If SLB comes on campus, it will just be 1 round of interview comprising of both behavioral + technical questions. Else, it will be a 2 rounds of phone interview - 1st one with HR and the last one with a Senior Manager (not necessarily the team you are going to join).
The on campus interview was fairly in dept covering questions ranging from basic STAR type questioning to more technical ones like - elaborate on the stress vs strain curve of a material. Questions were also raised on the exact role itself - Manufacturing and/or Supply Chain are the typical intern roles offered for Industrial Engineers for internships under REMS. Knowing/reading about the following domains might be of real help -
1) Basic Manufacturing Processes & Supply Chain Systems
2) Material Properties, elasticity, Oil & Gas service cycles
3) Types of component designing
4) Characteristics of pressure vessels, their designing
5) Quality related issues pertaining to manufacturing
6) 6 Sigma