ARE THERE REGULATORY IMPEDIMENTS OR OTHER PROBLEMS ASSOCIATED WITH MAKING BENEFICIAL USE OF THE WATER PUMPED TO THE SURFACE (PRODUCED WATER) FROM OIL AND GAS EXPLORATION?

As the US expands the development of fossil energy resources to meet our ever-increasing demand for energy, we must address the environmental issues associated with this development. For every barrel of oil produced, approximately 10 barrels of brackish or saline water is generated.

In order to drill an oil or gas well, the land must first be cleared and leveled and access roads built. Because water is used in drilling, a source must be located. If there is no natural source nearby, a water well may be drilled. Finally, reserve pits are dug to dispose of rock cuttings and drilling mud. These pits are either dug in the ground and lined to protect the environment or are steel tanks which serve the same purpose.

While the well bore is being drilled, a fluid, called drilling mud, is used to

• lift rock cuttings from the hole,
• keep the drill bit cool and lubricated and
• fill the well bore with fluid to equalize pressure and prevent water or other fluids in underground formations from flowing into the well bore during drilling.

Mud is pumped from the surface down through the inside of the drill pipe, passes through the holes in the drill bit, are travels back to the surface through the space between the drill bit and the walls of the hole. As the drill bit grinds rocks into drill cuttings, these cuttings mix with the mud and are carried to the surface through the mud flow. In order to reuse the mud, the solids must be separated from the mud.

Because of the large volumes of brackish produced water being generated, the treatment of this water is increasingly being looked at as a way to supplement our limited fresh water resources in many parts of the country. Several issues still must be addressed to use this water including:

• Costs of treatment and removal of organic contamination.
• Disposal of the associated concentrate from treatment.
• The treatment level required for beneficial reuse.
• The regulatory and policy issues.

As the US demand for fresh water outstrips available supplies, we are increasingly turning to desalination to create fresh water. Presently we generate over 5 billion gallons a day of produced water. In the past, this water was handled as a waste and reinjected, often at significant cost to the producer. If this water can be retreated as a valuable product that can benefit others, then a once expensive by-product of oil and gas exploration quickly becomes a safe consumer product in a zero-waste environment.