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Seismic Production Calculations
Contents
Chapter 1: Formats
Chapter 2: Linking Production to a Configuration
Chapter 1: Formats
Seismic production totals can be reported in the following formats. For simplicity the formulae below assume a shotpoint increment of 1 but the increment is considered if it is a higher value.
Points
Points are calculated based on the FSP and LSP using the formula Points = LSP - FSP + 1
Kilometres
Kilometres can be calculated by either the Fence method or the Gatepost method:
-Fence considers the number of Shot Point Intervals
-Fence Km = (LSP - FSP) × SP Interval (m) ÷ 1,000
-Gatepost considers the number of Shot Points
-Gatepost Km = (LSP - FSP + 1) × SP Interval (m) ÷ 1,000
Go to Setup → Configuration → General “tab” to opt between Fence or Gatepost
CMP Kilometres
CMP Kilometres are calculated using the formula CMP Km = Km × #CMP
#CMP is taken from the production log, on the ‘Start of Line Recording’ item, using the fields Charged CMPs and Accepted CMPs.
By default, these will be set to #CMP = #Streamer in configuration × #Source in configuration
If the production log Charged CMPs or Accepted CMPs are changed from their default values, new sequences will default to use the new values, and a warning will be displayed to show that the #CMPs do not match the configuration.
Square Kilometres
Square Kilometres are calculated using the formula
Sq Km = CMP Km × Bin size XLine (m) ÷ 1,000
Most commonly Sq. Kms are manually adjusted by overriding the Charged CMPs on the production sequences. However, in special cases it can be necessary to override the Sq Km Factor on the configuration, and when this is done, then the Sq Kms are calculated using the formula Sq Km = Km × Sq Km Factor. Please note that if the manual square kilometre factor is used, the CMP entries on the Start of Line will not be considered.
Default Sq Km factor = #CMP × Bin size XLine (m) ÷ 1,000
Chapter 2: Linking Production to a Configuration
Each sequence added to the production log is linked to a configuration, which can be changed immediately after adding a new sequence, or by reselecting the sequence from the sequence list.
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