Method and apparatus for estimating surface wave coda using time-reversal experiments
AssigneeCgg Services SAS
InventorCorentin Chiffot
Life of this patent
Estimating the term…
Abstract
Surface wave coda in seismic data recorded with a data acquisition system over an underground formation is estimated using time-reversal experiments. First time-reversal experiments use a first time-reversal mirror including a target source and one or more other sources to obtain estimates of surface waves traveling from other receivers to a target receiver. Second time-reversal experiments obtain a coda estimate for a surface wave traveling from the target source to the target receiver using a second time-reversal mirror including the target receiver and the other receivers.
Claims20
A method for estimating surface wave coda in seismic data recorded with a data acquisition system over an underground formation, the method comprising:
- defining a first time-reversal mirror including a target source and one or more non-target sources of the data acquisition system, and a second time-reversal mirror including a target receiver and one or more non-target receivers of the data acquisition system;
- using the first time-reversal mirror to simulate first time-reversal experiments on an input dataset representative for the seismic data, to obtain estimates of surface waves traveling from the non-target receivers to the target receiver;
- muting each of the estimates and each surface wave trace from the target source to one of the non-target receivers in the second time-reversal mirror, up to a respective coda start time, to obtain a computed coda dataset;
- and
- using the second time-reversal mirror to simulate second time-reversal experiments on the computed coda dataset, to obtain a coda estimate for a surface wave travelling from the target source to the target receiver,
- wherein the coda estimate is then used to obtain information about a near-surface layer and/or removed coda from the seismic data before further processing to extract structural information about the underground formation.
A data processing apparatus configured to estimate surface wave coda in seismic data recorded with a data acquisition system over an underground formation, the apparatus comprising:
- an interface configured to obtain the seismic data;
- and
- a data processing unit connected to the interface and configured
- to define a first time-reversal mirror including a target source and one or more non-target sources, and a second time-reversal mirror including a target receiver and one or more non-target receivers,
- to use the first time-reversal mirror to simulate first time-reversal experiments on an input dataset representative for the seismic data, to obtain estimates of surface waves traveling from the non-target receivers to the target receiver,
- to mute each of the estimates and each surface wave trace from the target source to one of the non-target receivers in the second time-reversal mirror, up to a respective coda, to obtain computed coda dataset, and
- to use the second time-reversal mirror to simulate second time-reversal experiments on the computed coda dataset, to obtain a coda estimate for a surface wave travelling from the target source to the target receiver,
- wherein the coda estimate is then used to obtain information about a near-surface layer and/or removed coda from the seismic data before processing to extract structural information about the underground formation.
A non-transitory computer readable media storing executable codes which, when executed by a processor make the processor perform a method for estimating surface wave coda in seismic data recorded with a data acquisition system over an underground formation, the method comprising:
- defining a first time-reversal mirror including a target source and one or more non-target sources, and a second time-reversal mirror including a target receiver and one or more non-target receivers;
- using the first time-reversal mirror to simulate first time-reversal experiments on an input dataset representing seismic data acquired with the data acquisition system, to obtain estimates of surface waves traveling from the non-target receivers to the target receiver;
- muting each of the estimates and each surface wave trace from the target source to one of the non-target receivers in the second time-reversal mirror, up to a respective coda, to obtain computed coda dataset;
- and
- using the second time-reversal mirror to simulate second time-reversal experiments on the computed coda dataset, to obtain a coda estimate for a surface wave travelling from the target source to the target receiver,
- wherein the coda estimate is then used to obtain information about a near-surface layer and/or removed coda from the seismic data before processing to extract structural information about the underground formation.
Dependencies are inferred from the claim text.