Well location selection
In addition to geological and geophysical information, Southwestern Energy evaluates the geographical and topographical attributes of each site to determine the best location for a well pad. In some cases, technology allows us to drill multiple wells on a single well pad, which helps reduce the total number of pads needed for operations. By utilizing multi-well pads, we reduce the surface footprint. Following our evaluations, we work with the surface owner to place the well pad and access roads to balance our operational requirements with the surface owner’s needs. As our company’s operations have become more focused on tight gas and other unconventional resources, horizontal drilling has become the normal drilling process. In our Fayetteville Shale project, we use a two-phase horizontal drilling process.
Drilling phase one
A relatively small surface rig uses air to drill the shallower part of the well. Surface casing is set and cemented to seal off shallow, fresh water from the wellbore and to protect the wellbore from collapse. Once surface casing has been set and cemented, the surface rig drills the vertical section of the well to kick-off point.
Drilling phase two
A larger rig is brought in to drill the turning section and lateral portions of the well. State-of-the-art technology allows us to “steer” the drill bit thousands of feet horizontally, keeping it in the right place as it moves through the formation. As the well is being drilled, a mixture of water and additives, called mud, is pumped into the hole to cool the drilling assembly and move the rock cuttings to the surface. When the targeted distance is reached, production casing is set and cemented. Like the shallower casing used in phase one, the production casing permanently secures the wellbore. At this point, drilling operations have ended, the drilling rig is moved and the well is ready for completion. In our other operating areas, the drilling process uses a single rig to drill the vertical and horizontal sections using the same steps as described above. |
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