Laying communication lines in the traditional way requires the use of special equipment that destroys the soil mass to the level of the bookmark. In turn, horizontal directional drilling (HDD) is guided by the method of trenchless formation of a channel or shaft into which a pipe or cable is carried. Of course, the installations used in this case perform technologically more complex actions and require more energy costs. However, there are many advantages that justify the HDD methodology. Drilling technology without creating a trench allows for the laying of communications in conditions where the destruction of the soil surface is not allowed. This is especially true in urban areas, but the features of this drilling method do not end there.
Technology Overview
The technique of drilling along a horizontal line is to form a well by cutting soil according to the method of angular puncture. That is, an installation with a working head is introduced into the bowels of the earth in such a way that the surface under which the communication channel is planned to be maintained remains intact. The traditional method and technology of horizontal drilling are implemented using a rock cutting tool. This is a drill bit with emitter and bevel. The head performs pilot drilling, and then through the control system the main part of the work is carried out with changing the parameters of the well formation depending on the requirements of the project.
A considerable part of the work is done even before the start of drilling. Experts study the properties and qualities of the soil, the location of functioning communications, etc. The sounding of the soil mass with the registration of other underground objects is the most important stage of preparation, after which you can begin horizontal directional drilling. Monitoring technologies for possible intersections of the existing communication with the design allow not only to resolve the issue with access to work, but also to determine the optimal tactics and trajectory of well construction.
Drilling correction
The main difficulty in performing this type of drilling is not in the mechanical destruction of the soil, but in maintaining the correct direction of the crown. Head control is implemented by correcting its position on the vertical and horizontal plane. Mechanically, this task is performed through a flexible cable. One end is fixed at the end of the drill rod, while the other is controlled by the operator of the HDD complex. Drilling technology also provides for the possibility of expanding an already completed well. To perform this operation, the drill bit is replaced by a rimmer - this is a device that acts as a channel expander with a reverse action. By rotation, the unit forms the necessary dimensions of the shaft, along with this dragging the pipeline.
Drilling location
Effective management of the drilling process is not possible without the use of a working head location system. Since the immediate position of the crown is not visually monitored, special monitoring systems are provided that also take into account the HDD method. The method and technology of the modern device of horizontal wells, in particular, involve the use of location probes. These are special sensors located in the part of the drill head.
The connection of the probe with the operator is provided by means of a synchronization device. Thus, the user can track the location of the drill, recording information about its direction, angle and temperature. The collection of these and other data is mandatory because it allows you to completely secure horizontally directed drilling. Technologies of traditional well formation most often make it possible to control the head without using scanning devices. But in this case, the installation works in inaccessible areas, so the loss of control can lead to unpredictable results.
Flushing mixtures and solutions
The productivity of the drilling rig depends on the quality of the used drilling fluids. For example, such mixtures can increase the speed of the drill, improve process safety and even have a beneficial effect on the environmental situation in the event area. To date, solutions with components that prevent clogging of the HDD installation have been successfully used. Drilling technology involves the use of compounds that include lubricants, polymer particles, fillers that improve abrasive effects, etc. Bentonite mixtures, which are easy to prepare, are also popular.
Applied Equipment
The work involves machines consisting of several functional blocks. Standard equipment provides for the presence of a chassis, a body with a frame, a power plant, a hydraulic station for servicing the mentioned solutions, a control panel, etc. A separate place in the complex is occupied by a drill carriage, which can be represented by different designs, not to mention interchangeable heads. With regard to performance, HDD technology among the key indicators marks the pulling force of the pipeline. The parameters of the ultimate length and expansion of drilling are also important.
Advantages of the method
Not always, but in many cases, during the operation of communication systems organized using this technology, they can be rehabilitated and repaired without the need to create the same trench. In addition, in conditions of increased occurrence of groundwater there is no need for water reduction, which expands the scope of HDD. Horizontal directional drilling, as already noted, requires the use of more sophisticated equipment, however, in terms of logistics organization, this is one of the most affordable ways to create wells.
Conclusion
As new technological solutions are introduced in the field of construction and industrial production, end users get a lot of advantages. However, there is a downside to the use of modern modernized techniques and methods, including HDD. The drilling technology in this case imposes a considerable responsibility on the staff. Accidents during operation rarely occur, but, for example, a channel collapse can cause enormous damage. For this reason, drilling equipment manufacturers and technologists especially emphasize the importance of conducting an initial study of the terrain and soil characteristics.