HYDRAULIC FRACTURING OF NATURAL GAS WELLS IN MICHIGAN 

Description

Natural gas production from hydrocarbon rich shale rock formations, known as “shale gas,” is 

one of the most rapidly expanding trends in onshore domestic gas exploration and production. 

Shale gas reservoirs are not conventional ones as normally seen in oil and gas development. 

The gas is more tightly locked into these shale gas reservoirs and its development relies on 

hydraulic fracturing (“hydrofracking,” or “fracking”). Hydraulic fracturing is a one-time procedure 

that is part of the completion of some types of oil or natural gas wells. More recently, horizontal 

drilling is being utilized, particularly in the deeper gas reservoirs. The purpose of both of these 

technologies is the same: to increase exposure of more reservoir rock formation to the well bore 

to maximize gas production. 

Horizontal drilling has been used commercially since the 1980s but has not been widely applied 

for natural gas development until recent years. Hydraulic fracturing has been utilized 

throughout the United States for more than 60 years. In Michigan, since the 1960s, more than 

12,000 wells have been hydraulically fractured. Most of these are Antrim Shale Formation gas 

wells in the northern Lower Peninsula. 

Hydraulic fracturing involves pumping water at high pressure to create fractures in reservoir rock 

that allow the oil or natural gas to flow more freely to the well bore. Proppants, usually silica 

sand, are added to the water to hold the fractures open once they are created. Small 

concentrations of chemicals are added to improve the effectiveness of the fracture job. 

Typically, a compound is added to increase the viscosity of the water to enable it to carry the 

proppant more effectively. Another typical compound is a friction‐reducing additive, to allow 

fracturing fluids and proppant to be pumped to the target zone at a higher rate and reduced 

pressure than if water alone were used. Other additives include: biocides to prevent 

microorganism growth that could plug the fractures; stabilizers to prevent corrosion of metal 

pipes; and acids to remove drilling mud damage near the wellbore. Some of the chemical 

additives can have adverse health or environmental impacts if they are not properly handled 

and contained. 

After a hydraulic fracture treatment, when the pumping pressure has been relieved from the 

well, the water‐based fracturing fluid begins to flow back through the well casing to the 

wellhead. Typically, 25 to 75 percent of the hydraulic fracturing fluid is recovered initially as 

“flowback” water. The rest remains in the gas-bearing formation or is recovered over time along 

with the gas that is produced. The flowback water may be mixed with native water from the 

formation itself (together, this is termed “produced water”) that generally contains salts and 

other dissolved constituents. 

Regulation of Hydraulic Fracturing

Michigan has comprehensive laws and rules, enforced by the Michigan Department of 

Environmental Quality (DEQ), that regulate hydraulic fracturing as well as every other aspect of 

oil and gas drilling and production. The DEQ has not found any cases where hydraulic 

fracturing has caused adverse impacts to the environment or public health in Michigan. 

Despite the benign history of hydraulic fracturing in Michigan, it recently has become a concern 

to many people primarily due to issues raised in other states. In addition, there has been recent 
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interest in the Utica/Collingwood formations in Michigan, which are relatively deep and are 

expected to require significantly larger volumes of fluids for hydraulic fracturing. In response, 

the DEQ in May 2011 issued Supervisor of Wells Instruction 1-2011 that improves 

environmental protection measures and fosters greater transparency. The Instruction applies to 

high-volume hydraulic fracturing operations. It sets standards for water withdrawal evaluation; 

monitoring and reporting of fracturing pressures and rates; providing information on chemical 

additives; and reporting of flowback water. 

The concerns over hydraulic fracturing center on five issues: (1) migration of gas or fracture 

fluids, (2) water use, (3) management of produced water, (4) surface spills, and (5) identification 

of chemical additives. Each issue is addressed in turn below. 

Migration of gas or fracture fluids. A major concern in natural gas development is the 

prevention of migration of gas or other fluids out of the reservoir and into overlying strata, 

particularly fresh water aquifers. In cases where this has occurred, it has been the result of well 

construction problems and not of hydraulic fracturing itself. At depths of about 2000 feet or less, 

fractures propagate horizontally due to the natural stress regime of the rock. This confines the 

fractures to the gas reservoir. At greater depths, fractures may propagate vertically; however, 

characteristics of overlying rock layers prevent fractures from extending above the top of the 

gas reservoir. 

The installation of steel pipe (“casing”), encased in cement, is key to preventing migration of gas 

or fluids. Michigan regulations require that each oil and gas well have a casing and cementing 

plan that will effectively contain gas and other fluids within the wellbore, whether related to 

fracturing or not. Surface casing must be set a minimum of 100 feet into the bedrock and 100 

feet below any fresh water zones and cemented from the base of the casing to the ground 

surface. Before fracturing or other operations can take place to complete a well for production, 

an additional string of production casing must be set to the depth of the reservoir and cemented 

in place. Depending on depth, additional protective casing may be required. To provide 

additional protection for aquifers and well integrity, the DEQ imposes a permit condition for wells 

in shallow reservoirs prohibiting hydraulic fracturing within 50 feet of the base of the surface 

casing. In addition, Instruction 1-2011 requires reporting of volumes, rates, and pressures 

(including pressure immediately outside of the pipe used to inject the fracturing fluid). Also, 

DEQ staff check wells in the vicinity to assure there are no wells or other features that could 

serve as conduits for unwanted movement of fracturing fluids. 

Water use. A fracture treatment of a typical Antrim gas well requires about 50,000 gallons of 

water. In the emerging Utica/Collingwood Shale gas development, the amount of water needed 

to fracture a horizontal well may be up to 5,000,000 gallons or more. To put this in perspective, 

5,000,000 gallons is the volume of water typically used by eight to ten acres of corn during a 

growing season. Withdrawal of water for oil and gas operations is exempt from the 

requirements of Michigan’s water withdrawal statute; however, Instruction 1-2011 requires the 

operator to perform the same water withdrawal impact assessment as any other user of large 

volumes of water. It also requires installation and monitoring of an observation well if there is a 

freshwater supply well within one-quarter mile. The DEQ will not approve a withdrawal of water 

for hydraulic fracturing if it is likely to cause a significant adverse impact to groundwater or 

surface water. 

Management of produced water. Proper management of produced water is essential in 

protecting public health and the environment. In Michigan, produced water must be managed 
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and disposed of according to strict rules specifically applying to those fluids. The fluids must be 

contained in steel tanks and transported to disposal wells where they are injected into deep rock 

layers that are isolated from fresh water supplies. The disposal wells are licensed by both the 

DEQ and the U.S. Environmental Protection Agency, and must be tested periodically to assure 

well integrity. Instruction 1-2011 requires reporting of the volume of flowback water recovered 

after a hydraulic fracturing operation. 

Surface spills. Spills of chemical additives or flowback water can have adverse environmental 

or public health impacts. Michigan requires secondary containment under tanks, wellheads, 

and other areas where spills may be most likely. If a spill does occur, it must be reported 

immediately to the DEQ, and all spills must be promptly recovered and cleaned up according to 

strict requirements. 

Identification of chemical additives. Instruction 1-2011 requires oil and gas operators to provide 

to the DEQ copies of all Material Safety Data Sheets (MSDSs) for additives used in hydraulic 

fracturing. The MSDSs include information on physical characteristics, toxicity, health effects, 

first aid, reactivity, storage, disposal, protective equipment, and spill response. The DEQ will 

post the MSDSs on the Department’s web site for public review. While the details on some of 

the chemical compounds used in hydraulic fracturing are exempted from disclosure on the 

MSDSs under federal law, the MSDSs will provide enough information for the DEQ to track and 

monitor spills. 

Conclusions

Michigan’s laws and rules effectively protect water and other natural resources as well as public 

health and safety from potential adverse effects of hydraulic fracturing. The DEQ has more than 

50 staff employed in enforcing these state requirements. To date, only two productive 

Utica/Collingwood Shale gas wells have been drilled in Michigan and the potential for more 

extensive development is unknown; however, the DEQ is taking a proactive approach in 

addressing large-scale hydraulic fracturing as well as other issues associated with deep shale 

gas development. 

While fracturing of deep shale gas wells may require larger volumes of water on a per well 

basis, the development is expected to require significantly fewer wells. The DEQ is proposing a 

well density of up to 640 acres per well, and has convened a hearing to address well spacing. 

By comparison, much of the past oil and gas development has been based on 40 to 80 acres 

per well. The hearing is under continuation as more information is acquired. 

Prepared by: Office of Geological Survey 

 Department of Environmental Quality 

 Updated May 31, 2011