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Medium Frequency Pseudo Noise Geological RadarSystem and methods are disclosed for transmitting and receiving electromagnetic pulses through a geological formation. A preferably programmable transmitter having an all-digital portion in a preferred embodiment may be operated at frequencies below 1 MHz without loss of target resolution by transmitting and over sampling received long PN codes. A gated and stored portion of the received signal may be correlated with the PN code to determine distances of interfaces within the geological formation, such as the distance of a water interfaces from a wellbore. The received signal is oversampled preferably at rates such as five to fifty times as high as a carrier frequency. In one method of the invention, an oil well with multiple production zones may be kept in production by detecting an approaching water front in one of the production zones and shutting down that particular production zone thereby permitting the remaining production zones to continue operating.
Document ID
20040015214
Acquisition Source
Marshall Space Flight Center
Document Type
Other - Patent
Authors
G Dickey Arndt
James R Carl
Kent A Byerly
B Jon Amini
Date Acquired
August 21, 2013
Publication Date
November 25, 2003
Subject Category
Mechanical Engineering
Report/Patent Number
NASA-Case-MSC-23029-1
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-Patent-6,651,739
Patent Application
US-Patent-Appl-SN-793817
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