Patent ID: 8136603
Filing Date: 2012-03-20
Classification: E21B

Abstract:
1. A method of running casing into a well, comprising: (a) suspending a casing string in the well with a spider located at the rig floor, and gripping and supporting a new joint of casing above the casing string with a casing lifting mechanism; (b) with a snider load sensor, sensing a weight of the casing string being supported by the spider; (c) rotating the new joint of casing to make up threads of the new joint of casing with the casing string so that the new joint of casing now becomes part of the casing string; then (d) with the casing lifting mechanism, lifting the casing string; then (e) releasing the spider and lowering the casing string until the upper end of the casing string is near the spider; then (f) gripping the casing string with the spider, then releasing the casing lifting mechanism and repeating steps (b)-(e); and (g) before releasing the spider in step (e), assuring that the casing lifting mechanism is gripping the casing string by requiring the weight being sensed by the spider load sensor be no greater than a selected amount.