U.S. patent application number 13/398389 was filed with the patent office on 2013-08-22 for optical fluid analyzer sampling tool using open beam optical construction.
This patent application is currently assigned to Baker Hughes Incorporated. The applicant listed for this patent is Ansgar Cartellieri, Matthias Meister, Stefan Sroka. Invention is credited to Ansgar Cartellieri, Matthias Meister, Stefan Sroka.
Application Number | 20130213648 13/398389 |
Document ID | / |
Family ID | 48981394 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130213648 |
Kind Code |
A1 |
Sroka; Stefan ; et
al. |
August 22, 2013 |
OPTICAL FLUID ANALYZER SAMPLING TOOL USING OPEN BEAM OPTICAL
CONSTRUCTION
Abstract
An apparatus for estimating a property of a fluid of interest
downhole includes: a carrier configured to be conveyed through a
borehole penetrating an earth formation; an emitter disposed at the
carrier and configured to emit electromagnetic energy; and a sample
chamber configured to contain a sample of the fluid of interest and
having a window transmissive to electromagnetic energy emitted by
the emitter, the electromagnetic energy interacting with the sample
of the fluid of interest with a characteristic related to the
property; wherein a path of the emitted electromagnetic energy from
the emitter to the window of the sample chamber traverses a gas or
a vacuum.
Inventors: |
Sroka; Stefan;
(Adelheidsdorf, DE) ; Cartellieri; Ansgar;
(Lueneburg, DE) ; Meister; Matthias; (Celle
Niedersachsen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sroka; Stefan
Cartellieri; Ansgar
Meister; Matthias |
Adelheidsdorf
Lueneburg
Celle Niedersachsen |
|
DE
DE
DE |
|
|
Assignee: |
Baker Hughes Incorporated
Houston
TX
|
Family ID: |
48981394 |
Appl. No.: |
13/398389 |
Filed: |
February 16, 2012 |
Current U.S.
Class: |
166/264 ;
166/69 |
Current CPC
Class: |
E21B 49/10 20130101;
E21B 47/113 20200501 |
Class at
Publication: |
166/264 ;
166/69 |
International
Class: |
E21B 49/08 20060101
E21B049/08 |
Claims
1. An apparatus for estimating a property of a fluid of interest
downhole, the apparatus comprising: a carrier configured to be
conveyed through a borehole penetrating an earth formation; an
emitter disposed at the carrier and configured to emit
electromagnetic energy; and a sample chamber configured to contain
a sample of the fluid of interest and comprising a window
transmissive to electromagnetic energy emitted by the emitter, the
electromagnetic energy interacting with the sample of the fluid of
interest with a characteristic related to the property; wherein a
path of the emitted electromagnetic energy from the emitter to the
window of the sample chamber traverses a gas or a vacuum.
2. The apparatus according to claim 1, wherein the optical path
does not traverse an optical fiber.
3. The apparatus according to claim 1, wherein the optical path
traverses one or more optical elements configured to focus the
emitted electromagnetic energy.
4. The apparatus according to claim 1, further comprising a housing
configured to contain the gas or provide the vacuum.
5. The apparatus according to claim 4, wherein the housing is
further configured to support one or more optical elements
configured to focus the emitted electromagnetic energy.
6. The apparatus according to claim 1, further comprising an
analyzer configured to analyze electromagnetic energy that
interacted with the fluid of interest to estimate the property, the
electromagnetic energy that interacted with the fluid of interest
traversing the window and following a path that traverses a gas or
a vacuum.
7. The apparatus according to claim 6, wherein the analyzer
comprises a grating spectrometer.
8. The apparatus according to claim 1, wherein the window comprises
a crystal.
9. The apparatus according to claim 8, wherein the window is a
plate window having two parallel planes.
10. The apparatus according to claim 9, wherein an optical axis of
the plate window is perpendicular to the planes.
11. The apparatus according to claim 10, wherein the emitted
electromagnetic energy enters the window at an angle greater than
zero with respect to the optical axis.
12. The apparatus according to claim 7, wherein the crystal
comprises a sapphire crystal or a diamond crystal.
13. The apparatus according to claim 1, wherein the carrier
comprises a wireline, a slickline, a drill string, or coiled
tubing.
14. An apparatus for estimating a property of a fluid of interest
downhole, the apparatus comprising: a carrier configured to be
conveyed through a borehole penetrating an earth formation; an
emitter disposed at the carrier and configured to emit
electromagnetic energy; a sample chamber configured to contain a
sample of the fluid of interest and comprising a window
transmissive to electromagnetic energy emitted by the emitter, the
electromagnetic energy interacting with the sample of the fluid of
interest with a characteristic related to the property; and an
analyzer configured to receive and analyze electromagnetic energy
that interacted with the fluid of interest to estimate the
property; wherein a path of the emitted electromagnetic energy from
the emitter to the window and another path from the window to the
analyzer traverses a gas or a vacuum.
15. The apparatus according to claim 14, wherein the
electromagnetic energy emitted by the emitter and the
electromagnetic energy received by the analyzer traverses the same
window.
16. The apparatus according to claim 15, wherein the analyzer is
configured to perform reflective spectroscopy.
17. The apparatus according to claim 14, wherein the window
comprises a first window configured to pass the electromagnetic
energy emitted by the emitter and a second window configured to
pass the electromagnetic energy received by the analyzer.
18. The apparatus according to claim 14, wherein the analyzer is
configured for transmissive spectroscopy.
19. A method for estimating a property of a fluid of interest
downhole, the method comprising: conveying a carrier though a
borehole penetrating an earth formation; containing a sample of the
fluid of interest in a sample chamber comprising a window
transmissive to electromagnetic energy; and emitting
electromagnetic energy from an emitter disposed at the carrier to
the at least one window along a path that traverses a gas or a
vacuum; wherein the emitted electromagnetic energy traverses the at
least one window and interacts with the sample with a
characteristic related to the property.
20. The method according to claim 17, further comprising receiving
electromagnetic energy that interacted with the sample using an
analyzer configured analyze the received electromagnetic energy to
correlate the characteristic to the property.
21. The method according to claim 17, wherein the window comprises
a crystal plate having two parallel planes with an optical axis
perpendicular to the planes and the emitted electromagnetic energy
enters the window at an angle greater than zero with respect to the
optical axis.
Description
BACKGROUND
[0001] Earth formations are used for various applications such as
hydrocarbon production, geothermal production, and carbon dioxide
sequestration. In order to characterize formations of interest,
various types of downhole tools are conveyed through boreholes
penetrating the formations and used to take different types of
measurements.
[0002] One type of downhole tool is a fluid analysis and sampling
tool, which includes an optical fluid analyzer. In the optical
fluid analyzer sampling tool, a sample of a fluid of interest is
extracted and placed in a sample chamber. Then, a spectrum of light
either transmitted through or reflected from the fluid of interest
is measured and correlated to a property of the fluid of interest,
such as chemical composition. Typically, measurements are performed
every few seconds with a continuous flow of fluid through the
sample chamber. It would be well received in the drilling industry
if the optical fluid analyzer sampling tool could be improved to
increase the accuracy and precision of measurements.
BRIEF SUMMARY
[0003] Disclosed is an apparatus for estimating a property of a
fluid of interest downhole. The apparatus includes a carrier
configured to be conveyed through a borehole penetrating an earth
formation; an emitter disposed at the carrier and configured to
emit electromagnetic energy; and a sample chamber configured to
contain a sample of the fluid of interest and having a window
transmissive to electromagnetic energy emitted by the emitter, the
electromagnetic energy interacting with the sample of the fluid of
interest with a characteristic related to the property; wherein a
path of the emitted electromagnetic energy from the emitter to the
window of the sample chamber traverses a gas or a vacuum.
[0004] Also disclosed is an apparatus for estimating a property of
a fluid of interest downhole. The apparatus includes: a carrier
configured to be conveyed through a borehole penetrating an earth
formation; an emitter disposed at the carrier and configured to
emit electromagnetic energy; a sample chamber configured to contain
a sample of the fluid of interest and comprising a window
transmissive to electromagnetic energy emitted by the emitter, the
electromagnetic energy interacting with the sample of the fluid of
interest with a characteristic related to the property; and an
analyzer configured to receive and analyze electromagnetic energy
that interacted with the fluid of interest to estimate the
property; wherein a path of the emitted electromagnetic energy from
the emitter to the window and another path from the window to the
analyzer traverses a gas or a vacuum.
[0005] Further disclosed is a method for estimating a property of a
fluid of interest downhole. The method includes: conveying a
carrier though a borehole penetrating an earth formation;
containing a sample of the fluid of interest in a sample chamber
comprising a window transmissive to electromagnetic energy; and
emitting electromagnetic energy from an emitter disposed at the
carrier to the at least one window along a path that traverses a
gas or a vacuum; wherein the emitted electromagnetic energy
traverses the at least one window and interacts with the sample
with a characteristic related to the property.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The following descriptions should not be considered limiting
in any way. With reference to the accompanying drawings, like
elements are numbered alike:
[0007] FIG. 1 illustrates an exemplary embodiment of an optical
fluid analyzer sampling tool disposed in a borehole penetrating the
earth;
[0008] FIG. 2 depicts aspects of an open-beam optical path used in
the optical fluid analyzer sampling tool;
[0009] FIG. 3 depicts aspects of an optical axis of sapphire
windows in a sample chamber used for transmissive spectroscopy;
[0010] FIG. 4 depicts aspects of an optical axis of a sapphire
window in a sample chamber used for reflective spectroscopy;
and
[0011] FIG. 5 illustrates a flow chart of a method for estimating a
property of a material of interest downhole.
DETAILED DESCRIPTION
[0012] A detailed description of one or more embodiments of the
disclosed apparatus and method presented herein by way of
exemplification and not limitation with reference to the
Figures.
[0013] FIG. 1 illustrates a cross-sectional view of an exemplary
embodiment of a system to estimate a property of a downhole fluid
of interest. A bottomhole assembly (BHA) 11 is disposed in a
borehole 2 penetrating the earth 3, which includes an earth
formation 4. The BHA 11 includes an optical fluid sample analyzer
10 (i.e. downhole tool 10) configured to perform one or more types
of measurements on a downhole fluid of interest, which may be
disposed in the formation 4 or the borehole 2.
[0014] The BHA 11 is conveyed through the borehole 2 by a carrier
5. In the embodiment of FIG. 1, the carrier 5 is a drill string 6
in an embodiment known as logging-while-drilling (LWD). In an
alternative embodiment, the carrier 5 can be an armored wireline in
an embodiment known as wireline logging. Disposed at a distal end
of the drill string 6 is a drill bit 7. A drilling rig 8 is
configured to conduct drilling operations such as rotating the
drill string 6 and thus the drill bit 7 in order to drill the
borehole 2. In addition, the drilling rig 8 is configured to pump
drilling fluid through the drill string 6 in order to lubricate the
drill bit 7 and flush cuttings from the borehole 2. Downhole
electronics 9 may be configured to operate or control the downhole
tool 10, process data obtained by the downhole tool 10, or provide
an interface with telemetry for communicating with a computer
processing system 12 disposed at the surface of the earth 3.
Operating, controlling or processing operations may be performed by
the downhole electronics 9, the computer processing system 12, or a
combination of the two. Telemetry is configured to convey
information or commands between the downhole tool 10 and the
computer processing system 12.
[0015] In one or more non-limiting embodiments, the downhole tool
10 performs reflective or transmissive spectroscopy measurements to
determine a property, such as chemical composition, of a sample of
the downhole fluid of interest. To obtain the sample, the downhole
tool 10 includes a formation tester 13 configured to extract a
sample of the downhole fluid of interest from the formation 4 and
dispose the sample in a sample chamber 15. The sample chamber 15
may be configured to contain a static sample or to contain a
continuous flow of sample fluid through the sample chamber 15,
which may also be referred to as a probe cell or fluid cell. In one
or more non-limiting embodiments, the formation tester 13 includes
a probe 14 configured to extend from the tester 13 and seal to a
wall of the borehole 2. The formation tester 13 reduces pressure
within the probe 14 causing formation fluid to flow into the probe
14 from which the fluid can be disposed in the sample chamber 15.
Spectroscopy measurements are performed on the sample while the
sample is contained in sample chamber or while the fluid is
continuously pumped through the fluid cell.
[0016] To perform the spectroscopy measurements, the downhole tool
10 includes an emitter 19 configured to generate and emit
electromagnetic (EM) energy (e.g. light or photons). The emitted EM
energy enters the sample chamber 15 through a window, transmissive
to the EM energy, where the EM energy interacts with the atoms or
molecules of the fluid sample. The EM energy resulting from the
interaction has a characteristic related to the chemical
composition of the fluid sample. In general, the characteristic is
an amplitude or peak of received EM energy at one or more
wavelengths or frequencies. An analyzer 16 is configured to receive
the EM energy resulting from interactions with the fluid sample and
to measure the amplitude of the received EM energy as a function of
wavelength or frequency of the received EM energy. Hence, the
analyzer 16 can determine the characteristic amplitude peaks at one
or more wavelengths or frequencies and relate this information to a
chemical composition. In one or more embodiments, the analyzer 19
is a grating spectrometer.
[0017] It can be appreciated that providing strong optical signals
used to characterize the fluid sample can result in a higher signal
to noise ratio than if weaker optical signals were used. In order
to maximize the strength of optical signals used to characterize
the fluid sample, the downhole tool 10 includes an open-beam
optical path. The term "open-beam optical path" relates to at least
a portion of an optical path that traverses a gas or a vacuum and
excludes traversing an optical fiber in that portion of the path.
In one or more embodiments, open-beam optical paths completely
exclude an optical path traversing an optical fiber in order to
achieve the highest optical signal intensity possible with the
emitter 9.
[0018] In reflective spectroscopy, the light emitted by the emitter
9 follows an open-beam optical path and enters a window of the
sample chamber 15. The light reflected by interactions with the
fluid sample traverses the same window, follows an open-beam
optical path and is received and analyzed by the analyzer 16.
[0019] In transmissive spectroscopy with reference to FIG. 1, the
light emitted by the emitter 9 follows an open-beam optical path
and enters a first window of the sample chamber 15 (on left side).
Light due to interactions with the fluid sample that continues
through the fluid sample exits the sample chamber 15 at a second
window (on right side). From the second window, the light follows
an open-beam optical path and enters the analyzer 16 where the
received light is analyzed.
[0020] FIG. 2 illustrates a cross-sectional view depicting aspects
of using open-beam optical paths for transmissive spectroscopy. One
open-beam optical path is used to optically couple the light
emitted by the emitter 19 to a first window 21 of the sample
chamber 15. Light interacting with the sample and transmitted
through the sample exits the sample chamber 15 by way of a second
window 22. The light exiting the second window 22 is optically
coupled to the analyzer 16 by another open-beam optical path. In
one or more embodiments, the windows 21 and 22 are plates having
two parallel surfaces and the light entering or exiting the windows
21 and 22 is perpendicular to the surfaces. In one or more
embodiments, the emitter 19 may be an incandescent light bulb or
light emitting diode (LED) and part of an emitter assembly that
includes a reflector 20. The reflector 20 is configured to reflect,
focus or concentrate emitted light on to the first window 21 in
order to minimize or eliminate light leakage or loss and maximize
the optical signal provided to the sample or to the analyzer 16. A
lens 23 may also be used to focus or concentrate the emitted light
to minimize or eliminate light leakage. The lens 23 may be part of
the emitter assembly or be disposed external to the assembly in the
open-beam optical path. In one or more embodiments, the emitter is
a bulb with a tungsten filament. An advantage of the tungsten
filament is that it emits light at a temperature much higher than
the temperatures generally experienced downhole and, thus, the
emitted light will not be affected by the high downhole
temperatures. In one or more embodiments, the windows 21 and 22 are
made of a crystal such as sapphire or diamond for example. These
crystals are strong and can withstand the high downhole
temperatures and pressures.
[0021] The open-beam optical paths illustrated in FIG. 2 traverse a
gas, such as air or nitrogen for example, or a vacuum. In one or
more embodiments, a housing 24 is configured to contain the gas or
provide the vacuum. The housing 24 may also be used to support the
lens 23 or optical components in the open-beam paths. In general,
few if any optical components are used in the open-beam paths in
order to minimize or eliminate optical signal loss due to the
optical components. In one or more embodiments, no optical
components are used in the open-beam paths.
[0022] FIG. 3 illustrates a cross-sectional view of an embodiment
depicting aspects of transmissive spectroscopy where the emitted
light and the received light for analysis are non-perpendicular
(i.e., non-normal) to the windows 21 and 22. In the embodiment of
FIG. 3, the windows 21 and 22 are formed as sapphire crystal plates
with the optical axis or c-axis of the crystal being perpendicular
to the planes of the plates. In this embodiment, the refractive
index of the sapphire is independent of the incident angle of the
light. Thus, the tool 10 may be configured so that the incident
light or received light is non-perpendicular to the windows 21 and
22. FIG. 4 illustrates an embodiment depicting aspects of
reflective spectroscopy similar to the embodiment of FIG. 3. It can
be appreciated that the embodiments of FIGS. 3 and 4 depicting
non-perpendicular directions of emitted and received light with
respect to the sample chamber window or windows allows the optical
fluid sample analyzer 10 to be built in a compact form where space
in a downhole tool may be limited due the space limitations in a
borehole.
[0023] FIG. 5 illustrates a flow chart for a method 50 for
estimating a property of a fluid of interest downhole. Block 51
calls for conveying a carrier though a borehole penetrating an
earth formation. Block 52 calls for containing a sample of the
fluid of interest in a sample chamber comprising a window
transmissive to electromagnetic energy. Block 53 calls for emitting
electromagnetic energy from an emitter disposed at the carrier to
the at least one window along a path that traverses a gas or a
vacuum wherein the emitted electromagnetic energy traverses the at
least one window and interacts with the sample with a
characteristic related to the property. The method 50 may also
include receiving electromagnetic energy that interacted with the
sample using an analyzer such as a spectrometer. The method 50 may
also include the electromagnetic energy emitted by the emitter or
received by the analyzer traversing the window at a
non-perpendicular (i.e., non-normal) angle with respect to a plane
of the window.
[0024] It can be appreciated that the optical fluid sample analyzer
10 provides several advantages over traditional optical fluid
analyzers. Traditional optical fluid analyzers use optical fibers
to transmit light from a light source to a sample chamber for
interaction with a sample and for receiving light at a spectrometer
due to the interaction. However, light losses occur at each
coupling or interface with the optical fiber such as between the
light source and the optical fiber and between the optical fiber
and a window in the sample chamber or probe cell for example.
Similar light losses occur with the received light at optical fiber
interfaces and couplings. These light losses result in decreased
intensity of light available for interrogating the sample. A light
wavelength resolution in the range of a few nanometers is required
to distinguish hydrocarbon groups and lower intensity light may
result in a lower signal to noise ratio, lower resolution, and a
wavelength range that may affect measurements to distinguish
hydrocarbon groups. Further, the open-beam optical path lends
itself to providing a more compact configuration that conforms to
the space limitations in downhole tools. The compact configuration
allows the distance between sapphire windows in the sample chamber
or probe cell to be increased to reduce the risk of clogging the
chamber or cell by solids contained in the downhole fluid. Another
advantage of greater distance between the windows is that light
absorption by a thin layer of contamination on the windows is
reduced in relation to the light absorption in the fluid of
interest. Further, the open-beam configuration is more robust than
an optical fiber to the downhole drilling environment as the
optical fiber may get damaged with time due to severe vibrations
during drilling.
[0025] In support of the teachings herein, various analysis
components may be used, including a digital and/or an analog
system. For example, the downhole electronics 9, the surface
computer processing 12, the emitter 19 or the analyzer 16 may
include the digital and/or analog system. The system may have
components such as a processor, storage media, memory, input,
output, communications link (wired, wireless, pulsed mud, optical
or other), user interfaces, software programs, signal processors
(digital or analog) and other such components (such as resistors,
capacitors, inductors and others) to provide for operation and
analyses of the apparatus and methods disclosed herein in any of
several manners well-appreciated in the art. It is considered that
these teachings may be, but need not be, implemented in conjunction
with a set of computer executable instructions stored on a computer
readable medium, including memory (ROMs, RAMs), optical (CD-ROMs),
or magnetic (disks, hard drives), or any other type that when
executed causes a computer to implement the method of the present
invention. These instructions may provide for equipment operation,
control, data collection and analysis and other functions deemed
relevant by a system designer, owner, user or other such personnel,
in addition to the functions described in this disclosure.
[0026] Further, various other components may be included and called
upon for providing for aspects of the teachings herein. For
example, a power supply (e.g., at least one of a generator, a
remote supply and a battery), cooling component, heating component,
magnet, electromagnet, sensor, electrode, transmitter, receiver,
transceiver, antenna, controller, optical unit, electrical unit or
electromechanical unit may be included in support of the various
aspects discussed herein or in support of other functions beyond
this disclosure.
[0027] The term "carrier" as used herein means any device, device
component, combination of devices, media and/or member that may be
used to convey, house, support or otherwise facilitate the use of
another device, device component, combination of devices, media
and/or member. Other exemplary non-limiting carriers include drill
strings of the coiled tube type, of the jointed pipe type and any
combination or portion thereof. Other carrier examples include
casing pipes, wirelines, wireline sondes, slickline sondes, drop
shots, bottom-hole-assemblies, drill string inserts, modules,
internal housings and substrate portions thereof.
[0028] Elements of the embodiments have been introduced with either
the articles "a" or "an." The articles are intended to mean that
there are one or more of the elements. The terms "including" and
"having" are intended to be inclusive such that there may be
additional elements other than the elements listed. The conjunction
"or" when used with a list of at least two terms is intended to
mean any term or combination of terms. The terms "first" and
"second" are used to distinguish elements and are not used to
denote a particular order. The term "couple" relates to coupling a
first component to a second component either directly or indirectly
through an intermediate component.
[0029] It will be recognized that the various components or
technologies may provide certain necessary or beneficial
functionality or features. Accordingly, these functions and
features as may be needed in support of the appended claims and
variations thereof, are recognized as being inherently included as
a part of the teachings herein and a part of the invention
disclosed.
[0030] While the invention has been described with reference to
exemplary embodiments, it will be understood that various changes
may be made and equivalents may be substituted for elements thereof
without departing from the scope of the invention. In addition,
many modifications will be appreciated to adapt a particular
instrument, situation or material to the teachings of the invention
without departing from the essential scope thereof. Therefore, it
is intended that the invention not be limited to the particular
embodiment disclosed as the best mode contemplated for carrying out
this invention, but that the invention will include all embodiments
falling within the scope of the appended claims.
* * * * *