Method of preventing dropped casing string with axial load sensor
AssigneeTesco Corporation
InventorWarren P. Schneider
Life of this patent
Estimating the term…
Abstract
A method of running casing into a well utilizes a load sensor to avoid dropping the casing string accidentally. The rig has a spider at the rig floor that suspends a casing string in the well when in a gripping position. A casing lifting mechanism will place a new joint of casing on the casing string suspended in the spider. The new joint of casing is rotated to make up with the casing string. After makeup, the casing lifting mechanism lifts the new joint of casing and the casing string. The operator releases the spider to allow the casing string to be lowered further into the well. Before releasing the spider, a load sensor will send a signal indicating that the casing lifting mechanism is supporting a minimum amount of weight.
Claims11
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.
A method of running casing into a well with a rig having a casing gripper depending from a top drive, comprising:
- (a) providing the casing gripper with a casing gripper load sensor and a spider with a spider load sensor;
- (c) suspending a casing string in the well with the spider;
- (c) gripping a new joint of casing with the casing gripper, rotating the casing gripper and 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) raising the top drive and the casing gripper;
- (e) sending a signal from the easing gripper load sensor to a controller indicative of weight being supported by the casing gripper, and sending a signal from the spider load sensor to the controller indicative of weight being supported by the spider;
- (f) determining with the controller whether the weight sensed by the casing gripper load sensor indicates at least a selected minimum amount of weight is being supported by the easing gripper, and determining with the controller whether the weight sensed by the spider load sensor indicates no more than a selected minimum amount of weight is being supported by the spider;
- and
- (g) if both determinations in step (f) are in the affirmative, allowing the spider to be released, and if either determination in step (f) is in the negative, preventing the release of the spider.
A method of running casing into a well having a casing lifting mechanism and a spider at a rig floor, comprising:
- (a) providing the spider with a spider load sensor;
- (b) suspending the casing string in the well with the spider;
- (c) gripping a new joint of casing with the casing lifting mechanism, 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) lifting the casing lifting mechanism before releasing the spider;
- (e) with the spider load sensor, sensing weight supported by the spider after the casing lifting mechanism has been lifted and sending an electrical signal from the spider load sensor to a controller indicative of the weight being sensed by the spider load sensor;
- (f) determining with the controller whether the weight sensed indicates more than a selected minimum amount of weight is being supported by the spider;
- and
- (g) if step (f) is in the negative, allowing the spider to be released, and if step (f) is in the affirmative, preventing the release of the spider.
Dependencies are inferred from the claim text.