I have never done that my time in oil field but that was 25 yrs ago. You do not use blowout preventers ( BOPs) when spudding in for surface casting. You put BOPs on surface casting to drill rest of hole. I think since we has two rigs down there one drilling and one workover, workover can be used to drill casting while other rig drill rest of first well, then switch then out to complete first well. This is a actually very wish use of equipment. Great job guys Jim