TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThis paper shows a comparison of dual-array microseismic maps with single-well maps for horizontal wells in the Barnett shale. Results from two test cases showing gel and water fracturing maps are given and compared with initial production. Dual-array mapping provides for a much larger areal coverage and increased accuracy when accurate bottomhole locations and velocity structure are available, but do have trade-offs that need to be considered.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractMicroseismic mapping is extensively utilized in the Barnett Shale, to map hydraulic fracture complexity associated with interactions of the stimulation with pre-existing fractures. Previous studies have indicated a fair correlation between the well performance and extent of the seismically active volume. However, in addition to this measure of the extent of the stimulated fracture network, the characteristics of this fracture network is also expected to impact the well performance. In particular, the fracture spacing is believed to be important factor controlling the potential gas flow. In this paper, we utilize the density of the total seismic moment release (a robust measure of the microseism strength) as an indication of the seismic deformation that may correlate to the fracture density. The study uses a set of microseismic maps of hydraulic fracture stimulations, including cases where the stimulated reservoir volume measured by the extent of the seismically active region poorly correlated with the well performance. Incorporating the seismic moment density to assess the fracture density with the network extent, an improved correlation with the well performance was observed.

Microseismic mapping is extensively used in the Barnett Shale to map hydraulic fracture complexity associated with interactions of the stimulation with pre-existing fractures (fracs). Previous studies have indicated a fair correlation between the well performance and extent of the seismically active volume. However, in addition to this measure of the extent of the stimulated fracture network, the characteristics of this fracture network is also expected to impact the well performance. In particular, the fracture spacing is believed to be an important factor controlling the potential gas flow. In this paper, we use the density of the total seismic moment release (a robust measure of the microseism strength) as an indication of the seismic deformation that may correlate to the fracture density. The study uses a set of microseismic maps of hydraulic fracture stimulations, including cases in which the stimulated reservoir volume measured by the extent of the seismically active region poorly correlated with the well performance. Incorporating the seismic moment density to assess the fracture density with the network extent, an improved correlation with the well performance was observed.

The accuracy of microseismic monitoring is highly dependent on the quality of the velocity structure used in the analysis of the arrival time or waveform data. Because most rocks associated with hydrocarbon reservoirs are generally anisotropic, methods must be developed to circumvent the effects of anisotropy or to determine the anisotropy parameters for appropriate inclusion. Some field measurements of horizontal vs. vertical velocities are given to help assess the degree of transverse anisotropy. Synthetic case studies are also provided to show how various monitoring strategies and velocity models can affect the accuracy of the microseismic locations.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractMicroseismic mapping is extensively utilized in the Barnett Shale, to map hydraulic fracture complexity associated with interactions of the stimulation with pre-existing fractures. Previous studies have indicated a fair correlation between the well performance and extent of the seismically active volume. However, in addition to this measure of the extent of the stimulated fracture network, the characteristics of this fracture network is also expected to impact the well performance. In particular, the fracture spacing is believed to be important factor controlling the potential gas flow. In this paper, we utilize the density of the total seismic moment release (a robust measure of the microseism strength) as an indication of the seismic deformation that may correlate to the fracture density. The study uses a set of microseismic maps of hydraulic fracture stimulations, including cases where the stimulated reservoir volume measured by the extent of the seismically active region poorly correlated with the well performance. Incorporating the seismic moment density to assess the fracture density with the network extent, an improved correlation with the well performance was observed.