Hydraulic Fracturing and Well Stimulation

Technological developments in oil and gas exploration and production, including well stimulation, have greatly increased California’s energy security by ensuring a long-term, ample, affordable and reliable supply of domestic energy and reducing our dependence on foreign imports. Hydraulic fracturing and acid matrix stimulation are engineered practices that CRC uses to maximize production in certain fields, while reducing the number of wells and the surface footprint needed.

The State of California has been effectively monitoring well stimulation for decades as part of its comprehensive rules that address all aspects of oil and gas development. Senate Bill 4, which took effect on January 1, 2014, created a new well stimulation permit program and required the state to prepare an environmental impact report regarding well stimulation. The state’s Division of Oil, Gas and Geothermal Resources (DOGGR) reviews permit applications submitted by California Resources Corporation (CRC) and other operators that provide detailed information about the well, the stimulation job, and the presence or quality of local ground water. Operators are also required to conduct ground water and air monitoring during certain well stimulation jobs under the supervision of state agencies.

According to the U.S. Energy Information Administration (EIA), two-thirds of U.S. natural gas production and over half of U.S. crude oil production in 2015 came from wells that were hydraulically fractured. Because of California’s geology, hydraulic fracturing is not used in most oil and gas wells in the state. Only about 20% of the state’s production comes from wells that have undergone hydraulic fracturing. When the practice is used in California, operators typically require far less water than is customarily applied in other states like Colorado, North Dakota or Texas, and CRC typically recycles produced water for our well stimulation jobs.

Hydraulic fracturing is effective at increasing flow through tight rock formations that hold oil. These formations contain oil in pore spaces in the rock, and the creation of small fractures allows oil to flow more readily to the well. On most wells, a hydraulic fracturing operation takes just a few hours and occurs only once in the decades-long life of the well. Typically, hydraulic fracturing fluids are more than 99 percent water and an inert material such as sand. The remaining additives, often found in common household products like cosmetics and cleaning supplies, help carry the sand or inhibit corrosion.

Acid matrix stimulation dissolves minerals blocking the pore space and natural fractures in the rock to restore the flow from the oil and gas reservoir to the well. Acid matrix stimulation typically is a solution of 15 percent acid in water, and the acid is rapidly neutralized by the minerals in the oil and gas reservoir near the wellbore. Service companies have developed expertise in formulating well stimulation fluids with specific properties based on the mineralogy of the rock and the subsurface geology in the oil and gas reservoir. The ingredients in these stimulation fluids are used commonly in a variety of consumer products and widespread commercial and industrial applications and their properties are well understood.

CRC is committed to public disclosure about our hydraulic fracturing and well stimulation practices. In 2011, CRC’s predecessor was an early participant in FracFocus®, a website created by the Ground Water Protection Council and the Interstate Oil and Gas Compact Commission to provide for well-specific voluntary disclosure of hydraulic fracturing operations, including the ingredients used in hydraulic fracturing fluids. In addition to providing a national registry, the website provides factual information about hydraulic fracturing and groundwater protection. Please refer to the FracFocus website or to the DOGGR website for more information about hydraulic fracturing.

For more information, view our Hydraulic Fracturing infographic (PDF).