|API Spec 4F
|Box-on-box, swing-up, slingshot, telescope, variable height
|Drill floor height
|4.5 m-10.5 m (15 ft-35 ft)
|Maximum static load
|600 kN-5,850 kN (134,885 lbs — 1,315,132 lbs)
Choosing The Right Substructure
Several popular substructure designs exist today on the market, each with its own field of application. With years of experience producing each type, we are able to improve on the initial designs to create even more reliable substructures.
Sometimes special applications require special solutions, and for these applications we develop substructures of extended functionality.
The following describes the benefits and limitations of our most common designs:
As the name implies, the box-on-box substructure is installed piece by piece, each one lifted with a crane. We normally don’t use this type of substructure for our drilling rigs anymore, as the assembly is time consuming and there are better alternatives.
This substructure category mainly consists of two types, the swing-up and the slingshot substructure. Assembled on the ground using a crane, both types are raised as a single unit, either with the help of the drawworks or self-erecting by means of hydraulic cylinders.
The slingshot and swing-up substructures are a good choice for most land drilling rigs due to the easy and fast installation. For the same reason we typically equip our 2000 m, 3000 m, and 4000 m mobile rigs with this type of substructure.
The telescope substructure is also assembled on the ground and then self-elevated vertically using hydraulic cylinders. The smaller size of this substructure allows for an «assemble once, transport everywhere» kind of usage, which means that it can be moved on the road in one piece in a pre-assembled state.
Due to these advantages, the telescope substructure is the favourite choice for our 1000 m truck-mounted drilling rigs.
Variable Height Substructure
The variable height substructure is a new construction allowing for different drill floor heights. The height can be adjusted even after rig up and is advantuous when drilling in variable terrains or adding new blow out preventers.
The variable height substructure does not have a middle column. Its upper column is directly connected to the four legs of a k-type mast and lifted vertically by means of hydraulic cylinders.