Abstract:
Methods and systems for similarity indicator calculation associated with seismic data acquisition are described. A similarity indicator value can, for example, be based on a normalized partitioned intensity uniformity (PIU) metric. In another aspect, shot imprints are compared by mapping a base (reference) shot imprint onto a current sample of a shot imprint before calculating the similarity indicator value. The similarity indicator value is associated with the shot imprint location used in the calculation and allows re-shooting of only the areas where an insufficient quality of shot data is detected based on a preconfigured threshold value for the similarity indicator.
Abstract:
System, medium and method for de-blending seismic data. The method for acquiring blended seismic data associated with a subsurface of the earth includes receiving coordinates of a sail line associated with first and second shot point locations; towing first and second source arrays in water along the sail line; shooting the first and second source arrays with a constant delay parameter so that a seismic trace recorded by a seismic sensor has at least a first uncontaminated portion that includes seismic energy generated substantially only by one of the first and second source arrays and a second portion that includes seismic energy generated by both the first and second source arrays; and recording blended seismic data generated by the first and second source arrays with the seismic sensor.
Abstract:
There is a method for acquiring seismic data over a survey area. The method includes deploying streamer and source vessels to acquire seismic data along a survey line; performing one pass with the streamer and source vessels along the survey line for collecting wide azimuth (WAZ) data; and performing another pass with the streamer and source vessels along the survey line for collecting narrow azimuth (NAZ) data.
Abstract:
Method and system for acquiring seismic data. The marine seismic acquisition system includes a first vessel that follows an inline direction (X); a first source array (S1) configured to generate first seismic waves; and a second source array (S2) configured to generate second seismic waves. The first and second source arrays are towed by the first vessel along the inline direction (X) and a first inline distance (d) between (i) a first center of source (CS1) of the first source array (S1) and (ii) a second center of source (CS2) of the second source array (S2) is different from zero.
Abstract:
Method and system for acquiring seismic data. The system includes a first streamer vessel configured to tow a first source array and a first streamer spread; a first source vessel configured to tow a second source array; and a second source vessel configured to tow a third source array. The first to third source arrays are distributed along a non-linear profile while the first streamer vessel and the first to second source vessels move along an inline direction (X).
Abstract:
Methods and systems for generating multi-criteria shot indicators are described. The multi-criteria shot indicator values can be weighted and the weighting factors can themselves incorporate one or more sensitivity factors. In another aspect, the shot indicators are related to the 4D repeatability and/or the 3D stability of seismic features associated with individual shots or sets of shots. The multi-criteria shot indicators can be evaluated in real-time onboard a seismic vessel and included as part of an infill reshoot decision making/quality control process.
Abstract:
Methods and systems for quality control of seismic data illumination map generation are described. The quality control is based on determined fold differences calculated using the actual position of the sources and receivers in the determination of the seismic illumination. In another aspect, sub-surface complexity is considered in preparing a map of seismic illumination. The seismic data illumination map can be evaluated in real-time onboard a seismic vessel and included as part of an infill reshoot decision making/quality control process.
Abstract:
The arrangement of air-gun subarrays is controlled by adjusting a geometric parameter, such as, an inline distance, an attack angle and/or a cross-line position for one or more subarrays. The adjustment is performed to achieve a target energy distribution for signals emitted by the air-gun subarrays.
Abstract:
Presented are methods and a system for efficiently acquiring seismic data based on a virtual seismic spread. A streamer vessel and a source vessel are used in combination and in a specific spatial arrangement collect seismic data. The source arrays can be fired simultaneously, creating blended seismic data that is separated with a deblending algorithm or sequentially to collect seismic data directly. The virtual seismic spread can be configured to reduce survey time or decrease capital costs and health safety and environment exposure based on the size of the streamer array towed by the streamer vessel.
Abstract:
Systems and methods for acquiring blended and unblended seismic data during a single seismic survey. The blended and unblended seismic data is generated with a plurality of sources that are fired in a dedicated sequence. The sequence involves firing all the sources at a first time, advancing the sources along a given path, firing only a first source at a second time, later than the first time, advancing the sources, firing again all the sources at a third time, later than the second time, advancing the sources, firing only a second source at a fourth time, later than the third time, and so on until a desired subsurface is fully surveyed.