Perhaps the biggest misconception about natural gas drilling in the Barnett Shale is that the rig is a permanent, or even long-term, fixture. The fact is, even though the rig comes first, and is hard to miss, its high-profile task takes only about three weeks per well. During the drilling phase, work continues 24/7 to maintain the integrity of the wellbore (hole). To minimize the number of padsites in the city, multiple wells may be drilled from a single location. When finished with the first well, the rig may skid, or “scoot over,” to drill another well on the same padsite, or may leave and perhaps return later to drill additional wells.
Noise reduction in urban settings
Chesapeake is pioneering urban drilling, making constant strides to create an urban friendly presence. In urban settings, a sound engineer measures current background noise at the drilling site and evaluates the topography and proximity of neighbors to determine what sound reduction measures are necessary. When needed, a customized sound plan is developed to reduce drilling rig and related noises. Options may include hospital-grade mufflers, acoustic blankets, rubber flooring or sound walls ranging from 16 feet to 32 feet on one or more sides. The noise mitigation plan at each site is customized for that particular location.
- A rig is on-site for about three weeks
- Work must take place 24/7 to maintain the integrity of the wellbore
- Sound reduction measures mitigate noise in urban settings
Drillsites are selected based on a number of factors, including the availability of land suitable to drill on; city permits; proximity to buildings, parks and other infrastructure; geologic considerations; proximity to natural gas pipelines or the feasibility of installing new pipelines; as well as a company's lease position in the area. Ultimately, energy companies strive to select sites that are least-intrusive to daily life.
From a physical standpoint, minor short-term disruptions may occur on-site, just like any typical urban construction project, but the majority of residents will experience few, if any, changes to daily life. Natural gas drilling is designed to have minimum impact on the environment, and new pipelines pose no more danger than the common public natural gas lines that already service most neighborhoods. Economically, you will notice a big difference as natural gas production brings millions of dollars in revenue, new jobs and income streams to local property owners, municipalities and other taxing jurisdictions.
The goal of responsible energy companies is to produce the most minerals for their royalty owners, which include school districts and municipalities. Natural gas drillsites are chosen to provide safety and security at every location, to minimize disruption to neighborhoods, and to find access routes that are as unobtrusive as possible.
The natural gas drilling process begins with padsite preparation, which typically lasts approximately one week, depending on the location. Next, the setup of the rig and the drilling of the natural gas well will take approximately two to three weeks per well. Although the rig is the most visible part of our operations, it is temporary and will be removed once the gas drilling is completed. At a later point, hydraulic fracture stimulation, commonly referred to as "fracing," will take place. Fracing usually takes three to five days to complete. Even with multiple-well padsites, the entire process frequently takes less time than construction of a house or other building in the same area.
During the approximately three weeks of natural gas drilling, operations run continuously 24 hours a day, seven days a week. Once fracing begins, the process may take three to five days to complete and is restricted to daylight hours.
Multiple measures are in place to ensure that gas drilling operations are sensitive to urban neighbors. In urban areas, operators must work with municipalities in minimizing the effects of noise and light from the natural gas drillsite, determining truck routes and implementing security measures.
Chesapeake uses state-of-the-art sound mitigation techniques to effectively reduce the sound coming from urban sites. Directional lighting may also be employed, allowing safety lights to be aimed away from nearby residences yet still keeping rig workers safe at night. Please be assured that Chesapeake has an excellent safety record and is committed to ensuring the maximum safety and well-being of all residents and the environment.
As with any construction site, there will be additional truck traffic for setting up and taking down equipment. After the natural gas wells are completed, the energy company returns to monitor and maintain the site. At some natural gas wellsites where piping isn’t an option, trucks may return to remove water from the on-site storage tanks.
In urban environments. extra precautions to mitigate sound include using blankets around the engine, constructing sound walls around the natural gas drillsite and installing mufflers as necessary. Based on a sound survey, experts determine the design and placement of the sound walls, which typically remain until all operations are completed.
Once natural gas drilling is completed and the operating equipment is in place, urban wellsites are fenced and landscaped. Because of that, they are frequently more appealing than other utilitarian structures, such as water pump houses or electrical stations. In many cases, the energy company makes other improvements to the area surrounding a drillsite.
The Hidden Creek site in Burleson, Texas, which is located between a golf course and a baseball field,
is an excellent example of how a wellsite can blend in with its surroundings.
Chesapeake has a state-of-the-art cementing and casing program that protects the aquifers from any natural gas drilling activities. The hole is first drilled using freshwater mud, which is a mixture of freshwater and bentonite clay. As the natural gas well is drilled, the clay actually plates out on the side of the hole, forming what is called a “wall cake,” preventing any migration of well bore fluid into the aquifer before it is cased.
Then, steel casing and surrounding layers of concrete are installed to isolate the natural gas well from the drinking water aquifers through which the well penetrates. The depth at which the surface casing must extend is mandated by the Railroad Commission of Texas (RRC). In Barnett Shale operations, the surface casing is typically set to a depth of 1,200 - 1,300 feet, more than 400 feet below the Trinity Aquifer.
After it is determined that the well can produce natural gas, additional strings of casing and tubing are set through the aquifers to provide even greater separation between the natural gas stream and the freshwater tables. The five layers of steel casing and cement which go into the construction of a natural gas well virtually eliminate the possibility of the contamination of any freshwater zones.
The RRC also requires documentation of drinking water aquifer intervals, the design and installation of surface casing relative to those intervals, and the reporting of characteristics of the wellbore along with completion and production data. Other states have similar programs in place to protect drinking water resources.
