Importance of the Study of Environmental Aspects in the Exploitation of Unconventional Reservoirs for Risk Assessment of the Activity in Argentina

MARÍA AGUSTINA DE LA ZERDA; RAMIRO SARANDÓN; ELEONORA ERDMANN

Buenos Aires

Congreso; SPE-LACPEC-2017; 2017

SPE

There is an expectation that the exploitation of unconventional hydrocarbons (UH) reservoirs will contributeto satisfy the growing demand of energy, since conventional reservoirs are on a declining stage. However,environmental consequences of the fluids used on unconventional formations are an aspect that has notbeen analyzed in depth in the region. Approximately 10-40% of the volume injected of fracturing fluidsreturns to the surface during the hydraulic fracturing process. The flowback not only includes the chemicalsadded, but may also contain various substances suspended from the formation. This situation demands thedevelopment of appropriate technologies for flowback treatment and the need to consider the existing legalcontext and the ecologic and environmental conditions. The impacts associated with UH activities that needto be analyzed in order to accomplish control and standardization, include those related to consumptionof surface water or groundwater, potential contamination of regional water resources, treatment and finaldisposal of flowback. It is possible to achieve the sustainability of the activity, based on an environmentalanalysis.The objective of this work is the analysis of the environmental aspects associated to the extraction of UH(shale and tight). A comparative analysis of the activity, in a national and international context, includinglegal aspects, technologies used and environmental risk is performed. Additionally, possible mitigationmeasures of environmental risks are evaluated. The study includes the analysis of the existing environmentallegislative framework in different regions where the exploitation of UH could be made. It also includesthe analysis of the actual effluent management strategy. A description of the environmental conditions,including climatic, geological, hydrological and ecological conditions is performed in areas with completionactivities, in order to identify the regions with higher level of environmental risk. Possible technologiesfor flowback water treatment and reuse are analyzed, depending on physicochemical characteristics andvolumes of water. The novelty of this work is the analysis of the factors that determine the environmentalrisk in the extraction of UH, especially in the hydraulic fracturing process, which includes technologies,environmental conditions at the site and the legal context in the region. This allows identify the areas ofhigher and lower level of environmental risk in order to proceed to the identification, implementation anddevelopment of potential mitigation measures to achieve the sustainability of the activity.