Marcellus Shale Fracking – Transloading Bulk Materials for Marcellus Shale Drilling

Posts Tagged ‘vertical drilling’

The Marcellus horizontal drilling is legal and practical due to the way the formation of shale rock has formed. When a drilling company just drills straight down, or what is called vertical drilling, their borehole only intersects the shale layer that is a small and limited area.

The shale layer in the Marcellus shale region is not vertical but horizontal, like nearly all layers of the earth’s mantle. The horizontal drilling is vertical drilling at the top, but a directional drill head changes the course and direction of the borehole during the drilling process.

The main advantage of this process is that a greater area of the shale rock bed is exposed in the borehole. This increases the possibilities of the drilling to intersect with a natural gas pocket. Because of this increased area of exposure when fracking is needed to increase the amount of natural gas or oil from the shale rock bed, a better result is achieved.

The secondary advantage is that multiple boreholes can be started on the same platform, but go in different directions. This allows for more underground area that can be covered without a greater impact on the surface environment.

Horizontal drilling is accomplished by starting a vertical shaft downward. As the hole is being drilled, the direction is guided sideways. This is not a 90-degree turn like on a street, but a slow curving arch that could take hundreds of feet before the corner is achieved.

With this style of drilling, most wells are capable of extracting up to 5 times more natural gas and oil than with a vertical borehole alone. The time it takes to drill a horizontal well is comparable to a vertical well, which is only 30 to 45 days. The time is dependent on the depth the well is to penetrate to.

In the region of Marcellus, horizontal drilling is the most common and economically practical application for the extraction of natural gas and oil from below the surface.

The term horizontal drilling is also called directional drilling and slant drilling. This type of drilling is nothing new and has been around since the early 1900s.  The early methods were achieved through the use of bent or curved piping.

The true horizontal drilling did not occur until the development of the downhole drill motors that were developed in the 1970s. They used a stationary pipe for power with a rotating drill head and a piece of bent pipe or snub pipe that allowed for the direction of the hole to be changed.

The latest technological advances have come with the rotary steerable tools that allow the operator to drill in the direction they desire with more accuracy.

Compared to vertical drilling, the benefits of this type of hole boring are a greater access and exposure of a reservoir, along with more options on the placement of a drilling platform. This method is how energy companies are recovering oil and gas reserves that are located under towns and villages.

This process has also changed the way many companies now approach drilling. There are instances where up to 40 different drilling platforms are placed closely together. Each one heads off in a different direction underground to recover the energy reserves that are trapped below ground. Because the platforms are located in a smaller area, the environmental impact is reduced.

In years to come, more wells will use the horizontal drilling techniques to recover more energy to meet the demands of consumers.