HDD - drilling technology. Horizontal directional drilling

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Laying communication lines in the traditional way requires the use of special equipment that destroys the soil mass to the level of the laying. In turn, horizontal directional drilling (HDD) focuses on the method of trenchless formation of a channel or shaft into which a pipe or cable is laid. 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 technique. The technology of drilling without creating a trench allows laying 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 the soil using the corner puncture method. 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 it is planned to conduct a communication channel retains its integrity. Traditional method and technologyhorizontal drilling is carried out using a rock cutting tool. This is a drill bit with an emitter and a bevel. The head performs pilot drilling, and then the main part of the work is carried out through the control system with a change in the parameters of well formation depending on the requirements of the project.

A large part of the work is done even before the start of drilling. Specialists study the properties and qualities of the soil, the location of functioning communications, etc. Probing of the soil mass with the registration of other underground objects is the most important stage of preparation, after which horizontal directional drilling can begin. Technologies for monitoring possible intersection routes of the existing communication with the project one allow not only to solve the issue of access to work, but also to determine the optimal tactics and trajectory of well construction.

Correction of drilling parameters

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 bit. The head is controlled by correcting its position in 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, and the other is controlled by the operator of the HDD complex. The drilling technology also provides for the possibility of expanding an already finished well. To perform this operation, the drill nozzle is replaced by a rimmer - this is a device that performschannel expander function with reverse action. By rotating, the unit forms the required dimensions of the shaft, at the same time pulling the pipeline.

Drilling location

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

Probe communication with the operator is provided by means of a synchronization device. In this way, the user can track the location of the drill by recording information about its direction, angle and temperature. The collection of this and other data is mandatory, as it allows you to completely secure horizontal directional drilling. Traditional well formation technologies most often make it possible to control the head without the use of scanning devices. But in this case, the installation works in inaccessible zones, so the loss of control can lead to unpredictable results.

Wash mixtures and solutions

The performance of a drilling rig largely depends on the quality of the drilling fluids used. For example, such mixtures can increase the speed of the drill, improve safetyprocess and even have a beneficial effect on the environmental situation in the area of the event. To date, solutions with components that prevent clogging of the HDD unit are successfully used. Drilling technology involves the use of compounds that include lubricating additives, polymer particles, fillers that improve abrasive action, etc. Bentonite mixtures are also popular, which are easy to prepare.

Applied equipment

Machines consisting of several functional blocks are involved in the work. Standard equipment includes a running gear, 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 drilling carriage, which can be represented by different designs, not to mention interchangeable heads. As far as performance is concerned, HDD technology lists the pull force of the pipeline as one of the key indicators. The parameters of the maximum length and expansion of drilling are also important.

Dignity of the method

Not always, but in many cases already during the operation of communication systems organized according to this technology, it is possible to sanitize and repair them without the need to create the same trench. In addition, in conditions of increased occurrence of groundwater, there is no need for dewatering, which expands the scope of HDD. Horizontal directional drilling, as already noted, requires the use ofmore complex 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 into the construction and industrial production, end users will receive a lot of benefits. However, there is a downside to the use of modern modernized techniques and methods, including HDD. The drilling technology in this case imposes considerable responsibility on the operating 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 study of the terrain and soil characteristics.