The vast majority of water managed by Occidental is co-produced from hydrocarbon reservoirs with oil and gas. Occidental separates produced water, which is typically saline, from the produced oil and gas, and recycles it in a closed loop by reinjection into mature oil and gas reservoirs as part of its improved oil recovery (IOR) or enhanced oil recovery (EOR) operations. Generally, since the ratio of water to oil and gas extracted increases over time, the extraction, processing, treatment and reinjection of produced water is integral to the design and efficient operation of Occidental's mature oil and gas fields. More recently developed oil and gas fields are in the primary recovery phase and do not require water injection to produce oil and gas. Although operations that use IOR or EOR tend to require more water than operations in the primary recovery phase, Occidental strives to use non-freshwater and recycled or reused sources in place of freshwater for both types of operations. Occidental also obtains water from other non-potable sources, seeking to use the lowest-quality water acceptable for operational activities, and it recycles produced water and wastewater wherever feasible.
Occidental's operations employ advanced production technologies and control systems to enhance the efficiency of resource utilization, including both energy and water. Occidental has implemented major water treatment, reuse and recycling projects in many locations, including the United States and Oman. Occidental also is developing or enhancing water-related technologies. This includes new approaches for the treatment of produced water and wastewater streams, such as a pilot project testing recycled produced water in Hobbs, New Mexico. Occidental continues to evaluate new opportunities for beneficial reuse of water, such as for agricultural and ecological use or ranching operations.
Oil and gas production has unique water management characteristics, such as the production and reinjection of saline water from oil and gas reservoirs, that warrant different consideration compared to other industries and users. A good example is the extensive recycling of large volumes of produced water in a closed loop process back to the hydrocarbon-producing reservoirs from which it originated. Typically, saline produced water that is not recycled is disposed of by injection into deep saltwater reservoirs designated for that purpose by regulatory agencies. In certain locations, produced water has low salinity and can be reused beneficially or discharged to surface water bodies.
Discharge to surface water bodies requires a permit or authorization that sets water quality parameters consistent with the receiving water body and may specify treatment requirements. Additionally, discharges or runoff from Occidental's facilities are evaluated for water quality under other applicable regulations and company policies. In certain locations, such as in the United States and in Colombia, discharges of treated water from Occidental's facilities support riparian (or riverbank) habitats by providing a more consistent flow of freshwater than would otherwise exist.