TECHNICAL FIELD

This disclosure relates to apparatus, systems, and methods for raising and lowering a mast of a drilling rig, and, more particularly, raising and lowering a mast of drilling rig with a pair of hydraulic pistons and a plurality of raising lines.

BACKGROUND

Land drilling rigs for oil and gas operations typically include a mast structure. The mast of a drilling rig is used to provide support to a crown block and a drill string of the rig. Drilling rig masts are typically positioned in a horizontal orientation during transportation of the rig to the drilling site, and are then raised to a substantially vertical position at the drilling site. The mast is typically raised at the drilling site. Failure of the raising device during the process of raising or lowering the mast can cause the mast to collapse, resulting in damage to the mast and increased risk of injury to employees at the drilling site. Mechanical failures of mast raising devices are difficult to predict or detect, making prevention of mast collapse particularly challenging.

SUMMARY

In an example implementation, a drilling rig system includes a drilling rig that includes a mast, a pair of hydraulic pistons coupled to a pair of front legs of the mast and configured to apply a first force to the mast, the first force acting in a direction opposing a force generated by a weight of the mast, a plurality of raising lines coupled to a crown block of the mast and to a pair of rear legs of the mast opposite the front legs and configured to apply a second force to the mast, the second force acting in a direction opposing the force generated by the weight of the mast, and a drawworks assembly coupled to the plurality of raising lines and configured to apply a force acting away from the crown block of the mast to at least one of the plurality of raising lines to generate the second force.

In an aspect combinable with the example implementation, each hydraulic piston of the pair of hydraulic pistons is configured to apply half of the first force to the mast.

In another aspect combinable with any of the previous aspects, the first force is greater than the second force.

In another aspect combinable with any of the previous aspects, the first force is at least nine times greater than the second force.

In another aspect combinable with any of the previous aspects, the plurality of raising lines are configured to apply a third force to the mast in response to failure of at least one of the pair of hydraulic pistons, and the third force is greater than or equal to the force generated by the weight of the mast.

In another aspect combinable with any of the previous aspects, the pair of hydraulic pistons is configured to move the mast between a horizontal orientation and a vertical orientation.

In another example implementation, a drilling rig system includes a drilling rig including a mast, a pair of hydraulic pistons coupled to a pair of front legs of the mast, a plurality of raising lines coupled to a crown block of the mast and to a pair of rear legs of the mast opposite the front legs, and a drawworks assembly coupled to the plurality of raising lines, and a control system communicably coupled to the drilling rig and configured to perform operations including activating the pair of hydraulic pistons to apply a first force to the mast, the first force acting in a direction opposing a force generated by a weight of the mast, and in response to failure of at least one of the pair of hydraulic pistons, activating the plurality of raising lines to apply a second force to the mast, the second force acting in a direction opposing a force generated by the weight of the mast.

In an aspect combinable with the example implementation, the second force is greater than or equal to the force generated by the weight of the mast.

In another aspect combinable with any of the previous aspects, activating the plurality of raising lines to apply a second force to the mast includes activating the drawworks assembly to apply a force to an at least one of the plurality of raising lines, the force acting away from the crown block of the mast.

In another aspect combinable with any of the previous aspects, the first force is at least nine times greater than the second force.

In another aspect combinable with any of the previous aspects, activating the pair of hydraulic pistons to apply a first force to the mast moves the mast between a horizontal orientation and a vertical orientation.

In another aspect combinable with any of the previous aspects, activating the plurality of raising lines to apply a second force to the mast maintains a current vertical position of the mast.

In another aspect combinable with any of the previous aspects, activating the plurality of raising lines to apply a second force to the mast moves the mast between a horizontal orientation and a vertical orientation.

In another aspect combinable with any of the previous aspects, the operations further include activating the plurality of raising lines to apply a third force to the mast, the third force acting in a direction opposing the force generated by the weight of the mast, and the first force and the third force are applied concurrently.

In another aspect combinable with any of the previous aspects, the first force is greater than the third force.

In another example implementation, a method includes applying a first force to a drilling rig mast using a pair of hydraulic pistons coupled to a pair of front legs of the drilling rig mast, the first force acting in a direction opposing a force generated by a weight of the drilling rig mast, and in response to failure of at least one of the pair of hydraulic pistons, applying a second force to the drilling rig mast using a plurality of raising lines coupled to a crown block of the drilling rig mast and to a pair of rear legs of the drilling rig mast opposite the front legs, the second force acting in a direction opposing the force generated by the weight of the drilling rig mast.

In an aspect combinable with the example implementation, the second force is greater than or equal to the force generated by the weight of the drilling rig mast.

In another aspect combinable with any of the previous aspects, applying a second force to the drilling rig mast using a plurality of raising lines includes applying a force to an end of at least one of the plurality of raising lines using a drawworks assembly coupled to the plurality of raising lines.

In another aspect combinable with any of the previous aspects, applying a second force to the drilling rig mast using a plurality of raising lines includes engaging a brake of a drawworks assembly coupled to at least one of the plurality of the raising lines.

In another aspect combinable with any of the previous aspects, applying a second force to the drilling rig mast using a plurality of raising lines further includes rotating a portion of the drawworks assembly to increase the second force applied by the raising lines to the mast.

In another aspect combinable with any of the previous aspects, the first force moves the drilling rig mast between a horizontal orientation and a vertical orientation.

In another aspect combinable with any of the previous aspects, applying the second force maintains a current vertical position of the drilling rig mast.

In another aspect combinable with any of the previous aspects, applying the second force moves the drilling rig mast between a horizontal orientation and a vertical orientation.

Another aspect combinable with any of the previous aspects further includes applying a third force to the drilling rig mast using the plurality of raising lines, the third force acting in a direction opposing the force generated by the weight of the drilling rig mast, and the first force and the third force are applied concurrently.

In another aspect combinable with any of the previous aspects, the first force is greater than the third force.

In another aspect combinable with any of the previous aspects, the first force is nine times greater than the third force.

Example embodiments of the present disclosure may include one, some, or all of the following features. For example, a drilling rig mast raising apparatus according to the present disclosure may prevent the drilling rig mast from collapsing following failure of one or more raising devices. A drilling rig mast raising apparatus according to the present disclosure may prevent interruptions in the process of raising or lowering a drilling rig mast. A drilling rig mast raising apparatus according to the present disclosure may allow for completion the process of raising or lowering a drilling rig mast following failure of one or more raising devices. A drilling rig mast raising apparatus according to the present disclosure may help prevent injuries caused during raising and lowering a drilling rig mast. A drilling rig mast raising apparatus according to the present disclosure may help prevent injuries caused by failure of a hydraulic raising piston system.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

