The demand for natural gas and fuel has increased exponentially all over the world. Transporting crude oil and gas via tankers and trains has proven to be hazardous not only to the workers but also to the public and the environment. Pipeline transport is a safe alternative but comes with its own set of challenges such as theft, leaks and explosions. However; the benefits far outweigh the challenges.
It is estimated that there are approximately 2.5 million miles of pipelines to transport fuel products from source to market in the USA. The oil and gas industry is, therefore, a significant customer of piping construction and repair contractors, and the availability of horizontal directional drilling (HDD) trenchless technology is creating opportunities for improved efficiency and costs.
HDD is a trenchless process that allows the installation of new piping underground in a shallow arc along a predesigned bore path. This eliminates trenching entirely and can be carried out over long distances. (Take the Quiz: Think You Know HDD? Prove It!)
The development of this technology has saved time and expense for the construction and maintenance companies, especially in the oil and gas sector. Environmental concerns and increased monitoring of oil and gas-related activities have made HDD even more appealing.
Benefits of HDD to the Oil and Gas Industry
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HDD can be carried out with little to no trenching. The only excavation required is for the launch and retrieval pits.
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HDD is an accurate and reliable method with a proven track record of dependability.
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Time required for set up and construction is shorter than open trench methods.
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Planning and engineering is carried by considering latest guidelines (including environmental concerns) making it very reliable.
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The interruption to the general public in terms of lost time and business is greatly minimized to almost eliminated with trenchless methods.
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Significant reduction in terms of carbon footprint, up to 75%.
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Reduces the direct and indirect costs associated with open trenching
Oil and Gas Pipeline Construction and Repair
It is estimated that by 2050, the US will produce 35.24 trillion cubic feet of shale gas. New shale gas exploration sources require the laying of new pipes in order to get the gas from the source to the processing plants for distribution. No wonder then that the oil and gas industry is eyeing HDD for efficient and quick installation of pipelines to create a network that will make transportation easier and safer. This has also caused a rise in demand for trenchless rehabilitation for steel piping used in the construction of oil and gas pipelines. These pipes are subject to corrosion and can be easily monitored using trenchless inspection techniques and regularly repaired or replaced before its integrity is threatened.
The following factors are contributing towards the shift to HDD by oil and gas companies:
Environmental Factors Supporting HDD
Digging continuous trenches has a far greater impact on the environment than using HDD technology. This is particularly important in areas where there is a sensitive ecology like wetlands. Geological surveys can be conducted throughout the area in order to determine the best route for the pipeline taking environmental considerations into account. Environmental groups monitor the loss of natural vegetation and reduction in forestation as a result of construction activities, and as such, increasing pressure is placed on companies to minimize this impact when commencing new construction projects. (Read also: Trenchless and the Environment: How No-Dig Construction Saves Ecosystems).
Erosion and sedimentation are also factors that favor HDD techniques over the conventional digging of trenches. Disruption to soil layers through trenching increases the risk of erosion, especially during heavy rainfall, which can expose underground pipes, causing damage and creating an opportunity for human interference. The resulting loss of soil also causes damage to surrounding vegetation and the loss of valuable ecosystems for living organisms.
Technological Improvements of HDD Equipment and Methods
As technology has improved in HDD systems, they have become more attractive to the oil and gas sector. These improvements include the following:
Improved Steering Capabilities of HDD Rigs
There has been an improvement in the measurement and steering capabilities of HDD rigs in order to accurately install the piping in the optimum route. Steering can be improved by increasing the flexibility at the head of the drill string. Due to the improved accuracy in steering, smaller bore casings can be used, which saves on cost, while obstacles can be avoided more easily. (Read also: A Quick Guide to Underground HDD Steering and Tools.)
New Chain Drives
Rack and pinion technology has generally replaced the chain drives to move the carriage forward. The newer drives are more durable and reliable, which makes the operation more efficient and means that projects run more smoothly and to schedule.
Mud System Improvements
Improvements in mud systems have also yielded positive returns in terms of HDD installation projects. The constituents of mud, pumping and filtration systems all influence the effectiveness of the drilling operation.
Grouting and Lining Materials Advancements
Lining materials and chemical grouts have advanced due to the applications of trenchless technology. As rehabilitation companies have gained access to increased lengths of piping and been able to more accurately determine rehabilitation needs, the companies providing solutions have developed their products in accordance with these advances.
Regulatory Pressure
The United States Department of Transportation has a regulatory board for pipelines called the Pipeline and Hazardous Materials Safety Administration (PHMSA). Requirements for the integrity management of pipeline networks are specified and monitored. Over time, the increasing demands of integrity testing and inspection of older pipelines have raised concerns with piping that may have been laid many years ago in rural and undeveloped land, but now lie underneath housing, roads and commercial activities. HDD technology is ideally suited to respond to this increase in regulatory demand, as piping can be repaired or replaced with minimum surface disruption; this includes the use of robotic pipe repair.
Regulatory pressure is also driving some improvements in HDD technology itself through the development of standards for the treatment and disposal of drill mud and cuttings. (Read also: Drill Cuttings: How CRI Technology is Solving Disposal Headaches.)
Cost-Effectiveness
While trenchless technology is expensive by itself and needs heavy investment, the cost is quickly covered, especially in large diameter installations. The amount of time, equipment and manpower are much lesser compared to open trenching, thereby making it cost-effective.
Conclusion
The oil and gas industry, with its vast network of interconnecting pipeline systems, is taking advantage of the benefits of trenchless technologies like HDD. The sheer length of piping alone makes the task of integrity management a major undertaking, which requires efficient and cost-effective methods of construction and repair.
Environmental factors, technological improvements, regulatory pressure and cost-effectiveness have all played a role in the shift towards HDD and this trend seems likely to continue and grow for the foreseeable future.