty fluid
outlet check valves 108 (108a-f), a clean fluid inlet 58, which is
controlled to be in an open or closed position by a corresponding
one of a plurality of clean fluid inlet user selectable position
valves 111 (111a-f) individually associated with a one of the
membrane pumps 110a-f, and a clean fluid outlet 60, which is
controlled to be in an open or closed position by corresponding one
of a plurality of clean fluid outlet user selectable position
valves 112 (112a-f).
[0020] The dirty fluid inlet check valve 109 associated with a
membrane pump 110 is fluidly connected to a low pressure dirty
fluid manifold 62 leading bi-directionally therefrom. In one
direction or at one end thereof, the low pressure dirty fluid
manifold 62 is connectable to a fracking fluid waste receptacle
114, for example a tank trailer, and in the other direction or at
the other end thereof the low pressure dirty fluid manifold 62
extends to a dirty side master check valve 115. The low pressure
dirty fluid manifold 62 is here connected through the dirty side
master check valve 115 to a plurality of, in this aspect, two low
pressure pumps 116a and 116b. The low pressure pumps 116a,116b are
each connected, on the outlet side thereof, through a fracking
fluid side fluid inlet line 64 to the inlet of the dirty side
master check valve 115. They are also connected, at the inlet side
thereof through appropriate piping 66 or hoses, to a water source
121 and a chemistry source 122, for example a surfactant. The low
pressure pumps 116a, 116b, also include a mechanism for
incorporation of the proppant, for example sand, into the fluid
being pumped therethrough. Here, a hopper 68 is configured to
receive the proppant therein, and a screw auger, or other
conveyance, intermixes the proppant with the fluid entering the
inlet side of the low pressure pumps 116a, b, which fluid is then
pumped to approximately 110 to 120 psi at the outlet of the low
pressure pump 116a, b. The low pressure pump or pumps 116a, 116b
receives or pulls chemistry, water, and proppant from the chemistry
source 122, water source 121, and proppant source 120,
respectively, and pressurizes the fluid mixture to flow in the
direction of the dirty side master check valve 115 in the direction
of the membrane pump 110 at a relatively low pressure, for example
120 psi (127 KPa).
[0021] On the clean fluid side of the fluid circuit 100, one or
more high pressure pumps 133 are fluidly connected, through a high
pressure clean fluid source manifold 70, to the clean fluid inlets
58 of the membrane pumps 110, and the clean fluid outlets 60 of the
membrane pumps 110 are fluidly connected to a return manifold 76 to
return the clean fluid back to a fluid reservoir, such as one or
more water tanks 134. The clean fluid inlet 58 (58a-f) to each
membrane pump 110 is controlled to be open or closed by a clean
fluid inlet user selectable position valve 111 (111a-f). A clean
fluid inlet line 72 extends from each of the clean fluid inlet user
selectable position valves 111a-f toward and to the clean fluid
source manifold 70. The clean fluid inlet user selectable position
valves 111a-f are controlled by a computer to be opened or closed
based upon the output of a pressure transducer or volume detector
of the membrane pump 110a-f with which they are each associated.
The clean fluid source manifold 70 extends from the connection
thereof to the clean fluid inlet lines 72 associated with each
membrane pump 110a-f, to one or a plurality of on/off valves 130.
The on/off valves 130 are each connected via appropriate piping to
a high pressure check valve 131. Each high pressure check valve 131
is fluidly located between the on/off valve 130 and a pressure
regulator 132. Each pressure regulator 132 is connected to the
outlet of a high pressure pump 133, and is set to establish the
maximum pressure of the clean fluid that goes into the fluid lines
leading to the membrane pumps 110, for example 15,000 p.s.i. If the
fluid outlet pressure of one of the high pressure pumps 133
overshoots the maximum desired pressure, the pressure regulator 132
reduces the pressure at the outlet thereof to bring the fluid
pressure of the clean fluid reaching the clean fluid inlet line 72
associated with each of the membrane pumps 110a-f within the
desired pressure range.
[0022] The fluid piping for the high pressure clean fluid connects
each pressure regulator 132 to a high pressure pump 133, which are
each capable of compressing fluid received from the connected
plurality of water tanks 134 to 15,000 psi (103.4 MPa). A series of
connection lines 145 allow water to be pulled from any tank of the
plurality of water tanks 134 by any of the high pressure pumps 133,
and the surface of the water in the water tanks may be exposed to
local ambient,. i.e., atmospheric, pressure.
[0023] A clean fluid outlet user position selectable valve 112a-f
is fluidly connected between an associated one of the clean fluid
outlets 60a-f, such that a single one of the clean fluid outlet
user position selectable valves 112a-f is fluidly connected to a
single one of the clean fluid outlets 60a-f at the inlet thereof
and to the return manifold 76 at the outlet thereof. The clean
fluid outlet user selectable position valves 112a-f are controlled
by a computer or controller, such as an Field Gate Programmable
Array or FGPA, in response to signals received from a pressure
transducer or volume reader or sensor located on the clean fluid
side of the inside of an associated one of the membrane pumps
110a-f. The return manifold 76 fluidly connects the clean fluid
outlets 60a-f of the several membrane pumps 110a-f to a heat
exchanger and water filter unit 136, from which a chilled water
line 78 extends to return the clean fluid to the water tanks 134.
The heat exchanger and water filter unit 136 cools the returning
water and filters out any particulates larger than a user
selectable size from the returning clean fluid.
[0024] Each of the membrane pumps 110a-f is configured to
pressurize the dirty fluid, here a fracking fluid, and to pump it
to enter the injection unit 101 and associated well bore and to
pressurize the fracking fluid to a pressure on the order of 15,000
p.s.i. To allow high pressure fluid at around 15,000 psi (103.4
MPa) to be present in the well bore, fracking fluid, here a
combination of water, proppant, and chemistry is pumped by the low
pressure pump or pumps 116a, b to a pressure of at 110 to 120
p.s.i. (760 to 827 KPa). When the pressure in the dirty fluid side
or dirty fluid volume 50 of a membrane pump 110 is less than this
pressure, dirty fluid will be pumped toward the dirty side master
check valve 115 in the direction of the membrane pumps 110a-f. By
proper cycling of the clean fluid and the dirty fluid, the volume
of dirty fluid present in a membrane pump 110a-f can be pumped
toward the well bore in a continuous flow until the volume of dirty
fluid in the membrane pump 110a-f is exhausted therefrom.
[0025] Referring initially to FIG. 2, the membrane pump 110 is
shown at rest, or at volume equilibrium, where the volume of dirty
fluid in the dirty fluid volume 50 (i.e., on the dirty fluid side
of the membrane 98) and volume of clean fluid in the clean fluid
volume 52 (i.e., on the clean fluid side of the membrane 98) are
equal within the membrane pump. As the membrane 98 is flexible, the
fluid volumes of the dirty fluid volume 50 and clean fluid volume
are variable, depending on the relative pressures therein. When the
pressure in the dirty fluid side of the membrane 98 is greater than
that on the clean fluid side thereof, the dirty fluid volume 50
increases, while the clean fluid volume decreases, and vice
versa.
[0026] To pump the dirty fluid to the high pressure needed for
fracking, the dirty fluid inlet check valve 109 and the clean fluid
outlet user selectable position valve 112 are open, and the dirty
fluid outlet check valve and the clean fluid inlet user selectable
position valve 111 are closed. In this state, the clean fluid
outlet 60 is ultimately exhaustible to ambient air pressure at one
or more of the water tanks 134, and hence the dirty fluid at 120
psi will push the clean fluid from the clean fluid volume 52 of the
membrane pump 110, replacing the volume of clean fluid pushed out
of the clean fluid volume 52 of the membrane pump 110 with a
corresponding volume of dirty fluid in the dirty fluid volume 50 of
the membrane pump 110. This caused the volume of the clean fluid
volume to contract, and the membrane 98 moves through the position
shown in FIG. 3 to that of FIG. 4, where the dirty fluid volume is
nearly 100% of the internal volume of the housing 96 of the
membrane pump 110 and the clean fluid volume approaches 0% of the
internal volume of the housing 96 of the membrane pump 110. Once
the clean fluid has been pushed out of the membrane pump 110, the
pressure inside the dirty fluid volume 50 and the pressure in the
low pressure dirty fluid manifold 62 will equalize, and the dirty
fluid inlet check valve 109 will close as the pressure on opposed
sides of it equalizes allowing the spring thereof to close the
poppet against the seat thereof, isolating the dirty fluid volume
50 from the dirty fluid in the low pressure dirty fluid manifold
62. Then, the clean fluid outlet user selectable position valve 112
is closed, and the clean fluid inlet user selectable position valve
111 is opened, causing high pressure clean fluid to enter the clean
fluid volume 52 and increase the pressure of the dirty fluid in the
dirty fluid outlet 56. Once the dirty fluid in the dirty fluid
volume 50 reaches a pressure sufficiently greater that the pressure
in the high pressure dirty fluid manifold 94, to push the poppet
against the spring to lift off of the seat of the dirty fluid
outlet check valve 108, the dirty fluid will be pushed out of the
membrane pump 110, into the high pressure dirty fluid manifold 94
and thence into the well bore, with the position of the membrane 98
moving in the sequence shown from FIG. 4 to FIG. 7. Here, the clean
fluid volume 52 increases as the dirty fluid volume 50 decreases,
as the dirty fluid is being forced into the high pressure dirty
fluid manifold 94. Then, by again opening the clean fluid outlet
user selectable position valve 112 and closing the clean fluid
inlet user selectable position valve 111, the dirty fluid at 120
psi (127 KPA) will enter the dirty volume side 50 of the membrane
pump 110 and push the clean fluid out of the membrane pump 110 and
into the return manifold 76 toward the water tank(s) 134.
[0027] To properly cycle the valving controlling the clean fluid
inlet 58 and clean fluid outlet connected to the clean fluid side
or clean fluid volume 52 of the membrane pump 110, a detection
paradigm for determining whether the membrane pump is full of dirty
or full of clean fluid is needed. For example, as shown in FIG. 4,
to sense that the membrane 98 is fully filed with dirty fluid, the
membrane 98 may include a conductive surface formed or adhered
thereto on the clean fluid side thereof, for example a thin metal
sheet 154, and a pair of, spaced from one another, electrical
contacts 156a, b, connected to a source of power and ground,
respectively are provided on the inner wall of the membrane pump
110 in a location where the metal sheet 154 can come into contact
with them when the dirty fluid volume 50 nears 100% of the membrane
pump 110 volume.. A current or voltage detector 160 is connected to
the ground path of the circuit, and the detector is readable by a
controller 158. When the sheet 154 contacts both contacts,
electricity flows through the sheet 154 and is detected by the
detector, causing the controller to close the user selectable
position valve 112 on the pump clean fluid outlet 60, and open the
user selectable position valve 111 on the clean fluid inlet 58.
This same sheet 154 and electrical contacts can be employed to
detect when the membrane pump is at its full capacity of clean
fluid, by locating a second sheet on the opposed side of the
membrane 98 and the second pair of electrical contacts 156a, b,
spaced form one another adjacent the dirty fluid inlet and outlet,
to sense when the dirty fluid has been fully exhausted from the
dirty fluid volume 50 (dirty fluid side) of the membrane pump
110.
[0028] The clean fluid inlet user selectable position valve 111,
controlled by a controller 158 in response to a signal from
pressure transducer, volume sensor, or membrane sensor inside of
the membrane pump 110, opens in response to the membrane pump 110
filling with dirty fluid. Clean fluid is then pushed by the high
pressure pump 133, which pumps fluid at a pressure of up to 15000
psi from the connected plurality of water tanks 134, into the clean
fluid volume 52 side of the membrane pump. Clean fluid is pushed or
flowed through the pressure regulator 132, which sets the maximum
pressure that goes into the lines leading to the membrane pumps,
through the high-pressure check valve 131, and through the on/off
valve 130 to the clean fluid inlet 58. Clean fluid enters the
membrane pump 110, causing an increase in pressure in the dirty
fluid therein, this higher pressure causing closing of the dirty
fluid inlet check valve 109 and opening of the dirty fluid outlet
check valve 108.
[0029] In one aspect, the functionality of the inlet and outlet
user selectable position valves 111, 112 can be combined in a
single valve, for example a three way, two position, valve, wherein
the clean fluid inlet 58 and the clean fluid outlet 60 are
selectively and exclusively the clean fluid source manifold 70 and
the return manifold 76 respectively. Using this valve, the clean
fluid inlet 58 is fluidly connected to the clean fluid source
manifold 70 when the clean fluid outlet 60 is fluidly disconnected
from the return manifold 76, and the clean fluid outlet 60 is
fluidly connected to the return manifold 76 only when the clean
fluid inlet 58 is fluidly disconnected to the clean fluid source
manifold 70.
[0030] The membrane pump 110 pushes the dirty fluid out of the
dirty fluid outlet check valve 108, allowing the dirty fluid to
exit the membrane pump 110 and flow into the high pressure dirty
fluid line 94, through the first check valve 107, which opens in
response to the high pressure fluid, through the first fracture
relief valve 105, and the ball or gate valve 103 controlling access
to each injection unit 101 and its associated well bore. At the
beginning of the fracking process, multiple full membrane pump
volumes of dirty fluid may need to be flowed into the well to form
a continuous liquid column of dirty fluid between the injection
unit and the formation. Thereafter, as each membrane pump 110 pumps
its volume of dirty fluid into the high-pressure dirty fluid line,
the pressure thereof will increase. A number of additional volumes
of dirty fluid will then be pumped into the high-pressure dirty
fluid manifold 94 raising the pressure therein, and at the
formation, to the fracking pressure. If the pressure in the well
bore or the high pressure dirty fluid manifold 94 spikes, the first
fracture relief valve 105 will open to allow pressurized fluid to
flow out into the atmosphere, preventing damage to the fluid
circuit 100. If equilibrium is reached, i.e., the fluid pressure in
the high pressure dirty fluid manifold 94 and fluid pressure in the
clean fluid source inlet 70 become equal, then the pumping of the
dirty fluid from the membrane pumps 110a-f will stop, but the
pressure will be maintained in the high pressure dirty fluid
manifold 94 at the pressure of the clean fluid source manifold
70.
[0031] The clean fluid in the membrane pump 110 exits through the
clean fluid outlet 60, which is controlled to be in an open or
closed state by the clean fluid outlet user selectable position
valve 112. The clean fluid flows from the clean fluid outlet 60
toward the heat exchanger and water filter unit 136. The heat
exchanger and water filter unit 136 cools the pressurized water to
allow it to continue to flow through the clean fluid circuit as a
liquid, i.e., to prevent it from gaining heat during each
pressurization thereof resulting in higher and higher fluid
temperature over time. The clean fluid flows from the heat
exchanger and water filter unit 136 back into the plurality of
water tanks 134 to be used again in the membrane pump110 to
pressurize the dirty fluid.
[0032] The use of a separate dirty fluid circuit(s) and clean fluid
circuit(s), in conjunction with the pumping using a membrane 98 to
provide variable, isolated from one another, dirty fluid and clean
fluid volumes 50, 52 within a pressure vessel, here membrane pump
110, enables fluid isolation of the lower pressure dirty fluid from
the higher pressure dirty fluid, and, with proper valving, allows
the inlet and outlet to the pump on the dirty fluid side thereof to
automatically cycle in response the cycling of the inlet and outlet
valves on the clean fluid side of the membrane 98. Additionally,
within operational tolerance, the input pressure to the dirty fluid
volume 50 of the membrane pump 110 remains the same pressure
throughout a single operation, such as a fracking operation, using
the dirty fluid. Likewise, because the dirty fluid inlet valve 109
operates as a pressure relief valve, wherein it opens solely based
on the pressure differential across the inlet from the low pressure
pump 116a, b and outlet to the dirty fluid volume 50 side thereof,
and the spring constant of a spring therein providing a force to
help maintain it in a closed position, the characteristics of
filling a specific membrane pump 110 will remain relatively
constant over multiple filling cycles, leading to operational
stability and predictability of the fill time of the dirty fluid
volume 50 of the membrane pump 110. This occurs because the vent
manifold 76 pressure will be of a similar value each time the clean
fluid user selectable position outlet valve 112 is opened. Thus the
pressure drop in the clean fluid volume 52, and thus the dirty
fluid volume 50, should be repeatable from one pumping cycle to
fill and then exhaust the dirty fluid volume 50 to the next pumping
cycle to fill and then exhaust the dirty fluid volume 50. On the
high pressure side, the dirty fluid outlet valve 108 opens only
after the clean fluid entering the clean fluid volume side 52 of
the membrane pump 110 has achieved the release pressure of the
dirty fluid outlet valve 108, which is a function of the pressure
in the dirty fluid manifold 94 and the force of the spring holding
the dirty fluid outlet valve 108 in a closed position until the
pressure in the dirty fluid volume 50 of the membrane pump is equal
to or slightly greater than the pressure in the high pressure dirty
fluid manifold 94, at which point it opens allowing the membrane
and clean fluid on the clean fluid volume 52 side of the membrane
pump 110 to push the dirty fluid into the high pressure dirty fluid
manifold 94. Initially, before any fluid is flowed, the pressure in
the high-pressure dirty fluid manifold 94 is at or near atmospheric
pressure. Once fluid is present from in the high pressure dirty
fluid membrane and in the borehole to the subterranean zone where
fracking is to occur, as additional dirty fluid is pushed into the
high-pressure dirty fluid manifold 94 in each pumping cycle of the
membrane pump 110, the pressure therein increases. Therefore, in
each subsequent pumping cycle the pressure of the dirty fluid in
the dirty fluid volume of the membrane pump 110 needs to reach a
higher pressure to cause the dirty fluid outlet valve 108 to open.
However, the difference in pressure across the membrane pump 110
side and the high-pressure dirty fluid manifold 94 sides of the
dirty fluid outlet valve remains the same for each cycle. Thus,
where a single membrane pump 110 is used to charge the high
pressure dirty fluid manifold 94 with dirty fluid, the pressure in
the high pressure dirty fluid manifold 94 will rise in a step wise
fashion, the dirty fluid in the high pressure dirty fluid manifold
94 maintaining its pressure at a first pressure during fill cycles
of the membrane pump 110 with dirty fluid, increasing in pressure
as the manifold pump 110 operates to push the dirty fluid therefrom
into the high pressure dirty fluid manifold 94 to achieve a second
pressure higher than the first pressure, and maintaining that
second pressure during another fill cycle of the membrane pump 110
with dirty fluid. Thus, the pressure in the high-pressure dirty
fluid manifold 94 will rise in a step wise fashion until the
desired pressure therein is reached, while the pressure in the
low-pressure dirty fluid manifold 62 remains relatively constant.
Where multiple membrane pumps 110 are employed, they can each
independently pump dirty fluid into the high pressure dirty fluid
manifold 94, which will occur when the pressure of the dirty fluid
in the dirty fluid volumes of the membrane pumps 100 are greater
than that in the high pressure dirty fluid manifold 94, either
simultaneously with one another, in time separated pumping's from
one another, or with overlaps in their pumping periods into the
high pressure dirty fluid manifold 94.
[0033] In one aspect, the high pressure fluid delivery capability
enabled herein is portably mounted, and can be deployed to a site
requiring a source of dirty high pressure fluid, connected to any
local fluid connections, such as fluid sources and a fluid delivery
locale, and after the need for the high pressure fluid capability
is over, disconnected from the local fluid connections and
redeployed or moved to storage. For example, as shown in FIG. 9,
one or more membrane pumps 110, here two membrane pumps 110, are
disposed on a mobile vehicle device, for example an over the road
trailer 140 supported on tires 142 and a selectively deployable
front stand 144. The trailer 140 includes a front kingpin plate 146
for connection of the trailer to a tractor truck cab (not shown).
Each membrane pump 110, here two membrane pumps 110, is supported
on a dedicated skid 150, shown schematically. The dirty fluid, and
clean fluid, hard piping connections, for example the low pressure
dirty fluid manifold 62, high pressure dirty fluid manifold 94, and
associated valves 108, 109 for fluid connection of the dirty fluid
into and out of the membrane pumps 110, and the clean fluid source
manifold 70 and return manifold 76, and associated user selectable
position valves 111, 112 for selectable supply, and venting of,
clean fluid to the membrane pumps 110 are also carried on the
trailer 140 and fluidly hard connected to the membrane pumps 110.
Trailer hydraulic connection valves 152, for example gate or ball
valves, are provided at the opposed ends of the low pressure and
high pressure dirty fluid manifolds 62, 94 and the opposed ends of
the clean fluid source manifold 70 and return manifold 76.
Alternatively, fluid connectors or couplings may be provided at are
provided at one or both of the opposed ends of the low pressure and
high pressure dirty fluid manifolds 62, 94 and one or both of the
opposed ends of the clean fluid source manifold 70 and return
manifold 76. A controller box 162, housing the controller 158, is
also mounted on the trailer 140 and selectively connected to the
user positionable selection valves 111, 112 and the pump fullness
detectors, such as the detector 160.
[0034] In use, one or more membrane pumps 110 may be required for a
particular application requiring the high-pressure dirty fluid. For
example, where more membrane pumps 110 than can be mounted on a
single trailer 140 are needed, manifolds on adjacent trailers can
be connected together, as appropriate, through the trailer
hydraulic connection valves 152. Alternatively, the opposed ends of
the low pressure and high-pressure dirty fluid manifolds 62, 94 and
the opposed ends of the clean fluid source manifold 70 and return
manifold 76 can be closed off with caps, or left open. In any case,
one of the opposed ends of the low pressure dirty fluid manifold 62
and one of the opposed ends of the clean fluid source manifold 70
are used to connect the membrane pumps 110 to sources of dirty and
clean fluid respectively, whether directly form a pump or through
an appropriate manifold on another trailer, one of the opposed ends
of the high pressure dirty fluid manifold 94 is connectable to a
formation through a well bore, and one of the opposed ends of the
return manifold 76 is connectable to a fluid storage tank. As a
result of this construct, a desired pumping capacity can be
deployed, used, and removed from a user site, adjacent one or more
wellheads of well bores requiring a supply of high-pressure
fracking fluid.
[0035] Referring to FIG. 8, an additional use of the membrane pumps
96 hereof is shown, wherein a mud pump for providing drilling mud
under pressure to a wellbore is shown and described. The mud pump
operates in a similar fashion to the fracking fluid delivery system
of FIGS. 1 to 7, except a drilling mud composed of a liquid base,
for example water, and one or more additives such as weighing
agents to increase the weight per cubic foot of the liquid, as well
as other agents such as clay, corrosion inhibitors salts and
lubricants are mixed together before the mud is flowed to a well
bore.
[0036] A mud fluid circuit 100' utilizing membrane pumps 110 to
pressurize a drilling mud is shown in FIG. 8. During operation of
the fluid circuit to pressurize the mud for delivery to a borehole
having a drill string selectively disposed therein to drill the
borehole deeper into the earth, the fluid circuit components are
located in close proximity to a drilling rig 204 located over the
borehole being drilled. Here, a mud delivery unit 206 is located at
the opening of the borehole into the earth, to allow drilling mud
to be pumped into the borehole. The drilling mud may be delivered
at ambient atmospheric pressure, or at a pressure greater than
atmospheric where the opening of the borehole into the earth can be
isolated from the ambient atmospheric pressure at the borehole
opening into the earth location. In this case, a higher pressure
than the pressure created by the weight of the drilling mud in the
borehole can be experienced or imposed at the bottom, or cutting
face, of the borehole. The mud delivery unit 206 is connected to a
piping connected to a drilling mud ball or gate valve 103'. The
drilling mud ball or gate valve 103' isolates flow into or out of
the borehole and flowing through the mud delivery unit 206. In FIG.
8, three mud delivery units 206 are shown connected to the fluid
circuit 100, each through a drilling mud ball or gate valve 103'
associated with, and dedicated to, a different one of the mud
delivery units 206. A fluid flow line 90 from each of the one or
more drilling mud ball or gate valve(s) 103' leads to a common flow
line or manifold 92 attached to a first mud pressure relief valve
105'. The mud pressure relief valve 105' allows emergency pressure
relief to occur during an upset or other deleterious event during a
drilling operation. The mud pressure relief valve 105' is
positioned between the manifold 92 leading to the one or more mud
ball or gate valve(s) 103' and a first check valve 107 leading to
one or more membrane pump(s) 110 through a high pressure mud line
or mud manifold 94'. The check valves in this circuit only open if
there is a pressure differential between the fluid ports of the
check valve sufficiently great to cause the check valves poppet or
seal to move off of a seat thereof. Each of the check valves
herein, unless otherwise specified, generally include a seat, a
poppet which can move against the seat to seal off an opening
through the seat and thus close the valve, or move away from the
seat to allow fluid to pass through the opening, and a biasing
element, typically a spring, which if the pressure is the same on
the inlet and outlet sides of the valve, pushes the poppet against
the seat to keep the valve closed and will maintain the check valve
in this closed position until the pressure difference between the
inlet which ports fluid to the portion of the poppet exposed within
the circumference of the seat and the and the outlet is sufficient
to overcome the force of the spring biasing the poppet against the
seat. When the pressure on the valve inlet causes the pressure on
the inlet side of the poppet to exceed the spring force, the poppet
moves away from the seat and fluid can flow through the valve. If
there is one and only one membrane pump in the fracking circuit,
the inlet to the first check valve 107 is connected through the
high-pressure mud manifold 94 to a mud outlet check valve 108'
connected to the high-pressure outlet of membrane pump 110. If
there are multiple membrane pumps 110, as shown in FIG. 1 six
membrane pumps, the first check valve 107 is connected through the
high pressure dirty fluid manifold 94 (here carrying drilling mud)
to the outlet of multiple outlet check valves 108, for example
108a-f, each membrane pump 110 having one mud outlet check valve
108 connected between the membrane pump 110 and the high pressure
mud manifold 94 connected to the first check valve 107.
[0037] Each of the one or more membrane pumps 110 includes a
housing providing a pressure vessel capable of securely holding in
fluid at pressures of up to 15,000 or more psi, and a flexible,
stretchable membrane 98 (FIG. 2, of a rubber or rubber like
material) disposed therein and separating the dirty fluid volume 50
of the membrane pump 110 from the clean fluid volume 52 thereof.
Each membrane pump includes a dirty fluid inlet 54, which is
controlled to be open or closed by a dirty fluid inlet check valve
109 to allow a dirty fluid, here drilling mud containing the
weighing agents, additives, etc., therein into the dirty fluid
volume of the pump, a dirty fluid outlet 56, which is controlled to
be open or closed by a dirty fluid outlet check valve 108, a clean
fluid inlet 58, which is controlled to be open or closed by a clean
fluid inlet user selectable position valve 111, and a clean fluid
outlet 60, which is controlled to be open or closed by clean fluid
outlet user selectable position valve 112.
[0038] The dirty fluid inlet check valve 109 attached to the
membrane pump 110 is connected to a low pressure dirty fluid
manifold 62, here containing the pre-mixed drilling mud, leading
bi-directionally therefrom. In one direction the low pressure dirty
fluid manifold 62 is connectable to a mud waste receptacle 114',
for example a tank trailer, and in the other direction the low
pressure dirty fluid manifold 62 extends to a dirty side master
check valve 115. The low pressure dirty fluid manifold 62 is here
connected through the dirty side master check valve 115 to a
plurality of, in this aspect, two low pressure pumps 116a and 116b.
The low-pressure pumps 116a,b are each connected, on the outlet
side thereof, through a mud side fluid inlet line 64' to the inlet
of the dirty side master check valve 115. They are also connected,
at the inlet side thereof through appropriate piping 66 or hoses,
to a water source 121 and a chemistry source 122, for example
corrosion inhibitors, salts, lubricants and other mud additives.
The low pressure pumps 116a, b, also include a mechanism for
incorporation of the solid additives for the mud, for example
granulated or powdered barite and bentonite, into the fluid,
typically water, being pumped therethrough. Here, a hopper 68 is
configured to receive the solid additives therein, and a screw
auger, or other conveyance, intermixes the solid additives with the
fluid in the pump, which is then pumped to approximately 120 psi at
the outlet of the low-pressure pump 116a, b. The low pressure pump
or pumps 116a,b pulls chemical additives, water, and solid
additives such as weight additives from the chemistry source 122,
water source 121, and solid additives source 120'a, respectively,
and pressurizes the mixture to flows a low pressure mud in the
direction of the dirty side master check valve 115 and in the
direction of the membrane pump 110 at approximately 120 psi.
[0039] On the clean fluid side of the fluid circuit 100, one or
more high pressure pumps 133 are fluidly connected, through a high
pressure clean fluid source manifold 70, to the clean fluid inlets
58 of the membrane pumps 110, and the clean fluid outlets 60 of the
membrane pumps 110 are connected to a return manifold 76 to return
the fluid back to a fluid reservoir, such as a water tank 134. The
clean fluid inlet 58 to each membrane pump 110 is controlled to be
open or closed by a clean fluid inlet user selectable position
valve 111. A clean fluid inlet line 72 extends from the clean fluid
inlet user selectable position valve 111 toward and to a clean
fluid source manifold 70. The clean fluid inlet user selectable
position valve 111 is controlled by a computer to be opened or
closed based upon the output of a pressure transducer or volume
detector of the membrane pump 110. The clean fluid source manifold
70 extends from the connection thereof to the clean fluid inlet
lines 72 associated with each membrane pump 110, to one or a
plurality of on/off valves 130. The on/off valves 130 are each
connected via appropriate piping to a high-pressure check valve
131. Each high-pressure check valve 131 is fluidly located between
the on/off valve 130 and a pressure regulator 132. The pressure
regulator 132 sets the maximum pressure that goes into the fluid
lines leading to the membrane pumps 110. If a high-pressure pump
overshoots the maximum desired pressure, the regulator reduces the
pressure at the outlet thereof to bring the fluid pressure reaching
the membrane pumps 110 within the desired pressure range.
[0040] The fluid piping for the high pressure clean fluid connects
each pressure regulator 132 to a high pressure pump 133, which are
each capable of compressing fluid received from the connected
plurality of water tanks 134 to 15,000 psi. A series of connection
lines 145 allow water to be pulled from any tank of the plurality
of water tanks 134 by any of the high-pressure pumps 133.
[0041] The clean fluid outlet user position selectable valve 112 is
located on the clean fluid outlet 60 and between the outlet and the
return manifold 76. The clean fluid outlet user selectable position
valve 112 is controlled by a computer in response to a pressure
transducer or volume reader inside of the membrane pump 110. The
return manifold connects to the clean fluid outlets 60 of the
several membrane pumps 110 to a heat exchanger and water filter
unit 136, from which a chilled water line 78 extends to return the
clean fluid to the water tanks 134. The heat exchanger and water
filter unit 136 cools the returning water.
[0042] The membrane pump 110 pressurizes the mud to enter the
injection unit 101 and borehole at up to approximately 15,000 psi.
To allow high-pressure fluid at around 15000 psi to be present in
the borehole the mud flows toward the dirty side master check valve
115 in the direction of the membrane pump 110 at 120 psi, to which
pressure it has been compressed by the low-pressure pump or pumps
116. By proper cycling of the clean fluid and the dirty fluid, the
volume of dirty fluid, i.e., mud, present in the membrane pump can
be pumped toward the well bore in a continuous flow until the
volume of mud in the membrane pump is exhausted therefrom. In each
fill and drain cycle of the clean fluid side of each membrane pump
110, a discrete volume of mud is pressurized to a pressure greater
than that of the mud in the mud manifold 94', and thence pushed out
of the dirty side of the membrane pump and through the mud outlet
check valve 108' into the mud manifold 94'. Thus, if the borehole
is sealed to allow pressurization thereof using high-pressure mud,
this pushing of the mud into the mud manifold results in an
increase in mud pressure in the borehole. Additionally, as the
borehole is being drilled, the membrane pumps pump the mud into the
borehole to increase the quantity of the mud therein in relation to
the increasing volume thereof. Thus, the membrane pumping system
for pumping a fracking fluid is likewise useable to mix, and pump,
drilling mud, to one or more boreholes being drilled.
* * * * *