Book excerpt: Development of unconventional reservoirs like tight- gas sandstones differs from conventional oil and gas reservoirs. Conventional surface seismic measurements generally do not give results that can drive the business in tight-sandstone fields because of its failure in reservoir-scale lithology and fracture identification. In this monograph we use an uncommon 3-D VSP survey done with horizontal vibrators and multi-level 3-C geophone tool to detect the lithology and fracture distribution in the subsurface.