Emission tomography principles in seismic researches

Based on the principles of emission tomography, new effective techniques for 3D mapping of active media, real-time detection and localization of seismic and microseismic sources were developed. Also, a system of 3D seismic prospecting of complex geological media by means of diffraction tomography with controlled irradiation and adaptive filtering was developed.
Materials and methods
Microseismic data recorded by seismic arrays, seismic prospecting data, and data of seismic networks. Methods of scanning geological media and optimal adaptive filtering.
Results
(I) It was shown for the first time that the spatial distribution of end ogenous microseismic activities is stable over time. Emission tomography methods may be used to solve many exploration problems.
(II) A robust and fast method for the detection and location of seismic events of different levels was developed on the basis of the principles of emission tomography. It can use any types of seismic waves (within coherent or incoherent analysis).
(III) The emission tomography approach was also used to develop a 3D seismic prospecting method (diffraction tomography with controlled irradiation). It increases the resolution and reliability of the detection of inhomogeneities in the geological medium. This is achieved by focusing the emittingand receiving seismic arrays on the internal points of the medium, and stacking and optimal adaptive matched filtering of the received signals.
Сonclusions
This pioneering study has stimulated the intensive development of various passive seismic methods that are now widely used. The proposed method for the detection and localization of seismic events provides the possibility of rapid analysis and monitoring of seismicity associated with macro- and microseismic sources and hydraulic fracturing. The 3D seismic prospecting method can be used for post-processing of complex fragments of CDP seismic sections to reveal local inhomogeneities where there are no traceable seismic boundaries. For this purpose, this technique should be implemented in seismic data processing systems.