scholarly journals The concept of well integrity in gas production activities

2016 ◽  
Vol 23 (2) ◽  
pp. 205-213 ◽  
Author(s):  
Peter Reichetseder
Keyword(s):  
Drinking Water ◽  
Shale Gas ◽  
Environmental Protection Agency ◽  
Marcellus Shale ◽  
The United States ◽  
Gas Production ◽  
Well Integrity ◽  
Drinking Water Resources ◽  
The Us ◽  
Geological Situation

Abstract Shale gas production in the US, predominantly from the Marcellus shale, has been accused of methane emissions and contaminating drinking water under the suspicion that this is caused by hydraulic fracturing in combination with leaking wells. Misunderstandings of the risks of shale gas production are widespread and are causing communication problems. This paper discusses recent preliminary results from the US Environmental Protection Agency (EPA) draft study, which is revealing fact-based issues: EPA did not find evidence that these mechanisms have led to widespread, systemic impacts on drinking water resources in the United States, which contrasts many broad-brushed statements in media and public. The complex geological situation and extraction history of oil, gas and water in the Marcellus area in Pennsylvania is a good case for learnings and demonstrating the need for proper analysis and taking the right actions to avoid problems. State-of-the-art technology and regulations of proper well integrity are available, and their application will provide a sound basis for shale gas extraction.

scholarly journals Emerging unconventional shale plays in Western Australia

2013 ◽  
Vol 53 (1) ◽  
pp. 313 ◽  
Author(s):  
K. Ameed R. Ghori
Keyword(s):  
Shale Gas ◽  
Early Stage ◽  
Marcellus Shale ◽  
Gas Production ◽  
Source Rocks ◽  
Lower Permian ◽  
Upper Ordovician ◽  
Canning Basin ◽  
The Us ◽  
Gas Potential

Production of shale gas in the US has changed its position from a gas importer to a potential gas exporter. This has stimulated exploration for shale-gas resources in WA. The search started with Woodada Deep–1 (2010) and Arrowsmith–2 (2011) in the Perth Basin to evaluate the shale-gas potential of the Permian Carynginia Formation and the Triassic Kockatea Shale, and Nicolay–1 (2011) in the Canning Basin to evaluate the shale-gas potential of the Ordovician Goldwyer Formation. Estimated total shale-gas potential for these formations is about 288 trillion cubic feet (Tcf). Other petroleum source rocks include the Devonian Gogo and Lower Carboniferous Laurel formations of the Canning Basin, the Lower Permian Wooramel and Byro groups of the onshore Carnarvon Basin, and the Neoproterozoic shales of the Officer Basin. The Canning and Perth basins are producing petroleum, whereas the onshore Carnarvon and Officer basins are not producing, but they have indications for petroleum source rocks, generation, and migration from geochemistry data. Exploration is at a very early stage, and more work is needed to estimate the shale-gas potential of all source rocks and to verify estimated resources. Exploration for shale gas in WA will benefit from new drilling and production techniques and technologies developed during the past 15 years in the US, where more than 102,000 successful gas production wells have been drilled. WA shale-gas plays are stratigraphically and geochemically comparable to producing plays in the Upper Ordovician Utica Shale, Middle Devonian Marcellus Shale and Upper Devonian Bakken Formation, Upper Mississippian Barnett Shale, Upper Jurassic Haynesville-Bossier formations, and Upper Cretaceous Eagle Ford Shale of the US. WA is vastly under-explored and emerging self-sourcing shale plays have revived onshore exploration in the Canning, Carnarvon, and Perth basins.

Remote Site Production of Sterile Purified Water from Available Surface Water

2004 ◽  
Vol 19 (3) ◽  
pp. 266-277 ◽  
Author(s):  
Michael A. Taylor ◽  
Elaine F. Alambra ◽  
John Anes ◽  
Joel Behnke ◽  
Brandusa Enachescu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Environmental Protection Agency ◽  
The United States ◽  
Quality Attributes ◽  
Sterile Water ◽  
Functional Capabilities ◽  
The Us ◽  
Single Use ◽  
Product Water ◽  
States Pharmacopeia

AbstractA water purification and sterilization device was tested for its functional capabilities. Challenge water consisting of potable water augmented with bacteria, endotoxin, virus, suspended solids, and dissociable ions (sodium chloride, lead or arsenic salts) was passed through the device. The product water quality attributes were analyzed. The device demonstrated reduction in bacteria of >7 logs, endotoxin was reduced by >4 logs, virus was reduced by >4 logs, and dissociable ions were reduced by >3 logs. The product water of the device met the limits for a range of chemical entities specified by the United States Pharmacopeia and Association for the Advancement of Medical Instrumentation. The product water met the quality attributes of Sterile Water for Injection, USP, Sterile Purified Water, USP, and the Water for Dialysis. The device provides a logistical advantage in reducing the weight of transport of packaged water by 83% and the cube by 67%. It operates manually by gravity and is disposable after a single use. The device provides an effective alternative to the transport and use of packaged sterile water in remote locations by production of sterile water at the pointof-need using available water. It also is capable of producing safe drinking water following the production of clinical waters. This device has been cleared by the US Food and Drug Administration for production of three liters Sterile Purified Water, USP from Environmental Protection Agency (EPA) grade drinking water.

Potential Regulatory Problems Associated with Atrazine, Cyanazine, and Alachlor in Surface Water Source Drinking Water

1994 ◽  
Vol 8 (4) ◽  
pp. 852-861 ◽  
Author(s):  
Henry Nelson ◽  
R. David Jones
Keyword(s):  
Drinking Water ◽  
Surface Waters ◽  
Environmental Protection Agency ◽  
Water Source ◽  
The United States ◽  
Corn Belt ◽  
Annual Average ◽  
The Us ◽  
Us Epa ◽  
Lakes And Reservoirs

Post-application seasonal (May-July) average concentrations of atrazine, cyanazine, and, to a lesser extent, alachlor sometimes exceed their Maximum Contaminant Levels (MCLs) (3 ug/L for atrazine and 2 ug/L for alachlor) or Maximum Contaminant Level Goal (MCLG) (1 ug/L for cyanazine) in surface waters of the Mississippi and Great Lakes Basins. These three chemicals are among the primary pre-emergent herbicides applied to corn. MCLs and MCLGs are compared to annual average concentrations for regulatory purposes. However, annual average concentrations are much less frequently reported than post-application seasonal averages. In most cases, both seasonal and annual average concentrations are substantially less than the MCLs or MCLG. However, actual and estimated annual mean concentrations occasionally exceed the MCLs or MCLG. Actual or estimated exceedences occur more frequently for atrazine and cyanazine than for alachlor, and may occur more frequently in lakes or reservoirs with long retention times than in streams and rivers. Additional year round data, and data for lakes and reservoirs, are needed to determine the extent to which such exceedences occur throughout the corn belt. The American Water Works Association (AWWA) believes that substantial numbers of Community Water Systems (CWSs) within the corn belt are currently, or will be, in violation of the revised Safe Drinking Water Act (SDWA) with respect to atrazine and cyanazine. They are concerned that such violations could result in numerous CWSs having to implement expensive tertiary treatment systems such as granular activated carbon to decrease herbicide concentrations. The United States Environmental Protection Agency, (US EPA) is continuing to review data on the pesticide concentrations in reservoirs and lakes that registrants have been submitting over the last 18 mo under the 6(a)(2) adverse impact provision of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). The US EPA is also currently using computer modeling and other methods to evaluate potential alternative and/or supplemental herbicides to reduce atrazine use. In June 1992, the US EPA approved revised labeling that is designed to reduce indirect atrazine loadings to surface waters. Additional mitigation methods have been proposed and are being considered.

scholarly journals New Hybrid Approach for Developing Automated Machine Learning Workflows: A Real Case Application in Evaluation of Marcellus Shale Gas Production

Fuels ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 286-303
Author(s):  
Vuong Van Pham ◽  
Ebrahim Fathi ◽  
Fatemeh Belyadi
Keyword(s):  
Artificial Intelligence ◽  
Machine Learning ◽  
Shale Gas ◽  
Field Data ◽  
Marcellus Shale ◽  
Hybrid Approach ◽  
Gas Production ◽  
Bayesian Optimization ◽  
Real Field ◽  
Engineering Problems

The success of machine learning (ML) techniques implemented in different industries heavily rely on operator expertise and domain knowledge, which is used in manually choosing an algorithm and setting up the specific algorithm parameters for a problem. Due to the manual nature of model selection and parameter tuning, it is impossible to quantify or evaluate the quality of this manual process, which in turn limits the ability to perform comparison studies between different algorithms. In this study, we propose a new hybrid approach for developing machine learning workflows to help automated algorithm selection and hyperparameter optimization. The proposed approach provides a robust, reproducible, and unbiased workflow that can be quantified and validated using different scoring metrics. We have used the most common workflows implemented in the application of artificial intelligence (AI) and ML in engineering problems including grid/random search, Bayesian search and optimization, genetic programming, and compared that with our new hybrid approach that includes the integration of Tree-based Pipeline Optimization Tool (TPOT) and Bayesian optimization. The performance of each workflow is quantified using different scoring metrics such as Pearson correlation (i.e., R2 correlation) and Mean Square Error (i.e., MSE). For this purpose, actual field data obtained from 1567 gas wells in Marcellus Shale, with 121 features from reservoir, drilling, completion, stimulation, and operation is tested using different proposed workflows. A proposed new hybrid workflow is then used to evaluate the type well used for evaluation of Marcellus shale gas production. In conclusion, our automated hybrid approach showed significant improvement in comparison to other proposed workflows using both scoring matrices. The new hybrid approach provides a practical tool that supports the automated model and hyperparameter selection, which is tested using real field data that can be implemented in solving different engineering problems using artificial intelligence and machine learning. The new hybrid model is tested in a real field and compared with conventional type wells developed by field engineers. It is found that the type well of the field is very close to P50 predictions of the field, which shows great success in the completion design of the field performed by field engineers. It also shows that the field average production could have been improved by 8% if shorter cluster spacing and higher proppant loading per cluster were used during the frac jobs.

scholarly journals Assessing clarity of message communication for mandated USEPA drinking water quality reports

2015 ◽  
Vol 14 (2) ◽  
pp. 223-235 ◽  
Author(s):  
Katherine Phetxumphou ◽  
Siddhartha Roy ◽  
Brenda M. Davy ◽  
Paul A. Estabrooks ◽  
Wen You ◽  
...  
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Environmental Protection Agency ◽  
Water System ◽  
System Size ◽  
The United States ◽  
National Sample ◽  
Evaluation Tool ◽  
Index Index ◽  
State Of The Science

The United States Environmental Protection Agency mandates that community water systems (CWSs), or drinking water utilities, provide annual consumer confidence reports (CCRs) reporting on water quality, compliance with regulations, source water, and consumer education. While certain report formats are prescribed, there are no criteria ensuring that consumers understand messages in these reports. To assess clarity of message, trained raters evaluated a national sample of 30 CCRs using the Centers for Disease Control Clear Communication Index (Index) indices: (1) Main Message/Call to Action; (2) Language; (3) Information Design; (4) State of the Science; (5) Behavioral Recommendations; (6) Numbers; and (7) Risk. Communication materials are considered qualifying if they achieve a 90% Index score. Overall mean score across CCRs was 50 ± 14% and none scored 90% or higher. CCRs did not differ significantly by water system size. State of the Science (3 ± 15%) and Behavioral Recommendations (77 ± 36%) indices were the lowest and highest, respectively. Only 63% of CCRs explicitly stated if the water was safe to drink according to federal and state standards and regulations. None of the CCRs had passing Index scores, signaling that CWSs are not effectively communicating with their consumers; thus, the Index can serve as an evaluation tool for CCR effectiveness and a guide to improve water quality communications.

scholarly journals An approach for developing a national estimate of waterborne disease due to drinking water and a national estimate model application

2006 ◽  
Vol 4 (S2) ◽  
pp. 201-240 ◽  
Author(s):  
Michael Messner ◽  
Susan Shaw ◽  
Stig Regli ◽  
Ken Rotert ◽  
Valerie Blank ◽  
...  
Keyword(s):  
Drinking Water ◽  
Environmental Protection Agency ◽  
Water System ◽  
Credible Interval ◽  
The United States ◽  
Water Systems ◽  
Epidemiologic Studies ◽  
Incidence Rates ◽  
Waterborne Disease ◽  
Public Water Systems

In this paper, the US Environmental Protection Agency (EPA) presents an approach and a national estimate of drinking water related endemic acute gastrointestinal illness (AGI) that uses information from epidemiologic studies. There have been a limited number of epidemiologic studies that have measured waterborne disease occurrence in the United States. For this analysis, we assume that certain unknown incidence of AGI in each public drinking water system is due to drinking water and that a statistical distribution of the different incidence rates for the population served by each system can be estimated to inform a mean national estimate of AGI illness due to drinking water. Data from public water systems suggest that the incidence rate of AGI due to drinking water may vary by several orders of magnitude. In addition, data from epidemiologic studies show AGI incidence due to drinking water ranging from essentially none (or less than the study detection level) to a rate of 0.26 cases per person-year. Considering these two perspectives collectively, and associated uncertainties, EPA has developed an analytical approach and model for generating a national estimate of annual AGI illness due to drinking water. EPA developed a national estimate of waterborne disease to address, in part, the 1996 Safe Drinking Water Act Amendments. The national estimate uses best available science, but also recognizes gaps in the data to support some of the model assumptions and uncertainties in the estimate. Based on the model presented, EPA estimates a mean incidence of AGI attributable to drinking water of 0.06 cases per year (with a 95% credible interval of 0.02–0.12). The mean estimate represents approximately 8.5% of cases of AGI illness due to all causes among the population served by community water systems. The estimated incidence translates to 16.4 million cases/year among the same population. The estimate illustrates the potential usefulness and challenges of the approach, and provides a focus for discussions of data needs and future study designs. Areas of major uncertainty that currently limit the usefulness of the approach are discussed in the context of the estimate analysis.

Arsenic in drinking water-problems and solutions

1999 ◽  
Vol 40 (2) ◽  
pp. 69-76 ◽  
Author(s):  
T. Viraraghavan ◽  
K. S. Subramanian ◽  
J. A. Aruldoss
Keyword(s):  
United States ◽  
Drinking Water ◽  
Ion Exchange ◽  
Environmental Protection Agency ◽  
The United States ◽  
Activated Alumina ◽  
Column Studies ◽  
Maximum Contaminant Level ◽  
Aluminum Salts ◽  
Contaminant Level

The current United States maximum contaminant level for arsenic in drinking water is set at 50 μg/l. Because of the cancer risks involved, Canada has already lowered the maximum contaminant level to 25 μg/l; the United States Environmental Protection Agency is reviewing the current allowable level for arsenic with a view of lowering it significantly. Various treatment methods have been adopted to remove arsenic from drinking water. These methods include 1) adsorption-coprecipitation using iron and aluminum salts, 2) adsorption on activated alumina, activated carbon, and activated bauxite, 3) reverse osmosis, 4) ion exchange and 5) oxidation followed by filtration. Because of the promise of oxidation-filtration systems, column studies were conducted at the University of Regina to examine oxidation with KMnO4 followed by filtration using manganese greensand and iron-oxide coated sand to examine the removal of arsenic from drinking water; these results were compared with the data from ion exchange studies. These studies demonstrated that As (III) could be reduced from 200 μg/l to below 25 μg/l by the manganese greensand system. In the case of manganese greensand filtration, addition of iron in the ratio of 20:1 was found necessary to achieve this removal.

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