Waste Management

Exploration and Production Waste

Specific types of wastes are produced during oil and natural gas exploration and production operations, the largest portion of which is naturally occurring material removed from the subsurface. Exploration and Production wastes fall into four primary categories:

Produced water -- the saline water brought to the surface with oil and gas;
Drilling waste -- the rock cuttings and fluids that are produced from drilling a new wellbore into the subsurface;
Associated wastes -- a broad category of a variety of small volume waste streams that encompasses all other types of wastes uniquely "associated" with oil and natural gas production; and
Industrial wastes -- these are the wastes that are not uniquely associated with oil and gas production that are nonetheless generated at well sites. Examples include paint, spent solvents, and packaging materials.

The first three categories of E&P wastes are managed under special provisions of the Resource Conservation and Recovery Act (RCRA) that recognize the unique nature of these waste streams. Requirements for the management and disposal of these three categories of wastes are set by state regulations. The latter category of wastes, industrial wastes, are managed and disposed under the same set of state and federal regulations that apply to such wastes from any other industry.

Because exploration and production in the United States takes place at over 860,000 separate sites across 33 states, no single mechanism exists for tabulating the volume of wastes generated by the industry. Nevertheless, it is important to the industry to understand its waste volumes and how they are managed.

API has conducted statistical surveys of the industry to gather information about E&P wastes -- most recently for 1995. This survey updated a survey conducted a decade earlier covering 1985. Both studies examined the volume of produced water, drilling waste, and associated wastes generated as a result of exploration and production of oil and gas in the U.S., and how those wastes were managed and disposed.

The total volume of waste generated annually by the oil and gas industry decreased substantially over the decade between 1985 and 1995, as shown by the table below:

Million barrels per year	1995	1985
Produced water	17,910.7	21,000
Drilling waste	148.7	361
Associated wastes(a)	20.6	12
Total	18,080	21,373
(a) In 1985, completion fluids were excluded from associated wastes. In 1995, completion fluids were included, and accounted for 43% of the total volume of associated wastes.

E&P Waste Disposal Practices (Thumbnail)

The management and disposal of E&P wastes also shows a trend toward less discharge and more reuse, recycling, and reclamation. Because produced water accounts for over 98% of total E&P wastes, it is not surprising that the largest share of wastes are injected to the subsurface. This injection may be back to the subsurface formation from which it was removed (used for enhanced oil recovery) or for disposal in specially selected formations underground. All types of injection must follow extensive government regulations.

For more information about oil and gas exploration and production wastes and how they are managed, copies of the reports on API's 1995 and 1985 surveys of E&P wastes and waste management may be printed or downloaded (as pdf files) using the links below.

Overview of Exploration and Production Waste Management Volumes and Waste Management Practices in the United States
May 2000

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Size: 900 KB | Date: June 7, 2007 | License: Free

API 1985 Production Waste Survey -- Statistical Analysis and Survey Results, October 1987

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Size: 7.7 MB | Date: June 7, 2007 | License: Free