Main content | back to top
Shell is currently exploring the potential for natural gas development in Western Pennsylvania. Below are the four main stages of drilling activity that follow pad and road construction.
Stage One: Small Rigs (Conductor and Top Hole)
Once the well pad is prepared, the first rig you will see arrive on site is a small conductor rig. This rig essentially creates the “starter hole” in the ground and lines the hole with pipe. This portion of drilling is usually completed in one week.
The conductor rig is followed by another small rig called a top hole rig, which begins drilling the vertical section of the well. It usually takes 4 to 7 days to drill one well using this small rig. The only caveat is when we drill into the Utica. In that case we skip the top hole rig and jump directly to stage two.
Depending on the number of wells planned on a single well pad, the drilling time will vary.
Stage Two: Horizontal Drilling Rig
The next stage involves the Horizontal Drilling Rig, which is also referred to as “The Big Rig”. This larger rig drills the remaining vertical and horizontal portions of the well. It can typically take between ten days to one month to drill a single horizontal well on a single well pad. Again, in the case of multiple wells on a well pad, the time on location may be extended. Due to the rig’s size, it can take several days to set up and dismantle the rig in order to move from one well pad to another.
During this stage, drilling activities are conducted 24 hours a day, seven days a week. About 12 individuals will remain in trailers on site for the duration of the horizontal drilling. Lights from the drilling rig can be seen at night, and there is an increase in truck activity.
Stage Three: Completions (Hydraulic Fracturing)
The completions stage is when the well is stimulated, or hydraulically fractured. Stimulating the well is what makes it possible for the natural gas to flow. As illustrated in the picture, this stage involves the most activity and equipment.
Trucking activity is at its peak during this stage. Most of the trucks will be transporting storage tanks to hold both fresh and produced water, as well as sand. Some of the trucks staged on location provide the necessary power to stimulate the well by fracturing the shale and using hydraulic fracturing fluids to hold the small fractures in the rock open.
Once the well is stimulated, we capture the fluids that were pumped down in the well as part of the flowback process. Shell discloses its hydraulic fracturing fluids on www.fracfocus.org. Completions is also a 24/7 operation. This stage can last between 15-30 days. None of the workers supporting completions activities will sleep in trailers on the well location.
Stage Four: Flaring
The final stage in drilling and testing exploratory wells is flaring. Flaring allows us to test the gas flow in order to estimate the well’s production potential. Flaring is used when the gas is not yet suitable to go directly into a pipeline.
A flare is a slender 30 – 40 foot high vertical pipe with a flame at the top. The flame can be up to 40 feet high and usually lasts for one month.
Hopefully this helped provide a high level overview of our activities and what you can expect to see on a well pad. If you have any questions or concerns, please feel free to call the Shell Appalachia Call Center at 877-842-7308.