Identification of fault planes that intersect horizontal wellbores is critical to optimizing formation stimulation, preventing waste of valuable time and materials, and avoiding the establishment of fluid flow pathways into nontarget formations, such as aquifers. We can detect and locate microseismic events accurately over a broad area using a large near surface seismic monitoring array. In addition, source mechanism inversion techniques can be used to determine the method of failure experienced by the rock formation, expanding our understanding of the dynamics involved in hydraulic fracturing. Events in this analysis are segregated into two populations based upon the distinct source mechanisms present. Spatial and temporal analysis of frequency magnitude distributions (FMD) allows us to characterize trends useful in assessing the hydraulic treatment efficiency. This information can assist in interpretation of faults in a 3D seismic volume to delineate faults in reservoirs, or when used alone, identify faults of subseismic displacement to further optimize future well placement. Also b values and source mechanisms can help to better define stimulated reservoir volumes (SRV) by indicating the effective level of stimulation.

A B S T R A C TDuring the Alleghenian Orogeny, Upper Silurian-Pennsylvanian sediments were deformed by occasional gently dipping planar forethrusts and abundant, large, steeply dipping kink bands that extend down to the Silurian Syracuse Salt decollement. As the internal bedding dip within the kink bands is frequently steep, kink bands are poorly imaged in seismic reflection data. Therefore, they can have the appearance of steep reverse faults; however, geosteering data indicate that where these structures intersect the wellbore, they are folds, not faults. Kink bands occur on a range of scales, and their upward extent is controlled by a series of detachment levels, including at the organic-rich Marcellus and Geneseo Shales; a hierarchy of kink bands is therefore recognized. The detachment levels were sites of kink band reflection, resulting in upward converging pairs of kink bands that formed pop-down structures that protruded into the underlying salt.The dips of the thrusts and kink bands calculated from seismic interpretation fit well with theoretical models and published empirical descriptions: reverse structures dipping at less than 45°a re thrusts, those with dip angles over 45°are kink bands. Areas of thick, primary salt are dominated by large anticlines, with their hinterlandward flanks defined by kink bands that extend to the present-day topographic surface. The structures may have initiated as sinusoidal folds, which became increasingly asymmetrical as they developed.The recognition of this style of deformation can improve the accuracy of horizontal well placement and has implications for reservoir permeability and integrity.

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Identification of fault related microseismicity in hydraulic fracture treatments is crucial to understanding how treatments are stimulating a reservoir. Evaluating b values in combination with event source mechanism provides a reliable and intuitive method for separating fault related microseismic events from standard fracture related events. Typically this analysis is conducted after a treatment is complete and serves as a diagnostic tool to provide possible explanations for reduced production or designing future treatments on nearby wells to avoid an identified fault feature. Being able to identify such features in real time allows the operator to not only identify faults but to stop treatment and avoid these features all together saving time and materials that would otherwise be pumped into an area that doesn't contribute to the overall stimulation of the reservoir, and could reduce production on the well. When evaluating b-values in real time, a technique that can identify faulting early in the initiation of fault stimulation is crucial for preserving the most resources during treatment.

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