Method for directly performing automatic crack detection on prestack depth migration seismic data

Abstract

The invention belongs to the field of the seismic data interpretation, and specifically relates to a method for directly performing automatic crack detection on prestack depth migration seismic data.For the own limitation of the traditional time domain fracture automatic tracking technology due to the prestack time migration algorithm, a result is server hundred meters deviated from the actual drilling since the fracture of a complex construction region cannot correctly return to home, and the huge economic loss is caused. The technical scheme disclosed by the invention is as follows: [1] depth domain seismic attribute optimization and extraction: sorting crack sensitive attributes uninvolved with time-varying parameters in the prestack depth migration seismic attribute as one class so asto be served as transverse fracture attribute, selecting the specific optimal attribute from the transverse fracture attribute through the test; [2] depth domain seismic attribute boundary enhancement: performing boundary enhancement on the optimal attribute; and [3] depth domain crack automatic identification: performing automatic crack tracking identification on the boundary-enhanced optimal attribute. The automatic tracking algorithm generally selects ant tracking, and the main parameters are positive or passive tracking mode and a facture dip angle selected on a rose diaphragm.

Description

technical field [0001] The invention belongs to the field of seismic data interpretation, in particular to a method for automatic crack detection directly on pre-stack depth migration seismic data. Background technique [0002] With the growth of global oil and gas demand and the advancement of unconventional oil and gas reservoir exploration and development technology, the automatic identification technology of faults and fractures on seismic data volumes has become a key link in well deployment and production stimulation. Especially for the preliminary exploration risk control and horizontal well design of fractured shale gas, the overall distribution pattern of small faults and fractures is a geological task that must be implemented in the oil and gas field exploration stage. [0003] The traditional fault and crack detection techniques are all time-domain seismic attribute tracking, the most representative one is the ant body attribute. The problem with this technique i...

AI Technical Summary

Problems solved by technology

The problem with this technique is that the structurally constrained filtering in the detuning will amplify the fault shadows, making the predicted fault position deviate from the actual geological situation

[0006] However, the waveform of prestack depth migration loses the time attribute of signal analysis, which means that many seismic attributes in the time domain cannot be directly extracted in the depth domain in principle

However, when the deep time is converted back to the time domain, the waveform will be distorted due to the approximation of the velocity model, thereby reducing the reliability of the fracture attribute.

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