Well Control for Supervisors on Land or Offshore Rigs. The IWCF Level 4 Drilling Well Control course is essential training for those working in wellsite supervisory roles and for office-based personnel that are primarily involved in the operational decision-making process and/or well design. Second Edition. January 2010. WCS - Well Control school, Huston, Tx. 672 pages. ISBN: 978-0-9752644-1-6This manual was compiled for use as the primary for blowout prevention courses conducted around the world by WCS - Well Control school. Hireright background check how far back