ALL Consulting, LLC
June 2012
Executive Summary
This primer has been compiled to provide a review of the practice of hydraulic fracturing and its importance to the development of Canadian shale oil and natural gas resource plays. Discussions address the technology involved with hydraulic fracturing, chemicals used, variations in North American shale geology, oil and gas regulations, best management practices, potential pathways of
fluid migration and the risk involved, and past incidents attributed to hydraulic fracturing. The intent of the primer is to provide a baseline of information that illustrates that no two shales are alike, understanding and designing a fracture requires specific data that must be collected, technology has made many shale gas resources available for extraction but only in the last few years, regulations are in place to protect groundwater and the environment, best management practices are employed by industry, and although there are past incidents the risks of contamination from the act of fracturing the rock are minute. Hydraulic fracturing is defined as the process of altering reservoir rock to increase the flow of oil or natural gas to the wellbore by fracturing the formation surrounding the wellbore and placings and or other granular material in those fractures to prop them open.
Hydraulic fracturing makes possible the production of oil and natural gas in areas where conventional technologies have proven ineffective. Recent studies estimate that up to 95% of natural gas
wells drilled in the next decade will require hydraulic fracturing.1 This technology has been instrumental in the development of North American oil and natural gas resources for nearly 60 years. It is the combining of hydraulic fracturing with horizontal drilling and innovative earth imaging that has revitalized the oil and gas industry in North America over the last two decades. Hydraulic Fracturing is a highly engineered, modeled, and monitored process, using precisely selected types and volumes of chemicals to improve performance. These chemicals typically make up less than 1% of fracturing fluid. Experience and continued research have improved the effectiveness of the process and allowed the use of reduced chemical volumes and more environmentally benign chemicals. The natural gas and oil extraction industry is facing ever-increasing scrutiny from governments, the public, and non-governmental organizations (NGOs). These stakeholders rightly expect producers and service companies to conduct hydraulic fracturing operations in a way that safeguards the environment and human health. Many of the concerns raised about hydraulic fracturing are related to the production of oil and gas and can be associated with the development of a well, but are not directly related to the act of hydraulically fracturing a well. It is important to
distinguish those impacts that can potentially be attributed to hydraulic fracturing from those that cannot so that mitigation measures and regulatory requirements can be directed towards the proper activities and responsible parties.
While the environmental risks associated with oil and gas development—including the practice of hydraulic fracturing—are very small due to advanced technology and regulation, the use of best management practices (BMPs) can reduce and mitigate those risks that remain. Most of the commonly used BMPs identified for hydraulic fracturing and oilfield operations address issues at the surface. These include reducing impacts to noise, visual, and air resources and impacts to water sources, wildlife, and wildlife habitats. There are also several BMPs that can be used to mitigate risks associated with the subsurface environment. BMPs are generally voluntary, site specific, and proactive in nature. They are most effective when incorporated during the early stages of a development project.
Regulation of hydraulic fracturing has been carried out for decades under existing Federal, Provincial, and Territorial regulations. Although specific regulatory language has not necessarily used the term “hydraulic fracturing,” requirements for surface casing, cementing, groundwater protection, and pressure testing have been prevalent in most regulatory regimes, all of which are directly applicable to the minimization of risks associated with hydraulic fracturing. The Federal government regulates oil and gas activities on frontier lands, certain offshore and territorial lands, and those lands set aside for the First Nations people. Each Province with oil and gas production has its own specific regulations governing these requirements. In addition, the government of the Yukon Territory has powers similar to those of a Provincial government. While there are no current shale gas prospects in the Northwest Territories and Nunavut, there are regulations in place that would cover initial development.
The recent increase in oil and gas development activities centers on the technological strides to access the oil and natural gas found in shale formations. As far as the geology of shale goes, it is a sedimentary rock that is comprised of consolidated clay-sized particles that were deposited in low-energy depositional environments and deep-water basins. It has very low permeability, which limits the ability of hydrocarbons in the shale to move within the rock. The oil and gas in a shale formation is stored in pore spaces or fractures or adsorbed on the mineral grains; the volume and type (oil or gas) varies depending on the porosity, amount of organic material present, reservoir pressure, and thermal maturity of the rock.
There is no specific recipe for an ideal shale basin. However, the right combinations of geologic and hydrocarbon properties can make oil and gas production of a shale formation commercially viable. While each shale basin is different, geologic analogues to Canadian shale basins can be found in commercially producing U.S. basins, suggesting technical and operational approaches to producing oil and gas from the Canadian shales.
Along the same lines as the geologic comparison to U.S. shales for the purpose of gaining insight; an effort to identify the potential hydraulic fracturing chemicals that would be used in Canadian shale plays was performed for chemicals used in analogous U.S. shale plays. This data was collected from the voluntary reporting of chemicals used by multiple U.S. operators and service companies and through private communication with operators in various basins in the United States.2 In addition, water volume data was gathered and analyzed from the same sources. This information is useful because understanding the volumes and types of chemicals anticipated for the various shales across Canada can lead to a reduction in the number and volume of chemicals used. In addition, the Province of British Columbia, as well as many U.S. states are requiring public disclosure of the chemicals used during hydraulic fracturing through both laws and regulations.
Given the public concern about contamination of ground water from hydraulic fracturing, it is important to examine the pathways through which contamination could theoretically occur. The analysis in this report considers only the subsurface pathways that would potentially result from the hydraulic fracturing operation, and not those events that may occur in other phases of oil and gas activities. Five pathways are examined:
Analysis of each of these pathways demonstrates that it is highly improbable that fracture fluids or reservoir fluids would migrate from the production zone to a fresh water source as a result of hydraulic fracturing.
Numerous instances of environmental contamination across North America have been attributed in the popular media to hydraulic fracturing. In fact, none of these incidents have been documented to be caused by the process of hydraulic fracturing. The term “hydraulic fracturing” is often confused, purposefully or inadvertently, with the entire development lifecycle. Environmental contamination can result from a multitude of activities that are part of the oil and gas exploration and production process, but none have been attributed to the act of hydraulic fracturing. All of these activities are distinct from the process of hydraulic fracturing. This report presents a summary of many of those incidents, along with information that shows why they have not been caused by hydraulic fracturing, or why further study is needed to determine a cause.
During the last decade shale development has increased the projected recovery of gas-in-place from about 2% to estimates of about 50%; primarily by the advancement and reworking of technologies to fit shale formations.3 These adapted technologies have made it possible to development vast gas reserves that were entirely unattainable only a few years ago. The potential for the next generation of technology to produce even more energy with advances in hybrid fracs, horizontal drilling, fracture complexity, fracture flow stability, seismic imaging, and methods of re-using fracture water is enormous.