Microseismic monitoring of borehole fluid injections: Data modeling and inversion for hydraulic properties of rocks

TLDR

Attention to microseismic monitoring during geothermal or hydrocarbon reservoir operations has increased, and microseismicity during borehole fluid injections can characterize reservoirs several kilometers from boreholes. The study seeks to use microseismic data to measure in‑situ hydraulic properties of rocks at interwell scales to guide field‑production optimization. This is done by analyzing microseismic monitoring during borehole fluid injections to delineate conductive fracture geometry and infer fluid‑flow paths. Microseismic monitoring during borehole fluid injections can image hydraulic fractures, map natural fractures, and track flood fronts in enhanced oil recovery, providing reservoir characterization up to several kilometers from boreholes.

Abstract

Attention paid to microseismic monitoring during geothermal or hydrocarbon reservoir operations has grown considerably over the last several years. The observation of microseismicity occurring during borehole fluid injections or extractions has a large potential in characterizing reservoirs at locations as far as several kilometers from boreholes (Talwani and Acree, 1985; Adushkin et al., 2000; Fehler et al., 2001). The most common application has been hydraulic fracture imaging and growth characterization (e.g., Phillips et al., 1997; Urbancic et al., 1999). Longer-term microseismic monitoring has been used to map oil-producing natural fractures (e.g., Rutledge et al., 1998); it also shows promise in tracking flood fronts in the case of enhanced oil recovery (e.g., Maxwell et al., 1998). Beyond delineating conductive fracture geometry and inferring fluid-flow paths, microseismic data could potentially be used to measure in-situ hydraulic properties of rocks at interwell scales, providing information that could further guide operations to optimize field production.