Browsing by Subject "Monitoring"

Now showing 1 - 20 of 29

Above-zone pressure monitoring at Cranfield, MS
(7th IEAGHG Monitoring Network Meeting, 2011-06-07) Mickel, Tip; Hovorka, Susan
Analytical model of leakage through fault to overlying formations
(2012) Zeidouni, Mehdi
A fault is generally composed of a fault core surrounded by damage zones and can accommodate both lateral and vertical flow. In this paper we develop an analytical model to evaluate the leakage rate through a fault and corresponding pressure changes in the injection zone and a shallower permeable interval. The leaky fault connects the upper interval and the target zone, which are otherwise separated by a confining layer. We account for both across-fault and upfault flow to honor the general architecture of the fault. We extend the two-formation analytical solution to consider multiple overlying formations with alternating confining layers offset by the fault. The solution methodology involves writing and transforming the coupled governing flow equations successively into the Laplace and Fourier domains and solving the resulting ordinary differential equations. The solution is verified through comparison with existing analytical solutions for bounding cases. Two examples are presented to demonstrate behavior and potential applications of our analytical model.
Application of Numerical Models to Development of the Frio Brine Storage Experiment
(EPA Modeling Workshop, 2005-04-06) Hovorka, Susan D.
Assessing potential impacts of CO2 leakage on shallow groundwater quality in the SECARB Phase III early test site using single-well push-pull tests
(2012 AGU Fall Meeting, 2012-12-03) Yang, Changbing; Mickler, Pat; Reedy, Bob; Scanlon, Bridget
Assessing potential impacts of CO2 upward migration on drinking groundwater quality at the SECARB Phase III early test site
(2013 Carbon Storage RD Project Review Meeting, 2013-08-20) Yang, C.; Hovorka, S. D.; Trevino, R. H.
Borehole Seismic Monitoring of Injected CO2 at the Frio Site
(American Geophysical Union Fall Meeting, 2005-12-05) Daley, T. M.; Myer, L. R.; Hoversten, G. M.; Peterson, J. E.
The recently completed CO2 injection in the brine aquifer of the Frio Formation in southeast Texas provided an opportunity to test borehole seismic monitoring techniques. Designed tests included time-lapse VSP and crosswell surveys which investigated the detectability of CO2 with surface-to-borehole and borehole-to-borehole measurement. The VSP method uses surface seismic sources in conjunction with borehole sensors to measure the seismic properties (such as velocity and reflection strength) in the vicinity of the borehole. By moving the source location, seismic properties can be mapped spatially around the sensor well. A large change (about 70%) in VSP reflection amplitude from the Frio zone was observed. Because of the relatively small amount of CO2 injected (about 1600 tons), and the thin injection interval (about 6 m thick at 1500 m depth), CO2 detectability by the VSP method was not an assumed certainty. The initial result is therefore quite promising for use of the VSP method. The crosswell method measures wave propagation between wells and can tomographically image the interwell volume. The crosswell survey was conducted using the injection well (for sensors) and a nearby monitoring well (for the source) which is about 30 m offset. Crosswell source locations were centered on the injection interval. The crosswell sensors were also centered on the injection interval, which is the 6-7 m thick, upper C sand in the Frio formation which is at a depth of about 1500 m. Initial analysis of the crosswell data shows good quality P- and S-wave direct arrivals. Time-lapse tomographic imaging maps the changes in velocity (up to 1 km/s) due to the CO2 plume.
Calibration and monitoring systems for neutrinoless double beta decay searches in the SuperNEMO experiment
(2021-05-12) Salazar, Ramon Maurilio; Lang, Karol, 1955-; Ritchie, Jack L; Andeen, Timothy R; Gebhardt, Karl
The double beta decay process offers a practical way to learn more about neutrinos. If this decay is observed to occur without the emission of these particles (neutrinoless double beta decay), it would imply that they have a Majorana nature, allowing for the measurement of their effective mass. The SuperNEMO experiment is focused on the search for neutrinoless double beta decay (0νββ) using a unique approach which combines tracking and calorimetry techniques. The SuperNEMO demonstrator will operate for 2.5 years, and the maintenance of its energy resolution throughout this time is a key parameter in its search for the 0νββ process. Two different systems have been developed for this purpose: The Radioactive Source Calibration System (RSCS) and the Light Injection and Monitoring System (LIMS). The RSCS will perform absolute calibrations of the detector at least twice a month through the automatic insertion and retrieval of ²⁰⁷Bi sources, while the LIMS will run daily surveys of the demonstrator using pulsed LED light to monitor the stability of its energy response to within 1%.
Case Study: Monitoring an EOR project to document sequestration value
(2008) Hovorka, Susan D.
CO2 storage, monitoring, verification, and accounting
(Texas-Norway Symposium, 2013-11-19) Nunez-Lopez, Vanessa
CO2-EOR as geologic storage: Monitoring for permanence
(NA 2050 Sequestration Working Group, 2013-10-08) Hovorka, Susan D.
Continuous pressure monitoring for large volume CO2 injections
(9th International Conference on Greenhouse Gas Control Technologies (GHGT-9), 2008-11-16) Meckel, T. A.; Hovorka, S. D.; Kalyanaraman, N.
Elevated formation fluid pressure resulting from large-volume injection of carbon dioxide (CO2) for sequestration is a key factor affecting storage seal integrity (containment risk) and ultimate capacity. Current methods for predicting pressure evolution (e.g. natural gas storage, EOR, groundwater withdrawal/recharge) have unique considerations (temporal cyclicity, associated production) and have only recently been applied for the injected volumes, durations, and extents of sequestration projects. Monitoring pressure dynamics (buildup during injection and subsequent falloff upon cessation) is a fundamental and relatively inexpensive technique for monitoring storage performance. Our research employs multiple numerical techniques to predict the evolution of pressure within reservoirs and to evaluate the potential impact on confining systems (seals), thus constraining site-specific sequestration storage integrity and capacity. We focus on the use of pressure measurements for pragmatic integrative monitoring of reservoir, seal, and well performance. The results presented here focus on real-time pressure and temperature evolution in a dedicated observation well, combining observations from both the injection interval and a monitoring interval 120 m higher for early detection of unanticipated migration out of the injection zone via wellbores or confining system. Results indicate that for the Cranfield reservoir, increases (and by inference, decreases corresponding to pressure loss due to out of zone migration) in injection rates of 100’s of tons per day are observable from less than a kilometer distance from the source.
Detection of anthropogenic CO2 in dilute groundwater: field observations and geochemical modeling of the Dockum aquifer at the SACROC oilfield, West Texas, USA
(9th Annual Conference on Carbon Capture & Sequestration, 2010-05-10) Romanak, Katherine D.; Smyth, Rebecca; Yang, Changbing; Hovorka, Susan
Detection of CO2 leakage in overlaying aquifers using time lapse compressibility monitoring
(12th Annual Conference on Carbon Capture Utilization & Sequestration, 2013-05-13) Hosseini, Seyyed Abolfazi; Zeidouni, Mehdi
Do monitoring schemes work? : modeling collective and private benefits under collective action
(2021-05) Behmer, Torben; Jensen, Nathan M. (Nathan Michael), 1975-
Does monitoring corruption work? If so, which types of monitoring schemes are most effective at reducing corruption? To answer these questions, we specifically focus on the collective action problem between citizens as they determine whether to report public officials' requests for bribes, or to give in to them. In exploring the ways in which monitoring mitigates citizen behavior, we introduce: (i) collective benefits that are subject to top-down principal-agent challenges; and (ii) private benefits that are subject to horizontal accountability challenges. These challenges notwithstanding, we then illustrate how citizens' optimal strategy may be altered in the presence of monitoring. Expanding on findings under full rationality, we calculate stability sets on the basis of citizens' beliefs in the others' willingness to cooperate. Contrary to existing research that advocates for "big bang" approaches and considers incremental ones as counterproductive, we find that even incremental monitoring interventions mitigate corruption by making citizens more likely to report bribe requests. Moreover, we illustrate under what circumstances investment in collective, or private, benefits is more efficient policy. A byproduct of the stability set approach, our model is remarkably flexible, and appears capable of explaining transitions to low corruption equilibria around the globe. Our results suggest that monitoring corruption is not only a good use of scarce resources but that success is mainly a matter of policy design.
Evaluating time-lapse borehole gravity for CO2 plume detection at SECARB Cranfield
(11th Annual International Conference on Greenhouse Gas Technologies, 2012-11-18) Hovorka, Susan; Dodds, Kevin; Krahenbuhl, Richard; Reitz, Anya; Li, Yaoguo
An evaluation of rural sanitation in India
(2015-08) Mauro, Benjamin Matthew; Eaton, David J.; Weaver, Catherine
One billion people practice open defecation globally resulting in approximately 900,000 deaths via contaminated water and contact with human excreta. India is home to 600 million of the individuals engaging in open defecation, and poor sanitation is estimated to cause over 400,000 deaths annually. The Swachh Bharat Mission, the Indian government's scheme to increase sanitation coverage across India, promotes toilet construction by subsidizing the costs. The program has produced limited uptake in hygienic behavior change, and toilet construction goals are not being met. This study evaluates the effectiveness of sanitation interventions in 22 studies in the rural setting. The review identifies successful sanitation interventions and highlights gaps in the existing literature. Three types of studies were evaluated: infrastructure interventions, education interventions, and interventions that employed a combination of the two methods; and the review of the studies found that interventions utilizing community mobilization and subsidies as a part of their outreach were more likely to increase toilet coverage in the rural environment. The review also provides recommendations for future interventions, research, and implementing organizations operating in the rural sanitation environment. The report was written to inform the work of Humanure Power, an NGO working to end open defecation in rural Bihar, India. The potential for conditional cash transfers and pit latrine volumes were explored as solutions to inducing behavioral change, and the report outlined an evaluation framework for the rural environment. This report provides a framework that tracks multiple indicators and incorporates local help to build a sustainable sanitation tracking system to account for the difficulties of program monitoring and evaluation in a resource-limited environment.
Executive summary: Recent results of the SACROC groundwater geochemistry summary
(Federal Requirements Under the Underground Injection Control (UIC) Program for Carbon Dioxide (CO2) Geologic Sequestration (GS) Wells – Notice of Data Availability and Request for Comment (EPA-HQ-OW-2008- 0390-0297), 2008) Romanak, Katherine D.; Smyth, Rebecca C.; Yang, Changbing; Hovorka, Susan D.; Nicot, Jean-Philipe; Lu, Jiemin
Expert-based development of a standard in CO2 sequestration monitoring technology
(2014) Hovorka, S. D.; Nicot, J. -P.; Zeidouni, M.; Sun, A. Y.; Yang, C.; Sava, D.; Mickler, P. J.
Extraction of dissolved gaseous hydrocarbons from brine at an engineered CO2 injection, Cranfield, Mississippi
(American Geophysical Union Fall Meeting, 2011-12-13) Romanak, Katherine
Frio brine storage experiment—lessons learned
(8th International Conference on Greenhouse Gas Control Technologies, 2013-06-19) Hovorka, Susan D.
The Frio Brine pilot is a closely monitored, small-volume (1,600 tons), short-duration experiment using injection of CO2 into high-permeability brine-bearing sandstone to test the feasibility of geologic sequestration. The experiment differed from the geoscience and engineering community’s extensive previous experience in injection of CO2 and other fluids into the subsurface. It was, from inception to completion, focused on assessing monitoring strategies. An important objective of this study is to convey lessons learned to the next generation of developers of geologic CO2-injection-pilot projects. For the experiment, CO2 was injected for 10 days 1500 m below the surface. The evolution of the plume was successfully monitored with diverse tools, including downhole pressure and temperature, wireline logging, fluid sampling, cross-well techniques, and vertical seismic profiling. The injection period was brief and the formation was steeply dipping with high permeability; therefore the nineteen months since injection period takes us well into the post injection phase of monitoring. As predicted, CO2 remains stored within the formation. Surface leak detection techniques have thus far failed to detect any clear evidence of leakage except immediately above the injection zone, probably through engineered systems.