Perm Journal of Petroleum and Mining Engineering (Dec 2015)
Development of the methodology for evaluation of possibilities to determine reservoir types based on pressure build-up curves, geological and reservoir properties of the formation (case study of famen deposits of Ozernoe field)
Abstract
One of the features of geological structure of Famen deposits of Ozernoe field is naturally fractured reservoir zones. Results of hydrodynamic study of wells on unsteady regime that were processed by Warren-Root model show that naturally fractured zones are oriented North-East. In order to prove existence of zones with different reservoirs statistical analysis was performed. Wherein geological and physical reservoir parameters (absolute elevation, thickness, permeability), several parameters of well performance (initial rate, productivity index) and litho-facial analysis (on cores and seismic) were additionally involved. In this paper interval probabilities that belong to naturally fractured and pore types are determined. Average values of varying intervals compared with interval probabilities. Based on that data pair correlation coefficients calculated and regression equations are built taking into account all studying parameters. Correlation between probability values and addition values are shown on graph. Graphs show probability of naturally fractured reservoir existence for different values of geological and technological parameters. To build the optimal forecast model using individual probability generalized probability were calculated. Scheme that reflect its change on the area of the deposit is built. Analysis show that wells belong to cavitation type determined base on pressure build-up curves in accordance with Warren-Root model is proved by obtained reservoir characteristics. The methodology for reservoir type determination has several advantages, can be implemented on the other fields that are similar in terms of geological structure and Oil and Gas province.
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