Oil and Gas at Your Door? (2005 Edition) - Earthworks

Oil and Gas Development and Impacts
capture and more fully combust the waste gases. The tanks can be carried from site to
site. This practice avoids the costs associated with excavating and reclaiming flare pits,
and avoids the potential liability associated with cleaning up soils contaminated by flaring.
FIGURE I-40. FLARE TANKS REDUCE HAZARDOUS EMISSIONS BY MORE FULLY COMBUSTING WASTE GASES.
Source: Wellco Energy Services, Inc. 346
5. Waste minimization during drilling operations. The state of Texas has produced a document
Waste Minimization in the Oil Field that provides a general overview of waste minimization
techniques for wastes arising from oil and gas operations, including drilling operations.
347 The document also provides case studies of successful waste minimization projects
and a bibliography of useful technical references. The document includes dozens of
examples of alternative drilling practices, such as:
• Product substitution. Replacing conventional, toxic products with less toxic, yet effective,
substitutes. For example, companies are substituting low toxicity glycols, synthetic
hydrocarbons, polymers, and esters for conventional oil-based drilling fluids.
The use of these substitutes eliminates the generation of oil-contaminated cuttings
and other contamination by the oil-based fluid and decreases concerns related to site
clean-up when the well is abandoned. Drilling engineers have published numerous
technical papers that describe the successful application of substitute drilling fluids.
In many instances, this substitution has resulted in significant cost savings.
Similarly, companies have designed alternatives to the conventional water- and chemical-based
hydraulic fracturing techniques, by substituting carbon dioxide for the more
common and more toxic fracing fluids.
• Process or procedural modifications. For example, in the past few years the drilling
industry has improved the technology of slim hole drilling. If feasible, slim hole drilling
reduces the volume of wastes (e.g., drilling fluid and the drill cuttings) produced during
drilling. The total cost of a slim hole drilling operation may be considerably less
than for conventional hole sizes, and smaller casing is required, which may help
reduce the total cost of the operation.
• Reduction in water use. For example, companies can reclaim water from waste drilling
fluids by using mechanical or chemical separation techniques such as large bowl centrifuges,
hydrocyclones, and/or chemical flocculants. The reclaimed water may then be
reused, thus reducing the demand on, and cost of, new water sources. Dewatering of
wastes may also result in a reduction of the volume of drilling waste to be managed,
thus saving waste management costs, easing site closure concerns and costs, and
reducing future potential liability concerns.
• Preventative maintenance. For example, chemicals and materials should be stored so
that they are not in contact with the ground (e.g., stored on wooden pallets), or exposed
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