Environmental control of well integrity

Abstract

The Environmental Control Technology (ECT) approach is used in this chapter to discuss prevention of fluids migration outside oilfield wells resulting from the loss of external (mechanical) integrity (EMI) of the well’s outer annuli. (Integrity of the well’s production installation also known as internal mechanical integrity, IMI, is outside the scope of this chapter.) Discussed is the mechanism of integrity loss after well cementing that could be alleviated by modifications of cement placement technique. Also discussed is the problem of long-term leaking of wells affected by Sustained Casing Pressure (SCP) at their wellheads. Conventional downhole intervention techniques for SCP remediation have been improved and could be potentially replaced by modern surface intervention methods. The chapter also briefly addresses integrity of injection wells and the relevant testing methods.