SPE Drilling & Completion
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Summary

The process of gas development is intensive and involves risk to the environment. Statistics confirm that 0.5 to 1% of wells drilled result in a blowout. Causes of these exploration risks are identified as violations of environmental laws enforced by the Pennsylvania Department of Environmental Protections (DEP), operational pollution (accidental spills and leaks), and operator's policy. In addressing this concern, a risk-assessment methodology was used to evaluate all violations by operators in the State of Pennsylvania from January 2008 to November 2010, by use of Statistical Analysis Software (SAS). The most significant causes of environmental damage and risk were determined by use of the doubly repeated measure analysis of covariance (ANCOVA). The category effect and interaction effect were used to prove the usefulness of the developed model, which helps explain the safety level of the locality. There were a total of 2,601 violations between 2008 and 2010 committed by 65 different operators in the Marcellus Shale, out of which only 27 of the operators showed significance difference based on environmentally damaging violations (ranked 5 to 10). A statistical comparison was made to understand the difference between the operators based on the 2,601 total violations. The most significant incidents are ranked [on the basis of Borda count (Saari 1985)] 3, 5, 9, 10, which accounts for 67% of all the violations. These data reflect several environmental concerns that are currently prevalent in the Marcellus-shale area. This research identifies environmental incidents, causes and effects of exploration risk, and safety impediments in the Marcellus gas play. It also presents guidelines for feasible options to minimize environmental risks and consequently increase the degree of safety in the area. Recommendations on how to mitigate these impending problems are presented.

© 2012. Society of Petroleum Engineers

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History

• Original manuscript received: 10 February 2012
• Revised manuscript received: 13 September 2012
• Manuscript approved: 1 October 2012
• Published online: 14 December 2012