The first directional drilling rigs were developed more than 100 years ago, but it has only been recently that directional drilling applications have taken off. Today there are more than 1 million of the most advanced horizontal directional drilling (HDD) rigs worldwide—and demand for these rigs is not slowing down anytime soon. With new challenges arising all across the planet, from off-shore to urban areas, there has been an ever-increasing need for HDD rigs to drill under difficult circumstances.
In addition to the full range of conventional drilling operations currently being performed, many nonconventional and challenging directional drilling projects have proved successful in recent times. This article will focus on some of the challenges facing conventional directional drilling and highlight current technologies and trends in solids control and drilling fluids for horizontal directional drilling rigs.
One of the biggest challenges that directional drillers face is controlling solids during drilling operations. It has been estimated that as much as 25% of all time spent on a borehole can be attributed to its maintenance. This can be attributed to several factors that include poor initial hole conditions, the presence of sensitive formations, and the lack of effective solids control equipment.
At the early stages of directional drilling, many companies did not have a real solid control program in place. Many times they depended on mud pits to manage their cuttings, even in advanced rig designs.
The use of cuttings pits is not only costly but can also cause environmental concerns if not closely monitored. Today’s HDD drillers are turning to cutting management tools such as cuttings presses, centrifuges, and specialized cutting retention systems in order to control the amount of solids generated during drilling.
In addition to solids control, directional drillers have been challenged with other areas that have required the development of new technologies. These include drilling under sensitive environmental conditions such as those found off-shore and in urban areas and penetrating deeper formations where higher densities of solids are generated during drilling operations.
As time goes on, drillers will continue to encounter new challenges that require the development of new technologies—especially when it comes to HDD. With this in mind, research and development groups are working towards creating rigs that will be able to drill boreholes with absolute precision while minimizing operating costs at the same time. One area that is receiving a lot of attention is steerable technology.
Today’s steerable rigs can be steered up to 30 degrees in either direction, making them much more flexible than ever before. This type of manoeuvrability allows drilling operations to take place around the clock, even when a rig is located at a tight site or has to drill under restricted conditions. In addition, cutting designs have become larger and more efficient, allowing these systems to handle higher densities of solids.
Despite the advances that have been made over the past several years, many believe that the most significant advancement in HDD technology has been related to directional accuracy. Today’s rigs can drill with an accuracy of up to 100 ft laterally and about 10 ft vertically—ensuring that the well will be placed exactly where it is needed.
These types of advancements have allowed drillers to create new wells in urban areas and under-sensitive environmental conditions such as those found off-shore.
No matter what advancements are made in the future, one thing is certain: HDD technologies continue to march forward—helping horizontal directional drilling rig operators to drill faster and more efficiently than ever. In addition, these advancements have allowed drillers to complete projects that were once thought impossible—making the future of HDD technology look brighter than ever before.