Characterization of fractures using interferometry techniques with multi-hole, multi-polarization borehole radar

摘要

The fracture system in the subsurface formations is one of the most critical factors that control many science and engineering fields such as the migration and development of hydrocarbon resources, the distribution and development of groundwater resources, groundwater contamination and remediation, the stability and instable sliding of geological blocks, the seismogenesis of great earthquakes and so on. Detailed characterization of formation fracture systems concerns all aforementioned sub-disciplines of earth sciences and technologies. Unfortunately, it has been a long term challenge to geophysicists for many years. The most promising fracture detection setup using radar technique should be single hole, multi-offset reflection mode. Nevertheless, there are a number of technical difficulties to physically realize multi-offset reflection in a single borehole. Liu and He (2007) proposed a wave interferometric virtual source (WIVS) approach to convert cross-hole transmission mode radar data to single hole, multi-offset reflection representation. A better detection of fractures has been demonstrated by using this approach. In this paper we expanded the WIVS approach to consider multi-hole, multi-polarization borehole sources. A case study using synthetic data set with five boreholes and vertically and horizontally polarized radar wavefield is demonstrated in this paper.