Frequently Asked Questions

What is hydraulic fracturing?

Hydraulic fracturing is the process of creating small cracks, or fractures, in underground geological formations to allow natural gas​ and oil to flow into the wellbore and up to the surface where the it is collected and prepared for sale to a wide variety of consumers. Variables such as the permeability and porosity of the surrounding rock formations and thickness of the targeted shale formation are studied by geoscientists before the hydraulic fracturing process is conducted. The result is a highly sophisticated and carefully engineered process that creates a network of fractures that are safely contained within the boundaries of the targeted deep shale natural gas and oil formation.

During the hydraulic fracturing process, a mixture of water, sand and other chemical additives designed to protect the integrity of the geological formation and enhance production is pumped under high pressure into the shale formation to create small fractures. The mixture is approximately 98% water and sand, along with a small amount of special-purpose additives. The newly created fractures are “propped” open by the sand, which allows natural gas and oil to flow into the wellbore where it is collected at the surface and subsequently delivered to a wide ranging group of consumers.

How does natural gas and oil end up in reservoirs or pockets?

Natural gas and oil has been formed over tens of millions of years from the deposits of organic matter that have been buried by thousands of feet of sedimentation from erosion. When natural gas and oil is formed, it slowly migrates through pores in the source rocks (usually organic-rich shale and sometimes limestone) to create natural gas and oil reservoirs. These reservoirs are created when the gas and oil becomes “trapped” by the existence of a nonporous, impermeable rock layer above the porous layer. This barrier prevents further upward migration and these reservoirs become the targets for drilling operations. It is these accumulated deposits that form the collection of natural gas and oil reserves that comprise the massive unconventional shale reserves that have vastly increased the domestic deposits.

Why is hydraulic fracturing necessary?

Without the recent and significant technological advancements made in horizontal drilling and in hydraulic fracturing, the natural gas and oil found in deep shale formations would be, uneconomic and unrecoverable. The creation of small cracks, or fractures, in the shale allows the natural gas and oil trapped within the very dense rock formations to flow to the surface.

What chemicals are used in hydraulic fracturing?

Approximately 98% of the volume of materials used during the hydraulic fracturing of deep shale gas and oil wells is made up of water and sand. Other typical ingredients include a friction reducer, gelling agent and antibacterial agents. A typical hydraulic fracturing mixture and a list of typical additives include:

 

Fracturing Ingredients
Product Purpose Downhole Result Other Common Uses*
Water and Sand: ~ 98%
Water Expand the fracture and deliver sand Some stays in formation, while the remainder returns with natural formation water as produced water (actual amounts returned vary from well to well) Landscaping and manufacturing
Sand
(Proppant)		 Allows the fractures to remain open so that the natural gas and oil can escape Stays in formation, embedded in fractures (used to "prop" fractures open) Drinking water filtration, play sand, concrete and brick mortar
Other Additives: ~ 2%
Acid Helps dissolve minerals and initiate cracks in the rock Reacts with minerals present in the formation to create salts, water and carbon dioxide (neutralized) Swimming pool
chemicals and cleaners
Anti-bacterial Agent Eliminates bacteria in the water that produces corrosive byproducts Reacts with micro-organisms that may be present in the treatment fluid and formation; these micro-organisms break down the product with a small amount of the product returning in the produced water Disinfectant; sterilizer for medical and dental equipment
Breaker Allows a delayed breakdown of the gel Reacts with the crosslinker and gel once in the formation, making it easier for the fluid to flow to the borehole; this reaction produces ammonia and sulfate salts, which are returned to the surface in produced water Hair colorings, as a disinfectant, and in the manufacture of common household plastics
Clay stabilizer Prevents formation clays from swelling Reacts with clays in the formation through a sodium-potassium ion exchange; this reaction results in sodium chloride (table salt), which is returned to the surface in produced water Low-sodium table salt substitutes, medicines and IV fluids
Corrosion inhibitor Prevents corrosion of the pipe Bonds to metal surfaces, such as pipe, downhole; any remaining product that is not bonded is broken down by micro-organisms and consumed or returned to the surface in the produced water Pharmaceuticals, acrylic fibers and plastics
Crosslinker Maintains fluid viscosity as temperature increases Combines with the breaker in the formation to create salts that are returned to the surface with the produced water Laundry detergents, hand soaps and cosmetics
Friction reducer “Slicks” the water to minimize friction Remains in the formation where temperature and exposure to the breaker allows it to be broken down and consumed by naturally occurring micro-organisms; a small amount returns to the surface with the produced water Cosmetics including hair, make-up, nail and skin products
Gelling agent Thickens the water to suspend the sand Combines with the breaker in the formation, making it easier for the fluid to flow to the borehole and return to the surface in the produced water Cosmetics, baked goods, ice cream, toothpastes, sauces and salad dressings
Iron control Prevents precipitation of metal in the pipe Reacts with minerals in the formation to create simple salts, carbon dioxide and water, all of which are returned to the surface in the produced water Food additives; food and beverages; lemon juice
pH Adjusting Agent Maintains the effectiveness of other components, such as crosslinkers Reacts with acidic agents in the treatment fluid to maintain a neutral (non-acidic, non-alkaline) pH; this reaction results in mineral salts, water and carbon dioxide - a portion of each is returned to the surface in the produced water Laundry detergents, soap, water softeners and dishwasher detergents
Scale inhibitor Prevents scale deposits downhole and in surface equipment Attaches to the formation downhole with the majority of the product returning to the surface with the produced water, while the remaining amount reacts with micro-organisms that break down and consume it Household cleansers, de-icers, paints and caulks
Surfactant Increases the viscosity of the fracture fluid Returns to the surface in the produced water, but in some formations it may enter the natural gas stream and return in the produced natural gas Glass cleaners, multi-surface cleansers, antiperspirants, deodorants and hair colors

*Other common uses of the product may not be in the same quantity or concentration.

Are hydraulic fracturing chemicals dangerous?

When used properly, hydraulic fracturing chemicals are no more dangerous than any industrial or household chemicals. However, they do require safe work practices, proper site preparation and attentive handling to ensure safety and the protection of the public, employees, contractors and the environment. Each chemical used during the hydraulic fracturing process has a Material Safety Data Sheet (MSDS), which is readily available at a central location for all personnel on the jobsite. The MSDS outlines the hazards associated with wellsite chemicals and the appropriate steps to protect the user and the environment. It is important to note that in deep natural gas and oil shale drilling operations target hydraulic fracturing zones that are, on average, located almost 1.5 miles below the earth’s surface and many thousand of feet below freshwater formations, and are separated by thousands of feet and the immense weight of tons of protective rock barriers. These depths and formations make the potential for migration into freshwater zones a near scientific impossibility.

How can regulatory agencies confirm that operators are complying with regulations?

Agencies confirm that operators are complying with regulations through a number of established methods such as permitting, completion reports and inspections. These methods are more fully described below.

When is a permit acquired?

Regulatory agencies require permits before construction. A detailed review of applications is conducted by the agencies to verify that project designs meet requirements before work is performed on the targeted location. Once the design is approved, a permit with specific operating instructions is provided to the operator. Depending upon the targeted location, additional permits may be required.

What type of agency reporting is required?

The operator is required to submit completion reports to the proper state agency to provide information on the final freshwater casing protection design program for each well. This information includes the size and amount of casing to be used in the well and the amount of cement used to seal off the casing from the surrounding earth. The location where the hydraulic fracturing will occur and the type of stimulation materials (hydraulic fracturing fluids) are also detailed on the report. Any additional operational equipment installed in the wellbore will also be noted on the report.

When are inspections conducted?

Agencies can, and do, conduct inspections during or after drilling, construction and production to verify that all project work performed by the operator is in compliance with the proper regulations and permits.

How can I be sure that my groundwater is protected?

Each state implements specific programs to protect its underground drinking water resources. Steel casing with surrounding layers of cement are installed to isolate the well and protect the drinking water aquifers through which the wellbore penetrates. The depth at which the surface casing extends below these freshwater aquifers is mandated by each state’s regulatory agency.

Chesapeake’s cementing and casing programs are designed and implemented to comply with these regulations and generally exceeds them. A specialized well survey (cement bond log) is also used to verify the integrity of the cementing program.

After it is determined that the well is capable of producing natural gas or oil, a tubing string is set to provide an added layer of separation between the natural gas and oil stream and freshwater aquifer. The multiple layers of steel and cement which go into the construction of a well, when properly installed, virtually eliminate the possibility of contamination to these freshwater zones.

What is the likelihood of a spill at the wellhead during the hydraulic fracturing process?

Spills at the wellhead during hydraulic fracturing activities are extremely rare. The piping and hydraulic fracturing equipment used to transport fluids to the wellhead are inspected and pressure tested prior to the start of each hydraulic fracturing job. The equipment is pressure rated and continuous monitoring occurs during operations to ensure that pressures remain below the safety-rated pressure levels. Raw chemicals are maintained inside lined secondary containment areas to catch any releases before they can migrate off the site. Likewise, the sites are specifically constructed to contain any releases.

In addition, preventative maintenance is also used to ensure that equipment is functioning properly and performing its intended function.

What best management practices​ (BMPs) does Chesapeake employ in its hydraulic fracturing operations to ensure the containment of fluids on location?

Chesapeake and its partners actively use a number of BMPs​ on the wellsite during hydraulic fracturing operations to prevent fluid spills and run-offs. As previously described, primary preventative measures involve routine pressure testing and maintenance of hydraulic fracturing equipment prior to commencing operations, proper handling and temporary storage of materials and employee training on spill prevention practices. Based on lessons learned during the course of its operations, Chesapeake has implemented additional BMPs to further mitigate the potential for spills and negative impacts to the environment. Some of which include:

  • Sites designed and constructed to minimize storm water run-off, which prevent fluids from flowing off the location.
  • Department of Transportation-approved chemical containers are maintained inside lined secondary containment areas to catch potential leaks.
  • Secondary containment and diversion systems are used at hose and pipe connections to catch and contain potential leaks.
  • Structured processes are implemented for the transfer of chemicals to provide the safest approach possible for employees, contractors and the environment.
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