Horizontal Directional Drilling

The immense task of maintaining and expanding the utility infrastructure around the world is a challenging one. The traditional methods of replacement and repair primarily revolved around open trench construction. These traditional methods often prove to be costly and troublesome, especially with today’s congested and buried infrastructure. The high cost of open trench construction is often driven by necessary restoration of roadways, sidewalks, driveways, and landscaping. Other problems often stem from the disruption of traffic and the danger to workers in high traffic areas. To overcome the drawbacks of open trench construction, the government, utility, and construction industries started looking for alternative methods for replacing and repairing the underground infrastructure. One of the alternative construction methods, and perhaps the fastest-growing technology in the trenchless industry, is horizontal directional drilling (HDD). HDD has experienced rapid growth in the construction industry over the past few decades. The horizontal-directional-drilling process represents a significant improvement over traditional cut-and-cover methods for installing pipelines beneath obstructions, such as roadways, driveways, historical areas, landscaped areas, rivers, streams, and shorelines, which warrant specialized construction attention. To efficiently and properly utilize the many benefits offered by HDD construction, design engineers should have a working knowledge of the HDD process. This knowledge will assist them in developing constructible designs that can be executed in the field while meeting the requirements of the utility company. This book is written for the designers, engineers, and utility company personnel who are involved or interested in HDD construction. The tools and techniques used in the HDD process are an outgrowth of the oilwell-drilling industry. The first use of directional wells in oil fields was motivated by economics. The oil fields off the California coast were the spawning grounds for directional drilling practices and equipment. Later oil and gas discoveries in the Gulf of Mexico and other countries promoted the expansion of directional drilling technology and practices. The horizontal drilling rigs used for utility and pipeline construction are similar to the oil-well-drilling rigs with the major exception that a horizontal drilling rig is equipped with an inclined ramp as opposed to a vertical mast.