ACS – Anti Collision System
The Anti Collision System protects the mast and drilling equipment in the center line from collisions and damage when operating the traveling equipment. The system continuously monitors all of the traveling equipment’s movements (traveling block; power swivel …) in the mast. Safety is achieved by controlling the position of the traveling equipment with precisely predictable stops in any position within the safety zone. This provides a high level of protection to prevent personnel injury and damage to the mast or drill floor equipment.
The Anti Collision System can be extended with the existing hoist control system (crown-o-matic and floor saver), which prevents collision using mechanic system. Movement of the traveling equipment within the safety area depends on the position of the interlocked equipment, the desired direction, and the hook position. If it enters the minimum safety distance, movements are automatically stopped (by controlling the emergency breaking system and clutch) in order to safely prevent any collisions with the crown block, and working platform (rig floor).
A rotary encoder, also called a shaft encoder, is an electromechanical device used to convert the angular position of a shaft or axle to a digital code. As such, it is a type of transducer, as it transforms information about physical positioning to an electronic signal. A shaft encoder/transducer is also commonly used in oil and gas drilling, to assist with determination of position or depth in a drilling operation. A drawworks used to raise and lower a traveling block, from which is suspended a traveling block, the drill string and the bottom hole assembly. It is important to know the position of the traveling block regarding the crown block and rig floor. From the drawworks, the drilling line extends to the crown blocks, which are located at the top of the derrick, and then down to the traveling block. The drilling line is passed several times between the traveling blocks and the crown blocks and then fastened to a fixed point called the dead-man anchor. The driller controls the drawworks, which, via the pulley system, controls the position of the traveling block in the derrick. To measure the movement of the traveling blocks, a drawworks encoder (DWE) is mounted on the shaft of the drawworks. One revolution of the drawworks will pay out a certain amount of drilling line and, in turn, move the traveling blocks a certain distance. Calibration of the movement of the traveling block to the revolutions of the drawworks is required and done by Driller or A/D depending on rig floor / x-mass tree height.