Analysis of Environmental Aspects of Exploiting Unconventional Reservoirs
Authors: Wilson Adam 
Published: October 2018

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 185546, “Importance of the Study of Environmental Aspects in the Exploitation of Unconventional Reservoirs for Risk Assessment of the Activity in Argentina,” by M.A. De La Zerda and E. Erdmann, SPE, Instituto Tecnologico de Buenos Aires, and R. Sarandon, Universidad Nacional de La Plata, prepared for the 2017 SPE Latin America and Caribbean Petroleum Engineering Conference, Buenos Aires, 17–19 May. The paper has not been peer reviewed.

This paper presents an analysis of the environmental aspects of the exploitation of unconventional reservoirs in order to evaluate the risk of the activity. To this end, the existing normative framework, the natural and socioeconomic conditions of the area, and the applicable technologies are considered. The novelty of this work is the analysis of the factors that determine the environmental risk including technologies, environmental conditions at the site, and the legal context in the region.

Methodology

A review and comparative analysis was performed of the general and environmental regulatory framework in Argentina where unconventional exploration or exploitation activities are carried out. This analysis was completed with a review of the effluent-management strategy, comparing it with criteria used by other countries, especially the United States.

In order to perform a preliminary evaluation of the environmental risk, a structured, conceptual, and qualitative analysis was conducted in specific sectors corresponding to each of the areas of exploration and exploitation.

Depending on the information available at the regional level, and based on the analysis of satellite images, each site was characterized according to 20 parameters. Parameters 1–9 represented the natural physical environment, 10–13 represented biotic or ecological factors, and 14–20 represented human environment:

Temperature—Low temperatures result in a longer time for recovery; biochemical processes are slower. Extreme temperatures result in operational technological challenges.

Precipitation—High levels of precipitation make the land less stable, raising the risk of water erosion, landslides, torrential phenomena, floods, and other extreme events.

Contour—Abrupt land contour changes increase the risk of erosion, landslide, or mass removal.

Wind—Frequent and intense winds increase the dispersion of atmospheric pollutants, especially particulate matter, and can lead to potential contamination of populated or productive areas.

Water Depth—Deeper groundwater increases the risk of contamination by intentional or accidental spills, as well as contact with hazardous substances.

Wetlands—The proximity to wetlands (e.g., streams, rivers, lakes, and ponds) increases the risk of contamination by intentional or accidental spill.

Water Resources—The availability of water resources affects hydraulic-fracturing operations.

Land Quality—High-quality land results in greater risk to the environment from an accidental spill or degradation from occupation, erosion, or contamination.

Hydrologic Regime—Increased intermittence of the watercourse increases the risk of torrential activity, erosion, and flooding, raising the risk of accidents during the operation phase.