Approaches for Petrophysical Modelling and Logging Interpretation of Thin Laminated Achimov Deposits Reservoir

Abstract

Currently, due to the depletion of terrigenous oilfields with thick reservoirs, more oilfields with worse formation properties are being involved into production. One of the example of such implementation is Achimov layer, which is shaly-sand deposits of deepwater genesis, associated with the fondoform part of clino-cycle on the Neocomian age. Difficult geology aspects, high degree on unexploration contributes to the presence of various problems in the development of these sediments. Some problems also has historical background: in the past Achimov deposits were the transition interval for more deep-located Jurassic deposits which leads to low representativity of core data and narrow complex of logging tools. Achimov sediments represented by complex anisotropic reservoirs and usually have thin laminations of siltstones and sandstones. Vertical resolution of these laminations could vary from the first centimeters to the first dozen centimeters. Identification of perspective intervals and reliable estimation of their formation properties by the logging is assosiated with a number of difficulties, main of which is insufficient vertical resolution of tools. Althought there are a lot if articles written about laminated sediments, most of them offer solution in up-to-date logging methods and modern logging tools interpretation. Our aim is to extract the maximum amount of information using an existing data set. Thus, we are faced with the task of finding an approach to petrophysical modeling and interpretation of highly laminated reservoirs depending on the completeness of the input data set.