DBPapers
DOI: 10.5593/sgem2017/14/S05.044

REVERSE MODELLING OF MICROSEISMIC WAVES PROPAGATION FOR THE INTERPRETATION OF THE DATA FROM HYDRAULIC FRACTURING MONITORING IN POLAND

M. Antoszkiewicz, M. Kmiec, M. Szkodo, R. Jankowski
Monday 11 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7408-00-3 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 14, 351-356 pp, DOI: 10.5593/sgem2017/14/S05.044

ABSTRACT

A hydraulic fracturing job was performed to stimulate gas flow from a horizontal wellbore located in Poland. The whole operation was overseen by means of microseismic monitoring. For this purpose, an array of 12000 geophones was deployed on ground in form of patches distributed unevenly in a region of 4km from the wellbore. The array was constantly recording seismic signals during whole fracturing processed. Such recorded signals can by analyzed to locate, both in time and space, events connected to cracking rocks. The information on rock cracks gives great insight into rock structure and process progress, which can facilitate more efficient resource usage and better overall fracturing results. Unfortunately, the rock formations overlaying reservoir rock strongly attenuate signal to a level that it is indistinguishable from background noise. Therefore, there is a need for a specialized algorithms that utilize coherence of signals that are related to real seismic events. One of such methods is reverse time modelling. Basing on a ground velocity model, one can simulate recorded wave propagation backwards in time. With this approach a wavefield focuses at the hypocenter of the recorded event. In our research modeling of wave propagation back in time was applied to seismic data acquired during hydraulic fracturing in Poland.

Keywords: microseismic, surface, reverse time modelling