Horizontal drilling of wells. Horizontally directed drilling. Horizontal drilling technology

Drilling is an integral part of the construction of various structures, industrial and residential buildings. In addition, this operation is indispensable in cases where it is necessary to establish water supply of a detached house, which is not going to be laid by the central water supply in the foreseeable future. Separately it is worth noting the horizontal drilling of wells, which is increasingly used in recent years.

What it is?

If you explain in a nutshell, this method allows you to drill wells for some kind of communications so that trenches and soil dumps are not formed at the same time. For this purpose, special installations are used which are capable of penetrating the soil of any hardness without damaging the upper layer of the soil. The duration of such a trench can reach several kilometers!

In order to perform horizontal drilling of wells, the UGNB-4M or UGNB-3M4 units are used, whose capabilities make it possible to turn a "puncture", whose diameter is only a few millimeters, into a trench 450 mm in diameter and larger. After this, pipes are injected into the borehole from high-pressure polypropylene or metal.

Why is horizontal drilling so popular?

From a technical point of view, horizontal wells have a huge number of advantages over classical methods of work execution. A huge plus is that this method of drilling does not involve the destruction of the upper soil layer. This gives a unique possibility of laying wells under reservoirs and territories with free-flowing soil. In addition, the technology of horizontal drilling involves laying pits under the lines of power lines or oil pipelines.

It should be noted that other drilling methods are generally inadmissible in densely populated areas, as well as in need of communications under overpasses, bridges and other important structures.

Bureaucratic side of the question

Not surprisingly, all of the above advantages contribute to the multiple simplification of obtaining all the documents necessary for carrying out work in bureaucratic sidelines. This is largely due to the fact that for punching horizontally located pits there is no need to block traffic, which is especially true for large cities, where horizontal drilling for pipe laying is used everywhere.

Even if there is a groundwater mirror close to the surface of the earth, this is not an obstacle to drilling. Since today complex computer equipment is used for this purpose, the operator can conduct a pit with millimetric deviations, without hitting the aquifer.

The economic aspect

If we talk about the economic side of the case, then in this case this method has a lot of advantages. So, one horizontal directional drilling unit helps several times to reduce the number of personnel required for work, which saves on wages. So, in most cases, brigades of three people will suffice for drilling. Compare this with the usual laying of the pit, when only auxiliary workers may need more than a dozen!

Since the time for horizontal drilling goes a little, you can significantly reduce the estimated cost. The cost of tools, equipment and nutrition of technicians will be minimal. If you receive all the necessary coordination documents, you will know in advance about all the cables in the ground, you will be spared also the need to repair damaged communications, which were laid earlier, at your own expense.

In addition, the method of horizontal drilling helps a couple of hours to lay a pipe under a busy highway, without destroying its coverage.

What are the stages of the work?

In order for the work to be carried out as efficiently as possible, it is necessary to perform all of the following steps in a clear sequence.

• First, all the equipment is being prepared, but before that, a mandatory soil sampling for analysis is done.
• They make a "puncture", otherwise called a pilot well.
• The diameter of the puncture is gradually increased.
• Pull the pipes into the resulting trench.
• At the final stage of the work, the received communications are checked and accepted.

Once again, we remind you that horizontal well drilling requires strict adherence to instructions, otherwise problems may arise. In order to better understand the very principle of such drilling, we will dwell a little more at each stage.

Initial stage of drilling

As we already said, it is necessary to study the properties of the soil in the place where you are going to start the laying of the well. The composition of the soil needs to be known in detail, since the depth of the laying of communications depends entirely on this. To determine the degree of soil density, specialists conduct directional sounding. Once the analysis is over, you can get all the necessary permits to work in your local government. In the next stage, horizontal well drilling involves laying a so-called pilot well.

Trial "puncture"

Everything, after that begins laying a pilot, pilot well. As a rule, a small-diameter drill head is used for this. Its promotion is easy to control: the head is connected to a bar, the movements of which allow for flexible adjustment of the trenching. The bar itself is a pipe, each section of which can reach three meters, and the diameter is 60-80 mm. Since the sections can be connected to each other, if necessary, they are increased.

Since it is often necessary to pass layers of very hard ground with an abundance of stones, we would recommend purchasing rock drill heads with diamond dust and made of especially hard alloys. Despite their high cost, you will quickly return money, as ordinary models in very difficult conditions very quickly fail.

The most difficult way for drilling is to pass as accurately as possible along the route laid by the engineers. Recently, horizontal directional drilling is most often used, which greatly facilitates this difficult task.

What is the essence of directional drilling?

The case in the special drilling head: it has a built-in transmitter, the signal from which is displayed on the receiving equipment of the operator. As soon as the route deviates from the planned one by at least a few millimeters, a warning is immediately displayed on the display. Since any drilling involves the risk of destruction of the soil and collapse, to protect against such unpleasant consequences, use bentonite (special cementing solution).

In particular, horizontal drilling under the road necessarily involves its use, since without a mortar the pit is almost certain to fall under the weight of the road surface and from the vibrations of passing cars.

How does the trial well expand?

We have already mentioned that after a "puncture" a trial well needs to be expanded to a larger diameter. To do this, use a special expander. Important! It is stretched in the opposite direction, moving from the end of the drilled well to its beginning. The principle of its action is similar to that for a drill: when moving, the tool rotates, cutting off excess layers of soil.

Note! In order to easily extend through the resulting borehole pipe, the diameter of the expander must exceed its size by approximately 30-35%. In addition, if the diameter of future communications is too large, it is not allowed to immediately launch a tool of large diameter downhole. In this case, several pushers are gradually pushed through the puncture, gradually increasing their diameter.

Pipe laying

Almost any horizontally directed drilling ends with a gasket through the received trench of pipes. The process itself is quite interesting. Again from the end of the well extends the expander. A grip for the pipe is attached to it. Accordingly, with the help of monitoring equipment and the operator, the pipe is started to pull along the well in the desired direction. The operator can adjust the guide bars at any time, correcting any deviation from the previous course.

Which pipes can be used?

At the very beginning of the article, we already noted that the most commonly used polymer pipes. There are several reasons for this at once. First, they are much more durable than their metal counterparts. In addition, polypropylene can almost decades to maintain absolute chemical stability. Simply put, such a water pipeline will not emit any harmful substances into the water.

However, there are also cases where it is more desirable to use metal varieties. It's about laying communications, which will pass high temperature fluids, as well as chemically aggressive compounds. Many plastics under such conditions for a long time can not stand, begin to crumble and collapse. The figure shows the simplest design of a horizontal well.

The final stage of work

When all tasks are completed at the beginning of work, it is time to prepare all the required documents and hand over the ready object to the customer. Only qualified engineers are allowed to do this, which can produce a technical justification for all the activities carried out. This requirement is also related to the fact that the paved communications must necessarily have an exact link to the terrain displayed in the documentation attached to the submitted project.

What settings are used during the work?

It should be noted that today there are dozens of models of such equipment, which is classified by many parameters. In addition, in the catalogs of the largest industrial companies you will be able to find hundreds of different types of replaceable drill heads with emitters of different power, exchangeable guide bars made of hard alloys with increased strength, etc.

Alas, our companies started producing this equipment only in the middle of the 2000s, when the market was already occupied with products from Germany, the USA and France. However, to date, this is largely offset by the fact that in terms of strength characteristics and cost, any horizontal drilling rig of Russian design is capable of giving a head start to its foreign counterparts.

Most often, construction companies in our country are buying them. The reason is not even in support of domestic producers, but in the excellent adaptation of Russian models to domestic conditions. This is very important, since in the conditions of the north imported drilling equipment is often faster out of order than its Russian counterparts. Given the decent price difference, the savings ultimately come out significant.

In addition, for domestic equipment much easier and cheaper you can get both supplies and spare parts in case of breakage.

Frequently used models

The most promising for today are drilling rigs of the following models:

• UGB-2M4, UGB-2MG. They differ in their extreme compactness and low price. Ideal for small construction companies, they do not require large expenses for personnel training.
• UGNB-3M4, UGNB-4. These installations are somewhat more expensive, but they almost completely repeat the possibilities of much more expensive imported units. It is also important that they are ideally suited to the harsh climatic conditions of our state.

Note that you in any case prepare drilling operators, and training should be performed on the most realistic and modern simulators. Considering that sometimes it is necessary to lay pits in millimeters from some dangerous objects (high voltage cables, for example), such thoroughness does not look like a waste of money. This is especially important when using foreign drilling rigs, since their control displays are not always easy and intuitive.

It should be noted that all costs are instantly "repulsed". Imagine how much you save money, when in the shortest time lay pipes under roads or buildings! In the case when classical methods of drilling are used, sometimes it takes more than one month for documents to be coordinated only!