To extract tight gas and oil, it is necessary to drill down into the rock, extend horizontally into the hydrocarbon reservoir, and then inject large amounts of water – mixed with sand and small quantities of chemicals – under high pressure. This process, called hydraulic fracturing, fractures the rock and releases the gas and oil into the well. This technique has been used for many years in the oil and gas industry.
Some environmental groups and communities have raised concerns about the use of hydraulic fracturing. They question the high volumes of water used, the risk of chemical release into water sources and the potential release of methane gas or other chemicals into the air.
Shell is a leader in promoting safe and responsible tight gas and oil operations. We developed and adopted a set of five global principles that govern all our onshore tight gas and oil activities, covering safety, air quality, water protection and use, land use and engagement with local communities. Each tight gas or oil project takes into account the local context, the geology of the area and impacts such as noise and traffic. We then design our activities to best suit the local conditions. We are also implementing technologies that will reduce the environmental impact of tight gas, including capturing methane emissions and measures to improve the detection of leaks.
In the USA, we collaborate with the Center for Sustainable Shale Development (CSSD) and its partners. These include environmental organisations, foundations and oil and gas companies. CSSD has developed 15 voluntary performance standards for covering air quality, water resources and climate, and began auditing our USA Pennsylvania tight gas operations against these standards in 2014. In early 2015 our operations in Appalachia received CSSD certification.
We are also working collectively with other oil and gas companies and industry associations such as the American Petroleum Institute (API) to develop a common position on methane emissions reduction.
Water
We aim to protect groundwater sources and reduce water consumption in our drilling and production activities. We work with local authorities to secure water for our operations while reducing the potential impacts on local communities and the environment. For example, we install barriers to isolate our wells from fresh-water aquifers and, wherever possible, we test and sample water wells before and after drilling to ensure there is no contamination. We publicly disclose the chemicals we use in the hydraulic fracturing process, to the extent allowed by our suppliers.
In the Karoo region of South Africa, where Shell applied for rights to explore for natural gas, we funded a comprehensive study of water stress (when demand for water exceeds supply). The results will be used to guide plans to conserve water and use alternative water sources. In Canada, we have installed water systems to capture, transfer and reuse water at our Groundbirch and two Deep Basin fields. (See “Water”).
To read more about the Shell Onshore Operations Principles visit www.shell.com/onshore-operating-principles.
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Tight gas: community concerns and our approach | |
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Concerns raised by communities |
Shell operating principles: examples in practice |
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Chemicals could be released into local water sources. |
We always have at least two physical barriers in the section of the well that passes through the potable groundwater aquifer, so that we prevent the production stream from mixing with potable groundwater. |
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In Appalachia, USA, we test the quality of water wells around our sites both before and after drilling to ensure we can detect any changes. |
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High volumes of water are used in hydraulic fracturing which can compete with other local water needs. |
We design our operations to reduce the use of potable water and to use non-potable water as reasonably practicable. |
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In Groundbirch, Canada, we have invested in the construction of a reclaimed water plant for the City of Dawson Creek. The plant treats sewage and waste water to be reused in our operations and by the local government. |
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Methane gas and other chemicals could be released into the air from hydraulic fracturing sites. |
We use infrared cameras and other methods as well as maintenance programmes to find any leaks. |
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In Appalachia, USA, our leak detection and repair programme includes audible, visual, olfactory inspection as well as gas imaging camera inspections. These take place at well sites, compressor stations and metre stations. |
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Noise and traffic could affect local communities. |
We work to understand and reduce the impact from our operations on wildlife and livestock. This includes limiting activities during specific times. |
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In Groundbirch, Canada, we engage with local farmers to ensure that any major movement of equipment does not coincide with their cattle drives. |
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Effects of operational land use on local communities. |
We assess the impacts of our operations on the community and find ways to reduce the consequences and strengthen the opportunities. |
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In Sichuan, China, we located our well pads on hillsides to avoid impacting people’s livelihoods or causing resettlement of the community. |
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