Methodological approaches to identification of Achimov-type exploration targets in the Arctic zone of West Siberian north

Petroleum potential of Lower Cretaceous deposits in the study area is associated with the Sukhodudinsky and Nizhnekhetsky deposits. Following the new seismic interpretation project and historical data analysis, seismostratigraphic model is created that confirms the clinoform architecture of Sukhodudinsky and Nizhnekhetsky formations within the Arctic zone of West Siberian north. Based on the model of Neocomian clinoform structure of Western Siberia, the authors developed and tested a methodology of identification of the main elements in each clinoform cycle, they are paleoshelf edge line and paleoslope foot line. According to seismic time section analysis and maps of slope angle gradients, the lower and upper paleoslope break lines are determined, and a pattern of slope angle behaviour is identified for the paleoshelf edges and paleoslope foots formed. The authors recommend to measure angles of clinoform sequence boundaries after paleoreconstruction. They present a method for Achimov-type exploration target localization in the context of limited information in the underexplored regions of West Siberian north. The conventional surfaces were used in addition for analysis of time thickness of clinoform sequence; these surfaces are connecting the upper and lower slope break lines at the beginning and the end of the clinoform formation. Using the method proposed, zones of the expected reservoir occurrence are modelled. The efficiency of the developed method for Achimov-type exploration target localization in the context of limited information is confirmed by drilling new wells in the study area