The ConocoPhillips Global Onshore Well Management Principles apply throughout the life cycle of onshore wells, including fracking operations, and guide how we protect and respect people and the environment.
Our drilling and completion design and operating practices are guided by a robust and carefully defined set of internal well management standards. Additionally, we follow industry best practices to ensure onshore well integrity, engineering wells for specific geology and purpose with appropriate reviews and approvals. Well casing, the steel pipe cemented into the ground at various stages during the drilling of a well, provides the primary layers of protection between the oil and gas being produced and the rock formations transected by the well.
“Cementing” is the process of placing a cement sheath around casing strings in a well. It is a critical part of well construction and is a fully designed and engineered process. Cement fills the space between the well casing and the drilled wellbore, isolating different subsurface zones and providing structural support for the well. Cement is fundamental in maintaining integrity throughout the life of the well and helps protect casing from corrosion.
The ConocoPhillips Wells Excellence Cementing Manual provides the minimum global requirements for all ConocoPhillips operated wells, providing guidance based on industry best practices and following American Petroleum Institute cement testing methods.
We provide for zonal isolation through careful consideration of such factors as annular clearance and casing centralization, proper wellbore conditioning, and the use of American Petroleum Institute cement blends proven to deliver long-term cement integrity. Cement bond logs, ultrasonic cement evaluation tools or wireline temperature surveys are also utilized to verify proper cement placement when required.
Various types of mechanical integrity tests are used to assess well integrity and seals over the productive life of the well. Operating pressure limits are established and casing strings are monitored to ensure that well integrity concerns, such as leaks, are quickly detected and appropriately addressed.
Yes. Our U.S. gas wells have been completed using green completions even before regulatory requirements were implemented. We actively work to reduce the emission of GHGs by reducing the venting and flaring of methane gas and comply with regulatory requirements such as the U.S. Environmental Protection Agency's air pollution standards for the oil and natural gas industry - 40 CFR 60, Subpart OOOO, known as “Quad O” - that mandate green completions for gas wells.
Our U.S. Lower 48 business unit has carried out energy efficiency improvements through greater utilization of photovoltaic solar panels on field equipment and optimizing compression in the San Juan Basin, where we are now using solar-powered chemical injection units in place of gas-powered pumps on some wells, thus reducing emissions and fuel use. Additionally, we work with our service providers to evaluate alternative energy sources for well pad operations.
We have used alternative fuel sources such as CNG/LNG, field natural gas and co-op electrical to power drilling and completion engines where feasible to reduce air emissions and reduce traffic. Our operations near the Little Missouri State Park in the Bakken play is just one example where we used power from a local utility rather than generating power with diesel driven generators to reduce noise and emissions.
Our approach to groundwater is risk-based and begins with considering our internal Guidance for Groundwater Baseline Assessment and Monitoring. We conduct groundwater quality assessments where it is determined that a baseline risk assessment will be informative to drilling and completion activities and where such data is required by law.
During drilling activities, groundwater protection is one of the most important objectives. To isolate and protect freshwater zones throughout the life of the well, we design and construct new wells with multiple barriers of steel casing and cement. We closely monitor system pressures during drilling and completion activities. When drilling through freshwater zones, we use air or freshwater-based fluids to prevent water contamination. We hold fluids recovered from hydraulic fracturing in tanks or lined pits and manage them in accordance with government-approved methods to ensure safety and environmental protection.
In addition to protecting groundwater, ConocoPhillips also measures, monitors and works to reduce our freshwater usage. We achieve this by finding opportunities to use brackish groundwater, and to recycle produced water when economically feasible.
Water and sand comprise up to 99.5 percent of the fracturing fluid mixture. Water is used to fracture the formation containing trapped oil or natural gas resources and acts as the carrier fluid for the chemical additives and proppant (typically sand). Chemical additives are necessary to reduce fluid friction, kill bacteria that are present in the formation and enhance the fluid’s ability to transport the propping agent. Since we partner with suppliers and contractors when drilling and completing wells, we are implementing a supplier registration, pre-qualification and compliance management system that includes data and information collection on vendor management practices for employing environmental friendly chemicals in drilling and cementing systems and for responsible sourcing of proppants. Service companies develop customized hydraulic fracturing fluids to more efficiently induce and maintain productive fractures. These frack fluids have unique characteristics, and therefore, the exact concentrations of some additives can be protected as proprietary information. While many states now have statutes or regulations that require public disclosure of the chemicals used in hydraulic fracturing utilizing FracFocus, in some states regulations or statutes provide the option for service companies to classify the exact fracture fluid chemistry as business confidential. The identity of some chemicals and their exact concentrations may be protected by confidential business information considerations and not disclosed on FracFocus. Together with our service providers for the U.S. Lower 48 business unit we are committed to not use diesel fuel or BTEX (Benzene, Toluene, Ethylbenzene, and Xylene) in fracking fluid.
We work with our service companies to replace chemicals classified as toxic whenever feasible.
In the Lower 48 Business Unit, audio, visual, and olfactory (AVO) inspections are routinely performed as part of operator responsibilities to identify leaks or other issues. Where required optical gas imaging (OGI) camera inspections are conducted and the repairs completed as necessary to meet specific permit and/or regulatory requirements. ConocoPhillips has also developed a voluntary OGI leak detection and repair program. We prioritize implementation of the program for locations with control devices and at compressor stations. The program requires that these locations are inspected on a periodic frequency (typically annual).