Prediction of casing critical buckling during shale gas hydraulic fracturing.

Oyeneyin, Babs; Bartlett, Mark; Njuguna, James; Mohammed, Auwalu I.

Abstract

Casing deformation during volume fracturing in shale gas horizontal wells is caused by both existing and induced stresses. These stresses jointly alter and compound the stress field around the casing leading to inefficient well stimulation as planned, lack of access into the well for recompletion, future workovers and present imminent danger of well integrity. Using two simulation scenarios, casing structural integrity was investigated in both radial and axial configurations under the mechanics of a combine system - casing, cement and formation rock. Results obtained show that time dependent rock slippage - creep during stimulation lead to an increase transverse displacement and corresponding stresses on the casing. In addition, the effect of combined loading results in significant increase in both displacements and stresses that can cause radial and axial permanent failure of the casing. This explains the lack of access into the casing during multi-stage hydraulic fracturing and future well intervention and recompletions and increased current understating of the downhole dynamics and casing structural integrity during volume fracturing. This new understanding is a major breakthrough in establishing casing health status during shale gas well stimulation.

Citation

MOHAMMED, A.I., OYENEYIN, B., BARTLETT, M. and NJUGUNA, J. 2020. Prediction of casing critical buckling during shale gas hydraulic fracturing. Journal of petroleum science and engineering [online], 185, article ID 106655. Available from: https://doi.org/10.1016/j.petrol.2019.106655

• Journal Article Type: Article
• Acceptance Date: Nov 4, 2019
• Online Publication Date: Nov 12, 2019
• Publication Date: Feb 29, 2020
• Deposit Date: Nov 11, 2019
• Publicly Available Date: Nov 13, 2020
• Journal: Journal of petroleum science and engineering
• Print ISSN: 0920-4105
• Electronic ISSN: 1873-4715
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 185
• Article Number: 106655
• DOI: https://doi.org/10.1016/j.petrol.2019.106655
• Keywords: Casing buckling; Rock slippage; Fracturing; In-situ stresses; Shale gas wells
• Public URL: https://rgu-repository.worktribe.com/output/748411