Forecast of the stress-strain state of the rock mass during hydrocarbon extraction at the Salmanovskoye (Utrenneye) field

Abstract

The author presents a forecast of the stress-strain state of the rock mass during hydrocarbon production at the Salmanov (Utrenneye) gas condensate field, which serves as a resource base for Arctic LNG 2 LLC. The calculations are based on core testing data and geophysical well logs that extend the physical and mechanical properties throughout the rock mass. Geomechanical modelling has been conducted using the "tent model" to simulate the deformation of productive objects.

Authors established correlations established between elastic modulus and Poisson's ratio with longitudinal wave velocity. These correlations allowed for the distribution of elastic properties across the reservoir based on geophysical well data. We identified that the compression index was linked to longitudinal wave velocity. We needed this to support the calculations in the tent model. The modelling results predict surface subsidence of up to 2 meters following the complete depletion of the field. This subsidence may lead to flooding due to the rising groundwater levels. Therefore, it is recommended to use higher sand fill levels in construction projects to mitigate this risk.

Horizontal deformations may approach the permissible limits for infrastructure and pipelines, potentially resulting in operational disruptions over time. These findings emphasise the importance of establishing a deformation monitoring system for the entire field, as well as implementing geotechnical monitoring for critical infrastructure facilities.