Company / Speaker: University of Leeds / Trevor Hughes (Schlumberger Cambridge Research), Evgeny Barmatov (Schlumberger Cambridge Research) and Richard Barker (University of Leeds)

Zoom Event – more details to follow

Advanced once-through flow cell methodology for validation of a new ‘staged’ inhibition approach for matrix acidizing treatments

Schlumberger recently introduced and patented a new staged acid corrosion inhibitor (ACI) treatment concept for application in matrix acidizing treatments. The staged treatment concept recognises that treatments which employ a fixed dosage of corrosion inhibitor may not be optimal in terms of their efficiency. The concept proposes staged pumping of a first fluid composition designed to establish a persistent inhibitor film (Stage 1) and a second fluid composition to maintain the film and its associated inhibited corrosion rate (Stage 2). The staged ACI concept has the potential to provide enhanced corrosion protection of wellbore casing and coiled tubing (CT) materials whilst using the same total quantity of inhibitor compared to conventional treatments.

In the present paper, a bespoke, electrochemical, millifluidic once-through flow cell was used for validation of the staged ACI concept. A once-through flow cell enables testing in a continuously flowing environment whilst maintaining a fresh acid solution, a controllable supply of inhibitor, and eliminating any contact of the electrode with the atmosphere. The system was used to quantify changes in corrosion behaviour during continuous flow and during transitions from the first to second stage inhibitor dosages, to find optimal inhibitor concentration for film-forming and film maintenance stages and to investigate the effect of metal pre-corrosion on inhibitor performance for carbon steel used as wellbore casing and CT materials