Oil and gas deposits are present in the strata of the Earth's crust and these hydrocarbon resources are accessed by drillingvertical and horizontal wells. In order to minimize risks and optimize results a better understanding of the strata around the proposed target or "payzone" is required. Direct observation of these sub surface formations is not possible, so, various tools are lowered into the wellbore to map the path of the well and to record the physical properties of rock surrounding the wellbore.













