FAQs
What types of utilities can be installed with HDD?
Horizontal directional drilling installations are versatile. At DTI, we install the pipe; you dictate the application. Our crews have installed electrical conduit, telecommunications lines, gas mains and service lines, water mains, forced sewer lines, gravity sewer lines, water wells, drainage lines, and more. If you need an underground pipe, we can directionally drill it.
How do you steer the drill bit?
Precision is everything. The three types of locating are walk-over, wire-line, and gyroscopic.
Most installations will be completed with walk-over locating technology. Walk-over locating systems work via a transmitter enclosed in the drill bit housing, sending an electromagnetic signal to the receiver above ground. Walk-over locating transmits real-time data regarding the projected depth, pitch, and tool-face of the drill-bit to the driller and locator.
How much space is needed for the drilling rig and other equipment?
While we require space for the entry and exit points, the overall footprint of an HDD project is significantly smaller than that of a trenching operation. The drill rig, mud system, and other support equipment can all be contained within a relatively small footprint.
Can you drill through rock?
With over 30 years of drilling experience, DTI has drilled through nearly all ground conditions. The ground type dictates which downhole tooling the crew uses.
How much is directional boring?
With any project, the exact cost is job-specific. You're encouraged to contact DTI to receive a project-specific range. We offer several flexible pricing options, including Daily Labor Rate, Unit Cost, and Not-to-Exceed.
How deep and long can a horizontal well be drilled?
There is no single, hard limit, as the maximum depth and length are highly dependent on the application, equipment, geology, and site-specific constraints.
Routine installations range from 10s to 1000s of feet in length, with a depth range from 5 to 75 ft.
Routine installations range from 10s to 1000s of feet in length, with a depth range from 5 to 75 ft.
Can you place multiple screens in one bore?
Yes, multi-screen or nested wells are a common installation technique for environmental remediation applications to achieve zone isolation and differential pumping or injection.
My site has no access issues, is horizontal worth exploring?
The value of HDD in this scenario shifts from avoiding surface obstacles to maximizing installation efficiency.
How deep can a horizontal well be installed?
The maximum achievable depth for a horizontal well is not a fixed number, but rather a function of several critical factors, primarily revolving around geology, drilling fluid pressure, and tracking technology.
Utility installations are typically 5 to 10 feet below ground surface. Environmental installations can range from 5 feet to upwards of 200 feet.
Utility installations are typically 5 to 10 feet below ground surface. Environmental installations can range from 5 feet to upwards of 200 feet.
Is drilling mud safe for the environment?
The safety of drilling mud (or drilling fluid) is paramount to our industry, and the short answer is that the materials we predominantly use are non-toxic and environmentally benign, provided they are properly managed.
The typical composition consists of:
- Water (85% - 98%): The base fluid, which must often meet drinking water standards.
- Bentonite Clay: This is the primary solid component. Bentonite is a naturally occurring, volcanic clay composed mostly of montmorillonite.
- Safety: Bentonite is considered non-toxic and is even listed by the U.S. FDA as a "Generally Recognized Safe Food Substance". It's the same clay used in cosmetics, ponds, agriculture, and engineering seals, among other applications.
How much space do you need for directional drilling?
Space is dependent on job-specific factors, including the material type and bore length. The required space is a function of the equipment (rig, pumps, mud system) and the pipe-handling area. Directional drilling operations are designed to be compact, taking up minimal space.
What is a typical setback distance?
A general rule of thumb for bore path geometry is a 5:1 ratio—for every 1 foot of target vertical depth, you need 5 horizontal feet of setback distance. When space is a limiting factor, this setback distance can be shortened.
How much waste does HDD product?
The waste generated by HDD primarily consists of drilled solids and spent drilling fluid (slurry), with the total volume typically estimated to be between three to six times the final borehole volume, depending on the geology and the fluid management process. Even with these volumes, HDD generates significantly less total disturbed material compared to traditional trenching, making it the preferred method for minimizing environmental impact and disposal costs.
Can you steer through rock?
Yes, we can steer through rock, but it requires specialized tools and techniques and is generally more challenging than steering through soil or clay.
What is biofouling?
Biofouling refers to the buildup of this biological film on the internal and external surfaces of well screens, casing, pumps, and associated piping. Biofouling results from microbial activity and subsurface geochemistry. Improper development of biodegradable polymer-based drilling fluid concentrates can stimulate biofouling.
What type of materials can you install using HDD?
High-Density Polyethylene (HDPE)
Polyvinyl Chloride (PVC)
Fusible PVC (FPVC)
Stainless Steel
Carbon Steel
Ductile Iron
Polyvinyl Chloride (PVC)
Fusible PVC (FPVC)
Stainless Steel
Carbon Steel
Ductile Iron
What is mud rotary drilling?
Mud rotary drilling is a drilling technique that utilizes the continuous circulation of a fluid, or "mud," pumped down the drill pipe and back up the borehole annulus to cool the bit, remove drilled cuttings, and stabilize the borehole walls.
What is the diameter of a typical horizontal remediation well?
Typically, horizontal remediation wells are 2-inch to 4-inch in diameter.
What happens if you run into an obstruction you cannot drill through in the subsurface.
The benefit of horizontal directional drilling is that we have full 3D control of the drill bit in the subsurface. Contrary to vertical drilling, where the borehole must be abandoned and the entire rig must be moved, if an obstruction is encountered that cannot be drilled through (such as large cobbles or boulders), the drill string can be retracted several rods and attempts can be made to maneuver around the obstruction from within the same borehole.
How do you track or locate the drill bit?
HDD locators track the drill bit using either Walk-Over Guidance Systems or Wireline and Gyro Systems.
The walk-over guidance system is the most common HDD tracking method where a locator walks above the bore path, using a portable receiver to detect and interpret the electromagnetic signal emitted by a sonde (transmitter) housed behind the drill bit to determine its real-time depth, pitch, and rotational orientation.
Wireline Systems uses physical cables - one downhole and one along the bore path - to send signals. Gyro Systems uses inertial measurement technology independent of magnetic fields to interpret depth, pitch, and rotational orientation.
What is a mud program?
A mud program is a detailed, customized plan that specifies the type, composition, testing, and management procedures for the drilling fluid (mud) used throughout a Horizontal Directional Drilling (HDD) project.
What site data do you need to begin design?
Geotechnical data, specifically boring logs and groundwater information.
Subsurface utility information.
Subsurface utility information.