Perm Journal of Petroleum and Mining Engineering (Jun 2017)
How to consider rock density in fluid flow model of oil fields during permeability modelling
Abstract
Data of experimental core study for a number of fields of Bashkirian dome is analyzed. Dependencies between parameters of porosity, bulk density and permeability of rocks are established. A representative series of core samples of Visean sandstone are divided into classes of tight formations (non-reservoirs), porous (granular) and super permeable reservoirs by linear discriminant analysis. Application of rock density parameter as an additional criterion to predict permeability values is justified. Each class of reservoirs was statistically analyzed. It is determined that permeability of tight formations (1st class) and super-permeable reservoirs (3rd class) is much less controlled by rock porosity and density than for porous reservoirs (2nd class), that is characterized by stable relationships between permeability coefficients with both porosity and density of rocks. A suggested permeability prediction technique is implemented in construction of a fluid flow model of Visean formation at one of Bashkirian dome deposits where for each reservoir class, multidimensional regression equations were constructed to determine permeability based on integrated effect of porosity and density. A comparison of two calculations of fluid flow models is given. During first calculation permeability is determined by a conventional method. Second calculation is performed by a proposed method where permeability is a function of porosity and density of rocks. Calculations showed a significant improvement in adaptation of a modified model in comparison with conventional approach. Proposed permeability modeling technique is recommended as an initial step in permeability tuning and adaptation of fluid flow model, which consider identified relationships between petrophysical characteristics of a formation.
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