EVOLVING OF A LOW PERMEABILITY FRACTURED RESERVOIR CONCEPTUAL MODEL

Abstract

The relevance of the research is caused by the need to study complex, heterogeneous fractured carbonate reservoirs, which are one of the sources of hydrocarbon production in an age of depleted clastic reservoirs resources. The main aim of the research is the revision of the conceptual model of the field, since the current model does not fully describe the actual behavior of the formation, complicates the selection of technological solutions for field development and optimizing, and does not allow an assessment of the potential effectiveness of the decisions made. Object of the research is the M1 reservoir is gas-condensate-oil, massive type, with a gas cap, confined to the ledge of the carbonate basement of the Devonian age at the Archinsky deposit. Methods: an integrated approach to the analysis of research results, analytical and numerical calculations, systematization, generalization, structuring of initial information on the field, simulation of several concepts, comparison with actual data. Results. The authors presented an alternative scenario of the geological structure and the main production mechanisms of the reservoir. Since the current model did not describe the actual behavior of the reservoir, the results of special studies indicate a complex geological structure of the complex, which made it difficult to predicti the distribution of reservoir properties. Moreover, the resolving frequency of seismic data limits the use of a full range of modern technologies for predicting productivity, lateral propagation of fractures, and petrophysical characteristics of a reservoir. The updated conceptual model assumes that according to the core description and geophysical studies of the Archinsky field, rocks of two types represent it: limestone and bauxite-like rocks. Fracturing of limestones, caused by the tectonic factor, is characterized by a uniform distribution over the section and the area of the field, and is the most influential parameter on the technological indicators of development. The technological mode of some wells and high depressions lead to water conning through a system of fractures that provide a hydrodynamic relation between productive and water-saturated intervals.

Keywords

• fractured carbonate reservoirs
• fracturing
• low permeable reservoirs
• concept model
• wettability
• water cut
• capillary pressure
• formation microimager
• limestones
• bauxites
• tectonic