Natural Gas: Drilling

There are primarily Five phases in the process of exploring for and producing natural gas in the Barnett Shale.

1) Identification of a “Prospective Area” for producing natural gas in the Barnett Shale.

A decision is made to work an area based on the available geological, geophysical, and existing production information, if any, along with risk factors and perceived economic returns.

Directional Drilling

2) Land Acquisition and Seismic Phase

Acquisition of the rights to the lands to explore and produce from the target area commences along with the process of acquiring 3-dimensional seismic (shooting 3-D seismic) information across the lands to attempt to evaluate the subsurface. The seismic process is performed to identify the best areas to drill and to identify those areas which may present drilling and/or completion issues.. The rights to explore for and produce gas are acquired by buying oil and gas leases from mineral/land owners. In Urban areas, buying leases and shooting 3-D seismic may require years to complete due to the shear number of home owners and commercial property owners located in an area.

3) Drilling Phase

The process of the drilling phase includes constructing the drill site area and drilling through the subsurface. Drilling is performed to provide a hole from the surface down through the Barnett Shale. The drilled hole provides to act as a conduit for the gas in the Barnett Shale to get to the surface. The Barnett Shale is located at 7000 feet to 8000 feet beneath the surface, pending where you are. Most of the current drilling in the Barnett Shale, and particularly in urban areas, is horizontal or “sideways” drilling. Horizontal drilling exposes significantly more reservoir rock to the well bore than would be the case with a conventional vertical well. In urban areas, the permit to drill involves as many surface issues as would be involved to build a commercial building.

(See "Direction Drilling" image)

4) Completion Phase

After the hole is drilled, the well is completed in an effort to get the well to produce. The drilled hole is lined with pipe and cemented in place. In the Barnett Shale formation, the completion process involves “hydraulic fracture stimulation” of the well to allow the natural gas to flow. The method is informally called fracing (pronounced "fracking") or “hydro-fracing. The technique is used to create “pathways” in the Barnet Shale formation to allow the gas to flow into the well more freely. The fracing method involves moving large amounts of water, sand and other materials, under great pressure, down into the well and out into the Barnett Shale formation.

(See "Fracture Stimulation" image)

Fracture Stimulation

5) Production Phase

The production process is the process of producing the natural gas from the well and delivering it to market. The gas flows from the Barnett Shall formation into the pipe of the well, up the pipe and out through special facilities that are installed at the surface of the well to separate water from the gas. The produced gas flows though a pipeline that must be installed to transport to areas where the gas is burned as fuel for manufacturing, generating electricity and for heat. In urban areas, one of the most difficult factors in producing the gas is the installation of the pipeline. The difficulties involved installing pipelines in urban areas includes overcoming the limited amount of space available for pipelines and the costs involved in working in and around streets, highways, and occupied buildings and homes. The entire process, from identifying the prospective area to the production phase can take between 3 to 5 years to complete in urban settings. Each phase of the process requires the expertise from different people including geologists, geophysicists, landmen, title attorneys, civil engineers and drilling-completion-production and pipeline engineers.

Energy Information Administration
Natural Gas Wikipedia