The Samgori field in the Republic of Georgia (CIS) has produced more than 165 million brls of oil since its discovery in 1974, and the development of recently‐discovered deep gas is now under way. The field produces oil from an Eocene volcaniclastic section which has been interpreted as being associated with an island arc. Available data from the field include well logs, porosity and permeability measurements from cores, chemical analyses of fluids produced, and reservoir‐performance history. These data comprise the basis for an investigation of generation, migration and entrapment of hydrocarbons. The Samgori field provides evidence that requisite parameters for significant accumulations of oil and gas are present in Georgia. The existence of other large fields depends primarily upon the occurrence of suitable reservoir rocks. Volcanogenic rocks offer potential reservoirs, but the importance of enhanced secondary porosity development must be emphasized. Regional porosity within the volcaniclastic section has developed as a result of zeolitization coupled with fracturing, a situation evidenced by infiltration of meteoric water over large distances. In view of this, reasonable possibilities exist for the occurrence of similar reservoirs nearby. The ability to predict zeolitization and fracturing elsewhere in Georgia would be critical to exploration success.