If it is of any interest TEX shareholders I found the following...

If it is of any interest TEX shareholders I found the following on a blog site:
"Shales that contain swelling clays will swell if they are wet long enough. This can be a serious problem in oil/gas well drilling since the swelling can result in getting the drill pipe stuck in the hole. If this happens the least that it is going to cost is the cost of the drilling rig etc while the pipe is getting unstuck and the worst case is having to abandon the well with the pipe and sometimes a down hole motor left in the well bore."