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 for a detached house, to which they are not going to lay a central water supply for the foreseeable future. Separately, it is worth noting horizontal well drilling, which has been increasingly used in recent years.
What it is?
If to explain in a nutshell, this method allows you to drill wells for some communications so that at the same time trenches and dumps of soil are not formed. For this purpose, special installations are used that are able to penetrate the soil of any hardness without damaging the topsoil. The duration of such a trench can reach several kilometers!
To perform horizontal drilling of wells, the UGNB-4M or UGNB-3M4 installations are used, the capabilities of which make it possible to turn a “puncture”, whose diameter is only a few millimeters, into a trench with a diameter of 450 mm or more. After that, pipes of high pressure polypropylene or metal are inserted into the well.
Why is horizontal drilling so popular?
From a technical point of view, horizontal wells have a huge number of advantages over classical work methods. A huge plus is that this method of drilling does not imply the destruction of the upper soil layer. This gives a unique opportunity to lay wells under water bodies and areas with loose soil. In addition, the technology of horizontal drilling involves laying pits under power lines or oil pipelines.
It should be noted that other methods of drilling are generally unacceptable in densely populated areas, as well as, if necessary, communications under viaducts, bridges and other important structures.
Bureaucratic side of the issue
It is not surprising that all of the above advantages contribute to the multiple facilitation of obtaining all the documents required for work on bureaucratic margins. 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 a groundwater mirror is located close to the surface of the earth, this is not an obstacle to drilling. Since today sophisticated computer equipment is used for this purpose, the operator can conduct a pit with millimeter deviations without touching the aquifer.
Economic aspect
If we talk about the economic side of things, then in this case, this method has many advantages. So, one installation of horizontal directional drilling helps to reduce the number of personnel required for work, several times, which saves on wages. So, in most cases, a crew of three will be enough for drilling. Compare this with the usual pit laying, when auxiliary workers alone may require more than a dozen!
Since time for horizontal drilling takes a bit, you can significantly reduce the estimated cost. The costs of tools, equipment and food technicians will be minimal. If you receive all the necessary coordination documents, learn in advance about all the cables available in the ground, you will also be spared from the need to repair damaged communications that were laid earlier at your own expense.
In addition, the horizontal drilling method helps to lay a pipe under a busy highway in a couple of hours without destroying its coating.
What stages does the work consist of?
In order for the work to be performed as efficiently as possible, it is required to perform all the steps below in a clear sequence.
- First, all the equipment is prepared, but before that they make a mandatory sampling of the soil sample for analysis.
- Make a "puncture", otherwise called a pilot well.
- The diameter of the puncture is gradually increased.
- Pipes are pulled into the resulting trench.
- At the final stage of work, verification and acceptance of the resulting communications is carried out.
We remind you once again that horizontal well drilling requires strict adherence to the instructions, as otherwise problems may arise. So that you better understand the very principle of such drilling, let us dwell a little more at each stage.
Initial drilling phase
As we already said, it is necessary to study the properties of the soil in the place where you are going to start laying the well. The composition of the soil must be known in detail, since the depth of the laying of communications completely depends on this. To find out the degree of soil density, specialists conduct directional sensing. Once the analyzes are over, you can get all the necessary work permits at your local government. At the next stage, horizontal well drilling involves laying a so-called pilot well.
Trial "puncture"
Everything, after that, the laying of a test, pilot well begins. As a rule, a small diameter drill head is used for this. It is not difficult to manage its progress: the head is connected to a rod, the movements of which allow flexible adjustment of the trench laying. The rod 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, they are increased if necessary.
Since it is often necessary to pass layers of very hard soil with an abundance of stones, we would recommend purchasing drill bits with diamond spraying and made of especially hard alloys. Despite their high cost, you will quickly return the money, since ordinary models in difficult conditions very quickly fail.
When drilling, it is most difficult to follow the route laid by engineers as accurately as possible. Recently, horizontally directed drilling is most often used, which greatly facilitates this difficult task.
What is the essence of directional drilling?
The point is a special drill head: a transmitter is built into it, the signal from which is displayed on the receiving equipment of the operator. As soon as the route deviates from the planned at least a few millimeters, a warning is immediately displayed on the display. Since any drilling involves a risk of soil destruction and collapse, bentonite (a special cementitious mortar) is used to protect against such unpleasant consequences.
In particular, horizontal drilling under the road without fail involves its use, since without a solution the pit will almost certainly fail under the weight of the road surface and from the vibrations of passing cars.
How to expand the test well?
We have already mentioned that after a “puncture” the test well needs to be expanded to a larger diameter. To do this, use a special expander. Important! It is pulled 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 the drill: when moving the tool rotates, cutting off excess soil layers.
Note! In order to freely extend the pipe through the well obtained , 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 run a large diameter tool through the well. In this case, several expanders are successively pushed through the puncture, gradually increasing their diameter.
Pipe laying
Almost any horizontal directional drilling ends with laying through the resulting pipe trench. The process itself is quite interesting. Again, an expander stretches from the end of the well. A hook for the pipe is hooked to it. Accordingly, with the help of monitoring equipment and an operator, the pipe begins to be pulled along the well in the desired direction. The operator can at any time make adjustments to the guide rods by correcting any deviation from the previously laid course.
What pipes can be used?
At the very beginning of the article, we already noted that polymer pipes are most often used. There are several reasons for this. Firstly, they are much more durable than their metal counterparts. In addition, polypropylene is able to maintain absolute chemical stability for almost decades. Simply put, such a water supply will not emit any harmful substances into the water.
However, there are also cases where it is preferable to use precisely metal varieties. We are talking about laying communications along which high-temperature fluids will pass, as well as chemically aggressive compounds. Many plastics in such conditions do not last long, they begin to crumble and collapse. The figure shows the simplest design of a horizontal well.
The final stage of work
When all the tasks laid down at the beginning of the work are completed, it is time to prepare all the required documents and hand over the finished object for acceptance to the customer. Only qualified engineers are allowed to do this, who can make a technical justification for all the measures taken. This requirement is also associated with the fact that the laid communications must necessarily have an exact location, displayed in the documentation attached to the submitted project.
What settings are used in the performance of 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 can find hundreds of varieties of interchangeable drill heads with emitters of different capacities, interchangeable guide rods made of hard alloys with increased strength, etc.
Alas, our companies started producing this equipment only in the mid-2000s, when the market was already occupied by products from Germany, the USA and France. However, today this is largely offset by the fact that in terms of strength characteristics and cost, any horizontal drilling rig of Russian design can give odds to its foreign counterparts.
Most often, construction companies in our country buy them. The reason is not even the support of domestic manufacturers, but the excellent adaptation of Russian models to domestic conditions. This is very important, since in the north, imported drilling equipment often fails faster than its Russian counterparts. Given the decent price difference, the savings ultimately come out substantial.
In addition, for domestic equipment it is much easier and cheaper to get both consumables and spare parts in case of breakdown.
Commonly Used Models
The most promising today are the drilling rigs of the following models:
- UGB-2M4, UGB-2MG. Differ in extreme compactness and low price. Ideal for small construction companies, do not require large training costs.
- UGNB-3M4, UGNB-4. These units are somewhat more expensive, but they almost completely repeat the capabilities of much more expensive imported units. It is also important that they are ideally suited for the harsh climatic conditions of our state.
Note that in any case, you should prepare drilling operators, and training should be carried out on the most realistic and modern simulators. Given 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, as their control displays are not always simple and intuitive.
It should be noted that all costs instantly “beat off”. Imagine how much money you save when laying pipes under roads or buildings as soon as possible! In the case when classical drilling methods are used, it sometimes takes more than one month to just coordinate documents!