Risk Register and Risk Ranking of Non Integral Wells

Abstract

Non-Integral Wells are common in every aged field and managing their integrity is becoming a challenging issue, particularly in large fields and for complex dual completions such as the case in ZADCO operated fields. As part of the Well Integrity Management System (WIMS), integrity concerns are identified, investigated and subsequently mitigation measures are recommended to restore the well integrity, all in a systematic approach. Well barrier integrity is given the highest priority; therefore a comprehensive Risk Register and Risk Ranking process is implemented by ZADCO Well Integrity Team. The Risk Register process utilizes every related data and integrity investigation results to evaluate the integrity of the well primary & secondary barriers for every flow path. An individual integrity assessment is performed on the different containment sections in a well such as wellhead, inner and outer annuli and zonal isolation. Based on the severity, consequences and likelihood of a barrier failure the individual containment is given a risk rank according to ADNOC/ZADCO risk matrix. The overall risk ranking of a well reflects the highest risk rank of any of its containments. To complete the risk register, existing safeguards are addressed and appropriate short and long term mitigation actions are recommended to keep the risk at ALARP.

Acoustic signal processing for well integrity monitoring systems

“…The physical-chemical reaction between the oil and seawater led to the formation of an oil-water emulsion, as illustrated in Figure 1 Therefore, it is essential that methods for diagnosis of well integrity are developed to allow such accidents to be prevented. Most of the research published by the Society of Petroleum Engineers on well integrity management systems is focused on risk assessment using a risk matrix to grade the integrity of the wellbore [4]- [6]. Stuart et al [7] acknowledged that recent high-profile blowout incidents have made it inevitable that regulators would press for the development of better systems.…”

“…6 shows the spatial spectrum responses of the conventional wideband SMF in (4.5) using the continuous frequency spectrum from30 33 =− f kHz when the water hose was at different pressures. Similar to the numerical simulations in the previous section, the spatial spectrum response using the conventional wideband SMF from the recording also suffered from ambiguity due to spatial aliasing.…”