Methods and devices for joint time-lapse full-waveform inversion with a time-lag cost function
AssigneeCgg Services SAS
InventorsZhiguang Xue, Zhigang Zhang, Ping Wang
Life of this patent
Estimating the term…
Abstract
Methods and devices according to various embodiments perform full-wave inversion jointly for datasets acquired at different times over the same underground formation using a time-lag cost function with target regularization terms. This approach improves the 4D signal within reservoirs and suppresses 4D noise outside.
Claims20
A method of monitoring targeted natural resources inside an underground formation, the method comprising:
- obtaining a baseline dataset and a monitor dataset acquired during seismic surveys performed at different times over the underground formation;
- generating a synthetic baseline dataset and a synthetic monitor dataset corresponding to the baseline dataset and the monitor dataset, the synthetic baseline dataset and the synthetic monitor dataset being generated using a baseline model and a monitor model of the underground formation, respectively;
- calculating a joint inversion time-lag cost function with a target regularization that includes a total variation, TV, norm and a model difference norm;
- updating the baseline model and the monitor model by minimizing the joint inversion time-lag cost function with the target regularization;
- and
- generating an image of the underground formation for identifying changes of location and/or volume of the targeted natural resources within the underground formation, between the different times when the baseline dataset and the monitor dataset were acquired, based on the updated baseline model and the updated monitor model.
A seismic data processing apparatus for monitoring evolution of targeted natural resources inside an underground formation, the seismic data processing apparatus comprising:
- an interface for obtaining a baseline dataset and a monitor dataset acquired during seismic surveys performed at different times over the underground formation;
- a data processing unit connected to the interface and configured:
- to generate a synthetic baseline dataset and a synthetic monitor dataset corresponding to the baseline dataset and the monitor dataset using a baseline model and a monitor model, respectively;
- to calculate a joint inversion time-lag cost function with target regularization term including at least one of a total variation, TV, norm and a model difference norm;
- to update the baseline model and the monitor model jointly such that to minimize the joint inversion time-lag cost function;
- and
- to generate an image of the underground formation to identify changes of location and/or volume of the targeted natural resources within the underground formation, between the different times when the baseline dataset and the monitor dataset were acquired, based on the updated baseline model and the updated monitor model.
A non-transitory computer readable recording medium storing executable codes that when executed on a computer make the computer perform a method for monitoring targeted natural resources inside an underground formation, the method comprising:
- obtaining a baseline dataset and a monitor dataset acquired during seismic surveys performed at different times over the underground formation;
- generating a synthetic baseline dataset and a synthetic monitor dataset corresponding to the baseline dataset and the monitor dataset, the synthetic baseline dataset and the synthetic monitor dataset being generated using a baseline model and a monitor model of the underground formation, respectively;
- calculating a joint inversion time-lag cost function with a target regularization that includes a total variation, TV, norm and a model difference norm;
- updating the baseline model and the monitor model by minimizing the joint inversion time-lag cost function with the target regularization;
- and
- generating an image of the underground formation for identifying changes of location and/or volume of the targeted natural resources within the underground formation, between the different times when the baseline dataset and the monitor dataset were acquired, based on the updated baseline model and the updated monitor model.
Dependencies are inferred from the claim text.