Features of the thermal field during fluid injection into the well during induction heating of the casing

Abstract

Pumping water into productive formations is one of the most common methods of oil field development. The effectiveness of reservoir flooding technology largely depends on the compliance of the design and actual volumes of water injection. Due to the violation of the tightness of the cement ring, fluid flows occur in the column space, which cause non-project withdrawal of the injected liquid into non-perforated layers. Identification and prompt elimination of backwater flows during injection of liquid into injection wells is one of the important tasks of efficient and environmentally friendly development of oil fields. The paper considers the use of induction heating of the casing string to determine the bottom-up backflow when pumping liquid into the well. The research is based on numerical modeling in the Ansys Fluent engineering package. Scenarios of absence and presence of overflow during injection of liquid into the well are simulated. It is shown that in a well without overflow, the temperature field disturbance propagates from the heated section of the column mainly radially into cement and rocks, in a well with overflow, the thermal disturbance from the heating section also propagates vertically in the direction of the overflow, and at a distance of up to 1 m above the heating section, temperature disturbances in the column body and the column space reach 2…3 K. It was found that the signs of overflow are also a decrease in the degree of heating of the casing string and an increased dynamics of cooling of the column over time compared with the absence of the column movement of the liquid. The results obtained serve as a theoretical justification for the fundamental informativeness of the active thermometry method in the diagnosis of backwater flows in injection wells.