What is the working principle and basic composition of a truck-mounted drilling rig?
3 Answers
Truck-mounted drilling rig's working principle and basic composition are as follows: 1. Composition: A type of mobile drilling unit. All drilling equipment (drill rig, water pump or air compressor, derrick, and sometimes power unit) is assembled on various types of vehicles to form an integrated system. Based on mounting methods, it can be divided into self-propelled and trailer-mounted types. 2. Principle: For self-propelled truck-mounted rigs, all equipment is installed on a truck or tractor chassis. During operation, the vehicle's own power drives the drill rig and water pump (or air compressor). Trailer-mounted rigs have all drilling equipment including the power unit installed on various types of trailers (such as wheeled trailers or sled trailers). During operation, the power unit on the trailer provides energy, while transportation is achieved by towing with trucks or tractors. Both types allow the derrick to be laid down on the vehicle or trailer frame for integrated relocation, significantly reducing installation and dismantling time.
Operator's Perspective: I work with truck-mounted drilling rigs every day, these machines are like mobile drilling factories. The working principle is quite straightforward - using the truck chassis as the base, the diesel engine drives the hydraulic system which transmits power to the drill rods and bits. Before drilling starts, we need to stabilize the vehicle with four hydraulic outriggers, otherwise it shakes violently during operation. When the drill bit bites into the formation, the matching mud pump kicks into action, pumping special drilling fluid down the hole that carries rock cuttings back up through the drill rod annulus. This system consists of six major components: the carrier truck, a 15-meter-high folding mast, the rotary assembly of the power head, a transmission capable of 200 RPM adjustment, mud circulation tanks, and a remote control console. Last month when drilling through granite layers, we wore out three roller cone bits - changing bits required working while suspended on the mast, which was quite thrilling.
From a Mechanic's Perspective: Having repaired dozens of truck-mounted drilling rigs, the core components consist of the power package + drilling module. The power section is composed of the truck engine and transfer case, distributing 480 horsepower to three systems via hydraulic pumps—the feed cylinder controls the drill rod's downward pressure, the rotary motor drives the drill bit at up to 300 RPM, and the mud pump unit maintains the circulation system. The drilling module is the most intricate part: the telescopic mast retracts to just 3 meters but extends up to 18 meters; the drill rods use hexagonal joints to prevent thread slippage and are swapped via quick-change chucks. The circulation system's worst nightmare is pipe blockage, so dual mud purification units are essential. During a recent inspection of a stuck drill, we found that worn stabilizers caused deviation, nearly burying a $200,000 impregnated diamond bit underground.
