Study on the influence of oilfield water injection on casing damage

Abstract

The casing damage of oil and water wells has seriously affected the normal production of the oilfield. This paper analyzes the high occurrence of casing damage in Saertu oil layer, and finds that there is a contradiction between the water injection production of the wells in Saertu formation and the prevention and control of casing damage. Although the wellhead oil pressure can be guaranteed to be lower than its fracture pressure during production, the injected energy at the wellhead includes pressure potential energy and kinetic energy. Because the fracture pressure of Saertu formation is relatively low, the total injected energy is often higher than its fracture pressure, resulting in water injection at an excess fracture pressure. Unreasonable water injection will lead to the destruction of the underground rock stratum, which acts on the casing and forms casing damage.