But would we want them to reduce our shares or keep drilling?

If cash was needed later, they could sell the shares. This ofcourse only works if you think SP is going up. We would'nt want them to loose money, would we? (that is our job). The effect of buying could in itself be that the SP would rise or at least be stabilized.

Buying and selling of own shares happens all the time, be it in a mid- or longterm program and not really ad hoc.