Technique of Allocation of Reservoirs of Alb-Aptsky Deposits of Tersko-Sunzhensky Oil and Gas-Bearing Areas

Abstract

The selection of oil and gas reservoirs and the determination of effective capacities is a critical step in calculating oil and gas reserves. From the results obtained at this stage, the economic feasibility of putting into operation an interval having, with the signs of a collector, filtration characteristics, directly depends. The limits of such reservoir characteristics correspond to conditional boundary values, these values are conditional and may vary based on the technical level of development of oil or gas fields at the time of the study. In modern conditions of rapid development of perfect development methods and changing economic demands, conditional boundary values vary quite widely. Alb-Aptian oil deposits of the Tersko-Sunzhensky oil and gas region (TSOGR) are complex types of pore-fracture reservoirs and are represented by rocks of sandy-silty-clay components. Experimental studies conducted on core samples taken from terrigenous sediments of TSOGR allowed us to establish the main features of these deposits, substantiate the main petrophysical dependencies and determine their reservoir properties. In the context of the Alb-Aptian sediments of the Tersko-Sunzhenskoye oil and gas region, by known methods, reservoirs were identified and effective thicknesses determined. In 2009-2012 reinterpretation of the stock materials of the results of well logging data and laboratory analysis of cores from a number of wells of the main fields drilled on the Lower Cretaceous deposits of TCHW was carried out and a better method for processing and interpretation of well log data of terrigenous rocks was proposed. An important feature of the integrated interpretation methodology implemented in ESKS technology of the Gintel automated geophysical data processing and interpretation system is the determination of a wide range of petrophysical parameters characterizing the lithological and fluid heterogeneity of the researched deposits. This allows us to more reasonably solve the problems of exploration and development of deposits. The technique of interpreting the GIS TABC data provides the determination of geological characteristics set for rocks, using which it is possible to determine the geological heterogeneity of the researched rock stratum, to develop a detailed three-dimensional geological model of all productive formations in a section and determine their estimated parameters. The detail of determining the geological characteristics of the rocks directly depends on the complex of logging data recorded in the wells. However, a feature of the TABC technique is that it uses systems of petrophysical models and algorithmic processing techniques that allow one to get the maximum geological information about the researched rocks even with a limited set of GIS data.