Source Mechanism Analysis to Determine Optimal Wellbore Orientation in the Eagle Ford Play

Telker, Cherie

Advancements in drilling technology in recent years have opened new opportunities in upstream O&G production. With new opportunities in shale plays throughout the continent, oil companies are looking for information that will help get the most out of their reservoir. Drilling the wellbore orthogonal to the anticipated fracture direction opens a maximum drainage area and minimizes stage requirements. Surface-based seismic monitoring can include focal mechanisms that reveal rock fracture orientation. These can be used to infer the optimal horizontal wellbore azimuth. In the Eagle Ford shale play, surface-based and shallow buried arrays have been used to monitor microseismic events coincident with hydraulic fracture stimulation treatments. Surface-based microseismic datasets from 87 well treatments in the Eagle Ford shale are used. 84 of 87 datasets contained usable focal mechanism information. Detailed analysis of the microseismic focal mechanisms was performed to determine the direction of rock fracture for each well treatment. Comparison of wellbore azimuth and fracture orientation can be performed for 97% of the Eagle Ford well treatment datasets in this study. Surface-based microseismic monitoring using a wide aperture, wide azimuth and high fold array make this analysis possible. The optimal horizontal wellbore orientation within the Eagle Ford study area was determined to vary from 120° to 160°.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013