With sustained high crude oil prices, operators of mature fields, enhanced oil recovery (EOR) projects, and unconventional plays are taking a fresh look at how to optimize development strategies and extract remaining resources efficiently and cost-effectively. Crosswell or interwell seismic technology offers a faster, simpler, higher resolution alternative to conventional surface seismic data—at a lower cost. A crosswell seismic survey deploys both transmitters and receivers downhole, directly in the zone of interest, using standard wireline conveyance. Due to recent breakthroughs, crosswell profiles up to a mile or more in length can image subtle reservoir details at five to ten times the vertical resolution of surface seismic. Operators today are maximizing production in brownfields with crosswell seismic data. They are also using time-lapse crosswell profiles to monitor subtle reservoir changes due to water flooding, EOR activity, and hydraulic fracturing. New applications that integrate crosswell seismic with microseismic are emerging as well.