METHOD OF SEARCH FOR OIL AND GAS DEPOSITS IN SHELF ZONES AND MARSH-RIDDEN TERRITORIES Russian patent published in 2003 - IPC

FIELD: geological prospecting operations in oil and gas industry with examination of marsh- ridden territories and shelf. SUBSTANCE: method is realized by execution of two stages of geochemical survey of explored territory and subsequent seismic prospecting. Both stages are conducted while territory is covered with snow and ice. Presence of zone or zones of hydrocarbon anomalies is established at first stage. With this in mind explored territory is divided with use of regular rectangular network. Samples are taken in crossing points of network, then laboratory analysis aimed at determination of content of hydrocarbons is conducted and as result outlines of each exposed hydrocarbon anomaly are found. At second stage boundaries of location of each zone are defined more accurately by taking samples in squares bordering on found outlines. Squares in this case are divided into four approximately equal parts. Exposed anomalies are studied by methods of seismic prospecting to establish spatial positions of oil and gas deposits and to define their boundaries more exactly. Obtained data are utilized to determine drilling locations of pioneer, exploratory and production wells. EFFECT: enhanced efficiency of method, reduced cost of prospecting operations.