Substructure and mast concepts
Our cylinder rigs are available with hook loads of 250 metric tons (275 short tons) to 750 metric tons (825 short tons) for super singles or doubles stroke. The mast can be designed telescopically or statically. Depending on the local requirements, the cylinder rigs are built with a self-erecting hydraulic slingshot or a containerized box-on-box substructure.
Characteristics of self-erecting slingshot substructure and telescopic mast:
- assembly in horizontal position with minimum footprint
- reduced crane capacities required
- hydraulic cylinder erection system for mast and substructure
- superior in remote areas where large cranes are unavailable or heavy machinery cannot reach the wellsite due to poor infrastructure
Characteristics of containerized box-on-box substructure:
- compact layout due to the main components being arranged in substructure containers
- efficient noise protection due to noise-insulated containers
- fast rig-up with minimized footprint due to vertically assembled mast
- superior in preserved or densely populated areas, for example in geothermal energy projects
Hydraulic cylinder hoisting and rotary system
Compared to conventional drawworks, the direct-acting hydraulic cylinder hoisting system of Herrenknecht Vertical rigs gives a direct feedback of the downhole conditions. This enables the driller to identify potential stuck pipe incidents and to better control the weight on bit (WOB).
Benefits of the cylinder hoisting system:
- dampening effect of the cylinders prevents top drive damage and minimizes maintenance costs
- capability of pushing the drill string adds weight on the bit and prevents stuck pipe or casing
- very slim timbered mast due to direct distribution of the hook load into the substructure
- reduced exposure to winds allows for continued operations in harsh environmental conditions
Horizontal to vertical pipe handling
No pipe is stored vertically at the mast of a Herrenknecht Vertical rig, reducing the load in height and eliminating a major source of noise. Tubulars are stored and prepared at ground level. Different pipe rack automation levels are possible, from manual handling to a mechanized racking system consisting of pipe boxes and a gantry crane. The horizontal catwalk provides the tubulars to the horizontal-to-vertical pipe handler that transfers the tubular doubles to the well center.
The pipe handler is equipped with grippers, which can handle all kinds of tubulars including HWDPs and casing up to 4.5 metric tons (5.0 short tons) and 24 1/2 inch diameter. In addition to the drilling and tripping process being fully hands-off, also casing can be run safely by the drilling crew without losing time, for example to change the grippers.
The hands-off pipe handling allows for the elimination of work in hazardous areas, improving safety significantly. The position of the derrick man is eliminated and during standard operations, no manual intervention is required at the rig floor.
Rig moving systems
Skidding and stepping systems for moving the rig in one or two directions are available. This allows for efficient pad drilling or drilling of geothermal doublets. The horizontal pipe rack stays in place when using the telescopic catwalk, which transfers the drill pipes to the handover position of the pipe handler over a distance of up to 10 meters. Extension lines can be included in a specialized cable container with drag chain, enabling the rig to be moved without any disconnection of the backyard for immediate spud-in on the next well.