Abstract
The process of drilling oil and gas wells generates large volumes of drill cuttings and spent muds. The American Petroleum Institute estimates that in 1995, about 150 million barrels of drilling waste was generated from onshore wells in the United States alone. Onshore and offshore operators have employed a variety of methods for managing these drilling wastes, depending on what state and federal regulations allow and how costly those options are for the wells in question. In the offshore, the options are limited to discharge, underground injection, and transport back to shore for disposal. Onshore operators have a wider range of options--some wastes are managed onsite while others are removed to offsite commercial disposal facilities. The onshore waste management options employed include landspreading and landfarming, evaporation and burial onsite, underground injection, incineration and other thermal treatment, bioremediation and composting, and reuse and recycling.
Some drilling waste management practices used in the past did not protect the environment and public health to the extent desired and were later prohibited by regulatory agencies. This paper reviews some of those past waste management practices and indicates how wastes are currently being managed. Over time, state and federal regulatory requirements will become stricter, drilling and mud system technologies will advance, and some companies may voluntarily adopt waste management options that have even less environmental impacts that those in use today. The paper also discusses some possible drilling waste management practices that are likely to be employed in the upcoming decade.
