In 2006, approximately 1,500 wells were drilled in the Barnett Shale, and the number will continue to increase over the coming years. So it is understandable that people are concerned with the amount of water used in gas well drilling.

The reality is that the largest users of surface water and ground water are municipalities who use more than 90 percent of the total fresh water while manufacturing, irrigation, steam electric generation, and livestock are also significant water-use industries. (source: Fort Worth Basin/Barnett Shale Gas Play: An assessment of present and projected freshwater use).

A consortium of energy companies have banded together to form the Barnett Shale Water Conservation and Management Committee to study the industry’s water use and discuss conservation and water management techniques to help conserve fresh water.

The study was performed under the direction of the Gas Technology Institute (GTI) and conducted by the consulting firm of Texerra.

What steps are being taken to ensure that our water resources are being used efficiently?
In 2006, 16 energy companies formed the Barnett Shale Water Conservation and Management Committee to develop "best practices" for companies operating in the Barnett Shale. The Texas Railroad Commission has also sponsored research on the issue. Several firms have undertaken projects in the Barnett Shale to reduce the amount of fresh water used in development activities. Mobile water purification units fueled by onsite natural gas are being utilized on drilling locations to treat a portion of the wastewater stream for reuse.

Recycling processes could allow reuse of approximately up to 10 percent of the returned fluid used in fracing wells. The key determinants in future water needs are population and economic growth. Over the long term, it is likely that the pace of drilling in the Barnett Shale will slow, thereby reducing the need for water for fracing. The Texas Water Development Board projections indicate that, after 25 years (which is within the resource planning cycle), no significant amount of water is expected to be used for Barnett Shale operations.

Where does the water used in drilling come from?
Drillers purchase surface water from cities or county water districts, acquire water from sources authorized to sell water from rivers such as the Brazos and Trinity River authorities, or might use water from a stock tank or pond with permission from the Texas Comission on Environmental Quality (TCEQ) and landowner as required.

Is drilling depleting our supply of water?
City municipalities use of water accounts for almost 90 percent of total water usage, while manufacturing, irrigation, steam electric generation, and livestock irrigation are also significant water-use industries. Of the 131 billion gallons of water sold in 2006 by the Tarrant Regional Water District (a major provider of water in the area), only 0.19 percent was used by the natural gas drilling industry.

The biggest threat to water availability in North Texas comes from the growing population. The TCEQ (the regulators of Texas’ water rights) estimates that the population in the 20-county area in the Barnett Shale will increase from 5.5 million residents to almost 9.5 million residents and that municipal use will continue to account for about 87 percent of the total water use over the next 25 years.

Just as the general population should work on water conservation efforts, operators are actively researching and testing technologies for reducing their freshwater consumption, primarily in the area of recycling the water produced following the fracture stimulation during the drilling process.

Early results are promising, yet more research is needed. The industry is committed to water conservation. 

Can the water used in fracing be recycled?
Several firms have undertaken projects in the Barnett Shale to reduce the amount of water used in development activities. Mobile water purification units fueled by on-site natural gas are being utilized on drilling locations to treat a portion of the produced water for reuse. Recycling could allow reuse of up to 5 percent of the returned water used in fracing wells.

Will drilling continue to use more and more water?
The key determinants in future water needs are population and economic growth. Over the long term, it is likely that the pace of drilling in the Barnett Shale will slow, thereby reducing the need for water. The Texas Water Development Board projections indicate, that after 25 years (which is within the resource planning cycle), no significant amount of water is expected to be used for Barnett Shale operations.

What is the purpose of drilling mud?
Drilling mud is used to remove the cuttings from the wellbore, maintain the stability of the wellbore, minimize formation damage, and to cool, lubricate and support the drill bit and drilling assembly.

What does drilling mud consist of?
Water-based drilling mud is a combination of fresh water and naturally occurring substances such as bentonite clay (gel), barium sulfate (barite) and calcium carbonate (chalk).

How is drilling mud disposed of?
The solids are separated from the water and disposed of by “landfarming”, a waste management practice in which the solids are mixed with or applied to the land surface in such a manner that the waste will not migrate off the landfarmed area. Landfarming is regulated by the Texas Railroad Commission. Landowners generally approve of the practice and consider it to be a natural fertilizer. The water is disposed of in salt water disposal wells.

How is the water used in fracturing disposed of?
It is disposed of in deep formations in wells that are regulated by state and federal agencies to assure all safety measures concerning employee and public health are met.

The study analyzed current and future projections of freshwater consumption by Barnett Shale gas producers. The study found that between 2000 and 2005, freshwater use of both surface and ground water was less than 1 percent.

While the percentage of total water use in the area will increase to some extent with additional well development, the incremental usage associated with the Barnett Shale will be a minor percentage of the future demand for water. According to the Texas Water Development Board: Barnett Shale operators will require less than 1 percent of surface water supplies and less than 10 percent of ground water in 2010 when drilling in the area will be at peak levels. These projections are still quite small when compared to usage by municipalities for drinking water, lawn irrigation and businesses.

NORM - naturally occurring radioactive material

What is NORM?
NORM refers to low level radioactive material from natural sources, and can be found in the soil of the earth’s crust, in the air we breathe, the food we eat, the water we drink and even in our own bodies.

There are many different types of radioactive materials found in nature. In fact, more than 30 different types of naturally occurring radioactive materials can be found in our back yards and are in our bodies. These materials are transferred to man via the water and food-chain cycle.

Everyone is exposed to some level of radiation from natural sources, such as the sun. In addition, many of the manmade items we use every day are a source of radiation, including a wristwatch, cigarettes, building masonry and even books. We are even exposed to radiation when we visit the dentist, either through x-rays received, wearing dentures or having dental work containing porcelain.

The average person in the United States is exposed to small amounts of radiation from natural sources each year. More than 80% of this exposure comes from background radiation sources, but consumer products can also contribute to exposure. For instance, a person who smokes one and a half packs of cigarettes per day increases his or her NORM exposure by more than 20 times average, and the use of porcelain dentures can result in NORM exposure 4 times average.

Where is NORM found in the Oil and Gas Industry?
NORM encountered in oil and gas exploration, development and production operations originates in subsurface formations, which may contain low level radioactive materials. NORM may be brought to the surface in the formation water that is produced in conjunction with the production of oil and gas. The concentration of radioactivity in the formation water is ultra-low, so low that it is only measurable after a sufficient amount of scale or sediment is accumulated.

During the course of oil and gas production operations, NORM found in produced waters may form scale in well piping, storage tanks and other surface equipment. It can take several years before scale accumulation in oilfield equipment reaches a regulatory threshold. Concentrations of NORM may also occur in sediments that accumulate in oilfield vessels and tanks. If this does occur, the pipe or vessels are dealt with according to regulatory standards.

What are the Potential Exposure Routes?
In oil and gas operations, most of the NORM resides inside of closed steel vessels and piping that reduces the exposure hazard for site workers. The quantity of materials affected by NORM at any given work location is small and the external radiation levels are not significant.

What is the Health Risk?
The health risk of NORM to the general public is virtually non-existent. The risk of NORM exposure to a site worker is only slightly increased.

It is highly unlikely that any one individual would receive a dose of one rem over the course of a year when working with NORM. However, if a dose of one rem were received, either from external sources or through the inhalation or ingestion of radium-226, then the risk incurred in terms of loss of life expectancy would only be 1.5 days. This risk is 240 times lower than the risk of dying when driving a motor vehicle. It is 827 times lower than the risk of developing and dying from cancer induced by non-radiation causes. It is 1,070 times lower than the risk of dying from heart disease, and 1,655 times lower than the risk of dying from cancer caused by smoking 1½ packs of cigarettes per day.

The distance a person is from a radioactive source is important to protection. The level of radioactivity is 4 times lower at two feet away and 16 times lower at 4 feet, compared to the level at one foot away. In addition, dense materials such as steel used in oilfield equipment blocks alpha and beta radiation and significantly reduces gamma radiation. It is only when equipment is opened to the atmosphere or piping is pulled out of the well, that potential exposure exists.

NORM found in oil and gas operations is generally found in two forms – as scale inside piping and tubing or as sediment inside tanks and process vessels. Exposure to either form can only occur when repair work is performed. As long as the NORM equipment is in use it presents no risk to workers or the public. When work is planned, appropriate measures are implemented to contain the solids and scale and remove any chance of exposure to site workers. When NORM equipment is taken out of service, the openings are covered to contain any loose material and prevent release to the environment.

What are the Texas State Regulations for Oil and Gas NORM?
The Railroad Commission of Texas (RRC) regulates the identification and labeling of equipment containing NORM and disposal of oil and gas NORM waste, Texas Department of Transportation regulates the transportation of NORM on public roads and the Texas Department of State Health Services (DSHS) regulates all other oil and gas NORM activities.

The RRC regulations define acceptable disposal methods for NORM. These regulations also require all equipment that contains NORM above a regulatory threshold to be labeled with the letters "NORM."

The DSHS NORM regulations include special worker protection requirements for oil and gas operations. Oilfield equipment such as piping and storage tanks, with NORM, above the regulatory threshold is subject to DSHS regulation. Transfer of NORM-containing equipment is allowed provided the equipment is reused in oil and gas operations. However, NORM-containing equipment that is taken out of oilfield service must be decontaminated before it is disposed or accepted at a metal recycling facility. The DSHS regulations require a specific license to perform this decontamination work.

Click HERE to read more from the Railroad Commission on NORM

What is the Oil and Gas Industry Doing to Protect the Public?

• Perform surveys to identify and label equipment containing NORM above regulatory thresholds.

• Properly label and store NORM equipment taken out of service prior to reuse, decontamination or disposal

• Use licensed contractors for removal, transportation, and disposal of NORM waste.

• Comply with applicable NORM regulations.

Read what the American Petroleum Institute has regarding NORM, click here

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