Expert-based development of a standard in CO2 sequestration monitoring technology

Bureau of Economic Geolog

Oil & Gas Water Use in Texas: Update to the 2011 Mining Water Use Report

In Spring 2012, we undertook an update of the hydraulic fracturing sections of the TWDB-sponsored report titled “Current and Projected Water Use in the Texas Mining and Oil and Gas Industry” that we published in June 2011 (Nicot et al., 2011). The 2011 report provided estimated county-level water use in the oil and gas industry in 2008 and projections to 2060. This 2012 update was prompted by two main events: (1) a major shift of the oil and gas industry from gas to oil production, displacing production centers across the state and impacting county-level amounts; (2) rapid development of technological advances, resulting in more common reuse and in the ability to use more brackish water. The timely update was enabled by a faster than anticipated development, translating into abundant statistical data sets from which to derive projections, and by an increased willingness of the industry to participate in providing detailed information about water use in its operations. This document follows the same methodology as the 2011 report but differs from it in two ways. Our current update clearly distinguishes between water use and water consumption. The 2011 report does not include reuse from neighboring hydraulic fracturing jobs, recycling from other industry operations or other treatment plants, and use of brackish water. Our update also presents three scenarios: high, low, and most likely water use and consumption with a focus on water consumption. This update has been reviewed by the TWDB and should supersede oil and gas industry projections from the 2011 report.Bureau of Economic Geolog

Impact of CO2 Impurities on Storage Performance and Assurance - Report on Tasks 3 and 4 (Geochemistry) Prepared for: CO2 Capture Project (Phase III)

This document presents the results of Tasks 3 and 4 out of 5 tasks, focusing on the geochemical impacts of impurities in the CO2 stream. Tasks 1 and 2 were dedicated to examining the effects on flow behavior. The impurities primarily consist of N2, O2, and Ar, with several minor reactive species potentially added, including CO, H2, SOx, and other trace gases. The research methodology involved laboratory autoclave experiments combined with geochemical numerical modeling. The autoclave utilized in the experiments is a 250-ml reactor capable of withstanding temperatures up to 150°C and pressures up to 400 bars, simulating conditions observed in reservoirs at depths of up to 12,000 ft. Pressure and temperature were automatically controlled by a computer, and the system allowed for water sampling during the experiments. Typically, 10 to 15 samples of the solution were collected during each experiment, which lasted 5 to 10 days. Rock samples were exposed to either a supercritical mixture of CO2 and O2 (generally 3.5% molar) or pure supercritical CO2, filling approximately half of the reactor cell. The other half of the cell contained a single core fragment or several large fragments (~8g total) submerged in approximately 140 ml of synthetic brine (~1.88 mol NaCl, corresponding to a TDS of 100,000-110,000 mg/L). The study analyzed three types of clastic rock samples: 1. A "dirty sandstone" of Miocene age obtained from a deep well in the shallow offshore region off the Texas coast. 2. A relatively clean sandstone from the Cretaceous-age Cardium Formation in Alberta. 3. A chlorite-rich sandstone from the Tuscaloosa Formation in Mississippi, sourced from the Cranfield site, which has been extensively studied by BEG for several years.Bureau of Economic Geolog

Ground Water Surface Water Interactions in Texas

Groundwater-surface water interactions need to be evaluated to optimize water management in Texas. This study provides an overview of the impacts of groundwater-surface water (gw-sw) interactions on water quality and water quantity using available data. A literature review was conducted to assess the status of knowledge of gw-sw interactions. A total of 300 references were compiled. References were subdivided into those related to water quantity issues, water quality including point and nonpoint sources of contamination, and methods such as seepage and temperature approaches and modeling analyses. Additional topics covered by the reference list include impacts of climate variability and land use/land cover changes on gw-sw interactions and ecological issues. A compilation of data and information sources for assessing gw-sw interactions in Texas is also provided. This section includes web links to online report catalogs and databases and a listing of offline reports and catalogs provided by state and federal agencies.Bureau of Economic Geolog

Oidium neolycopersici: Intra-specific variability inferred from AFLP analysis and relationship with closely related powdery mildew fungi infecting various plant species

Previous works indicated a considerable variation in the pathogenicity, virulence, and host range of Oidium neolycopersici isolates causing tomato powdery mildew epidemics in many parts of the world. In this study, rDNA internal transcribed spacer (ITS) sequences, and amplified fragment length polymorphism (AFLP) patterns were analyzed in 17 O. neolycopersici samples collected in Europe, North America, and Japan, including those which overcame some of the tomato major resistance genes. The ITS sequences were identical in all 10 samples tested and were also identical to ITS sequences of eight previously studied O. neolycopersici specimens. The AFLP analysis revealed a high genetic diversity in O. neolycopersici and indicated that all 17 samples represented different genotypes. This might suggest the existence of either a yet unrevealed sexual reproduction or other genetic mechanisms that maintain a high genetic variability in O. neolycopersici. No clear correlation was found between the virulence and the AFLP patterns of the O. neolycopersici isolates studied. The relationship between O. neolycopersici and powdery mildew anamorphs infecting Aquilegia vulgaris, Chelidonium majus, Passiflora caerulea, and Sedum alboroseum was also investigated. These anamorphs are morphologically indistinguishable from and phylogenetically closely related to O. neolycopersici. The cross-inoculation tests and the analyses of ITS sequences and AFLP patterns jointly indicated that the powdery mildew anamorphs collected from the above mentioned plant species all represent distinct, but closely related species according to the phylogenetic species recognition. All these species were pathogenic only to their original host plant species, except O. neolycopersici which infected S. alboroseum, tobacco, petunia, and Arabidopsis thaliana, in addition to tomato, in cross-inoculation tests. This is the first genome-wide study that investigates the relationships among powdery mildews that are closely related based on ITS sequences and morphology. The results indicate that morphologically indistinguishable powdery mildews that differed in only one to five single nucleotide positions in their ITS region are to be considered as different taxa with distinct host ranges

Monitoring Stray Natural Gas in Groundwater With Dissolved Nitrogen. An Example From Parker County, Texas

Concern that hydraulic fracturing and natural gas production contaminates groundwater requires techniques to attribute and estimate methane flux. Although dissolved alkane and noble gas chemistry may distinguish thermogenic and microbial methane, low solubility and concentration of methane in atmosphereâ equilibrated groundwater precludes the use of methane to differentiate locations affected by high and low flux of stray methane. We present a method to estimate stray gas infiltration into groundwater using dissolved nitrogen. Due to the high concentration of nitrogen in atmosphericâ recharged groundwater and low concentration in natural gas, dissolved nitrogen in groundwater is much less sensitive to change than dissolved methane and may differentiate groundwater affected high and low flux of stray natural gas. We report alkane and nitrogen chemistry from shallow groundwater wells and eight natural gas production wells in the Barnett Shale footprint to attribute methane and estimate mixing ratios of thermogenic natural gas to groundwater. Most groundwater wells have trace to nondetect concentrations of methane. A cluster of groundwater wells have greater than 10 mg/L dissolved methane concentrations with alkane chemistries similar to natural gas from the Barnett Shale and/or shallower Strawn Group suggesting that localized migration of natural gas occurred. Twoâ component mixing models constructed with dissolved nitrogen concentrations and isotope values identify three wells that were likely affected by a large influx of natural gas with gas:water mixing ratios approaching 1:5. Most groundwater wells, even those with greater than 10â mg/L methane, have dissolved nitrogen chemistry typical of atmosphereâ equilibrated groundwater suggesting natural gas:water mixing ratios smaller than 1:20.Plain Language SummaryHydraulic fracturing, horizontal drilling, and associated natural gas production have dramatically changed the energy landscape across America over the past 10 years. Along with this renaissance in the energy sector has come public concern that hydraulic fracturing may contaminate groundwater. In this study we measure the chemistry of dissolved gas from shallow groundwater wells located above the Barnett Shale natural gas play, a tight gas reservoir located west of the Dallasâ Fort Worth Metroplex. We compare groundwater chemistry results to natural gas chemistry results from nearby production wells. Most groundwater wells have trace to nondetectible concentrations of methane, consistent with no measurable infiltration of natural gas into shallow groundwater. A cluster of groundwater wells have greater than 10 mg/L dissolved methane concentrations with alkane chemistries similar to natural gas. Using dissolved nitrogen and alkane concentrations and their stable isotope ratios in combination with chemical mixing models, we conclude that natural gas transported from the shallower Strawn Group affected these groundwater wells rather than natural gas from the deeper Barnett Shale, which is the target of hydraulic fracturing in this area. These results suggest that hydraulic fracturing has not affected shallow groundwater drinking sources in this area.Key PointsDissolved nitrogen in groundwater provides a means to differentiate highâ and lowâ flux infiltration of stray gasNitrogen concentrations and isotope values may attribute natural gas sourcesPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146362/1/wrcr23523.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146362/2/wrcr23523_am.pd

Understanding and Managing Environmental Roadblocks to Shale Gas Development: An Analysis of Shallow Gas, NORM, and Trace Metals

The main objective of the project was to document occurrences of shallow gas in fresh-water aquifers in Texas either dissolved or free phase and identify controlling processes. A secondary somewhat independent objective was to contribute to the understanding of the nature and variability of flowback and produced water associated with hydraulic fracturing in the context of rock-water interactions. We undertook a large sampling campaign of aquifers in the footprint of major Texas plays (900+ water samples): Barnett in north-central Texas (555 unique locations), Eagle Ford in South Texas (118 unique locations), Haynesville in East Texas (70 unique locations), and in the Delaware Basin of West Texas (40 unique locations). Most of the wells (2/3) are relatively shallow residential wells sampled at or as close as possible to the wellhead but many wells are irrigation, municipal, or rig-supply wells. All samples were analyzed for major ions, dissolved gases, and, when CH4 > 0.1 mg/L, for methane and light alkanes carbon isotopes and trace elements. The vast majority of wells show some measurable methane and ~100 wells show methane > 0.1 mg/L. A total of ~20 wells have methane concentrations > 10 mg/L, these high concentrations were observed in all plays and present at least a thermogenic component. Some wells, generally with a < 10 mg/L concentration, show a clear microbial origin for methane. A number of samples show mixing between the two origins but also more complex behavior such as methane degradation. Samples with thermogenic methane are generally spatially organized in clusters. Overall the source of the dissolved methane is likely natural sourced from shallow natural gas accumulations in the Barnett Shale, lignite beds associated with a fault in the Haynesville shale, and lignite and degradation of oil and deep organic matter associated with a fractured zone in the Eagle Ford Shale. The Delaware Basin samples show no dissolved methane other than associated to a recent blowout. We also performed autoclave experiments in controlled conditions exposing shale core fragments to various fluids, examining reacted and unreacted rocks and documenting chemical composition of the evolving fluid through time. The experiments demonstrated that shales undergo typical geochemical processes during hydraulic fracturing such as carbonate and feldspar dissolution as well as ion exchange resulting in an increase in dissolved solids. Observations suggest that rock permeability is increased two to three-fold and that porosity is increased by 50%. Baseline sampling as it is currently practiced is not sufficient to resolve ambiguity of the source of the dissolved methane even if of thermogenic origin because it still could be natural. Additional analyses such as noble gases and isotopes are needed to better constrain origin of the methane.Bureau of Economic Geolog

Housekeeping genes for quantitative expression studies in the three-spined stickleback Gasterosteus aculeatus

Background During the last years the quantification of immune response under immunological challenges, e.g. parasitation, has been a major focus of research. In this context, the expression of immune response genes in teleost fish has been surveyed for scientific and commercial purposes. Despite the fact that it was shown in teleostei and other taxa that the gene for beta-actin is not the most stably expressed housekeeping gene (HKG), depending on the tissue and experimental treatment, the gene has been us Results To establish a reliable method for the measurement of immune gene expression in Gasterosteus aculeatus, sequences from the now available genome database and an EST library of the same species were used to select oligonucleotide primers for HKG, in order to perform quantitative reverse-transcription (RT) PCR. The expression stability of ten candidate reference genes was evaluated in three different tissues, and in five parasite treatment groups, using the three algorithms BestKeeper, geNorm and N Conclusion As they were the most stably expressed genes in all tissues examined, we suggest using the genes for the L13a ribosomal binding protein and ubiquitin as alternative or additional reference genes in expression analysis in Gasterosteus aculeatus.