Pressure Test After Wait on Cement (Woc): Analysis in Oil Well Casing Design

Abstract

This work discusses the load criteria known as pressure test after waiting-on-cement (WOC) through a detailed explanation of the calculation methodology and study cases. Well casing design is an important step on hydrocarbon exploration planning. New methodologies in this subject allows improvement on well structural integrity combined with time and costs reductions. In routine procedures, design may consider pressure test after WOC, which is an essential operation for cementation failures verification. During test pumping, additional loads are applied to the casing and, when combined, they must be lower than tubular resistances to ensure no failure, avoiding catastrophic consequences. The computational tool CWELL is used for analyzing a production casing string set next to the reservoir, submitted to the pressure test after WOC. Investigating different grades and linear weights on API tubes verifies the achievement of well safety requirements. Results indicate the importance of performing integrated analyzes to guarantee wells stability.

Integrated Evaluation of Cement and Kick Scenarios in Oil Well Design

“…The cement resisting capacity is generally evaluated at the bottom of the well, where the pressure conditions are measured and the waitingon-cement test occurs (WOC) (Bearden & Lane, 1961). Among the most critical scenarios considered in the industry, is the pressure test after cement hardening, which is a good indicator of failure in cementation (Vitorino et al, 2018).…”