Stress-Deformed State of the Breed in the Funnel of Depression

Analytical solutions of one-dimensional equations of poroelasticity, describing the stress distribution in the depression (repression) funnel, are obtained in this work. It is shown that the influence of the boundary conditions on the wellbore wall is significant only in a relatively small (~1 m) vicinity of the wellbore bottom zone. It has been established also that in fractured rocks in cased wells, the compressive angular stresses, which largely determine the filtration conductivity of the bottomhole zones, will be less than in uncased wells. A method is described that makes it possible to increase the tightness of preserved wells in depleted fields. The method consists in cutting out a section of the casing pipe above the productive formation, expanding the wellbore in this section, installing a spring metal centralizer in this section, followed by cementing it. The formation of such a rigid element associated with the casing will prevent rock displacement relative to this pipe and ensure the tightness of the near-wellbore zone of the well.