Drilling with compressed air continues to enjoy vast popularity. It is often the application of choice in dry, hard rock because the drilling fluid medium is inexpensive and, compared to water or weighted drilling mud, respectable rates of penetration can be achieved. In terms of economic considerations with respect to drilling fluid expenditures, air drilling has virtually no equal. However air drilling is not without its impediments; not the least of which is its reactivity with hydrocarbons.

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