MULTI-CHANNEL WAVEFORM CLUSTERING OF MICROSEISMIC DATA FROM A SINGLE BOREHOLE MONITORING: A CASE STUDY FROM A CBM FIELD

• Main Author: Septyana, Tepy
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40434
• Institution: Institut Teknologi Bandung

Microseismic observation for reservoir stimulation studies (especially hydraulic fracturing) has been a common practice to determine the orientation and dimension of hydraulic fracturing. Because the object of investigation is relatively smaller compared to other seismological studies, the need for accuracy and resolution of microseismic data for reservoir stimulation studies is relatively higher. On the other hand, the number and configuration of microseismic observation sensors in reservoir stimulation studies is often inadequate due to technical and economic aspects. Therefore, an independent analysis method is needed to ensure the quality of microseismic hypocenter locations to support interpretation. In this study, we applied full waveform data clustering from microseismic data. Assuming microseismic events with similar waveforms are related to the same source mechanism, and naturally have adjacent locations, the waveform clustering technique can be a good QC (Quality Control) tool for microseismic hypocenter solution. In this study, we propose multi-channel waveform clustering (MWC) so that each microseismic event is represented by the shape of the waveform in the time domain that comes from all the different components and channels. The MWC method was applied to microseismic monitoring data related to hydraulic fracturing on coalseams from a CBM (Coal Bed Methane) field. The MWC application provided a good quality control of microseismic hypocenter locations hence increased the confidence level in the interpretation of hydraulic fracturing results which is very important for CBM production optimization. The results revealed the orientation, length, and height of hydraulic fracturing in relation to cleat directions of coalseams.