Downhole Surveillance

摘要

Methods and apparatus for surveillance of a downhole environment: the response of least one optical fibre to an acoustic impulse is sampled and processed to provide an indication of the acoustic signals detected by at least one longitudinal sensing portion of the fibre(s). The data comprises data indicative of at least one characteristic of the acoustic impulse and data indicative of the downhole environment. The data indicative of at least one characteristic of the acoustic impulse is used to interpret the data indicative of the downhole environment to provide an indication of at least one characteristic of the downhole environment. For example, the data indicative of at least one characteristic of the acoustic impulse may provide a ‘signature’ of the impulse, which may be used to deconvolve the data indicative of the downhole environment to provide an indication of at least one characteristic of the downhole environment.

主权项

1. A method of surveillance of a downhole environment in a well comprising:
providing an acoustic impulse, interrogating at least one optical fibre arranged along the path a well bore with optical radiation; sampling data gathered from said at least one fibre in response to the acoustic impulse; and processing said data to provide an indication of the acoustic signals detected by at least one longitudinal sensing portion of said fibre, wherein the data comprises: (i) data indicative of at least one characteristic of the acoustic impulse and (ii) data indicative of downhole environment and the method comprises using the data indicative of at least one characteristic of the acoustic impulse to interpret the data indicative of downhole environment to provide an indication of at least one characteristic of the downhole environment.