Note: Descriptions are shown in the official language in which they were submitted.
CA 02656654 2009-02-27
Mobile Progressive Cavity Pump Service Unit
Abstract of the Disclosure
A transportable service trailer used for testing and inspection purposes of
Progressive Cavity (PC) Pumps at or near a wellsite. A test bench in the
trailer which
is used to determine pc pump efficiencies and torques. A pc pump handling
system
used for assembly, disassembly and testing pc pumps. A stator cleaning device
used to remove production fluid from stator bore. A small diameter camera
which is
used to view the stator bore and capture images of said stator bore for
analysis. A
racking system used to safely transport new pc pump components and tested
components. A system used to provide real time information to production
personal
and or consultants for analysis and proactive equipment selection.
Field of the Invention
This invention relates to a portable progressive cavity pump unit for testing
and
analysis of pc pump at or near a well site. In particular, the apparatus is
useful for
onsite evaluations of pc pump used in the production of fluids in wellbores.
The
service unit will provide information to determine weather a pc pump is
suitable to be
re-installed into a well.
Background of the Invention
PC pumps are a type of artificial lift system used to produce fluid in a
wellbore. The
pc pump consists of a rotor and a stator. The rotor which is a single external
threaded helical gear that rotates eccentrically inside a stationary double
internal
helical gear of the same minor diameter and twice the pitch length. The rotor
is a
precision machined from high strength steel and coated with a wear resistant
layer,
usually chrome. The rotor which is the rotating internal component of the pump
is
driven by the rod string. The stator consists of a moulded elastomer bonded to
the
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CA 02656654 2009-02-27
inside of a tube, the stator is attached to the tubing string and remains
stationary
during operation.
Progressive pump suppliers determine the condition of their product by
transporting
the pump from the well site to a test facility which includes a pump clean out
mechanism, a boroscope camera, and a bench test machine. Once the pump has
been tested it is either put in customer stock or delivered back out to the
well in
which it came from. If the pump does not meet the customer's specifications it
is
discarded.
This process provides the information necessary to determine the effectiveness
of
the pump. Unfortunately, this information is not available in a timely manner
because the pump has to be picked up and returned from site. The producer
often
has to run another pump while they wait the pump test information in order to
reduce
costly rig service charges. It is unfortunate the producer has to leave the
well before
they receive the pump test information. This information, although late,
contains key
clues to the cause of well failure. If this information was available sooner
it could be
used to determine which equipment (pump size, efficiencies, down-hole
accessories,
etc) should be re-installed in the well.
What is needed is a product that enabled pumps to be cleaned, inspected, and
tested on site. This equipment would generate all the information required to
determine the condition of the pump so that recommendations could be made
before
for the next pump install, without having to incur costly transportation time
while the
PCP is delivered to and from a test facility.
Failure is inevitable during operation and inspection and repair needs to be
performed. The current method utilized is; the pc pump that has been removed
from
a wellbore is to transported to a pc pump testing and service centre were an
evaluation can be performed. The rig will either wait for testing results and
direction
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CA 02656654 2009-02-27
or install a new or refurbished pc pump without evaluation results. The latter
is a
reactive approach rather than a proactive approach for pc pump selection.
Summary of the Invention
There is a need for field testing and evaluation of pc pump at the well site.
To avoid
high rig waiting costs and to prevent reactive pump selections on site pc pump
testing and evaluations will reduce rig waiting times and ensure a proactive
approach to pc pump selections.
Information gathered from on site testing and evaluations can be submitted in
real
time to production personal and or consultants who can then make an
informative
decision on what is need to be done to the well and what pc pump
configurations
need to be replaced back into the wellbore.
Accordingly, the present invention provides a transportable testing and
service
system for the evaluation of pc pumps at or near a wellsite:
a trailer or platform for transporting PC pump service equipment to site
a region on the trailer or platform for PC pump test bench
a region on the trailer or platform for PC pump handling system, assembly,
disassembly and testing were the stator can travel axially in either
direction.
a region on the trailer or platform for safe transportation of product
1. Means of performing a bench test on a pc pump to determine pump
efficiency and torque at or near the wellsite in a mobile unit (Figure 1)
i. The test bench (11) consists of a bearing box (12), hydraulic or
electric motor (13), stuffing box (14) to prevent fluid leakage,
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drive shaft (15), choke valve (16), fluid measuring system (17),
torque measuring system (18), fluid storage (19), charge pump
(20), hydraulic pump (connected to a power take-off or
generator used as prime mover(21).
2. PC Pump handling system which is needed to test the pc pump at or near
the wellsite in a mobile unit. A unique rotor and stator handling frame work
which is
needed to assemble, dissemble and test the pc pump. This handling system uses
unconventional means for the stator to travel axially for insertion and
removal of the
rotor. (Figure 2)
ii. The pc pump handling system consists of a stationary beam (1)
which is attached to the trailer (4) floor. The traveling beam (2)
is attached to the stationary beam (1) through a carriage (3)
system on wheels. The traveling beam (2) has been designed to
travel along the full length of the stationary (1) beam and extend
outside the trailer (4). The traveling beam (2) has traveling (5)
and fixed (6) supports that are used to support the stator (7) and
provide axial movement of the stator (7). The supports (5, 6)
utilize a clamping device (8) to prevent rotation of the stator (7)
and fix the stator (7) in position. The stationary beam (1) also
has traveling support (9) used to support the rotor (10). The
rotor (10) is attached to the test bench (11) and supported by
the rotor traveling supports (9), the stator (7) which is attached
to the supports (5, 6) on the traveling beam (2). The rotor (10) is
rotated with the test bench (11) and the stator (7) travels axially
on the traveling beam (2) which provides insertion and removal
of the rotor (10) into and out of the stator (7).
3. Means of cleaning the bore of the stator for visual inspection at or near
the
wellsite in a mobile unit, bore of stator must be cleaned to remove produced
fluid for
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visual inspection. High volume pump used to circulate water through stator
bore and
recapturing in containment.
4. Means of visually inspecting the bore of the stator with a camera at or
near
the wellsite in a mobile unit. Boroscope the stator bore which is a visual
inspection
device used to determine condition of the stator elastomer
5. Means of supporting new and used pump parts during transportation
6. Communications system to provide real time information back to production
personal and or consultants for analysis and proactive equipment selection.
Use of the Invention (Figure 3)
1. Pressurized Pump Wash System - Water & chemical is recycled through the
pump to clean any oil and sand from the pump.
2. Boroscope Stator Camera - Enables a visual inspection of the interior of
the
pump to identify any damage to the pump elastomer
3. Bench Test - If the pump is looks good after the boroscope inspection it
will
be connected to the bench test machine. The machine imitates down-hole
conditions while measuring the efficiency of the pump. If the efficiency meets
the customer's requirements the pump will be fit to be reinstalled.
4. Pump Handling Mechanism - Provides a means to safety load and unload the
PCP from the trailer.
5. Pump and Accessory Rack - Internal racking system that insures secure
transportation of stock pumps and accessories to and from site.
6. Report Station - Computer, printer, and software required to provide the
customer with the pump test report while on-site. The trailer will be complete
with wireless internet to allow the test reports to be emailed to other
interested parties that are not on site.
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