Some natural gas reservoirs (such as those of the Jonah field, Pinedale Anticline, or Bossier field) are composed of thin discontinuous lenticular sands ranging in length from tens to thousands of feet. Ultimately, production from these wells is controlled by the volume of sand that can be hydraulically fractured and put online. Currently, no method is available by which an operator can determine the extent of the sand bodies prior to completion. High-resolution subsurface seismic methods can address this problem: using crosswell seismic, an operator can image the reservoir up to thousands of feet away from the wellbore and grade the sand lenses prior to fracture treatment. This project will develop a magnetically-coupled borehole source that will allow crosswell seismic surveys to be conducted with 5 to 50 times the resolution of surface seismic at distances of a mile or more between the wells. Phase I will test the viability and robustness of a magnetically coupled source and conduct an accurate assessment of the output. In the course of the project, two versions of the magnetically coupled source will be designed, manufactured, assembled, and tested (including field tests).
Commercial Applications and Other Benefits as described by the awardee: A new magnetically coupled source should allow gas operators access to high resolution sub-surface seismic surveys. Based on this information, an operator could target the most prolific zones and avoid those less likely to produce, minimizing risks and costs while maximizing the productive potential of the reservoir
