Wellbore Stability of Shale below Salt Formation of Faqui Oilfield in Iraq

Abstract:

Serious borehole collapse has occurred in shale below salt formation of Fauqi oilfield in Iraq. The Lots of bedding shale cavings returned to ground. The strength of bedding shale cores with different bedding dip angle are tested, which changes along in a high degree with the dip angle and reach the minimum in 50°-60°. The experimental results are regressed by different strength criterion, which demonstrate that McLamore strength criterion is more accurate. The collapse pressure of shale below salt formation is calculated by Mohr-Coulomb criterion and McLamore criterion respectively. The maximum collapse pressure by Mohr-Coulomb criterion occurs in the maximum in-stress orientations and 90° deviation angle, and that by McLamore criterion occurs in the maximum in-stress orientations and 50°-60° deviation angle. By analyzing the actual drilling situation, McLamore criterion is proved to be more accurate and can be used in Fauqi oilfield.

• Periodical: Applied Mechanics and Materials (Volumes 641-642)
• Pages: 451-457
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.641-642.451
• Online since: September 2014
• Authors: Fan Zhang, Yun Long Mu, Shuang Cheng, Jin Gen Deng, Bao Hua Yu, Yuan Cao*
• Keywords: Bedding, Bedding Dip Angle, Shale, Strength Criterion, Wellbore Stability

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