METHOD AND APPARATUS FOR FLUID MIGRATION PROFILING
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Accused Products
Abstract
A method for obtaining a fluid migration profile for a wellbore, comprising the steps of obtaining a static profile for a logged region of the wellbore, obtaining a dynamic profile for the logged region of the wellbore, digitally filtering the dynamic profile to remove frequency elements represented in the static profile, to provide a fluid migration profile, and storing the fluid migration profile on a computer-readable memory.
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Citations
45 Claims
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1-14. -14. (canceled)
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15. A method for determining whether there exists flow of fluid along a vertical length of a wellbore outside of production casing thereof by obtaining a data profile for a region of the wellbore, the method comprising:
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a) placing a fiber optic cable in the wellbore to a depth of at least a portion of the wellbore; b) operating a laser light assembly to send laser light along the fiber optic cable, the fiber optic cable including a single mode or a multi-mode fiber optic line; c) collecting data from the fiber optic line using coherent Rayleigh or digital noise array data collection techniques; and d) processing the data. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A method of obtaining a noise profile for a region of a wellbore comprising:
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a) placing a fiber optic cable in the wellbore to a depth of at least a portion of the wellbore; b) operating a laser light assembly to send laser light along the fiber optic cable, the fiber optic cable including a single mode or a multi-mode fiber optic line; c) collecting data from the fiber optic line using coherent Rayleigh or digital noise array techniques; d) demodulating the collected coherent Rayleigh data or digital noise array data; and e) transforming the demodulated coherent Rayleigh data or digital noise array data to a format from which significant noise events occurring at a given location along the fiber optic cable can be determined.
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22. A method of obtaining a static noise profile for a region of a wellbore comprising:
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a) placing a fiber optic cable in the wellbore to a depth of at least a portion of the wellbore; b) pressurizing the wellbore and allowing the pressure to equilibrate; c) operating a laser light assembly to send laser light along the fiber optic cable, the fiber optic cable including a single mode or a multi-mode fiber optic line; d) collecting data from the fiber optic line using coherent Rayleigh or digital noise array techniques; e) demodulating the collected coherent Rayleigh data or digital noise array data; and f) transforming the demodulated coherent Rayleigh data or digital noise array data to obtain the static noise profile of the wellbore at the given depth. - View Dependent Claims (23, 31, 32)
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24. A method of obtaining a dynamic noise array profile for a region of a wellbore comprising:
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a) positioning a fiber optic cable in the wellbore; b) releasing pressure in a pressurized wellbore; c) operating a laser light assembly to send laser light along the fiber optic cable, the fiber optic cable including a single mode or a multi-mode fiber optic line; d) collecting data from the fiber optic line using coherent Rayleigh or digital noise array techniques; e) demodulating the collected coherent Rayleigh data or digital noise array data; and f) transforming the demodulated coherent Rayleigh data or digital noise array data to obtain the dynamic noise profile of the wellbore at the given depth. - View Dependent Claims (25, 26, 27, 28, 29, 30)
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33. A method of determining the location of a source of fluid migration along the length of a wellbore comprising:
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a) placing the fiber optic cable in the wellbore to a substantial depth of the wellbore; b) using a coherent Rayleigh interrogator apparatus to inject a light pulse into one end of a fiber optic cable; c) receiving backscattered light from the one end of the fiber optic cable; d) relating the intensity and time to detection of the backscattered light to a point in the fiber optic cable where light transmission through the fiber optic cable is affected by the fluid migration; and e) determining from the point the depth in the wellbore where there exists a point of fluid migration in the wellbore. - View Dependent Claims (34)
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35. A method of determining the location of a source of fluid migration along the length of a wellbore comprising:
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a) placing a fiber optic cable in the wellbore to a substantial depth of the wellbore; b) injecting light pulses into one end of the fiber optic cable; c) using digital noise array techniques to determine one or more locations along a length of the cable being impacted by pressure waves emanating from a source of noise due to fluid migration proximate the wellbore; and d) using time division multiplexing or wavelength division multiplexing when making the determinations as to the location of one or more sources of noise along the cable.
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36. A method of determining the location of a source of fluid migration along the length of a wellbore which fluid migration affects the transmission of light along a fiber optic cable comprising:
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a) placing an array of fiber optic transducers on the fiber optic cable, and placing the array and associated fiber optic cable in the wellbore in a first location therein to form a first array span along a length of the wellbore; b) pressurizing the wellbore; c) causing a laser light emitting source to send light down the fiber optic cable; d) collecting one or more of; coherent Rayleigh data from the fiber optic transducers in the location;
ordigital noise array data from the fiber optic transducers in the location; e) raising, or lowering, by one array span, the fiber optic transducers within the wellbore; f) repeating steps c-d until a desired length of the wellbore has been logged; g) demodulating data collected and obtained as a result of repetitively performing steps e-f; h) in the event coherent Rayleigh data is collected, applying a fast fourier transform to the demodulated data to extract significant acoustic events from background noise; and i) from the demodulated data for each array position within the wellbore determining a location of any fluid migration by analyzing the data to determine acoustic events which may indicate a source of fluid migration at a given array position within the wellbore. - View Dependent Claims (37)
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38. A method of determining the location of a source of fluid migration along the length of a wellbore which fluid migration affects the transmission of light along a fiber optic cable comprising:
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a) placing an array of fiber optic transducers on the fiber optic cable, and placing the array and associated fiber optic cable in the wellbore in a first location therein to form a first array span along a length of the wellbore; b) pressurizing the wellbore; c) causing a laser light emitting source to send light down the fiber optic cable; d) collecting data from the fiber optic transducers using coherent Rayleigh techniques;
ordigital noise array data collection techniques; e) raising, or lowering, by one array span, the fiber optic transducers within the wellbore; f) repeating steps c-d until a desired length of the wellbore has been logged; g) demodulating data collected as a result of repetitively performing steps e-f; h) in the event data is collected using coherent Rayleigh techniques, applying a fast fourier transform to the demodulated data to extract significant acoustic events from background noise; and i) from the demodulated data for each array position within the wellbore determining a location of any fluid migration by analyzing the data to determine events which may indicate a source of fluid migration proximate a given array position within the wellbore.
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39. A method of determining the location of a source of fluid migration along the length of a wellbore comprising:
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a) placing an array of fiber optic transducers on the fiber optic cable, and placing the array and associated fiber optic cable in the wellbore in a first location therein to form a first array span along a length of the wellbore; b) pressurizing the wellbore; c) causing a laser light emitting source to send light down the fiber optic cable to the transducers; d) collecting data from the fiber optic transducers using coherent Rayleigh techniques;
ordigital noise array data collection techniques; e) raising, or lowering, by one array span, the fiber optic transducers within the wellbore; f) repeating steps c-e until a desired length of the wellbore has been logged, the collected data forming a static noise profile for the wellbore; g) releasing pressure in the wellbore; h) operating the laser light assembly to send laser light along the fiber optic cable to the fiber optic transducers;
the fiber optic cable comprising a single mode or a multi-mode fiber optic line;i) collecting further data from the fiber optic transducers using coherent Rayleigh or digital noise array techniques; j) incrementally raising or lowering the fiber optic cable a defined distance within the wellbore; k) repeating steps (h) to (j) to collect the further data until a dynamic noise profile of the desired length of the wellbore is obtained; l) using a digital filtering protocol for digitally filtering the dynamic profile obtained in step (k) above to remove elements represented by the static profile obtained in step (f) above. - View Dependent Claims (40)
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41. A method for obtaining a fluid migration profile for a wellbore comprising:
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a) obtaining a static profile for a logged region of the wellbore, the static profile including events unrelated to fluid migration in the wellbore; b) obtaining a dynamic profile for the logged region of the wellbore, the dynamic profile including events related and unrelated to fluid migration in the wellbore; and c) digitally processing the static and dynamic profiles to filter out the events unrelated to fluid migration from the static profile, thereby obtaining the fluid migration profile. - View Dependent Claims (42, 43)
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44. An apparatus for obtaining a fluid migration profile for a wellbore comprising:
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a) a fiber optic cable assembly operable to obtain a static profile and a dynamic profile for a logged region of the wellbore, the static profile comprising events unrelated to fluid migration in the wellbore and the dynamic profile comprising events related and unrelated to fluid migration in the wellbore; and b) a data acquisition unit comprising; a laser light assembly optically coupled to and operable to transmit laser light to the fiber optic cable assembly; optical signal processing equipment optically coupled to and operable to process optical signals from the fiber optic cable assembly representing the static and dynamic profiles; and a computer-readable memory communicative with the optical signal processing equipment and having recorded thereon statements and instructions for processing the static and dynamic profiles to filter out events unrelated to fluid migration from the static profile, thereby obtaining a fluid migration profile. - View Dependent Claims (45)
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Specification