1. Introduction of horizontal directional drilling
The horizontal directional drilling is without excavation surface conditions, laying a variety of underground utilities (pipes, cables, etc.) of a kind of construction machinery, it is widely used in water supply, electricity, telecommunications, gas, gas, oil and other pipeline construction, it is suitable for sand, clay, pebbles and other DeKuang, most of the hard rock areas in China can be construction.Working environment temperature is 15 ℃ ~ + 45 ℃.Horizontal directional drilling technology of directional drilling technology to the oil industry and the traditional method of pipeline construction together a new construction technology, it has the construction speed, high precision, low cost advantages, is widely used in water supply, gas, electricity, telecommunications, natural gas and oil pipeline construction project.Horizontal directional drilling equipment, in more than ten years also obtained the rapid development, has become the developed country in the emerging industry.At present, its development trend is developing towards the features of large and small size, suitable for hard rock operation, self-supporting anchoring system, automatic stacking and extraction of drill pipe, automatic lubrication of drill pipe connection, electric shock prevention system and other automatic operation functions, ultra-depth guidance and monitoring, and wide application range.This kind of equipment is generally suitable for pipe diameter of 300~ 1200mm steel pipe, PE pipe, the maximum laying length of up to 1500m, suitable for soft soil to hard rock a variety of soil conditions, broad application prospects.
2. Features of horizontal directional drilling
1) directional drilling through construction will not obstruct the traffic, will not damage the green space, vegetation, will not affect the normal life and work order of shops, hospitals, schools and residents, solve the traditional excavation construction interference to the life of residents, to the traffic, the environment, the foundation of the surrounding buildings damage and adverse impact.
2) the crossing precision of modern crossing equipment is high, and it is easy to adjust the laying direction and burial depth. The arc laying distance of pipeline is long, which can fully meet the design requirements of burial depth and enable the pipeline to bypass the underground obstacles.
3) the buried depth of urban pipe network is generally less than 3 meters. When crossing the river, the buried depth is generally 9-18 meters below the riverbed. Therefore, horizontal directional drilling machine is adopted for crossing, which has no impact on the surrounding environment, does not damage the landform and environment, and meets the requirements of environmental protection.
4) when using horizontal directional drilling machine to cross the construction, there is no water or underwater operation, which does not affect the navigation of the river, does not damage the dam and riverbed structure on both sides of the river, and the construction is not subject to seasonal restrictions. It has the characteristics of short construction period, few personnel, high success rate, safe and reliable construction, etc.
5) compared with other construction methods, the speed of entering and leaving the site is fast, and the construction site can be adjusted flexibly, especially in urban construction can fully show its advantages, and the construction covers less land, the project cost is low, and the construction speed is fast.
6) when crossing a large river, as the pipeline is buried 9-18 meters below the ground, there is little oxygen and other corrosive substances in the ground, so it plays the role of natural anti-corrosion and heat preservation, and can ensure longer operation time of the pipeline.
3. Introduction of horizontal directional drilling system
All kinds of horizontal directional drilling RIGS are composed of drilling system, power system, directional control system, mud system, drilling tools and auxiliary tools. Their structures and functions are described as follows:
1) drilling system: it is the main body of drilling operation and backhaul operation through equipment. It is composed of the main machine of drilling machine and rotary table. The main machine of drilling machine is placed on the rig rack to complete drilling operation and backhaul operation.The rotary table is installed at the front end of the main engine of the drilling machine, connected with the drill pipe, and the requirements of different operating states can be achieved by changing the steering direction of the rotary table and the output speed and torque.
2) power system: the power source is composed of a hydraulic power source and a generator, which provides high-pressure hydraulic oil for the drilling rig system as the power of the drilling rig. The generator provides power for the supporting electrical equipment and lighting on the construction site.
3) directional control system: the directional control system is a directional tool that guides the drill bit to drill correctly by monitoring and controlling the specific position and other parameters of the drill bit in the underground by computer. Because of the control of this system, the drill bit can drill according to the designed curve.
4) mud system: the mud system is composed of a mud mixing tank, a mud pump and a mud pipeline to provide the drilling system with mud suitable for drilling conditions.
5) drilling tools and auxiliary tools: they are all kinds of tools used in drilling and reaming.Drilling tools are mainly suitable for all kinds of geological drill pipe, drill bit, mud motor, reamer, cutter and other tools.Auxiliary tools include clamps, swivel joints and tractor heads of various diameters.
