Dataset Information

Shale oil production and groundwater: What can we learn from produced water data?

ABSTRACT: As oil production in the Permian Basin surges, the impact of shale production on groundwater resources has become a growing concern. Most existing studies focus on the impact of shale production on shallow freshwater aquifers. There is little understanding of the shale development's impact on other groundwater resources (e.g., deep carbonate aquifers and deep basin meteoric aquifers). The possible natural hydraulic connections between shallow aquifers and formation water suggest such an impact can be consequential. This study explores the relationship between shale production and groundwater using produced water (PW) samples from active unconventional oil wells. Focusing on the most productive portion of the Permian Basin-the four-county region in Southeast New Mexico between 2007 and 2016, a large produced water dataset allows us to analyze the conditional correlations between shale oil production and PW constituents. The results suggest that (1) expanding from primarily conventional wells to unconventional wells during the recent shale boom has led to dramatic increases of the TDS, chloride, sodium, and calcium levels in groundwater (i.e., producing formation). (2) Nearby oil well density positively correlates with the TDS, chloride, and sodium levels in the PW samples.

SUBMITTER: Wang H

PROVIDER: S-EPMC8087075 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Microbial activity in the produced water from hydraulically fractured oil and gas wells may potentially interfere with hydrocarbon production and cause damage to the well and surface infrastructure via corrosion, sulfide release, and fouling. In this study, we surveyed the microbial abundance and community structure of produced water sampled from 42 Marcellus Shale wells in southwestern Pennsylvania (well age ranged from 150 to 1,846 days) to better understand the microbial diversity of produced water. We sequenced the V4 region of the 16S rRNA gene to assess taxonomy and utilized quantitative PCR (qPCR) to evaluate the microbial abundance across all 42 produced water samples. Bacteria of the order Halanaerobiales were found to be the most abundant organisms in the majority of the produced water samples, emphasizing their previously suggested role in hydraulic fracturing-related microbial activity. Statistical analyses identified correlations between well age and biocide formulation and the microbial community, in particular, the relative abundance of Halanaerobiales We further investigated the role of members of the order Halanaerobiales in produced water by reconstructing and annotating a Halanaerobium draft genome (named MDAL1), using shotgun metagenomic sequencing and metagenomic binning. The recovered draft genome was found to be closely related to the species H. congolense, an oil field isolate, and Halanaerobium sp. strain T82-1, also recovered from hydraulic fracturing produced water. Reconstruction of metabolic pathways revealed Halanaerobium sp. strain MDAL1 to have the potential for acid production, thiosulfate reduction, and biofilm formation, suggesting it to have the ability to contribute to corrosion, souring, and biofouling events in the hydraulic fracturing infrastructure.IMPORTANCE There are an estimated 15,000 unconventional gas wells in the Marcellus Shale region, each generating up to 8,000 liters of hypersaline produced water per day throughout its lifetime (K. Gregory, R. Vidic, and D. Dzombak, Elements 7:181-186, 2011, https://doi.org/10.2113/gselements.7.3.181; J. Arthur, B. Bohm, and M. Layne, Gulf Coast Assoc Geol Soc Trans 59:49-59, 2009; https://www.marcellusgas.org/index.php). Microbial activity in produced waters could lead to issues with corrosion, fouling, and souring, potentially interfering with hydraulic fracturing operations. Previous studies have found microorganisms contributing to corrosion, fouling, and souring to be abundant across produced water samples from hydraulically fractured wells; however, these findings were based on a limited number of samples and well sites. In this study, we investigated the microbial community structure in produced water samples from 42 unconventional Marcellus Shale wells, confirming the dominance of the genus Halanaerobium in produced water and its metabolic potential for acid and sulfide production and biofilm formation.

Project description:Microbial communities in shale oil fields are still poorly known. We obtained samples of injection, produced and facility waters from a Bakken shale oil field in Saskatchewan, Canada with a resident temperature of 60°C. The injection water had a lower salinity (0.7 Meq of NaCl) than produced or facility waters (0.6-3.6 Meq of NaCl). Salinities of the latter decreased with time, likely due to injection of low salinity water, which had 15-30 mM sulfate. Batch cultures of field samples showed sulfate-reducing and nitrate-reducing bacteria activities at different salinities (0, 0.5, 0.75, 1.0, 1.5, and 2.5 M NaCl). Notably, at high salinity nitrite accumulated, which was not observed at low salinity, indicating potential for nitrate-mediated souring control at high salinity. Continuous culture chemostats were established in media with volatile fatty acids (a mixture of acetate, propionate and butyrate) or lactate as electron donor and nitrate or sulfate as electron acceptor at 0.5 to 2.5 M NaCl. Microbial community analyses of these cultures indicated high proportions of Halanaerobium, Desulfovermiculus, Halomonas, and Marinobacter in cultures at 2.5 M NaCl, whereas Desulfovibrio, Geoalkalibacter, and Dethiosulfatibacter were dominant at 0.5 M NaCl. Use of bioreactors to study the effect of nitrate injection on sulfate reduction showed that accumulation of nitrite inhibited SRB activity at 2.5 M but not at 0.5 M NaCl. High proportions of Halanaerobium and Desulfovermiculus were found at 2.5 M NaCl in the absence of nitrate, whereas high proportions of Halomonas and no SRB were found in the presence of nitrate. A diverse microbial community dominated by the SRB Desulfovibrio was observed at 0.5 M NaCl both in the presence and absence of nitrate. Our results suggest that nitrate injection can prevent souring provided that the salinity is maintained at a high level. Thus, reinjection of high salinity produced water amended with nitrate maybe be a cost effective method for souring control.

Dataset Information

Shale oil production and groundwater: What can we learn from produced water data?

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets