A number of horizontal and extended reach wells is increasing year by year, but meanwhile the quantitative interpretation of logging data is still doubtful. There is no understanding of limits of logging tools and necessity to sel ect the optimal logging suite for the certain geological and technological conditions. This work includes some examples which allowed to make a conclusion about the advantages of the logging during the drilling processes, to evaluate uncertainties appeared in case of application of logging interpretation results of poor quality in geological and flow simulation models. Also, the questions regarding the methodology of logging data interpretation in horizontal wells are discussed as well. The problem with evaluation of properties in case of measurements at small angles of intersection between the axis of horizontal well and reservoir boundaries is highlighted. This led to the apparent smearing of logging curves by the measured depth and apparent changes of reservoir properties. Examples of spatial interpretation of logging data are illustrated as well. This interpretation allows accounting the influence of enclosing rocks and sloping angle, based on the process of direct modelling – comparison – updating. This process provides the restoration of true logging curves and as a result, it is possible to specify the profile of porosity and water saturation, which gives the prerequisite for improving geological and flow simulation models. The advantages of application of the azimuthal measurements RHOB for interpretation of intervals in heterogeneous section – specifying the effective length of the reservoir, porosity of the clean sandstone are shown. The options for accounting the anisotropy by means of direct modelling of logging records (spatial interpretation), results of core studies in two planes (parallel and perpendicular to the layering) and measurements of triaxial induction logging are suggested. Further steps for improving the current techniques of integrated interpretation are considered.
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