Abstract:
Method and system for generating a full acquisition path for a marine seismic acquisition system. The method includes receiving survey area information about a survey area to be seismically surveyed; selecting a radius (R) and a length (L) of a lace; selecting an overlap distance (OL) between first and second lanes; generating the full acquisition path by repeating the lace along a first lead line inside the first lane and along a second lead line inside the second lane and replicating the first and second lanes until the entire survey area is covered with laces; and sending the full acquisition path to a streamer vessel for performing the seismic survey.
Abstract:
Systems and methods for reducing survey time while enhancing acquired seismic data quality are provided. Data corresponding to plural source lines are acquired simultaneously, using sources at cross-line distance at least equal to their illumination width, with at least one source being towed above a streamer spread.
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:
A marine source element is configured to generate seismic waves. The source element includes a body and a source actuator attached to the body and configured to generate the seismic waves. The body is autonomous from a vessel towing streamers along a pre-plot line associated with a seismic survey.
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:
A marine streamer spread for acquiring seismic data, the spread including a streamer having a first portion and a second portion; the first portion including both first pressure sensors and pressure derivative sensors for acquiring the seismic data; and the second portion including second pressure sensors. The first portion imparts ghost diversity to the seismic data by having a variable-depth profile and the pressure derivative sensors impart polarity diversity to the seismic data.
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:
A method for determining interference noise recorded in a first seismic survey of a subsurface generated by a source in a second seismic survey. The method includes receiving seismic data recorded by seismic sensors of the first seismic survey, wherein the seismic data includes seismic waves that originate from the first seismic survey and seismic waves that originate from the second seismic survey; receiving actual relative shooting timing or actual shooting timing of seismic sources of the first and second seismic surveys; applying a processing algorithm to the seismic data to calculate the interference noise, wherein the processing algorithm that takes into consideration the actual relative shooting timing or the actual shooting timing of the seismic sources; and generating a final image of the subsurface based on the recorded seismic data from which the interference noise is subtracted.
Abstract:
A method controls a delay of an air-gun in an aquatic seismic source. The method includes a step of receiving an attribute of the air-gun during the aquatic seismic survey; a step of calculating, based on a time-delay algorithm that uses the attribute, the asynchronization time of the air-gun; a step of determining whether the asynchronization time is smaller than a given time threshold; a step of instructing a controller to (1) wait for a predetermined time before calculating again the asynchronization time of the air-gun if the asynchronization time is smaller than the given time threshold, or (2) calculate an updated asynchronization time for the air-gun based on the attribute if the asynchronization time is larger than the given time threshold; and a step of sending the updated asynchronization time to a gun controller of the air-gun for adjusting a delay time for firing the air-gun.
Abstract:
System and method for calculating a pre-plot for a marine seismic acquisition system. The method includes receiving as input a first number of streamer vessels and a second number of source vessels; receiving a geometry of an area to be surveyed; receiving a set of naturally different regions and/or humanly set targets for the area to be surveyed; calculating a first sailing path for a streamer vessel of the first number of streamer vessels; calculating a second sailing path for a source vessel of the second number of source vessels, based on the set of naturally different regions and/or humanly set targets; and entering the pre-plot into a navigation system of the streamer vessel and the source vessel so that the streamer and source vessels dynamically change an offset distance between them, while sailing during a seismic survey, based on the naturally different regions and/or humanly set targets.