Method and apparatus for utilizing time division multiple waveform transmitting
AssigneeExxonMobil Upstream Research Company
InventorsXinyou Lu, Scott C. Hornbostel, Dennis E. Willen
Life of this patent
Estimating the term…
Abstract
A method and apparatus of constructing a signal for a controlled source electromagnetic survey is described. In one embodiment, a method is described that includes determining a first waveform and a second waveform, the first waveform and second waveform related to a combined frequency spectrum and bandwidth associated with a geophysical survey line. Then, a signal is constructed by sequencing the first waveform with the second waveform. This signal may be utilized in a transmitter, which may be pulled by a vessel along the geophysical survey line.
Claims47
A method for constructing a signal for a source along a geophysical survey line for a controlled source electromagnetic survey comprising:
- determining a first waveform and a second waveform, the first waveform and second waveform related to a combined frequency spectrum and bandwidth associated with a geophysical survey line;
- and
- constructing a signal within a specific time interval along the geophysical survey line by a sequencing comprising sequencing the first waveform with the second waveform, thereby constructing a compound waveform which, except for any durations and gaps used to design spectral content of the compound waveform consistent with the combined frequency spectrum and bandwidth, provides essentially continuous transmission of electromagnetic energy;
- repeating the signal over one or more different time intervals along the geophysical survey line and collecting time domain electromagnetic data.
A transmitter for constructing a compound waveform for a source along a geophysical survey line for a controlled source electromagnetic survey comprising:
- an antenna;
- and
- waveform creation logic coupled to the antenna and configured to:
- provide a plurality of base waveforms, wherein the plurality of base waveforms are related to a combined frequency spectrum and bandwidth associated with a geophysical survey line;
- and
- construct a compound waveform having a specific time interval by sequencing the plurality of base waveforms, which compound waveform, except for any durations and gaps used to design spectral content of the compound waveform consistent with the combined frequency spectrum and bandwidth, provides essentially continuous transmission of electromagnetic energy;
- and
- repeat the compound waveform at another time interval along the geophysical survey line, thereby generating time domain electromagnetic survey data.
A system for conducting a controlled source electromagnetic survey with a compound waveform for a source along a geophysical survey line comprising:
- a vessel coupled to a transmitter via a cable, the transmitter comprising:
- a transmission circuitry;
- and
- waveform creation logic coupled to the transmission circuitry and configured to:
- provide a plurality of base waveforms, wherein the plurality of base waveforms are related to a combined frequency spectrum and bandwidth associated with a geophysical survey line;
- construct a compound waveform having a specific time interval by sequencing the plurality of base waveforms, which compound waveform, except for any durations and gaps used to design spectral content of the compound waveform consistent with the combined frequency spectrum and bandwidth, provides essentially continuous transmission of electromagnetic energy;
- and
- repeat the compound waveform at another time interval along the geophysical survey line, thereby generating time domain electromagnetic survey data;
- and
- at least one receiver configured to detect the compound waveform.
Dependencies are inferred from the claim text.