Microearthquakes induced by a hydraulic injection in sedimentary rock, East Texas

Abstract

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Microseismic mapping of a Cotton Valley hydraulic fracture using decimated downhole arrays

“…The cluster lies near the upper boundary of the treatment interval and implies that the majority of mapped seismicity is constrained to about 4% of the total injection depth interval (266 ft). This tube-like geometry of injection-induced seismicity is similar to a feature resolved by House et al (1996) from a subset of microearthquake data collected during a waste injection operation in the Frio Formation, East Texas (Keck and Withers, 1994). Fine-scale temporal patterns of the clustered seismicity show repeated sequences of events migrating toward the injection well.…”

Induced Microearthquake Patterns in Hydrocarbon and Geothermal Reservoirs: Six Case Studies

“…The nearinjection seismicity scatters around the injection well, while a distant cluster falls along a narrow, horizontal trend, aligned toward the injection borehole. The tight hypocentral distribution of the distant cluster is surprising, because one would expect that the unconsolidated nature of the Frio Formation would not support the development of such a well-defined zone of deformation (House et al, 1996). Withers and Rieven (1996) report a temporal migration towards the injection well within this group of events, and similar behavior for a second cluster recorded during a later injection.…”

“…Most were too small to be located reliably. A total of 54 well-recorded microearthquakes were chosen for further study, based on numbers of P-and S-wave arrivals (House et al, 1996;House and Flores, 2001). …”

Simultaneous recovery of origin time, hypocentre location and seismic moment tensor using sparse representation theory

“…By analysing the properties of the induced seismicity, interpreters generate estimates of fracture’s geometry, complexity, permeability and connectivity with pre‐existing faults and/or fractures (e.g. House et al 1996; Shapiro et al 1999; Maxwell et al 2002; Rothert & Shapiro 2007; Fischer et al 2008; Bayuk et al 2009; Warpinski 2009). A thorough understanding of the fractures induced through hydraulic injection is important for the planning and development of an oilfield (Cipolla & Wright 2002).…”

“…A thorough understanding of the fractures induced through hydraulic injection is important for the planning and development of an oilfield (Cipolla & Wright 2002). The source mechanism of microseismic events can provide information to elaborate models of fracture propagation (Warpinski 1994; Warpinski et al 2001), to study the state of stresses in the neighbourhood of the injection well (House et al 1996; Rutledge & Phillips 2003) and, in general, as a source of information to analyse the effectiveness of the induced fractures. The importance in obtaining information about fracture propagation during the injection process has been largely recognized (Maxwell et al 2002; LeCampion & Jeffrey 2004; Le Calvez et al 2006); however, the estimation of source mechanisms is still usually performed in a post‐processing stage.…”