In recent years, more and more fields with low-permeability reservoirs have been actively developed. It is known that the development of oil deposits in low-permeable reservoirs is characterized by the manifestation of abnormal properties of reservoir systems. At small differences in reservoir pressure per unit length, there is a deviation from the law of linear filtration (Darcy's law). It is established that liquid filtration begins after creating a certain initial pressure drop (gradient) between the input and output cross sections of the core samples. The initial reservoir pressure gradient is an important technological parameter necessary for evaluating the production capacity of low-permeability reservoirs.
The article presents the results of laboratory studies of liquid filtration on samples of low-permeable core taken from the AC3 reservoir of the V.N. Vinogradov field. The analysis and interpretation of the research results were carried out in two ways. The first way of interpretation is to extrapolate the linear part of the filtration curve (previously proposed by specialists of RN-UfaNIPIneft). A new approach to processing laboratory data by linearization of the nonlinear part of the filtration equation allows using all the study points for each of the core samples. As a result of the interpretation, experimental dependences of the initial pressure gradient on the effective oil permeability are constructed. A comparison of the dependencies obtained using the linearization method and using extrapolation of the linear part of the filtration dependence shows their good convergence. On the basis of the sector hydrodynamic model of the AC3 reservoir, calculations were carried out taking into account certain experimental data.
References
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