18 July 2017
A pneumatically operated device mounted on top of the kelly that, when actuated, causes the kelly to turn or spin. It is useful when the kelly […]
18 July 2017
In drilling a well, a channel or groove cut in the side of the hole, parallel to the axis of the hole. Key seating takes place […]
18 July 2017
A short joint on which are fixed either spiral or straight blades that are approximately 1/2 inch larger in diam than the largest drill collar in […]
18 July 2017
An entry of water, gas, oil, or other formation fluid into the wellbore during drilling. It occurs because the pressure exerted by the column of drilling […]