Drilling is often a difficult subject in and of itself. Laymen usually think of drilling as a simple digging operation done large. But there’s any number of extra considerations which one needs to think about. Basically, things don’t scale in a linear fashion when one needs to drill. And the situation can become even more complicated when directional drilling needs to be kept in mind.
For example, horizontal boring brings with it some additional complications. One of the most significant is the simple nature of the operation. Horizontal boring is typically performed in order to secure somewhat delicate items. This can include everything from pipelines to cables. This all means that one typically needs to consider a few extra points when working with horizontal drilling or boring.
The process begins by constructing something known as a pilot hole. The pilot hole consists of a drilled hole whose diameter is kept fairly small. Next, one will pump drilling fluid through the drill pipe. This leads over to the drill bit. And from here the high-pressure jets will grind the soil. Basically, it works with a drill stem to ensure that there’s always a stable and pliable area directly ahead of the drilling. An additional bonus here is that the fluid also carries the cuttings back to the entrance of the pilot hole. This creates something of a sample system for the people working the drill.
Of course, some level of correction will almost certainly need to be made during this process. The initial survey should have given considerable information about the area. And likewise, one will be able to use this information in order to properly work with the site. But work between pilot holes and the calculated bore path isn’t always a simple matter. There are a few different reasons for this fact.
One of the most important is simply that nature is variable. One can’t always be certain what conditions will be found as the drilling continues. And one simply tends to find himself needing to compensate for that uncertainty at one point or another. But this is usually a fairly straightforward process once one really understands the uncertainty of any given project.
The next step is to detach the bit and replace it with a reamer. This proceeds into proper pre-reaming. One will of course need to enlarge the whole to a point where it can contain the product lines. The reamer will be rotated after retraction. During this stage drilling fluid will remote soil in order to enlarge the hole. The exact speed of this pre-reaming stage will depend on the nature of the soil itself.
One should also keep in mind that additives can ensure a stable hole. One of the more popular choices for this purpose is bentonite. However, there’s a wide variety of options which should be chosen based on the material on hand. Bentonite tends to be good for creating a “cake layer”. Polymers tend to be useful for breaking up clay soils. And in general, one should look for a fairly evenly mixed fluid in order to prevent blockages.
Finally, one should focus on the pipe pullback. This stage takes the drill rod and reamer and places them onto a swivel. The swivel, in turn, is used as a go-between for the product line and the reamer. The main purpose of this arrangement is to keep torsional stress away from the rotating drill string. Otherwise transference might occur to the product pipe. Said pipe will be pulled into the drill hole. And once again one will need to place some focus on the drilling fluid. This liquid is pumped downward into the hole. And in doing so the product pipe should receive sufficient lubrication.