The productive layers of many oil deposits in the Republic of Tatarstan, as a rule, are characterized by different reservoir properties. In modeling, they are divided into strata with crossflow between layers, (layer-to-layer connectivity through the contact surface) and formations without crossflow between layers (layer-to-layer connectivity only through the wellbore). In the Tatneft PJSC, the technologies of multizone selective completion are widely used for enhanced oil recovery in case of multilayer deposits.
The authors suggest a method for determining the reservoir properties of a two-layer system using one-lift technology.
A direct problem of estimating the coefficient of hydroconductivity for layered layers and an inverse problem that is solved using piecewise constant functions are considered. Calculations using model problems showed that if the boundaries of the homogeneity zones are known, the error in determining the conductivity coefficient of highly permeable layers is 10-3-10-4. When introducing measurement errors of 1-3% in the initial data, the maximum error for high-permeability interlayers is 3-7%.
An example of calculation for wells is given. Well No. 2046 put into operation at the block 1 of the Berezovskoye field in July 1979. The well revealed terrigenous Tula and Bobrikovskian deposits. The results of calculations of permeability coefficients of layers of a multilayered reservoir are given. It is shown that the proposed algorithm allows to determine permeability coefficients of a layered deposit.
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