Reservoir Characterization of Clinoformian Achimovian Formations in Complex Environments of the “Anomaly” Bazhenian Deposits

Well known achimovian deposits widely spread in Western-Siberian petroleum province, are presented by frequently interbedding sandstones, siltstones and mudstones with thickness range of 5-10 m (thickness of separate sandstone layers reaches 20-45 m) and characterized by low acoustic contrast which gives very weak events on seismic data. In this context correlation of reflectors inside achimovian interval is a very challenging task. Besides that achimovian layers on a major part of Western Siberia have clinoformian structure. Formation tops correlation in such environment is far not a trivial problem without incorporation of seismic data. «Anomaly» bazhenian structure in the target area makes achimovian reservoirs interpretation extremely complicated. Presented work shows the overall performance of seismic AVO/AVA inversions technology for studying a structure of clinoformian achimovian deposits. By application of seismic inversion techniques the volume reservoir distribution in achimovian formation complex where obtained. Lithology and facial model of target layers were detailed and forecast of net and pay reservoir thicknesses for the each achimovian layer where obtained as well as recommendation for further exploration drilling were given.