What can I expect during directional drilling?

• Oct 26, 2021
• What can I expect during directional drilling? Drilling equipment creates noise during operations. Therefore, Enbridge will, when possible, restrict drilling activity to daylight hours if the equipment is close to occupied buildings or home...

What can I expect during directional drilling? Drilling equipment creates noise during operations. Therefore, Enbridge will, when possible, restrict drilling activity to daylight hours if the equipment is close to occupied buildings or homes. Construction crews may also reduce noise by using structures on the drill site that are designed to buffer and reduce surrounding sound levels. The length of time needed for drilling depends on the distance of the underground drill; the geology; the pipeline’s diameter; and, the progress of drilling operations. Sometimes, drilling can be completed in just a few weeks. Other times it may take a few months to complete. Advanced planning can provide an estimated completion time for any specific drill site. These timetables, however, can be affected by unforeseen conditions.

Is  there  regulatory oversight?

Yes. UNITED STATES: The design and construction of petroleum pipelines is governed by the Office of Pipeline Safety, a department under the U.S. Department of Transportation, Pipeline and Hazardous Materials Safety Administration. As part of the planning, technical codes and standards are followed in  preparing detailed geotechnical investigations and engineering surveys. Depending on the location and purpose of the HDD, some local, state or federal  authorizations or permits may also be required. 

CANADA: The design and construction of petroleum pipelines is governed by the National Energy Board. As part of the planning, technical codes and standards are followed in preparing detailed geotechnical investigations and engineering surveys. Depending on the location and purpose of the HDD, some local, provincial or federal authorizations or permits may also be required. Enbridge plans and performs HDD crossings according to exacting standards, and meets or exceeds regulatory requirements.

Are there environmental risks?

HDD is chosen as a construction technique to reduce or avoid environmental impact. As with any construction process, however, HDD is not 100 percent risk-free. Normally, the drilling mixture of water and bentonite clay remains within the tunnel, including the surface entry and exit points, as it circulates during drilling.  This  maintains the tunnel’s shape. However, the drilling mud can sometimes surface elsewhere through natural cracks or voids in subsurface soils. This is an unintended release of drilling mud referred to as inadvertent return. Highly specialized construction technicians using advanced monitoring equipment along with visual monitoring watch for potential problems. Often, the bentonite mixture itself will seal a hole, preventing and minimizing seepage.  However, if a significant amount of drilling  mud surfaces outside the drilling area, Enbridge may need to suspend drilling operations and implement more extensive cleanup and containment measures. Being only 5 percent bentonite, if the mixture enters a waterway, it is usually sufficiently diluted by the river so that no active cleanup is necessary.  In any case, Enbridge will work directly with the appropriate environmental agencies throughout the drilling  operation. In  some unusual situations, attempts to complete directional drilling may not be successful. In the event this occurs, Enbridge may need to propose and seek permits for alternative ways to cross the area using traditional  construction techniques and implement appropriate environmental protection measures in consultation with designated environmental agencies.