The Study Of Micro-seismic Wave Field Separation Technology

As an advanced fracture monitoring method, the micro-seismic technology has been used for production performance detection of reservoir, and has great significance in exploration and development. The accuracy of micro-seismic inversion results depends on that the data handled is good or not, this paper separates direct waves from complicated multi-wave fields through Radon transform, picks up accurate first arrival, and improves the precision of micro-seismic inversion.The specificity of excitation way of micro-seismic determines its characteristic of low SNR and poor consistency, this paper researches on its corresponding pre-processing methods. Through polarization technology we can make consistency revision on the detectors'azimuth of micro-seismic data to obtain unifying tri-component data, then improve its SNR through band-pass filtering and trace equalization, which set scientific foundation for future study.The Radon transform has been had a good effect on seismic event identification, wave field separation, velocity analysis etc in normal seismic data processing, this paper applies it to micro-seismic data processing based on the theory of Radon transform. According to basic principle of high resolution Radon transform, high resolution Radon transform in time domain is researched in detail, and alias frequency and end effect of Radon transform are researched deeply, and through research the technical difficult points caused by less traces and some unequal track pitch of micro-seismic are overcome better, and a Radon arithmetic suit for micro-seismic processing is designed. Application of Radon transform in de-noising and up-going down-going waves separation are researched. Simultaneously, aiming to the characteristic of parabolic type of direct wave, parabolic Radon transform is researched mainly. Through researches and experiments repeatedly on each parameter, suppression on other wave field type is realized, and direct wave field is separated better. Using Radon transform to separate direct waves from whole wave field of perforation, picking up first arrival and inversing, the residual of inversion result and perforation location meets the precision requirement of micro-seismic inversion application. To reflect the advantage of Radon transform, this paper also researches on F-K wave field separation, and compares with Radon transform through a simple model. The application of model and practical results show that: high resolution Radon transform can make energy of data converge, and enable inversion recovery, and shows a good capacity on wave field separation of micro-seismic.