Sidetracking from casing string with hollow whipstock. Landing the tail pipe below the cut casing window. Now, there is a hollow whipstock at the casing window interval and downhole equipment for permanent access to the side track. It is intended for wells without problem areas and transit zones at the window interval and without risk of open bore collapse at the window interval.
Stable carbonate rocks. No risk of sidetrack hole section collapse during production.