These are a couple of quick drawings of the drill-stem attached flow reducing mechanism I discussed on Grist.org. Successively larger versions would be sent down well to reduce the flow for an eventual top kill.
The force experienced by these drill stem attachments will manageable by the components as they are not subjected to the full force of the flow since each attachment is only meant to restrict the flow partially.
The force is equal to the pressure times the surface area of the attachment. These can be estimated to ensure the cam axis shafts and assembly won’t shear or disintegrate.
The cams can plate steel cut by a laser (very easily… I know a shop) and built up by lamination, bolting and /or welding together as many layers as required to attain required thickness.
The following is the front view.. or the view from the bottom of the well looking up the drill stem shaft. Since I’m currently handicapped by only having Visio to draw, it’s all square. It could be a cylindrical assembly. It would be August before I finished drawing it…. Regardless, the first of a few of these pushed deep into the well will be the smallest, followed by successively larger ones to block more and more of the diameter of the casing, reducing flow enough for a successful top kill.
This is extremely simple. It can be made quickly, and unless the drill stem has protrusions I don’t know about, can be implemented quickly.