[Society of Exploration Geophysicists, American Association of Petroleum Geologists, Society of Petroleum Engineers Unconventional Resources Technology Conference - Denver, Colorado, USA (12 August to 14 August)] Unconventional Resources Technology Conference, Denver, Colorado, 12-14 August 2013 - Lowering Drilling Cost, Improving Operational Safety, and Reducing Environmental Impact through Zonal Isolation Improvements for Horizontal Wells Drilled in the Marcellus Shale