SpecialReport: Horizontal & Innovative Drilling (60-70/85-90). This second orthogonal lineament orientation is parallel to surface attribute features in interpreted relay ramp structures. This suggests that within these features, a low stress bias and/or an orthogonal northwest-to-southeast joint set allows for complex fracture growth. The observed secondary source mechanism may yield additional insight into these features, perhaps confirming the existence of an open and conductive joint set with the 60-70/85-90 source mechanism failure planes, representing en echelon "twist hackle" fractures that form as mode 1 dilation occurs. Figure 5 shows event locations and amplitude displays for two wells in distinct structural environments. Well D has a single source mechanism. Well C exhibits more complex fracture growth (the zig-zag lineament pattern seen in the map view with orthogonal lineament directions), as well as an observed second source mechanism (60/87). Microseismic events and amplitudes also hold valuable information regarding the quantity and size of fractures generated during treatment. An event/amplitude ratio parameter was developed to represent the ratio of event count to the average event amplitude normalized to lateral length. This ratio's applicability was discovered by its strong empirical relationship to the rate transient parameter Sqrt(km)*Acm (or Arootk), which has been found to have extensive applicability in characterizing low-permeability reservoirs. Defined as the product of the total matrix surface area draining into the productive fracture system and the square root of matrix permeability, the Arootk parameter is computed per well and normalized by lateral length. Interestingly, the crossplot of Arootk and event/amplitude ratio created two distinct well populations with nearly identical linear trends. The relationship observed within each trend is seen as an increase in length-normalized Arootk with an increase in the length-normalized event/amplitude ratio (Figure 6A). These two trends correspond to wells located in varying structural environments (colored points on Figure 6B). Wells with high Arootk versus event/amplitude are within relay ramp structures that typically cross northwest-to-southeast fault features. Low Arootk versus event/amplitude wells are on the edge of such features or within transfer zones with dominant northeast-to-southwest regional attribute orientations. The reason for the strong empirical re- FIGURE 7A Main Fracture Types from Core/FMI Analysis Eagle Ford Eagle Ford Ptygmatic extension fractures, various azimuth Eagle Ford Eagle Ford En echelon w/shear offset Petal induced or open NF Bed bound regional and orthogonol extension sets Anacacho/AC A) En echelon set B) 60 degree dip w/shear C) Extension E-W strike FIGURE 7B Fracture Orientations from Core/FMI Analysis Seismic Line Source: Three-D seismic data owned by Global Geophysical SEPTEMBER 2015 65