Abstract

For practical application of geomechanical tools in PJSC TATNEFT, methods to calculate the stress state of rocks taking into account regional features are required. Commercial development of terrigenous deposits of the Romashkinskoye field has resulted in reservoir pressure depletion and the associated change in effective stresses. The minimum horizontal stress can be determined through hydrofrac data or calculated using values of vertical rock stress, formation pressure, and Poisson's ratio of producing rocks. The paper discusses analysis of pressure behavior during hydraulic fracturing to determine the current minimum horizontal stress. Procedure of calculating of vertical stress and the original reservoir pressure to obtain the values of initial minimum stresses in the fracked intervals of wells under study is presented. Difference between the initial and the current stress states in the target intervals of hydraulic fracturing in the Kynovskian and the Pashiyan horizons was determined. By the example of the Minnibaevskaya area of the Romashkinskoye field, change in the minimum horizontal stress vs. decline of reservoir pressure in the Devonian terrigenous productive formations was determined.

Key words:

minimum horizontal stress, matrix stress ratio, fracture analysis, G-function, horizontal stress variation, formation depletion, stress path, Biot coefficient.

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Authors

I.I. Girfanov, Junior Research Engineer, Core Analysis, PVT and Well Testing Department, TatNIPIneft Institute–PJSC TATNEFT
32, Musa Jalil st., Bugulma, 423236, Russian Federation
E-mail: gii@tatnipi.ru

For citation:

I.I. Girfanov O zavisimosti minimal'nogo gorizontal'nogo naprjazhenija ot stepeni snizhenija plastovoj jenergii v produktivnyh ot-lozhenijah terrigennogo devona Minnibaevskoj ploshhadi Romashkinskogo mestorozhdenija [On dependence of minimum horizontal stress on extent of pressure decline in Devonian terrigenous reservoirs of Romashkinskoye field Minnibaevskaya area]. Neftyanaya Provintsiya, No. 4(24), 2020. pp.107-119. DOI https://doi.org/10.25689/NP.2020.4.107-119 (in Russian)