Water management is a major emerging issue for the international petroleum industry and increased focus of regulatory attention. Issues include the utilization of fresh water required to sustain our industry as well as the handling of produced water, waste water treatment and recycle. Current practices and specific areas for improvement will be addressed.
Water is vital to all life on earth. Its central role in the maintenance of ecosystems, and our complete dependence on it to sustain life, make it a unique resource. There are no substitutes. Water is also an integral part of almost every aspect of petroleum industry operations. The exploration, production refining and distribution of petroleum products all produce and interact with vast quantities of water. The environmental implications of this relationship are significant, and pose one of the industry's most important challenges: maintaining supplies of dependable and affordable energy for an expanding world economy, while protecting water resources and the ecosystems which they sustain.
In the earliest stages of petroleum exploration, activities such as seismic surveys and well drilling may impact on surface and groundwater resources. Proper and complete environmental impact studies, and the mitigation measures they contain, can greatly alleviate negative consequences. Well drilling and completion strategies should include measures to protect high value aquifers and in particular shallow groundwater, which may interact with surface water bodies such as lakes, rivers and wetlands. Wastes generated during exploration, including DST (drill stem test) returns, completion fluids and camp wastes should be properly managed to prevent contamination of surface water or groundwater. Drilling of water supply wells for exploration camps or drilling needs should adhere to best practice, protecting aquifers from cross-completion and surface contamination.
As fields are discovered and move to production, new issues arise, in particular the need to safely dispose of large volumes of produced formation water. Subsurface re-injection options, often employed, should be examined carefully to ensure that contamination of high quality aquifers does not occur. Injection into formations that eventually discharge to surface, even at distance, should not occur without careful evaluation at the planning stage. Other production issues include the possibility of oil spills from pipelines or tanks, and poor waste management at production facilities, which may impact shallow groundwater and surface water resources. Drilling sumps, pits and wellheads may also contribute to water contamination.
Downstream activities, from refining to distribution to sales, all have significant potential to impact surface water, and notably, groundwater. Spills and leaks of refined hydrocarbon products can result in accumulations of non-aqueous phase liquids (NAPLs) within the subsurface. When NAPLs come in contact with groundwater, plumes of dissolved phase compounds such as benzene and other aromatics may develop. Such plumes may migrate considerable distances and have the potential to render groundwater unfit for human consumption. In developed countries, significant expenditure and effort has been devoted to the problems associated with leaking underground fuel storage tanks. These issues continue to present real challenges for the industry, including more commonly now in developing countries.
