Predicting Mean Time to Failure in Horizontal Wells through Metal Loss Analysis and Produced Water Composition
Loss of well integrity in many horizontal wells in the United States has resulted in huge capital losses to several operating companies. The occurrence of corrosion in horizontal wells in the US is attributed to several reasons. The deposition of iron (Fe) and manganese (Mn) from manufactured steel pipe and the inability to effectively treat the laterals plays a major role in corrosion mitigation in horizontal wells. Corrosion inhibitors are injected into the wells to help reduce the corrosion rates, however the effectiveness of these injection applications is hampered by the types of well design and fluid dynamics. Loss of Fe/Mn in the lateral sections of the well is a major concern for the oil industry. This research will investigate the amounts of Fe/Mn contributions from the laterals and also investigate the relationship between iron and manganese counts from produced water from oil fields in the US. This research will further investigate the mean time to failure in the laterals and suggest proactive plans for mitigating failures based on findings.
High Fe/Mn concentrations could lead to corrosion in producing wells. High densities of Fe/Mn found in produced water analysis reports has been attributed to the abundance of these two elements used in manufactured steel pipe. These elements are used due to their abundance in manufactured steel pipe and their lack of natural presence in formation fluids. Fe and Mn have a known ratio in steel pipe of approximately 100:1 (depending on steel type). These high concentrations could ultimately compromise the wells integrity.
This research emphasizes the need for considering iron and manganese counts as integral part of the corrosion monitoring. Moreover, considering the long lateral casings, which spans several thousands of feet in the US, injection of corrosion inhibitors will be ineffective in reducing Fe and Mn loss in the lateral sections. Monitoring of Fe and Mn over such long laterals is challenging and costly. It has therefore become crucial for oil companies to thoroughly understand the Fe/Mn contribution from the laterals that could lead to corrosion and develop mitigation strategies to lower corrosion rates in such high-risk wells. This will help to implement remedial measures to better define corrosion rates and quantify the risk of failure. This will also enable oil companies allocate resources for further development and not several remediation efforts.
B. A. Ofori et al., "Predicting Mean Time to Failure in Horizontal Wells through Metal Loss Analysis and Produced Water Composition," Proceedings of the Abu Dhabi International Petroleum Exhibition and Conference (2019, Abu Dhabi, UAE), Society of Petroleum Engineers (SPE), Nov 2019.
The definitive version is available at https://doi.org/10.2118/197521-MS
Abu Dhabi International Petroleum Exhibition and Conference 2019, ADIP 2019 (2019: Nov. 11-14, Abu Dhabi, UAE)
Geosciences and Geological and Petroleum Engineering
Center for Research in Energy and Environment (CREE)
Keywords and Phrases
Corrosion inhibitors; Corrosion protection; Corrosion rate; Depreciation; Failure (mechanical); Gasoline; Iron; Iron research; Oil fields; Pipeline corrosion; Produced Water; Risk assessment; Steel corrosion; Steel pipe; Time-to-failure, Corrosion mitigations; Corrosion monitoring; Formation fluids; Mitigation strategy; Operating companies; Remedial measures; Risk of failure; Water composition, Horizontal wells
International Standard Book Number (ISBN)
Article - Conference proceedings
© 2019 Society of Petroleum Engineers (SPE), All rights reserved.
01 Nov 2019