Flowline power generator

A flowline power generator especially adapted for use on a conduit or flowline carrying petroleum or hydrocarbon products is disclosed. A valve body incorporated in the flowline redirects at least a portion of the fluid flowing through the flowline into engagement with a turbine which drives an electrical generator. A gate valve is provided for bypassing the turbine to permit all of the flow in the conduit to bypass the power generator, and yet provide substantially the same pressure drop to protect downstream equipment from high-pressure surges. In the bypass configuration, the power generator can be repaired or completely removed. The valve body can be incorporated into the flowline with no power generator attached, and power generators can be subsequently installed at prescribed locations along the conduit.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the generation of mechanical or electrical power 
from the fluid dynamic energy of a fluid transported through a flowline or 
a pipeline and, more particularly, relates to the selective generation of 
electrical power at remote locations on a flowline or pipeline used to 
transport fluids without substantially changing the downstream fluid 
pressure in the flowline. 
2. Description of the Prior Art 
Electrical power is acquired for many operations performed in conjunction 
with the production, gathering, and distribution of fluids and various 
flow media in the petroleum industry. For example, multi-well gathering 
facilities require electrical power for heater/treater control panel, 
separator control panels, tank and flowline heaters, fire protection 
asistance, gas detector systems, electrohydraulic pumps, chemical 
injection pumps, telemetry equipment, and microprocessor-based control 
systems. Electrical power is also necessary on remote wells such as carbon 
dioxide producing and injection wells, gas injection wells, and water 
flood sites. Electrical power is necessary for actuating adjustable 
flowline chokes, power and flowline heaters, safety systems, and 
microprocessor-based telemetry equipment. Electrical power is necessary on 
pipelines, near pipeline valves for power in control systems for valve 
operators, line break systems, electrohydraulic power packs, and telemetry 
equipment. In offshore applications, electrical power is necessary for 
navigation systems such as fog horns, navigation lights, and communication 
systems. In short, there are a number of remote locations where continuous 
electrical power or intermittent electrical power is required for 
performing operations in the petroleum industry. In many of these 
locations it is uneconomical to employ engine-driven generators. Solar 
array panels have been employed to provide electrical power in remote 
locations. In offshore applications, marine cable has been laid to provide 
electrical power at remote locations. 
Various prior devices have been used in an attempt to generate electrical 
power from the fluid dynamic energy of a working fluid flowing through a 
line or pipeline in the petroleum industry. These systems have commonly 
employed impellers or turbine rotors mounted in the flowline with the axis 
extending either parallel to or coincident with the axis of the flowline, 
to generate sufficient shaft horsepower to drive a conventional electrical 
generator. For example, shaft-driven brush commutated DC permanent magnet 
generators driven by coaxial mud turbines have been employed downhole in a 
pipe string to power well logging and other equipment. 
In addition to conventional axial flow turbines, shaft horsepower has also 
been developed in other applications by use of impulse turbines powered by 
fluids engaging the turbines at their periphery. Impulse turbines driven 
by a series of nozzles located on the periphery of a chamber containing 
the turbine are disclosed in U.S. Pat. Nos. 4,060,336 and 4,150,918. 
No prior art method or apparatus using a turbine-driven generator to 
convert the fluid dynamic energy of a working fluid in a flowline into 
electrical power is known in which the turbine-driven generator may be 
attached or removed while the fluid is flowing through the line and 
without substantially changing the downstream fluid pressure as a 
consequence of such attachment or removal. Furthermore, no prior device 
provides for a selective fluid bypass capable of bypassing fluids around 
the turbine when electrical power is not required, and also permitting 
selective actuation of the turbine as desired without substantially 
affecting the downstream fluid pressure. 
SUMMARY OF THE INVENTION 
A method and apparatus for use in converting the fluid dynamic energy of a 
fluid flowing in a conduit, flowline, or pipeline to electrical energy 
available at prescribed locations intermediate the ends of the conduit 
comprises a fluid pressure engine, such as a turbine, driven by the fluid 
flowing in the conduit, connected to an electrical generator. A separate 
member such as a valve body is incorporable in the flowline at each 
prescribed location and the turbine and generator can be attached to the 
valve body. The valve body comprises a diverter tube apparatus for 
redirecting at least a portion of the flow in the conduit along a path 
transverse to the conduit. The redirected fluid is brought into engagement 
with the rotary turbine to generate shaft horsepower from the pressure 
drop of the working fluid through a nozzle located adjacent to the 
periphery of the turbine. In the preferred embodiment, the turbine rotates 
about an axis transverse or perpendicular to the axis of the fluid conduit 
or flowline. A bypass passage communicating with the valve body and 
shiftable between first and second positions, provides the means for 
diverting fluid from engagement with the turbine. This bypass passage can 
be shifted into a position communicating between both the upstream and 
downstream sections of the conduit. With the bypass passage communicating 
between the upstream and downstream conduit sections, the turbine and the 
generator can be removed from the valve body without interferring with the 
flow through the conduit or pipeline. Use of a valve body having this 
internal bypass section also permits attachment of a turbine generator at 
any location in which the valve body is incorporated into the conduit at 
any time during operation of the pipeline. The bypass section or gate is 
manipulated externally so that the bypass section or gate can remain 
closed until it becomes necessary to actuate the turbine power generator. 
In accordance with the method of this invention, the bypass passage is 
proportioned to produce substantially the same pressure drop as the 
turbine which it replaces. Thus, the turbine can be connected to or 
removed from the conduit without subjecting downstream apparatus to 
dangerous pressure surges.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
The turbine-driven, in-line electrical power generator 2 comprising the 
preferred embodiment of this invention includes a valve body 4 
incorporable in a flowline or pipeline 6, and an electrical generator 
assembly 8, a fluid pressure engine, such as turbine 10, and a valve gate 
assembly 18 and 20, including a bypass passage 18c. The turbine 10 and the 
generator assembly 8 can be mounted on the valve body 4. In the preferred 
embodiment of this invention, the flowline 6 comprises a conventional 
flowline or pipeline used for the transportation of petroleum fluids such 
as crude oil. For example, the line 6 can comprise a cross-country 
pipeline or it can comprise a line in a gathering system located in an oil 
field having a number of producing wells. Normally, although not 
necessarily, the line 6 will comprise a surface line where access for 
attachment, removal, or servicing of the power generating unit is 
available. The valve body 4 has flanged sections 4a at either end and 
means for receiving a plurality of studs 12 for attaching and 
incorporating the valve body 4 into the flowline. The valve body 4 is 
incorporated into the flowline at a time when no fluids are flowing in 
that portion of the flowline. Thus, valve bodies 4 can be inserted into a 
new pipeline at prescribed or predetermined locations at which electrical 
power may subsequently become necessary. The valve body 4 can be inserted 
into the flowline 6 independently of the generator 8 and turbine 10. 
Therefore, the generator 8 and turbine 10 need only be attached to the 
valve body 4 subsequent to the initial installation of the valve body 4 at 
the time when electrical power becomes necessary. 
Valve body 4 has a first or upstream flow passageway 14 aligned with the 
flow passageway through the upstream section of the pipeline or conduit 
section 6. In the preferred embodiment the inner diameter of upstream 
passageway 14 is equivalent to the inner diameter of the upstream conduit 
section. A similar downstream passageway 26 in valve body 4 also 
communicates with the downstream bore of flowline 6. In the preferred 
embodiment the second or downstream flow passageway 26 is coaxial to the 
upstream or first passageway 14. Intermediate the ends of the valve body 
4, a transversly extending wall or partition 78 separates the first or 
upstream passageway 14 from the second or downstream passageway 26. In the 
embodiment depicted in FIG. 1, a plug 70 containing an orifice 68 is 
insertible in partition 78. Orifice 68 provides direct communication 
between upstream flow passageway 14 and downstream flow passageway 26. The 
plug 70 is removable and can be replaced by a solid plug preventing direct 
communication between flow passageway 14 and flow passageway 26. As will 
be subsequently described, the provision for a plug, such as plug 70 
containing orifice 68, is related to the relative flow rates in the 
conduit 6 and the desired flow rates through the turbine 10. 
The intermediate partition 78 defines a transversely extending, third flow 
passageway 16, which communicates directly with the upstream passageway 
14. In the preferred embodiment of this invention, the transverse 
passageway 16 extends perpendicular to the axis of the upstream flow 
passage 14 and the axis of the tubular conduit 6. Flow passageway 16 opens 
on the exterior of the main valve body 4 and is shown in FIG. 1 positioned 
in alignment with a flow passage 18a located in a shiftable disk gate 18 
securable to the top of the valve body 4. A fourth flow passageway 24 also 
extending transversly to the axis of the conduit 6 is positioned on the 
opposite side of partition 78 from the third flow passageway 16. In the 
preferred embodiment of this invention, flow passage 24 has a diameter 
equal to or greater than the diameter of the downstream flow passageway 26 
with which the flow passage 24 communicates. Flow passage 24 opens on the 
planar upper surface 4c of valve body 4 which surface abuts the shiftable 
disk gate 18. A back-pressure valve 72 is located on the lower portion of 
valve body 4 and communicates at one end with the upstream flow passageway 
14. The back-pressure or check valve 72 can comprise a conventional 
back-check valve having a plunger or ball spring-loaded to engage a valve 
seat located therein. The spring-loaded ball or plunger (not shown) would 
be maintained in engagement with the valve seat to prevent flow of fluids 
from the downstream side of the valve 72 into the upstream flow passage 
14. When the pressure in upstream flow passage 14 is sufficient to 
overcome the spring load on the ball, the ball is forced off of its seat 
to permit flow from the upstream flow passage 14 into the back-pressure 
valve 72. When the pressure differential between the first and second 
passageways acting on the back-pressure valve 72 reaches the prescribed 
level, the valve opens and the RPM and torque of the turbine is thus 
maintained within prescribed limits. An axially extending channel 74, 
communicating with the downstream side of the back-pressure valve 14, 
joins a transversely extending flow passage 76. Transversely passageway 76 
in turn communicats with the downstream flow passages 24 and 26. Flow 
passage 74 is drilled in the side of the valve body 4 and intersects flow 
passage 76 which is drilled from the lower surface of the valve member 4. 
Flow passages 72 and 76 receive conventional plug members to seal the flow 
passages. 
A gate valve comprises two planar metal disk sections 18 and 20. Lower gate 
valve section or disk 18 is positioned in contact with the upper surface 
4c of valve body 4. A first vertical aperture 18a in disk 18 is alignable 
with valve body flow passage 16 in the position shown in FIG. 1. An O-ring 
seal 32 mounted in a groove in valve body 4 completely encircles fluid 
passageway 16 establishing sealing integrity at this juncture between the 
valve body and the gate disk 18. A larger O-ring seal 40 extends around 
and adjacent the periphery of disk 18 to further establish sealing 
integrity between the valve body 4 and the gate valve disk 18. A second 
vertical hole 18b extends through the gate valve disk 18 and is positioned 
in communication with flow passageway 24 in the valve body 4 in the 
configuration shown in FIG. 1. Gate valve disk 18 also includes openings 
for receiving pins 46 and 48, which are respectively engaged with threaded 
holes in the planar upper surface of the valve body 4. 
A second gate valve disk 20 is positioned in overlapping contact with gate 
valve disk 18. Planar gate valve disk 20 also has openings for 
respectively receiving pin 46 and pin 48. Pin 48, however, has a head 
which engages a shoulder on the upper side of the hole extending through 
disk 20. O-ring 42 is mounted in the upper surface of valve disk 18 to 
establish sealing integrity with opening 18b in the configuration shown in 
FIG. 1. An opening 20a on the opposite side of disk 20 is positioned in 
alignment with opening 18a in the configuration shown in FIG. 1. O-ring 
seal 34 establishes sealing integrity at the juncture between openings 18a 
and 20a. 
The generator assembly includes outer housing 30 and a flange 44 welded or 
otherwise rigidly secured to the base of generator housing 30. Housing 30 
is positioned with flange 44 in overlapping relationship to gate valve 
disk 20. Flange 44 has a hole for receiving bolt 46. It should be 
understood that additional bolts 46 can be provided for rigidly securing 
the generator assembly to the valve disk 20. O-ring seal 36 is positioned 
adjacent to the periphery of disk 20 to establish sealing integrity 
between disc 20 and flange 44. An annular opening 22 is defined on the 
lower surface of flange 44. As best seen in FIG. 2, annular opening 22 is 
in communication with the flow passageway comprising sections 16, 18a, and 
20a. An annular partition 52, positioned in engagement with the upper 
surface of disc 20 at the lower end of flange 44, separates the annular 
cavity 22 from an interior cavity 25. A nozzle 28 (FIG. 2) extends through 
annular partition 52 to establish communication between the outer cavity 
22 and the inner cavity 25. The inner cavity 25 defined by partition 52 
and by a recess in the upper surface of valve disk 20 is cylindrical and 
is adapted to receive a turbine rotor 10 positioned therein with its axis 
of rotation oriented perpendicular to flow passages 14 and 26 in the valve 
body 4. 
Turbine rotor 10 is described in more detail in U.S. Pat. No. 4,150,918, 
incorporated herein by reference. The outer portion of turbine rotor 10 
contains buckets l0a in alignment with nozzle 28 as described in more 
detail in said U.S. Pat. No. 4,150,918 for translating the kinetic energy 
of the fluid passing from nozzle 28 and into reacting engagement with the 
turbine rotor 10 into rotary mechanical energy developing sufficient shaft 
horsepower to drive the generator 8. The pressure drop through nozzle 28 
from the relatively high-pressure region in flow passages 14, 16, 18a and 
20a, and in the outer annular cavity 22 to the relatively lower pressure 
or downstream side in inner cavity 25 flow passages 20b, 18b, 24, and 26 
provides the energy to drive the turbine. The turbine shaft 50 extending 
perpendicular to the flow passages 14 and 26 and to the flow passage of 
conduit 6, extends upwardly into a conventional generator assembly 8. 
Rotation of turbine 10 and shaft 50 thus provides the rotary mechanical 
energy to drive a conventional generator for producing AC or DC electrical 
current. Bearings 58 are located around the periphery of shaft 50 in a 
conventional manner. 
The generator assembly 8 includes an upper bellows 64 surrounding upper 
bearings 62 located at the upper end of turbine shaft 50. Means are 
provided for equalizing the force on opposite sides of bearings 62 and 
bearings 58. A fluid is poured into the generator housing and air allowed 
to escape from the interior of bellows 62. A separate flowline 60 extends 
upwardly in the outer generator housing 30 on the exterior of the bellows 
64. Flowline 60 communicates with the inner cavity 25 in which turbine 10 
and in which relatively lower pressure working fluids are present. Working 
fluids are thus disposed on the exterior of the bellows acting against the 
pressure the fluid deposited on the interior thereof. The bellows acts to 
insure that the pressure of the fluid within the interior of the generator 
assembly is equal to the pressure in inner cavity 25 acting on the area of 
the lower end of the shaft adjacent to bearings 58. Thus, the fluid 
pressure acting on the sealed shaft ends is at all times balanced. 
Conventional electrical components 66 for controlling the power output by 
the conventional generator assembly 8 are located at the upper portion of 
the generator assembly within the outer generator assembly housing 30. 
Electronic control wires and power lines will be brought out through a 
high-pressure electrical connection 56. 
FIG. 3 illustrates the configuration of valve body 4 and of gate valve 
disks 18 and 20 when the generator assembly 8 is removed from valve body 4 
by unscrewing bolts 46. Note that valve disk 18 has been rotated to align 
a laterally extending flow passage 18c in the bottom face of disk 18 with 
both flow passages 16 and 24; thus, providing direct communication from 
flow passage 14 through passage 16 through flow passage 18c through flow 
passage 24 into flow passage 26. A restriction is preferably provided in 
passage 18c to simulate the pressure drop resulting from the passage of 
fluid through the nozzle 28 and turbine rotor 10 to prevent sudden 
pressure increases downstream when valve plate 18 is closed. 
Alternatively, the flow area of passage 18c is proportioned to yield the 
desired pressure drop. The valve disk 18 is shifted from the position 
shown in FIG. 1 to the position shown in FIG. 3 by engaging the periphery 
of the gate valve disk 18 by conventional means and rotating the valve 
disk. Rotation of the valve disk 18 is stopped by pin 48, which cooperates 
with an arcuate slot 18e in valve disk 18, when passages 18a and 18c are 
out alignment with passages 16 and 24 and when bypass portion 18c defined 
on the lower side of gate valve disk 18 is in the position shown in FIG. 
3. 
When the turbine and generator assembly as shown in FIG. 1 is to be 
removed, the first step is to rotate the gate valve disk 18 from its 
position shown in FIG. 1 to its position shown in FIG. 3. Flow continues 
in conduit 6 through passages 14 and 26 in valve body 4, but in the 
configuration shown in FIG. 3, fluid bypasses the turbine 10. The turbine 
10 and generator assembly 8 can thus be easily removed by disengaging 
bolts 46 from valve body 4 while fluid continues to flow through the 
conduit with substantially the same pressure drop as when the turbine 8 
was connected. If desired, shorter bolts 46' may be substituted for bolts 
46. The generator assembly 8 and turbine 10 attached thereto can also be 
assembled to a valve body 4 located in flowline 6 when it becomes 
necessary to tap the kinetic energy of the working fluid to generate 
electrical power at a prescribed location along the flowline. Once the 
generator assembly 8 and turbine 10 are assembled, the gate valve disk 18 
is rotated from the position shown in FIG. 3 to the position shown in FIG. 
1 to introduce fluid into the inner cavity 25 such that the pressure drop 
through nozzle 28 actuates the turbine 10. Again the downstream pressure 
remains substantially the same. 
Depending upon the flow rates through the conduit 6 and the optimum flow 
rates required through nozzle 28 for actuating turbine 10, it may be 
necessary to provide a continuously open alternate passageway which allows 
fluid to continuously bypass the turbine 10. Plug 70 containing orifice 68 
is securable in partition 78 for the purposes of providing a continuous 
vent from the high-pressure upstream flow passage 14 to the low-pressure 
downstream passage 26. Note that the pressure drop through the orifice or 
vent 68 is substantially equal to the pressure drop through orifice 28 and 
across to turbine 10. Thus a portion of the fluid in the conduit 6 may be 
used as a working fluid to drive the turbine 10 to produce electrical 
power while the remaining portion of the fluid may be vented through 
orifice 68. If for some reason the pressure of fluid in the flowline is 
greater than anticipated or fluctuates, the back-pressure valve 72 
communicating through passages 74 and 76 provides a separate fluid bypass. 
When the pressure in flow passage 14 exceeds the pressure in flow passage 
26 by an amount sufficient to urge the check valve 72 off its seat and 
against the action of a spring (not shown), fluid can flow through the 
conventional check valve directly between passages 14 and 26. It should be 
noted that the check valve 26 can be changed as desired, and the plug 70 
can be sized to provide the desired orifice opening 68. Furthermore, a 
solid plug can be incorporated in wall 68 and the device operated with no 
continuously open vent or bypass. 
The automatic maintenance of a substantially constant fluid pressure drop 
between the upstream conduit 14 and the downstream conduit 16 of the valve 
body 4 regardless of whether turbine 10 is attached and operating, is of 
extreme importance when handling upstream fluid pressures on the order of 
thousands of pounds per square inch. The method of this invention insures 
that no surges of high pressure will be transmitted to downstream 
equipment normally designed for lower pressure operation. 
FIG. 4 discloses an illustration of a typical situation in which the 
flowline power generator is used. Note that power generator 2 is 
positioned on flowline 6 with valve body 4 incorporating intermediate the 
ends of the flowline. Flowline 6 extends directly from a wellhead 100. 
Electrical power generated by flowline power generator 2 can then be used 
to power a microprocessor-based electrohydraulic single well control 
package 102. It should, of course, be understood that the example depicted 
in FIG. 4 is only one application of the flowline power generator 
disclosed herein. Other applications in flowlines extending directly from 
a single well in well gathering systems, or in pipelines delivering fluids 
from point-to-point, will be apparent to those skilled in the art. 
Although the invention has been described in terms of a specified 
embodiment which is set forth in detail, it should be understood that this 
is by illustration only and that the invention is not necessarily limited 
thereto, since alternative embodiments and operating techniques will 
become apparent to those skilled in the art in view of the disclosure. 
Accordingly, modifications are contemplated which can be made without 
departing from the spirit of the described invention.