Modified BIBO, LOT applied to trip out from deep HPHI well with simultaneous loss, ballooning

摘要

THE LEAK OFF test (LOT) and barrel in - barrel out (BIBO) procedures were modified and applied successfully to trip a very deep high-pressure, high-temperature (HPHT) well that was experiencing simultaneous loss and gain conditions. This is a common challenge for many HPHT wells, where margins between fracture gradient, mud weight and pore pressure are typically close. This article describes how these modified LOT and BIBO procedures were applied, as well as some of the risks and mitigations involved.