WO1999013307A1 - High sensitivity fiber optic pressure sensor for use in harsh environments - Google Patents
High sensitivity fiber optic pressure sensor for use in harsh environments Download PDFInfo
- Publication number
- WO1999013307A1 WO1999013307A1 PCT/US1998/018065 US9818065W WO9913307A1 WO 1999013307 A1 WO1999013307 A1 WO 1999013307A1 US 9818065 W US9818065 W US 9818065W WO 9913307 A1 WO9913307 A1 WO 9913307A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pressure
- changes
- bragg grating
- pressure sensor
- environment
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
- G01L11/02—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means
- G01L11/025—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means using a pressure-sensitive optical fibre
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L9/00—Measuring steady of quasi-steady pressure of fluid or fluent solid material by electric or magnetic pressure-sensitive elements; Transmitting or indicating the displacement of mechanical pressure-sensitive elements, used to measure the steady or quasi-steady pressure of a fluid or fluent solid material, by electric or magnetic means
- G01L9/0033—Transmitting or indicating the displacement of bellows by electric, electromechanical, magnetic, or electromagnetic means
- G01L9/0039—Transmitting or indicating the displacement of bellows by electric, electromechanical, magnetic, or electromagnetic means using photoelectric means
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings
- G02B6/02076—Refractive index modulation gratings, e.g. Bragg gratings
- G02B6/02171—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for compensating environmentally induced changes
- G02B6/02176—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for compensating environmentally induced changes due to temperature fluctuations
- G02B6/0218—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for compensating environmentally induced changes due to temperature fluctuations using mounting means, e.g. by using a combination of materials having different thermal expansion coefficients
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings
- G02B6/02076—Refractive index modulation gratings, e.g. Bragg gratings
- G02B6/02195—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for tuning the grating
- G02B6/022—Refractive index modulation gratings, e.g. Bragg gratings characterised by means for tuning the grating using mechanical stress, e.g. tuning by compression or elongation, special geometrical shapes such as "dog-bone" or taper
Definitions
- the present invention relates to optical sensors, and more particularly, to intrinsic fiber optic pressure sensors packaged for use in extremely harsh environments.
- the naturally existing pressure within an earth formation is often used as the driving force for oil extraction.
- the oil may be extracted from a single location or "zone" within the well, or oil may be extracted from multiple zones within the well. In either case, it is desirable to know the fluid pressure within the well at multiple locations to aid the well operator in maximizing the depletion ofthe oil within the earth formation.
- ESPs electrical submersible pumps
- the presently used electrical pressure and temperature sensors are limited for several reasons.
- the on-board electronics of such sensors must operate in a very hostile environment, which includes high temperature, high vibration and high levels of external hydrostatic pressure.
- Such electrical sensors also must be extremely reliable, since early failure may entail a very time consuming and expensive well intervention. Electronics, with its inherent complexity, are prone to many different modes of failure. Such failures have traditionally caused a less than acceptable level of reliability when these electrical sensors are used to monitor ESPs.
- optical interferometers for the measurement of wellbore conditions, such as downhole wellbore pressures and temperatures.
- optical interferometers are typically very sensitive to temperature variations and the downhole temperature of a specific position within a wellbore will change over time, depending upon different factors such as, for example, production rates, the types of fluids produced over the life ofthe well, and downhole wellbore conditions. Even optical interferometers designed of special material or construction are subject to inaccuracies because ofthe harsh borehole environment and because ofthe very tight tolerances in such precision equipment. Additionally, such optical interferometers are located at the end of an optical fiber and are only useful for making a single measurement at the point within the system the sensor is located.
- a reliable system is needed for accurately measuring the pressure of a harsh environment, such as a borehole. Additionally, such a system should be capable of measuring pressure at multiple locations within the harsh environment.
- An object of the present invention is to provide an improved pressure sensor for accurately monitoring pressure in an extremely harsh environment.
- a further object ofthe invention is to provide such a sensor which is particularly useful for accurately monitoring pressure at multiple locations within a wellbore of an oil and/or gas well.
- a still further object ofthe present invention is to provide such a sensor that is implemented utilizing intrinsic fiber optic sensors.
- a pressure sensor capable of measuring pressure in a harsh environment includes at least one intrinsic fiber optic sensor elements formed within a core of an optical fiber, a length ofthe optical fiber containing the sensor element is attached to a pressure sensitive structure and the pressure sensitive structure is responsive to pressure in a pressure field ofthe harsh environment such that changes in the pressure sensitive structure in response to changes in the pressure ofthe pressure field changes the strain in the length of optical fiber containing the sensor element.
- the optical fiber may be disposed within a capillary tube made of a high strength, corrosion resistant material, such as stainless steel, which is highly resistant to corrosion, pressure, and temperature effects of a high-pressure, high-temperature and corrosive environment.
- a capillary tube made of a high strength, corrosion resistant material, such as stainless steel, which is highly resistant to corrosion, pressure, and temperature effects of a high-pressure, high-temperature and corrosive environment.
- One or more sensors are located at a distal end ofthe capillary tube, and are positioned in desired sensing locations.
- each sensor element may include a Bragg grating sensing element, such as a Bragg grating point sensor, a resonant cavity formed with multiple Bragg gratings, or a lasing element formed with multiple Bragg gratings.
- the Bragg grating sensor elements are responsive to an optical signal and to a strain induced by the pressure sensitive structure, the strain being associated with the respective pressure field, for providing an optical sensing signal related to a magnitude ofthe pressure at the sensor location within the respective pressure field.
- the Bragg grating sensors may be mounted for either compression or tension associated with pressure within the pressure field.
- the change in strain in the Bragg grating associated with either compression or tension causes a change in grating spacing thus changing the wavelength of light reflected back to a proximal end ofthe fiber which is interconnected to a sensing device, and the variations in wavelength are directly related to pressure at the sensing location.
- the length of fiber may be mounted under an initial tension, which is increased or decreased, as the case may be, associated with the pressure in the environment being sensed.
- each sensor may be provided with a temperature compensation Bragg grating to compensate for changes in temperature at the sensing location.
- the temperature compensation Bragg grating may be mounted such that it is isolated from strain associated with pressure in the environment.
- the temperature compensation Bragg grating may be mounted to also be responsive to the pressure ofthe pressure field (either directly or inversely to the other Bragg grating).
- the pressure sensor ofthe invention may be used to monitor static and/or dynamic pressure variations.
- a plurality of pressure sensors manufactured in accordance with the invention may be serially connected to one another for pressure detection at multiple locations.
- the serial connected sensors may employ time division multiplexing (TDM) and/or wavelength division multiplexing (WDM) techniques to differentiate between signals from the different serially connected sensors.
- TDM time division multiplexing
- WDM wavelength division multiplexing
- Fig. 1 is a longitudinal cross-sectional view of a wellbore that schematically illustrates a fiber optic intrinsic sensor of the invention interconnected to an electrically submersible pump;
- Fig. 2 is a more detailed schematic block diagram ofthe fiber optic intrinsic sensor of Fig. 1;
- Fig. 3 is a cross-sectional view of a multi-element bellows structure used in the fiber optic intrinsic sensor of Fig. 2;
- Fig. 4 is a schematic block diagram of optical signal processing equipment utilized to analyze optical signals provided by the fiber optic intrinsic sensor of Figs. 1 and 2;
- Fig. 5 is a graph showing the reflectivity profile of pressure and temperature Bragg gratings used in the fiber optic intrinsic sensor of Figs. 1 and 2;
- Fig. 6 is a schematic block diagram of a second embodiment ofthe fiber optic intrinsic sensor of Fig. 1;
- Figs. 7 and 8 are a graphs showing the reflectivity profile of Bragg gratings used in the fiber optic intrinsic sensor of Fig. 6 showing the responsiveness ofthe sensors to changes in temperature and pressure;
- Fig. 9 is a schematic block diagram showing a plurality of a third embodiment ofthe fiber optic intrinsic sensor of Fig. 1 multiplexed together in a distributed pressure sensor; and Fig. 10 is a more detailed schematic block diagram of the fiber optic intrinsic sensor of Fig. 9.
- the present invention utilizes fiber optic sensors for measuring fluid pressure (static and/or dynamic).
- the pressure sensors of the present invention utilize resonant structures, called Bragg gratings, that are disposed at one or more locations within the waveguiding core of an optical fiber.
- the intrinsic fiber optic sensor elements utilized in accordance with the invention are disposed in a sensor 1 which is mounted in a mounting location, such as to the casing of an electrically submersible pump 2 within a wellbore 3 of an oil and/or gas well 5.
- a single pressure sensor will be described with respect to a first embodiment ofthe invention.
- multiple pressure sensors ofthe invention may be serially multiplexed for distributed pressure sensing using wavelength division multiplexing (WDM) and/or time division multiplexing (TDM) techniques.
- WDM wavelength division multiplexing
- TDM time division multiplexing
- the pressure sensor 1 is interconnected by an optical fiber assembly 15 with optical signal processing equipment 18.
- the optical signal processing equipment 18 is located above the surface 20 ofthe wellbore 3.
- the electrical submersible pump 2 is interconnected by an electrical cable 22 to an electrical submersible pump power supply and controller 25, which is also located above the surface 20 ofthe wellbore 3.
- the optical fiber assembly 15 includes an optical fiber 24 which may be protected from mechanical damage by placing it inside a capillary tube 31 made of a high strength, rigid walled, corrosion-resistant material, such as stainless steel.
- the tube 31 is attached by appropriate means, such as threads at 32, a weld, or other suitable method, to a sensor housing 33.
- the sensor housing 33 may be mounted to the casing ofthe ESP 2 (Fig. 1). Alternatively, the sensor housing 33 may be mounted in another location where it is desired to make a pressure measurement, such as any location along the length ofthe production tubing 12.
- the optical fiber 24 extends from the surface 20 (Fig. 1) ofthe well and contains a light guiding core which guides light along the fiber 24.
- excitation light may be provided by a broadband light source 49, such as a light emitting diode (LED) located within the optical signal processing equipment
- the Bragg gratings 47, 48 are used to implement the pressure sensor ofthe invention.
- the sensor housing 33 includes a first section 50 wherein the optical fiber 24 is introduced into the housing 33 from the capillary tube 31.
- the pressure seal 55 may include a ferrule or other suitable device, and the optical fiber may be sealed to the pressure seal 55 by a suitable adhesion method such as an adhesive compound, mechanical attachment (shrink or press fit), welding or soldering of a metal coated fiber to a metallic rigid member, fused silica bond, etc.
- the length of fiber 46 next passes into a temperature compensation section 62.
- a pair of ferrules 65,66 is mounted to the optical fiber 24 in spaced relation to one another.
- the ferrules 65,66 are attached to the fiber 46 by any suitable adhesion method, such as the adhesion methods described with respect to the pressure seal 55.
- the ferrules 65,66 are aligned and secured in place with setscrews 69,70, respectively, in the temperature compensation section 62.
- the positions of the ferrules 65,66 are fixed within a channel 75 formed within the temperature compensation section 62 by the setscrews 69,70.
- the temperature compensation Bragg grating 48 In the length of optical fiber positioned between the ferrules 65,66 is the temperature compensation Bragg grating 48.
- the set screws 69,70 and ferrules 65,75 may be positioned and adjusted to place the length of optical fiber 46 containing the temperature compensation Bragg grating 48 under an initial neutral strain, a tensile pre-strain, or in compression, as desired. Alternatively the fiber may be secure to always be in a slack condition so as not to see any mechanical strain.
- the setscrews 69,70 are illustrated as being received in spaced apart apertures 76,77 formed in the temperature compensation section 62. Additional apertures 78,79 may be provided in the temperature compensation section 62 for varying the location of the setscrews for contacting the ferrule 65,66.
- any other suitable method of attachment for purposes of isolation may be used.
- the set screws are sealed, for example, by placing a high temperature epoxy or weld over the top of the set screws 69,70. Additionally, if additional apertures 78,79 are provided for varying the location of the set screws 69,70, these apertures 78,79 are sealed against environmental pressure, for example, by inserting set screws and sealing the top of the set screws with high temperature epoxy, welding, or any other suitable sealing method.
- the fiber 24 exits the temperature compensation section 62 via the channel
- the pressure monitoring section 80 includes a sealed housing section 82, a pressure responsive multi-element bellows structure 85 and a fiber mounting section 88.
- the optical fiber 24 passes through the multi-element bellows structure 85 and is attached to a ferrule 90 by any of the above mentioned suitable adhesion methods.
- the ferrule 90 is located at the end of a ferrule support 92.
- the ferrule support 92 and ferrule 90 are part of the fiber mounting section 88.
- a seal such as an O-ring, is positioned between the ferrule support 92 and the end of the multi-element bellows structure 85 to thereby seal the internals 94 of the bellows structure from environmental pressure.
- the ferrule support 92 may be attached to the end of the bellows structure 85 by welding, high temperature epoxy, or other suitable method.
- An end cap 95 which also forms part of the fiber mounting structure 88, is placed over the ferrule support 92.
- the end cap 95 is mounted to the ferrule support 92 and the end of the multi-element bellows structure 85 to thereby securely seal the end of the bellows such that the internals 94 of the bellows is not subject to environmental pressure.
- the pressure monitoring Bragg grating 47 is approximately centered between the two ferrules 90,66.
- the pressure sensing Bragg grating 47 is placed under initial tensile strain.
- the Bragg grating may be placed under a neutral strain or in compression if desired in accordance with the present invention.
- the pressure sensor illustrated in Fig. 2 is a single point pressure sensor with the optical fiber 24 terminated within the ferrule 90.
- the distal end 96 of the fiber 24 within the ferrule 90 is terminated in an anti-reflective manner to prevent interference with the reflective wavelengths from the Bragg gratings 47,48.
- the distal end 96 of the fiber may be cleaved at an angle so that the end face is not perpendicular to the fiber axis.
- the distal end 96 of the fiber may be coated with a material that matches the index of refraction of the fiber, thus permitting light to exit the fiber without back reflection, and be subsequently dispersed in the index-matching material.
- the pressure sensor 1 is a single point pressure sensor.
- the end of the pressure sensing section 80 of the housing 33 is open at 97 and is therefore exposed to environmental pressure.
- a change in the pressure in the environment causes changes in the elongation and the compression of the multi-element bellows structure 85.
- Variations in the deflections of the multielement bellows structure 85 causes changes in the strain of the pressure sensing Bragg grating 47.
- these changes in strain in the pressure sensing optical fiber Bragg grating 47 are directly related to the pressure in the environment and are used providing a pressure signal indicative of the pressure in the environment.
- the multi-element bellows structure 85 is shown in greater detail in Fig. 3. Referring to Fig. 3, the bellows structure 85 includes several diaphragm elements
- the bellows structure 85 is made of a high strength, high temperature, and resiliently deformable material that may be easily machined, molded or formed, e.g., hydro-forming to the desired configuration.
- the elements 100, 101, 102 may be made of a machined titanium material.
- the bellows structure 85 is configured such that when the internal compartment 94 is sealed against external environmental pressure, for example as is accomplished in the pressure sensor configuration of Fig. 2, the bellows structure will expand and contract in an axial direction as illustrated by the line 108. This expansion and contraction is translated directly to the portion of the optical fiber containing the pressure sensing Bragg grating 47.
- the bellows structure is made from a high strength resiliently deformable material such as titanium, the material will need to be machined in order to arrive at the desired shape and therefore, the bellows is made in the several elements 100, 101, 102 as illustrated in Fig. 3 for ease of machining. These elements 100, 101 , 102 ar then welded together.
- the bellows structure is made of material which can be formed by die cast molding, for example, then the bellows structure can be made into a single unit and not require individual elements.
- the sensitivity of the bellows structure 85 to changes in pressure in the environment is enhanced. That is, for a given pressure change in the environment, the change in axial length of the bellows structure is greater for each additional bellows segment of the overall bellows structure.
- any number of bellows elements may be used to form the bellows structure 85 of the invention, depending on the desired degree of sensitivity of the element.
- the invention is illustrated as using a bellows for transmitting the pressure of the environment to change the strain in the optical fiber
- various methods and structures of pressure translation can be utilized, for example, by utilizing a diaphragm such as the diaphragm illustrated in commonly owned copending patent application serial number 08/786,704 filed on January 21, 1997, the disclosure of which is incorporated herein by reference.
- tubing delivery equipment for delivering the optical fiber 24 within the capillary tubing 31 down the borehole 3.
- the tubing delivery equipment provides for the delivery ofthe capillary tubing 31 and fiber 24 down the borehole 3, and for the delivery of optical signals between the optical signal processing equipment 18 and the fiber assembly 15, either directly or via interface equipment (not shown) as required.
- Fiber gratings are well suited for use as sensor elements. When a fiber grating is illuminated, it reflects a narrow band of light at a specified wavelength. However, a measurand, such as strain induced by pressure or temperature, will induce a change in the fiber grating spacing, which changes the wavelength ofthe light it reflects. The value (magnitude) ofthe measurand is directly related to the wavelength reflected by the fiber grating and can be determined by detecting the wavelength ofthe reflected light.
- the optical signal processing equipment 18 includes, at a minimum, the broadband source of light 49, such as the light emitting diode (LED), and appropriate equipment for delivery of signal light to the Bragg gratings 47,48 included within the core ofthe optical fiber 24. Additionally, the optical signal processing equipment 18 includes appropriate optical signal analysis equipment 50 for analyzing the return signals from the Bragg gratings 47,48.
- the broadband source of light 49 such as the light emitting diode (LED)
- LED light emitting diode
- Fig. 4 shows an arrangement for monitoring the wavelength shifts produced by the Bragg gratings 47, 48 to provide both static and dynamic pressure sensing. Additionally, the arrangement may also be used for monitoring wavelength shifts in a temperature measuring/compensation Bragg grating.
- Light from the broadband optical source 49 is coupled to the fiber 24 via a coupler 222.
- This coupler 222 directs light to the sensor assembly 1, and directs the reflected optical components from the Bragg gratings 47, 48 to the optical signal processing equipment 50 including wavelength monitoring sub-systems, 224 and 226.
- One of the wavelength monitoring systems 224 allows for the detection of wavelength shifts ofthe Bragg grating elements using an 'absolute' approach for static parameter monitoring (e.g. pressure & temperature).
- the other wavelength monitoring system 226 provides for detecting weak dynamically induced shifts for dynamic pressure monitoring.
- the returned optical components are directed into an optical wavelength analyzer 224, such as a scanning narrowband filter, which produces a measure ofthe Bragg wavelength ofthe signal light reflected by the Bragg grating 47.
- an optical wavelength analyzer 224 such as a scanning narrowband filter, which produces a measure ofthe Bragg wavelength ofthe signal light reflected by the Bragg grating 47.
- Static pressure can be deduced from the differential shift of the Bragg wavelengths produced by Bragg gratings 47.
- Temperature may be determined directly from a measure ofthe Bragg wavelength of the temperature compensation Bragg grating.
- a portion of the returned optical components is split off, using a coupler 223, to an alternative wavelength discriminator 226 to thereby provide high resolution monitoring of wavelength shifts.
- a portion ofthe returned optical components from the gratings are directed to a wavelength filter or router 225.
- This device separates the optical signals produced by each Bragg grating by means of selective filtering. The pass-bands of this device are wide enough to ensure that under normal operating conditions (full temperature & pressure range), the optical signal produced by a particular grating or gratings is always passed.
- the outputs ofthe router can then be analyzed using sensitive wavelength discriminators 226 to determine wavelength modulation effects due to dynamic pressure, associated for example with acoustic or seismic information.
- sensitive wavelength discriminators 226 By tuning the filter 225 passband, the separate gratings in the system can be analyzed individually.
- a wavelength division demultiplexer could be used to separate the wavelength components onto separate fibers that could then be each analyzed via separate high-resolution wavelength discriminators.
- An example of the type of wavelength discriminators suitable for this purpose is the interferometric detection approach described in U.S. Patent No. 5,361 ,130, the disclosure of which is incorporated herein by reference.
- optical signal processing equipment 50 Although a specific embodiment of the optical signal processing equipment 50 is described above, other optical signal analysis techniques may be used with the present invention such as the necessary hardware and software to implement the optical signal diagnostic equipment disclosed in U.S. Patent Nos. 4,996,419; 5,401,956; 5,426,297; and/or 5,493,390, the disclosures of which are incorporated herein by reference.
- Direct spectroscopy utilizing conventional dispersive elements such as line gratings, prisms, etc., and a linear array of photo detector elements or a CCD array;
- a tuneable filter such as, for example, a scanning Fabry- Perot filter, an acousto-optic filter such as the filter described in the above referenced U.S. Patent No. 5,493,390, or fiber Bragg grating based filters; and
- the optical signal processing equipment may operate on a principle of wave-division multiplexing as described above wherein each Bragg grating sensor is utilized at a different passband or frequency band of interest.
- the present invention may utilize time- division multiplexing for obtaining signals from multiple independent sensors, or any other suitable means for analyzing signals returned from a plurality of Bragg grating sensors formed in a fiber optic sensor string.
- an input optical signal such as a broadband optical signal
- the broadband light source 49 is provided by the broadband light source 49 to the optical fiber 24.
- the optical signal travels along the optical fiber 24 to the sensor 1.
- the broadband light encounters the temperature sensing Bragg grating 48.
- Bragg grating sensor is periodic refractive index variation in the core of an optical fiber that reflects a narrow wavelength of light, has a maximum reflectivity at a central reflectivity wavelength, and transmits all other wavelengths.
- the broadband light source signal is incident on the first (temperature sensing) Bragg grating sensor 48, a narrow wavelength band of light having a central wavelength ⁇ ⁇ is reflected therefrom, and light not reflected is transmitted through the grating 48 to the pressure sensing Bragg grating 47.
- the temperature sensing Bragg grating 47 reflects a narrow wavelength band of light having a central wavelength of ⁇ P . Light not reflected by the pressure sensing Bragg grating 47 is provided to the end ofthe optical fiber and is dispersed.
- the temperature sensing Bragg grating 48 will experience wavelength change (associated by change in strain) due to changes in temperature.
- the pressure sensing Bragg grating 47 will experience strain due to both changes in temperature and changes in the elongation of the bellows structure 85 (Fig. 2) associated with changes in the pressure in the environment. These strains will cause a wavelength shift in the central wavelength of the narrow band of light reflected by each Bragg grating sensor. For example, referring to Fig. 5, when the temperature sensing Bragg grating 48 is subject to a temperature strain, the central wavelength of reflected light ⁇ ⁇ shifts by an amount A ⁇ ⁇ to a new central wavelength ⁇ ⁇ .
- the Bragg grating sensors 47,48 are designed to provide a wavelength spacing such that when the central wavelength of one of the Bragg grating sensors shifts by a maximum amount, the central wavelength will still be in a desire bandwidth ⁇ which does not overlap with the bandwidth of any other Bragg grating sensor.
- Both ofthe Bragg grating sensors 47,48 are subject to the temperature ofthe environment, while only the pressure sensing Bragg grating 47 is subject to a change in strain associated with the pressure in the environment. Therefore, the temperature sensing Bragg grating 47 can be used to provide both a direct measurement ofthe temperature at the sensing location and to compensate for the wavelength shift in the pressure sensing Bragg grating 47 associated with temperature. Therefore, an accurate pressure measurement is provided. As will be understood by those skilled in the art, if it is desired to only instantaneous dynamic pressure, then temperature compensation is not required.
- the invention is described with respect to Fig. 2 as providing a temperature compensation Bragg grating 47 which is isolated from pressure strain so that it is only responsive to temperature changes.
- the temperature compensation Bragg grating may be made to be inversely responsive to pressure strain.
- a pressure sensing Bragg grating 147 is positioned within a bellows structure 185, in a similar manner as described with respect to the pressure sensing Bragg grating 47 of Fig. 2.
- a second, temperature compensation Bragg grating 148 is formed in the fiber 124 and is attached at an attachment point 149 to the bellows structure 185 on the opposite side as the pressure sensing Bragg grating 147.
- a portion ofthe fiber 150 on the side of the Bragg grating 148 opposite the mounting location 150 is fixed at a fixed reference location 151.
- the position ofthe fixed reference location 151 does not change with changes in pressure ofthe environment.
- the bellows structure must remain in communication with the environment in which pressure is sensed. Therefore, either the pressure reaches the bellows structure 185 via the end of the sensor, as described with respect to the first embodiment of Fig. 2, or aperture must be formed in the sensor housing, for example as described with respect to the third embodiment of Fig. 10.
- the strain in the two Bragg gratings change in an equal but opposite amount.
- the central wavelength ofthe pressure sensing Bragg grating ⁇ A and the temperature sensing Bragg grating ⁇ B change by the same amount in response to a change in temperature with no change in pressure (no deflection of the dimensions ofthe bellows structure) as given by:
- the wavelength shift ofthe two Bragg grating sensors 147,148 is opposite for a change in pressure:
- the difference between the wavelength of the two Bragg grating sensors 147, 148 will not change with temperature. Instead, the difference in the wavelength between the two Bragg grating sensors will only change due to pressure (causing a deflection in the position of the bellows 185).
- This configuration provides the significant advantages of inherent temperature compensation and enhanced pressure sensing.
- the change in central wavelength for the two Bragg grating sensors are subtracted from one another, the temperature component is canceled.
- the pressure component being equal and opposite, is doubled. Therefore, the system provides twice the wavelength shift for a given pressure change as compared to a sensor using a single Bragg grating.
- the Bragg grating sensors 147,148 are described as having an equal and opposite change in strain associated with change in pressure (causing a shift in the position of the bellows structure 185). This assumes that both Bragg gratings 147, 148 are in a similar pre-strain. neutral strain or compression condition and that the sensors operate generally linearly with changes in strain. However, if the Bragg grating sensors 147,148 do not respond linearly over the desired operating region, the response of the Bragg gratings 147, 148 can be characterized to thereby provide the desired temperature compensated pressure sensing in accordance with the invention.
- multiple pressure sensors constructed in accordance with the teachings of the invention may be multiplexed together to provide distributed pressure sensing.
- multiple pressure sensors 900, 901 , 902 may be multiplexed together over a single optical fiber 924.
- one of the pressure sensors 900 is shown. This sensor is of the same basic structure as the pressure senor 1 illustrated in Fig. 2. However, rather than terminating in a ferrule at the end of the bellows structure, the optical fiber 924 passes through a fitting 930 at the end of the bellows structure 985 for interconnection to the next pressure sensor 901.
- Both ends of the sensor 900 are interconnected to lengths of capillary tubing 935,936 to protect the optical fiber 924 along its length.
- the capillary tubing 935,936 may be connected to the sensor 900 by threads, welding, etc. for a secure, leak tight seal.
- the senor is provided with pressure seals 955,956 to isolate the capillary tubes from the pressure sensor.
- Apertures 970 are provided in the sensor housing adjacent to the bellows structure 985 such that the bellows structure is exposed to the pressure in the environment.
- the various pressure and temperature signals from the different sensors 900, 901 , 902 may be differentiated from one another using wavelength division multiplexing techniques.
- each Bragg grating is designed to operate at a central wavelength ⁇ within a bandwidth ⁇ that does not overlap with the bandwidth of the other Bragg grating sensors. Therefore, the temperature and pressure signals from each of the sensors 900,901 ,902 can be easily differentiated from one another based on the received wavelength.
- time division multiplexing techniques may be utilized to differentiate between signals from different Bragg grating sensors. As is known in the art, this well known technique is based on the position of each sensor along the length of the optical fiber 924 and the sequence that reflected signals will be received from each of the sensors.
- the multiplexed sensors 900, 901,902 of Fig. 9 may be of the type illustrated in Fig. 2, using an isolated temperature compensation Bragg grating sensor.
- the multiplexed sensors may be of the design illustrated in Fig. 6.
- the fixed reference location may be part of a pressure seal that isolates the pressure sensor from the capillary tube 936.
- an alternate embodiment of this invention can utilize a pair of reflective gratings within the same length of fiber, thus forming a resonant cavity of longer length.
- a resonant cavity will also reflect light of a particular wavelength corresponding to a central wavelength ofthe reflective gratings.
- a change in the cavity length due to a static strain, a dynamic strain and/or a temperature induced strain on fiber will result in phase shift in the reflected light due to the change in optical path length within the reflective cavity.
- Such a device termed a Fabry-Perot interferometer
- a Fabry-Perot interferometer can then provide a high sensitivity means of detecting strain in the optical fiber, and the resultant optical phase shift can be detected using standard interferometer instrumentation techniques.
- the pair of Bragg gratings may be used to form a lasing element for detection, for example by positioning an Erbium doped length of optical fiber between the pair of Bragg gratings.
Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69819754T DE69819754D1 (en) | 1997-09-08 | 1998-09-01 | HIGHLY SENSITIVE FIBER OPTICAL PRESSURE SENSOR FOR ROUGH ENVIRONMENTS |
EP98941114A EP1012553B1 (en) | 1997-09-08 | 1998-09-01 | High sensitivity fiber optic pressure sensor for use in harsh environments |
CA002303257A CA2303257C (en) | 1997-09-08 | 1998-09-01 | High sensitivity fiber optic pressure sensor for use in harsh environments |
AU89251/98A AU8925198A (en) | 1997-09-08 | 1998-09-01 | High sensitivity fiber optic pressure sensor for use in harsh environments |
NO20001161A NO322402B1 (en) | 1997-09-08 | 2000-03-07 | Temperature compensated pressure sensor and distributed pressure sensor system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/925,598 | 1997-09-08 | ||
US08/925,598 US6016702A (en) | 1997-09-08 | 1997-09-08 | High sensitivity fiber optic pressure sensor for use in harsh environments |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1999013307A1 true WO1999013307A1 (en) | 1999-03-18 |
Family
ID=25451980
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1998/018065 WO1999013307A1 (en) | 1997-09-08 | 1998-09-01 | High sensitivity fiber optic pressure sensor for use in harsh environments |
Country Status (7)
Country | Link |
---|---|
US (1) | US6016702A (en) |
EP (1) | EP1012553B1 (en) |
AU (1) | AU8925198A (en) |
CA (1) | CA2303257C (en) |
DE (1) | DE69819754D1 (en) |
NO (1) | NO322402B1 (en) |
WO (1) | WO1999013307A1 (en) |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999032911A1 (en) * | 1997-12-05 | 1999-07-01 | Optoplan As | Sensor for measuring strain |
WO2000033048A2 (en) * | 1998-12-04 | 2000-06-08 | Cidra Corporation | Fiber optic bragg grating pressure sensor |
WO2001014843A1 (en) * | 1999-08-19 | 2001-03-01 | Abb Research Ltd. | Fiber optic pressure sensor |
EP1179727A1 (en) * | 2000-08-02 | 2002-02-13 | Abb Research Ltd. | Fiber-optic bragg sensor for measurement of pressure and density |
WO2002097388A1 (en) * | 2001-06-01 | 2002-12-05 | Weatherford/Lamb, Inc. | Optical pressure sensor device having creep-resistant optical fiber attachments |
WO2007149733A2 (en) * | 2006-06-19 | 2007-12-27 | Baker Hughes Incorporated | Isolated sensor housing |
WO2009056623A1 (en) * | 2007-10-31 | 2009-05-07 | Shell Internationale Research Maatschappij B.V. | Pressure sensor assembly and method of using the assembly |
US7637167B2 (en) | 2008-04-25 | 2009-12-29 | Schlumberger Technology Corporation | Apparatus and method for characterizing two phase fluid flow |
WO2011042023A1 (en) * | 2009-10-05 | 2011-04-14 | Nkt Flexibles I/S | A flexible unbonded oil pipe system with an optical fiber sensor inside |
EP2510189A4 (en) * | 2009-12-08 | 2016-03-09 | Services Petroliers Schlumberger | Optical sensor having a capillary tube and an optical fiber in the capillary tube |
WO2017142921A1 (en) * | 2016-02-18 | 2017-08-24 | Weatherford Technology Holdings, Llc | Pressure gauge insensitive to extraneous mechanical loadings |
WO2018101828A1 (en) * | 2016-12-02 | 2018-06-07 | Fugro Technology B.V. | Embankment monitoring system |
Families Citing this family (155)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5832157A (en) * | 1996-07-12 | 1998-11-03 | Mcdermott Technology, Inc. | Fiber optic acoustic emission sensor |
US6787758B2 (en) * | 2001-02-06 | 2004-09-07 | Baker Hughes Incorporated | Wellbores utilizing fiber optic-based sensors and operating devices |
NO305004B1 (en) * | 1997-06-30 | 1999-03-15 | Optoplan As | Pressure Sensor |
RU2250438C9 (en) | 1998-06-26 | 2005-08-27 | Сидрэ Копэрейшн | Method and device for measuring parameters of fluids in pipes |
US6490931B1 (en) * | 1998-12-04 | 2002-12-10 | Weatherford/Lamb, Inc. | Fused tension-based fiber grating pressure sensor |
US6621957B1 (en) | 2000-03-16 | 2003-09-16 | Cidra Corporation | Temperature compensated optical device |
US6233746B1 (en) * | 1999-03-22 | 2001-05-22 | Halliburton Energy Services, Inc. | Multiplexed fiber optic transducer for use in a well and method |
US6463813B1 (en) | 1999-06-25 | 2002-10-15 | Weatherford/Lamb, Inc. | Displacement based pressure sensor measuring unsteady pressure in a pipe |
US7261002B1 (en) * | 1999-07-02 | 2007-08-28 | Cidra Corporation | Flow rate measurement for industrial sensing applications using unsteady pressures |
US6691584B2 (en) | 1999-07-02 | 2004-02-17 | Weatherford/Lamb, Inc. | Flow rate measurement using unsteady pressures |
US6536291B1 (en) | 1999-07-02 | 2003-03-25 | Weatherford/Lamb, Inc. | Optical flow rate measurement using unsteady pressures |
US6449402B1 (en) | 1999-11-19 | 2002-09-10 | Finisar Corporation | Method and apparatus for compensating an optical filter |
JP3519333B2 (en) * | 2000-02-10 | 2004-04-12 | エヌ・ティ・ティ・アドバンステクノロジ株式会社 | Optical fiber sensor |
US6601458B1 (en) | 2000-03-07 | 2003-08-05 | Weatherford/Lamb, Inc. | Distributed sound speed measurements for multiphase flow measurement |
US6813962B2 (en) * | 2000-03-07 | 2004-11-09 | Weatherford/Lamb, Inc. | Distributed sound speed measurements for multiphase flow measurement |
US6671055B1 (en) | 2000-04-13 | 2003-12-30 | Luna Innovations, Inc. | Interferometric sensors utilizing bulk sensing mediums extrinsic to the input/output optical fiber |
NO315762B1 (en) * | 2000-09-12 | 2003-10-20 | Optoplan As | Sand detector |
US6453108B1 (en) | 2000-09-30 | 2002-09-17 | Cidra Corporation | Athermal bragg grating package with course and fine mechanical tuning |
US6782150B2 (en) | 2000-11-29 | 2004-08-24 | Weatherford/Lamb, Inc. | Apparatus for sensing fluid in a pipe |
US6501067B2 (en) * | 2000-11-29 | 2002-12-31 | Weatherford/Lamb, Inc. | Isolation pad for protecting sensing devices on the outside of a conduit |
DE10140482B4 (en) * | 2001-08-17 | 2008-11-13 | Siemens Ag | Method and device for disturbance compensation of an optical sensor |
US6698297B2 (en) | 2002-06-28 | 2004-03-02 | Weatherford/Lamb, Inc. | Venturi augmented flow meter |
US7059172B2 (en) * | 2001-11-07 | 2006-06-13 | Weatherford/Lamb, Inc. | Phase flow measurement in pipes using a density meter |
US6971259B2 (en) * | 2001-11-07 | 2005-12-06 | Weatherford/Lamb, Inc. | Fluid density measurement in pipes using acoustic pressures |
US7275421B2 (en) * | 2002-01-23 | 2007-10-02 | Cidra Corporation | Apparatus and method for measuring parameters of a mixture having solid particles suspended in a fluid flowing in a pipe |
US7328624B2 (en) * | 2002-01-23 | 2008-02-12 | Cidra Corporation | Probe for measuring parameters of a flowing fluid and/or multiphase mixture |
US7474966B2 (en) * | 2002-01-23 | 2009-01-06 | Expro Meters. Inc | Apparatus having an array of piezoelectric film sensors for measuring parameters of a process flow within a pipe |
US7359803B2 (en) * | 2002-01-23 | 2008-04-15 | Cidra Corporation | Apparatus and method for measuring parameters of a mixture having solid particles suspended in a fluid flowing in a pipe |
US7032432B2 (en) * | 2002-01-23 | 2006-04-25 | Cidra Corporation | Apparatus and method for measuring parameters of a mixture having liquid droplets suspended in a vapor flowing in a pipe |
US6848316B2 (en) * | 2002-05-08 | 2005-02-01 | Rosemount Inc. | Pressure sensor assembly |
WO2004009957A1 (en) * | 2002-07-23 | 2004-01-29 | Halliburton Energy Services, Inc. | Subterranean well pressure and temperature measurement |
WO2004015377A2 (en) * | 2002-08-08 | 2004-02-19 | Cidra Corporation | Apparatus and method for measuring multi-phase flows in pulp and paper industry applications |
US6847034B2 (en) * | 2002-09-09 | 2005-01-25 | Halliburton Energy Services, Inc. | Downhole sensing with fiber in exterior annulus |
US6978832B2 (en) | 2002-09-09 | 2005-12-27 | Halliburton Energy Services, Inc. | Downhole sensing with fiber in the formation |
US20040065436A1 (en) * | 2002-10-03 | 2004-04-08 | Schultz Roger L. | System and method for monitoring a packer in a well |
GB2396211B (en) | 2002-10-06 | 2006-02-22 | Weatherford Lamb | Multiple component sensor mechanism |
US20040065437A1 (en) * | 2002-10-06 | 2004-04-08 | Weatherford/Lamb Inc. | In-well seismic sensor casing coupling using natural forces in wells |
US6888972B2 (en) * | 2002-10-06 | 2005-05-03 | Weatherford/Lamb, Inc. | Multiple component sensor mechanism |
US7036601B2 (en) | 2002-10-06 | 2006-05-02 | Weatherford/Lamb, Inc. | Apparatus and method for transporting, deploying, and retrieving arrays having nodes interconnected by sections of cable |
CA2513105C (en) * | 2002-11-12 | 2013-01-08 | Cidra Corporation | An apparatus having an array of piezoelectric film sensors for measuring parameters of a process flow within a pipe |
US7165464B2 (en) * | 2002-11-15 | 2007-01-23 | Cidra Corporation | Apparatus and method for providing a flow measurement compensated for entrained gas |
WO2004048906A2 (en) * | 2002-11-22 | 2004-06-10 | Cidra Corporation | Method for calibrating a flow meter having an array of sensors |
WO2004063675A2 (en) * | 2003-01-13 | 2004-07-29 | Cidra Corporation | Apparatus and method using an array of ultrasonic sensors for determining the velocity of a fluid within a pipe |
US7096719B2 (en) * | 2003-01-13 | 2006-08-29 | Cidra Corporation | Apparatus for measuring parameters of a flowing multiphase mixture |
CA2514696C (en) | 2003-01-21 | 2012-12-11 | Cidra Corporation | Measurement of entrained and dissolved gases in process flow lines |
EP1590637B1 (en) * | 2003-01-21 | 2008-11-05 | Expro Meters, Inc. | An apparatus and method of measuring gas volume fraction of a fluid flowing within a pipe |
US7343818B2 (en) * | 2003-01-21 | 2008-03-18 | Cidra Corporation | Apparatus and method of measuring gas volume fraction of a fluid flowing within a pipe |
US20060048583A1 (en) * | 2004-08-16 | 2006-03-09 | Gysling Daniel L | Total gas meter using speed of sound and velocity measurements |
US7058549B2 (en) * | 2003-01-21 | 2006-06-06 | C1Dra Corporation | Apparatus and method for measuring unsteady pressures within a large diameter pipe |
US6915686B2 (en) | 2003-02-11 | 2005-07-12 | Optoplan A.S. | Downhole sub for instrumentation |
US7159653B2 (en) | 2003-02-27 | 2007-01-09 | Weatherford/Lamb, Inc. | Spacer sub |
EP1599705B1 (en) | 2003-03-04 | 2019-01-02 | CiDra Corporation | An apparatus having a multi-band sensor assembly for measuring a parameter of a fluid flow flowing within a pipe |
US6986276B2 (en) * | 2003-03-07 | 2006-01-17 | Weatherford/Lamb, Inc. | Deployable mandrel for downhole measurements |
US6837098B2 (en) * | 2003-03-19 | 2005-01-04 | Weatherford/Lamb, Inc. | Sand monitoring within wells using acoustic arrays |
US6840114B2 (en) * | 2003-05-19 | 2005-01-11 | Weatherford/Lamb, Inc. | Housing on the exterior of a well casing for optical fiber sensors |
US6957574B2 (en) * | 2003-05-19 | 2005-10-25 | Weatherford/Lamb, Inc. | Well integrity monitoring system |
EP1631797A2 (en) * | 2003-06-05 | 2006-03-08 | CiDra Corporation | Apparatus for measuring velocity and flow rate of a fluid having a non-negligible axial mach number using an array of sensors |
CA2530596C (en) * | 2003-06-24 | 2013-05-21 | Cidra Corporation | System and method for operating a flow process |
US7134320B2 (en) * | 2003-07-15 | 2006-11-14 | Cidra Corporation | Apparatus and method for providing a density measurement augmented for entrained gas |
US7152460B2 (en) * | 2003-07-15 | 2006-12-26 | Cidra Corporation | Apparatus and method for compensating a coriolis meter |
WO2005010469A2 (en) | 2003-07-15 | 2005-02-03 | Cidra Corporation | A dual function flow measurement apparatus having an array of sensors |
US7299705B2 (en) * | 2003-07-15 | 2007-11-27 | Cidra Corporation | Apparatus and method for augmenting a Coriolis meter |
WO2005015135A2 (en) * | 2003-08-08 | 2005-02-17 | Cidra Corporation | Piezocable based sensor for measuring unsteady pressures inside a pipe |
US6910388B2 (en) * | 2003-08-22 | 2005-06-28 | Weatherford/Lamb, Inc. | Flow meter using an expanded tube section and sensitive differential pressure measurement |
US20080264182A1 (en) * | 2003-08-22 | 2008-10-30 | Jones Richard T | Flow meter using sensitive differential pressure measurement |
US6945117B2 (en) * | 2003-08-29 | 2005-09-20 | Dana Corporation | Gasket having a fiber-optic pressure sensor assembly |
US7104141B2 (en) * | 2003-09-04 | 2006-09-12 | Baker Hughes Incorporated | Optical sensor with co-located pressure and temperature sensors |
EP1942324B1 (en) * | 2003-09-04 | 2012-04-11 | Baker Hughes Incorporated | Optical sensor with co-located pressure and temperature sensors |
EP1664706B1 (en) * | 2003-09-04 | 2011-07-27 | Baker Hughes Incorporated | Optical sensor with co-located pressure and temperature sensors |
US7237440B2 (en) * | 2003-10-10 | 2007-07-03 | Cidra Corporation | Flow measurement apparatus having strain-based sensors and ultrasonic sensors |
US7050662B2 (en) * | 2003-11-19 | 2006-05-23 | Em Photonics, Inc. | Fiber Bragg grating compression sensor system |
US7367239B2 (en) * | 2004-03-23 | 2008-05-06 | Cidra Corporation | Piezocable based sensor for measuring unsteady pressures inside a pipe |
US7492463B2 (en) | 2004-04-15 | 2009-02-17 | Davidson Instruments Inc. | Method and apparatus for continuous readout of Fabry-Perot fiber optic sensor |
US7426852B1 (en) | 2004-04-26 | 2008-09-23 | Expro Meters, Inc. | Submersible meter for measuring a parameter of gas hold-up of a fluid |
US7480056B2 (en) * | 2004-06-04 | 2009-01-20 | Optoplan As | Multi-pulse heterodyne sub-carrier interrogation of interferometric sensors |
US7109471B2 (en) * | 2004-06-04 | 2006-09-19 | Weatherford/Lamb, Inc. | Optical wavelength determination using multiple measurable features |
US7159468B2 (en) * | 2004-06-15 | 2007-01-09 | Halliburton Energy Services, Inc. | Fiber optic differential pressure sensor |
US7196318B2 (en) * | 2004-07-16 | 2007-03-27 | Kin-Man Yip | Fiber-optic sensing system |
BRPI0403240B1 (en) * | 2004-08-10 | 2016-02-16 | Petroleo Brasileiro Sa | optical transducer for simultaneous measurement of pressure and temperature in oil wells and method for said measurement |
BRPI0403786A (en) * | 2004-09-09 | 2006-05-02 | Petroleo Brasileiro Sa | fiber optic differential pressure transducer |
WO2006112878A2 (en) | 2004-09-16 | 2006-10-26 | Cidra Corporation | Apparatus and method for providing a fluid cut measurement of a multi-liquid mixture compensated for entrained gas |
US7389687B2 (en) * | 2004-11-05 | 2008-06-24 | Cidra Corporation | System for measuring a parameter of an aerated multi-phase mixture flowing in a pipe |
EP1681540A1 (en) * | 2004-12-21 | 2006-07-19 | Davidson Instruments, Inc. | Multi-channel array processor |
US7311150B2 (en) * | 2004-12-21 | 2007-12-25 | Cdx Gas, Llc | Method and system for cleaning a well bore |
EP1674833A3 (en) * | 2004-12-21 | 2007-05-30 | Davidson Instruments, Inc. | Fiber optic sensor system |
US7302123B2 (en) * | 2005-03-10 | 2007-11-27 | Weatherford/Lamb, Inc. | Dynamic optical waveguide sensor |
US20060274323A1 (en) * | 2005-03-16 | 2006-12-07 | Gibler William N | High intensity fabry-perot sensor |
US7657392B2 (en) * | 2005-05-16 | 2010-02-02 | Cidra Corporate Services, Inc. | Method and apparatus for detecting and characterizing particles in a multiphase fluid |
US7526966B2 (en) | 2005-05-27 | 2009-05-05 | Expro Meters, Inc. | Apparatus and method for measuring a parameter of a multiphase flow |
WO2006130499A2 (en) | 2005-05-27 | 2006-12-07 | Cidra Corporation | An apparatus and method for fiscal measuring of an aerated fluid |
US7500793B2 (en) * | 2005-05-31 | 2009-03-10 | Greene, Tweed Of Delaware, Inc. | High-pressure/high-temperature seals between glass fibers and metals, downhole optical feedthroughs containing the same, and methods of preparing such seals |
US7249525B1 (en) | 2005-06-22 | 2007-07-31 | Cidra Corporation | Apparatus for measuring parameters of a fluid in a lined pipe |
EP1899686B1 (en) | 2005-07-07 | 2011-09-28 | CiDra Corporation | Wet gas metering using a differential pressure based flow meter with a sonar based flow meter |
WO2007009097A1 (en) * | 2005-07-13 | 2007-01-18 | Cidra Corporation | Method and apparatus for measuring parameters of a fluid flow using an array of sensors |
US20070055464A1 (en) * | 2005-08-17 | 2007-03-08 | Gysling Daniel L | System and method for providing a compositional measurement of a mixture having entrained gas |
WO2007033069A2 (en) * | 2005-09-13 | 2007-03-22 | Davidson Instruments Inc. | Tracking algorithm for linear array signal processor for fabry-perot cross-correlation pattern and method of using same |
US7503217B2 (en) | 2006-01-27 | 2009-03-17 | Weatherford/Lamb, Inc. | Sonar sand detection |
US20070252998A1 (en) * | 2006-03-22 | 2007-11-01 | Berthold John W | Apparatus for continuous readout of fabry-perot fiber optic sensor |
US7684051B2 (en) * | 2006-04-18 | 2010-03-23 | Halliburton Energy Services, Inc. | Fiber optic seismic sensor based on MEMS cantilever |
EP2021747B1 (en) * | 2006-04-26 | 2018-08-01 | Halliburton Energy Services, Inc. | Fiber optic mems seismic sensor with mass supported by hinged beams |
US7624650B2 (en) | 2006-07-27 | 2009-12-01 | Expro Meters, Inc. | Apparatus and method for attenuating acoustic waves propagating within a pipe wall |
US8115937B2 (en) * | 2006-08-16 | 2012-02-14 | Davidson Instruments | Methods and apparatus for measuring multiple Fabry-Perot gaps |
US7539361B2 (en) | 2006-10-05 | 2009-05-26 | Harris Corporation | Fiber optic device for measuring a parameter of interest |
US7624651B2 (en) * | 2006-10-30 | 2009-12-01 | Expro Meters, Inc. | Apparatus and method for attenuating acoustic waves in pipe walls for clamp-on ultrasonic flow meter |
US7673526B2 (en) * | 2006-11-01 | 2010-03-09 | Expro Meters, Inc. | Apparatus and method of lensing an ultrasonic beam for an ultrasonic flow meter |
EP2092278A2 (en) | 2006-11-09 | 2009-08-26 | Expro Meters, Inc. | Apparatus and method for measuring a fluid flow parameter within an internal passage of an elongated body |
US7840102B2 (en) * | 2007-01-16 | 2010-11-23 | Baker Hughes Incorporated | Distributed optical pressure and temperature sensors |
US8417084B2 (en) * | 2007-01-16 | 2013-04-09 | Baker Hughes Incorporated | Distributed optical pressure and temperature sensors |
CA2676246C (en) * | 2007-01-24 | 2013-03-19 | Halliburton Energy Services, Inc. | Transducer for measuring environmental parameters |
US7817285B2 (en) * | 2007-10-11 | 2010-10-19 | Baker Hughes Incorporated | Downhole uses of pressure-tuned semiconductor light sources |
US8061186B2 (en) | 2008-03-26 | 2011-11-22 | Expro Meters, Inc. | System and method for providing a compositional measurement of a mixture having entrained gas |
US8135245B2 (en) | 2008-12-05 | 2012-03-13 | General Electric Company | Fiber optic sensing system |
WO2010123566A1 (en) | 2009-04-22 | 2010-10-28 | Lxdata Inc. | Pressure sensor arrangement using an optical fiber and methodologies for performing an analysis of a subterranean formation |
US8547426B2 (en) * | 2009-06-15 | 2013-10-01 | Identix Incorporated | Low settle time micro-scanning system |
US8151648B2 (en) * | 2009-08-03 | 2012-04-10 | University Of Maryland | Ultra-miniature fiber-optic pressure sensor system and method of fabrication |
US11519802B1 (en) * | 2009-09-15 | 2022-12-06 | Astro Technology Group, Llc | Apparatus, fiber optic sensor assembly and sensor housing assembly utilizing viscous material composition to mitigate signal attenuation |
US8966988B2 (en) | 2010-08-03 | 2015-03-03 | University Of Maryland | Ultra-miniature fiber-optic pressure sensor system and method of fabrication |
US9557239B2 (en) | 2010-12-03 | 2017-01-31 | Baker Hughes Incorporated | Determination of strain components for different deformation modes using a filter |
US9194973B2 (en) | 2010-12-03 | 2015-11-24 | Baker Hughes Incorporated | Self adaptive two dimensional filter for distributed sensing data |
US9103736B2 (en) | 2010-12-03 | 2015-08-11 | Baker Hughes Incorporated | Modeling an interpretation of real time compaction modeling data from multi-section monitoring system |
US20120200422A1 (en) * | 2011-02-09 | 2012-08-09 | Baker Hughes Incorporated | Use of Digital Transport Delay to Improve Measurement Fidelity in Swept-Wavelength Systems |
US20130094812A1 (en) * | 2011-10-12 | 2013-04-18 | Baker Hughes Incorporated | Conduit Tube Assembly and Manufacturing Method for Subterranean Use |
US8590385B2 (en) * | 2011-12-12 | 2013-11-26 | General Electric Company | High pressure fiber optic sensor system |
CN102589585B (en) * | 2012-01-11 | 2014-12-17 | 哈尔滨工业大学深圳研究生院 | Fiber bragg grating array sensing system in cavity |
GB2500255B (en) * | 2012-03-16 | 2020-04-15 | Oxsensis Ltd | Optical sensor |
CN102724335B (en) * | 2012-04-16 | 2015-06-03 | 中兴通讯股份有限公司 | Waterproofing device |
GB2507666B (en) * | 2012-11-02 | 2017-08-16 | Silixa Ltd | Determining a profile of fluid type in a well by distributed acoustic sensing |
US9632071B2 (en) | 2013-07-25 | 2017-04-25 | General Electric Company | Systems and methods for analyzing a multiphase fluid |
US9103704B2 (en) | 2013-07-25 | 2015-08-11 | General Electric Company | Holding device to hold a reflector and an electromagnetic guiding device |
US10077649B2 (en) * | 2013-08-09 | 2018-09-18 | Halliburton Energy Services, Inc. | Optical fiber feedthrough incorporating fiber bragg grating |
US9410422B2 (en) | 2013-09-13 | 2016-08-09 | Chevron U.S.A. Inc. | Alternative gauging system for production well testing and related methods |
US9605534B2 (en) | 2013-11-13 | 2017-03-28 | Baker Hughes Incorporated | Real-time flow injection monitoring using distributed Bragg grating |
DE102014103721A1 (en) * | 2013-12-20 | 2015-06-25 | Endress + Hauser Conducta Gesellschaft für Mess- und Regeltechnik mbH + Co. KG | Optical sensor, in particular for determining substance concentrations in aqueous solutions by means of a chemiluminescence, absorption or fluorescence measurement |
US9341532B2 (en) | 2014-03-24 | 2016-05-17 | General Electric Company | Systems and methods for distributed pressure sensing |
US10161924B2 (en) * | 2014-03-24 | 2018-12-25 | National Technology & Engineering Solutions Of Sandia, Llc | Sensor system that uses embedded optical fibers |
CA3012210A1 (en) * | 2014-05-08 | 2015-11-12 | WellGauge, Inc. | Well water depth monitor |
US9240262B1 (en) | 2014-07-21 | 2016-01-19 | General Electric Company | Systems and methods for distributed pressure sensing |
WO2016032433A1 (en) | 2014-08-26 | 2016-03-03 | Siemens Aktiengesellschaft | Sealing system for optical sensors in gas turbine engines |
CN104612665B (en) * | 2014-12-31 | 2017-07-28 | 哈尔滨工业大学 | Three films two are put high voltage optical fiber pressure sensor and the measuring method of down-hole pipe pressure are realized using the sensor |
US10133017B2 (en) * | 2015-08-07 | 2018-11-20 | Pgs Geophysical As | Vented optical tube |
NL2015952B1 (en) * | 2015-12-11 | 2017-07-03 | Fugro Tech Bv | Pressure sensor and sensor system comprising one or more pressure sensors. |
CN105890679B (en) * | 2016-06-20 | 2019-11-22 | 天津大学 | The Fabry-perot optical fiber formula flow rate test method of local buckling water conservancy diversion |
US10288559B2 (en) | 2017-03-03 | 2019-05-14 | Honeywell International Inc. | Gas concentration sensor with improved accuracy |
US10748702B2 (en) * | 2017-04-28 | 2020-08-18 | Abb Power Grids Switzerland Ag | Transformer system and system for measuring pressure in a transformer tank |
WO2018227281A1 (en) * | 2017-06-12 | 2018-12-20 | Advanced Opto-Mechanical Systems And Technologies Inc. | Multi-parameter distributed fiber optic sensor system and methods of sensor manufacturing |
CN107356356A (en) * | 2017-06-27 | 2017-11-17 | 中国科学院武汉岩土力学研究所 | The fiber grating surrouding rock stress monitoring device and monitoring system of a kind of high-survival rate |
RU2655471C1 (en) * | 2017-08-11 | 2018-05-28 | Федеральное государственное унитарное предприятие "Всероссийский научно-исследовательский институт автоматики им. Н.Л. Духова" (ФГУП "ВНИИА") | Method of increasing the spectral sensitivity of the bragg buck strain converter |
CN107941306B (en) * | 2017-12-21 | 2023-09-05 | 珠海任驰光电科技有限公司 | Improved double-fiber grating packaged liquid level sensor and liquid level measurement method |
BR102018011823A2 (en) * | 2018-06-11 | 2019-12-24 | Faculdades Catolicas | set and method for measuring fluid flow in pipelines |
CN110017938A (en) * | 2019-03-20 | 2019-07-16 | 常州天利智能控制股份有限公司 | A kind of bellows type pressure sensor and the automatic controller with it |
US11585712B2 (en) | 2020-08-21 | 2023-02-21 | Simmonds Precision Products, Inc. | Fiber optic load sensors and systems therefor |
CN112833950B (en) * | 2021-01-07 | 2023-05-23 | 中国舰船研究设计中心 | Steam pipeline internal complex flow field distributed measurement system based on optical fiber sensing |
CN112964299B (en) * | 2021-02-09 | 2022-10-25 | 中北大学 | High-temperature and high-pressure resistant structure heat-sound-vibration three-parameter integrated in-situ sensor and system |
CN114858216B (en) * | 2022-05-07 | 2023-09-12 | 河北地质大学 | Geological disaster monitoring system based on optical fiber sensing technology |
CN116735445B (en) * | 2023-06-27 | 2024-04-12 | 华北科技学院(中国煤矿安全技术培训中心) | Fiber bragg grating sensor for monitoring oil pollution degree |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4589285A (en) * | 1984-11-05 | 1986-05-20 | Western Geophysical Co. Of America | Wavelength-division-multiplexed receiver array for vertical seismic profiling |
US4996419A (en) * | 1989-12-26 | 1991-02-26 | United Technologies Corporation | Distributed multiplexed optical fiber Bragg grating sensor arrangeement |
US5012090A (en) * | 1989-02-09 | 1991-04-30 | Simmonds Precision Products, Inc. | Optical grating sensor and method of monitoring having a multi-period grating |
WO1995030926A1 (en) * | 1994-05-06 | 1995-11-16 | The University Of Sydney | Variable property light transmitting device |
Family Cites Families (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5363463A (en) * | 1982-08-06 | 1994-11-08 | Kleinerman Marcos Y | Remote sensing of physical variables with fiber optic systems |
US4509370A (en) * | 1982-09-30 | 1985-04-09 | Regents Of The University Of California | Pressure-sensitive optrode |
US4545253A (en) * | 1983-08-29 | 1985-10-08 | Exxon Production Research Co. | Fiber optical modulator and data multiplexer |
US4577100A (en) * | 1983-12-27 | 1986-03-18 | United Technologies Corporation | Temperature compensated optical pressure sensor |
US4806012A (en) * | 1984-08-13 | 1989-02-21 | United Technologies Corporation | Distributed, spatially resolving optical fiber strain gauge |
JPS61277028A (en) * | 1985-05-31 | 1986-12-08 | Sumitomo Electric Ind Ltd | Sensor |
US4649529A (en) * | 1985-12-02 | 1987-03-10 | Exxon Production Research Co. | Multi-channel fiber optic sensor system |
EP0227556A1 (en) * | 1985-12-24 | 1987-07-01 | Schlumberger Industries | Optical sensor for physical magnitudes |
US4859844A (en) * | 1988-02-24 | 1989-08-22 | Hughes Aircraft Company | Comb filter pressure/temperature sensing system |
US4900937A (en) * | 1988-10-20 | 1990-02-13 | Bicron Corporation | Well logging detector with decoupling optical interface |
IT1237486B (en) * | 1989-06-23 | 1993-06-07 | Agip Spa | PROCEDURE AND DEVICE WITH OPTICAL FIBER INTERFEROMETRIC SENSORS FOR THE ANALYSIS OF THE DYNAMIC DEFORMATION OF A STRUCTURE OR ITS COMPONENTS |
US4932262A (en) * | 1989-06-26 | 1990-06-12 | General Motors Corporation | Miniature fiber optic pressure sensor |
US4932263A (en) * | 1989-06-26 | 1990-06-12 | General Motors Corporation | Temperature compensated fiber optic pressure sensor |
US5163321A (en) * | 1989-10-17 | 1992-11-17 | Baroid Technology, Inc. | Borehole pressure and temperature measurement system |
US5042898A (en) * | 1989-12-26 | 1991-08-27 | United Technologies Corporation | Incorporated Bragg filter temperature compensated optical waveguide device |
DE4037077A1 (en) * | 1990-11-22 | 1992-05-27 | Hilti Ag | METHOD AND DEVICE FOR FIBER OPTICAL FORCE MEASUREMENT |
US5144690A (en) * | 1990-12-03 | 1992-09-01 | Corning Incorporated | Optical fiber sensor with localized sensing regions |
US5485745A (en) * | 1991-05-20 | 1996-01-23 | Halliburton Company | Modular downhole inspection system for coiled tubing |
US5499533A (en) * | 1992-08-26 | 1996-03-19 | Miller; Mark | Downhole pressure gauge converter |
DE69314289T2 (en) * | 1992-12-07 | 1998-01-29 | Akishima Lab Mitsui Zosen Inc | System for measurements during drilling with pressure pulse valve for data transmission |
US5414507A (en) * | 1993-04-01 | 1995-05-09 | Hughes Aircraft Company | Fiber optics pressure sensor transducer having a temperature compensator |
KR960007884B1 (en) * | 1993-04-24 | 1996-06-15 | 국방과학연구소 | Optical fiber |
US5357806A (en) * | 1993-05-03 | 1994-10-25 | Halliburton Company | Capacitive differential pressure sensor and method of measuring differential pressure at an oil or gas well |
US5315110A (en) * | 1993-06-29 | 1994-05-24 | Abb Vetco Gray Inc. | Metal cup pressure transducer with a support having a plurality of thermal expansion coefficients |
US5351324A (en) * | 1993-09-10 | 1994-09-27 | The Regents Of The University Of California, Office Of Technology Transfer | Fiber optic security seal including plural Bragg gratings |
US5401956A (en) * | 1993-09-29 | 1995-03-28 | United Technologies Corporation | Diagnostic system for fiber grating sensors |
US5452087A (en) * | 1993-11-04 | 1995-09-19 | The Texas A & M University System | Method and apparatus for measuring pressure with embedded non-intrusive fiber optics |
US5548116A (en) * | 1994-03-01 | 1996-08-20 | Optoscint, Inc. | Long life oil well logging assembly |
US5399854A (en) * | 1994-03-08 | 1995-03-21 | United Technologies Corporation | Embedded optical sensor capable of strain and temperature measurement using a single diffraction grating |
US5684297A (en) * | 1994-11-17 | 1997-11-04 | Alcatel Cable | Method of detecting and/or measuring physical magnitudes using a distributed sensor |
US5675674A (en) * | 1995-08-24 | 1997-10-07 | Rockbit International | Optical fiber modulation and demodulation system |
US5646401A (en) * | 1995-12-22 | 1997-07-08 | Udd; Eric | Fiber optic grating and etalon sensor systems |
US5633748A (en) * | 1996-03-05 | 1997-05-27 | The United States Of America As Represented By The Secretary Of The Navy | Fiber optic Bragg grating demodulator and sensor incorporating same |
US5680489A (en) * | 1996-06-28 | 1997-10-21 | The United States Of America As Represented By The Secretary Of The Navy | Optical sensor system utilizing bragg grating sensors |
US5767411A (en) * | 1996-12-31 | 1998-06-16 | Cidra Corporation | Apparatus for enhancing strain in intrinsic fiber optic sensors and packaging same for harsh environments |
-
1997
- 1997-09-08 US US08/925,598 patent/US6016702A/en not_active Expired - Lifetime
-
1998
- 1998-09-01 AU AU89251/98A patent/AU8925198A/en not_active Abandoned
- 1998-09-01 EP EP98941114A patent/EP1012553B1/en not_active Expired - Lifetime
- 1998-09-01 CA CA002303257A patent/CA2303257C/en not_active Expired - Fee Related
- 1998-09-01 DE DE69819754T patent/DE69819754D1/en not_active Expired - Lifetime
- 1998-09-01 WO PCT/US1998/018065 patent/WO1999013307A1/en active IP Right Grant
-
2000
- 2000-03-07 NO NO20001161A patent/NO322402B1/en not_active IP Right Cessation
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4589285A (en) * | 1984-11-05 | 1986-05-20 | Western Geophysical Co. Of America | Wavelength-division-multiplexed receiver array for vertical seismic profiling |
US5012090A (en) * | 1989-02-09 | 1991-04-30 | Simmonds Precision Products, Inc. | Optical grating sensor and method of monitoring having a multi-period grating |
US4996419A (en) * | 1989-12-26 | 1991-02-26 | United Technologies Corporation | Distributed multiplexed optical fiber Bragg grating sensor arrangeement |
WO1995030926A1 (en) * | 1994-05-06 | 1995-11-16 | The University Of Sydney | Variable property light transmitting device |
Cited By (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1999032911A1 (en) * | 1997-12-05 | 1999-07-01 | Optoplan As | Sensor for measuring strain |
US6768825B2 (en) | 1998-05-06 | 2004-07-27 | Weatherford/Lamb, Inc. | Optical sensor device having creep-resistant optical fiber attachments |
WO2000033048A2 (en) * | 1998-12-04 | 2000-06-08 | Cidra Corporation | Fiber optic bragg grating pressure sensor |
WO2000033048A3 (en) * | 1998-12-04 | 2000-11-16 | Cidra Corp | Fiber optic bragg grating pressure sensor |
US6278811B1 (en) | 1998-12-04 | 2001-08-21 | Arthur D. Hay | Fiber optic bragg grating pressure sensor |
WO2001014843A1 (en) * | 1999-08-19 | 2001-03-01 | Abb Research Ltd. | Fiber optic pressure sensor |
EP1179727A1 (en) * | 2000-08-02 | 2002-02-13 | Abb Research Ltd. | Fiber-optic bragg sensor for measurement of pressure and density |
WO2002097388A1 (en) * | 2001-06-01 | 2002-12-05 | Weatherford/Lamb, Inc. | Optical pressure sensor device having creep-resistant optical fiber attachments |
GB2397647A (en) * | 2001-06-01 | 2004-07-28 | Weatherford Lamb | Optical pressure sensor device having creep-resistant optical fiber attachments |
GB2397647B (en) * | 2001-06-01 | 2005-07-20 | Weatherford Lamb | Optical pressure sensor device having creep-resistant optical fiber attachments |
WO2007149733A2 (en) * | 2006-06-19 | 2007-12-27 | Baker Hughes Incorporated | Isolated sensor housing |
WO2007149733A3 (en) * | 2006-06-19 | 2008-04-03 | Baker Hughes Inc | Isolated sensor housing |
GB2468221A (en) * | 2007-10-31 | 2010-09-01 | Shell Int Research | Pressure sensor assembly and method of using the assembly |
GB2468221B (en) * | 2007-10-31 | 2013-04-03 | Shell Int Research | Pressure sensor assembly |
WO2009056623A1 (en) * | 2007-10-31 | 2009-05-07 | Shell Internationale Research Maatschappij B.V. | Pressure sensor assembly and method of using the assembly |
AU2008320812B2 (en) * | 2007-10-31 | 2012-01-12 | Shell Internationale Research Maatschappij B.V. | Pressure sensor assembly and method of using the assembly |
US8176790B2 (en) | 2007-10-31 | 2012-05-15 | Shell Oil Company | Pressure sensor assembly and method of using the assembly |
US7637167B2 (en) | 2008-04-25 | 2009-12-29 | Schlumberger Technology Corporation | Apparatus and method for characterizing two phase fluid flow |
US9188256B2 (en) | 2009-10-05 | 2015-11-17 | National Oilwell Varco Denmark I/S | Flexible unbonded oil pipe system with an optical fiber sensor inside |
WO2011042023A1 (en) * | 2009-10-05 | 2011-04-14 | Nkt Flexibles I/S | A flexible unbonded oil pipe system with an optical fiber sensor inside |
EP2510189A4 (en) * | 2009-12-08 | 2016-03-09 | Services Petroliers Schlumberger | Optical sensor having a capillary tube and an optical fiber in the capillary tube |
WO2017142921A1 (en) * | 2016-02-18 | 2017-08-24 | Weatherford Technology Holdings, Llc | Pressure gauge insensitive to extraneous mechanical loadings |
GB2562974A (en) * | 2016-02-18 | 2018-11-28 | Weatherford Tech Holdings Llc | Pressure gauge insensitive to extraneous mechanical loadings |
US10370956B2 (en) | 2016-02-18 | 2019-08-06 | Weatherford Technology Holdings, Llc | Pressure gauge insensitive to extraneous mechanical loadings |
GB2562974B (en) * | 2016-02-18 | 2020-08-26 | Weatherford Tech Holdings Llc | Pressure gauge insensitive to extraneous mechanical loadings |
WO2018101828A1 (en) * | 2016-12-02 | 2018-06-07 | Fugro Technology B.V. | Embankment monitoring system |
NL2017916B1 (en) * | 2016-12-02 | 2018-06-18 | Fugro Tech Bv | Embankment monitoring system |
US10774492B2 (en) | 2016-12-02 | 2020-09-15 | Optics11 B.V. | Embankment monitoring system |
Also Published As
Publication number | Publication date |
---|---|
NO322402B1 (en) | 2006-10-02 |
CA2303257A1 (en) | 1999-03-18 |
CA2303257C (en) | 2005-05-10 |
EP1012553A1 (en) | 2000-06-28 |
AU8925198A (en) | 1999-03-29 |
NO20001161D0 (en) | 2000-03-07 |
DE69819754D1 (en) | 2003-12-18 |
US6016702A (en) | 2000-01-25 |
NO20001161L (en) | 2000-05-08 |
EP1012553B1 (en) | 2003-11-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6016702A (en) | High sensitivity fiber optic pressure sensor for use in harsh environments | |
US5892860A (en) | Multi-parameter fiber optic sensor for use in harsh environments | |
US5844667A (en) | Fiber optic pressure sensor with passive temperature compensation | |
US6137621A (en) | Acoustic logging system using fiber optics | |
US5877426A (en) | Bourdon tube pressure gauge with integral optical strain sensors for measuring tension or compressive strain | |
US6072567A (en) | Vertical seismic profiling system having vertical seismic profiling optical signal processing equipment and fiber Bragg grafting optical sensors | |
CA2309620C (en) | Coiled tubing sensor system for delivery of distributed multiplexed sensors | |
EP0950170B1 (en) | Apparatus for enhancing strain in intrinsic fiber optic sensors and packaging same for harsh environments | |
US6233746B1 (en) | Multiplexed fiber optic transducer for use in a well and method | |
US5925879A (en) | Oil and gas well packer having fiber optic Bragg Grating sensors for downhole insitu inflation monitoring | |
US6959604B2 (en) | Apparatus and method having an optical fiber disposed circumferentially around the pipe for measuring unsteady pressure within a pipe | |
US6450037B1 (en) | Non-intrusive fiber optic pressure sensor for measuring unsteady pressures within a pipe | |
CA2701773C (en) | Pressure sensor assembly and method of using the assembly | |
US5973317A (en) | Washer having fiber optic Bragg Grating sensors for sensing a shoulder load between components in a drill string | |
US20020196993A1 (en) | Fiber optic supported sensor-telemetry system | |
US6305227B1 (en) | Sensing systems using quartz sensors and fiber optics | |
EP1110065B1 (en) | Seismic sensing and acoustic logging systems using optical fiber, transducers and sensors | |
WO2007003445A1 (en) | Sensor system for gas lift wells | |
CN111928937A (en) | Optical fiber vibration sensing probe and optical fiber microseismic monitoring system | |
CN1908370B (en) | Optical fiber grating temperature-pressure sensor for high-pressure flow liquid testing | |
EP1332337B1 (en) | Multi-parameter interferometric fiber optic sensor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM HR HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
ENP | Entry into the national phase |
Ref document number: 2303257 Country of ref document: CA Ref country code: CA Ref document number: 2303257 Kind code of ref document: A Format of ref document f/p: F |
|
NENP | Non-entry into the national phase |
Ref country code: KR |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1998941114 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1998941114 Country of ref document: EP |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
WWG | Wipo information: grant in national office |
Ref document number: 1998941114 Country of ref document: EP |