HDD - drilling technology. Horizontal Directional Drilling

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, horizontally directed drilling (HDD) is guided by the method of trenchless formation of the channel or shaft, into which the pipe or cable is carried. Of course, the installations used in this case perform technologically more complex operations and require more energy costs. However, there are many advantages that justify the HDD method. The technology of drilling without creating a trench allows for the laying of communications in conditions where the ground surface is not allowed to break down. This is especially true in urban areas, but this feature of this drilling method does not end there.

General information about the technology

The technique of drilling on a horizontal line is to form a well by cutting the soil using the angle puncture method. That is, the installation with the working head is introduced into the bowels of the earth in such a way that the surface, under which the communication channel is planned, maintains its integrity. The traditional method and technology of horizontal drilling are realized with the help of a rock-cutting tool. This is a drill bit with an emitter and bevel. The head makes pilot drilling, and then through the control system, most of the work is performed with changes in the parameters of the formation of the well, depending on the requirements of the project.

Much of the work is done before drilling. Experts study the properties and qualities of the soil, the location of functioning communications, etc. Sounding the ground massif with the registration of other underground objects is the most important stage of preparation, after which it is possible to start horizontally directed drilling. Monitoring technologies of possible routes of crossing existing communication with the project allow not only to solve the issue of admission to work, but also to determine the optimal tactics and the trajectory of the well construction.

Correction of drilling parameters

The main difficulty of 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 realized by correcting its position along the vertical and horizontal planes. Mechanically, this task is performed through a flexible cable. One of its ends is fixed at the end of the drill rod, while the other is managed by the operator of the HDD complex. The drilling technology also provides for the possibility of expanding an already completed well. To perform this operation, the drill bit is replaced with a reamer - it is a device that performs the function of a channel expander with the reverse action. By rotation, the aggregate forms the necessary dimensions of the shaft, along with it dragging the pipeline.

Drilling location

Effective management of the drilling process is impossible without the use of a working head location system. Since the direct position of the crown is not visually observed, special monitoring systems are provided, which also takes into account the HDD method. The method and technology of the modern device of horizontal wells, in particular, involve the use of locating probes. These are special sensors, located in the part of the drill head.

The connection between the probe and the operator is provided by means of a synchronization device. Thus, the user can track the location of the drill by recording information about its direction, angle and temperature. The collection of these and other data is mandatory, as it allows to completely secure horizontal directional drilling. The technologies of the traditional formation of wells most often allow the control of the head without the use of scanning devices. But in this case, the installation works in areas of inaccessibility, so losing control can lead to unpredictable results.

Wash mixtures and solutions

The performance of the drilling rig largely depends on the quality of the washing solutions used. For example, such mixtures allow to increase the speed of operation of the drill, improve the safety of the process and even have a beneficial effect on the environmental situation in the area of the event. To date, solutions have been successfully used with components that prevent clogging of the HDD installation. Drilling technology involves the use of formulations that include lubricant additives, polymer particles, fillers, improves abrasion, etc. Bentonite mixtures that are easy to prepare are also popular.

Applied equipment

The work involves machines consisting of several functional blocks. The standard equipment includes a chassis, a body with a frame, a power plant, a hydraulic station for servicing the mentioned solutions, a control panel, etc. in the structure. A separate drill carriage, which can be represented by different structures, not to mention the interchangeable heads. With regard to performance, the HDD technology among the key indicators marks the pipeline pulling effort. Parameters of the limiting length and expansion of drilling are also important.

Advantages of the method

Not always, but in many cases already in the operation of communication systems organized by this technology, they can be renovated and repaired without the need to create the same trench. In addition, in conditions of increased groundwater table there is no need for water loss, which expands the scope of the HDD. Horizontally directed drilling, as already noted, requires the use of more sophisticated equipment, but in terms of logistics organization is one of the most accessible ways of creating wells.

Conclusion

With the introduction of new technological solutions in the field of construction and industrial production, end users receive a lot of advantages. However, there is a downside to the application of modern modernized techniques and methods, including HDD. The drilling technology in this case imposes a considerable responsibility on the personnel. Accidents in the process of work are rare, but, for example, the collapse of the channel can cause huge damage. For this reason, drilling equipment manufacturers and technologists especially emphasize the importance of conducting an initial survey of terrain and soil characteristics.