Engineering topics

Daley, Thomas M.

Publications and source records attributed to Daley, Thomas M..

14 records

DOE OSTI2023

Active‐Source Seismic Imaging of Fault Re‐Activation and Leakage: An Injection Experiment at the Mt Terri Rock Laboratory, Switzerland

Abstract We conducted a time‐lapse seismic experiment utilizing automated active seismic source and sensor arrays to monitor a reactivated fault within the Opalinus clay formation at the Mont Terri Rock Laboratory (Switzerland), an analog caprock for geologic carbon storage. A series of six brine injections were conducted into the so‐called Main Fault to reactivate it. Seismic instrumentation in five monitoring boreholes on either side of the fault was used to continuously probe changes in P‐wave travel‐times associated with fault displacement and leakage. We performed time‐lapse travel‐time tomography on five hundred sequential data sets; this revealed a zone of decreased P‐wave velocity, up to 16 m/s, during each injection cycle, followed by a velocity increase during shut‐in. These results demonstrate varying elastic property perturbations, both spatially and temporally, along the fault plane during reactivation. We then interpreted these velocity changes in terms of fault dilation induced by pressurized fluids along the fault.

58 GEOSCIENCES↗

DOE OSTI2022

Seismic monitoring of well integrity

Seismic tube waves, produced by flexure of the well boundary, pressure changes in the fluid in the well, and deformation of the material immediately surrounding the well, are particularly sensitive to variations in the state of the well. In this work, we evaluate a direct approach for generating and observing tube waves as a means of detecting well damage. While we find that it can be difficult to reliably excite observable tube waves without a very strong surface source, time-frequency techniques can be employed to increase the detectability of tube wave reflections. New technologies, particularly distributed acoustic sensing, hold great promise for evaluating well integrity by monitoring tube waves, temperature changes, and seismic noise due to well deformation and fluid leakage.

58 GEOSCIENCES↗

DOE OSTI2019

Dynamic Processes of CO 2 Storage in the Field: 1. Multiscale and Multipath Channeling of CO 2 Flow in the Hierarchical Fluvial Reservoir at Cranfield, Mississippi

A consistent picture of dynamic channeling, invasion, spreading, and breakthrough (CISB) of supercritical CO 2 in the hierarchical fluvial reservoir at Cranfield, Mississippi is presented after 10 years of integration and analysis of complementary field monitoring and characterization data. The dynamic CISB with small-scale CO 2 -flow channels in the F1-F2-F3 cross section (F1, F2, and F3 are one injection and two monitoring wells) was imaged by daily electrical resistance tomography (ERT) and time-lapse crosswell seismic surveys. One, three, and four CO 2 flow channels logged at F1, F2, and F3, respectively, were dynamically connected with strong temporal variations in CO 2 saturation during 221 days of drainage with injection rate doubling twice and 81 days of imbibition. Three intermediate-scale CO 2 flow channels (with highest CO 2 saturation) normal to the cross section were ERT-imaged during late-time drainage. A large-scale, sinuous fluvial CO 2 flow channel was imaged by repeat surface seismic survey at the end of the imbibition. The fluvial sandstone channel sinuously bypasses the F1-F2-F3 cross section in a point bar, but the channel is connected to the cross section through an intermediate-scale sandstone channel, forming a complicated flow channel network. The multiscale flow channel network (in the fluvial channel-point bar system) revealed from the observed CISB enables us to consistently interpret the hydrological monitoring data of three tracer tests, each conducted during an injection rate step, and preinjection hydraulic-thermal-tracer tests. Finally, this interpretation of the CISB and flow channel network can guide future modeling and data inversion to best understand the effects of natural heterogeneity on CO 2 storage efficiency and residual trapping.

58 GEOSCIENCES↗

DOE OSTI2019

Microhole VSP - CO2 EOR - Wickett, Texas

This data archive is three vertical seismic profile (VSP) data sets recorded in 2007 and 2008 using microhole technology to monitor a CO2 EOR flood in a Wickett, TX oil field (known as North Ward/Estes field). Five microhole wells with permanent vertical component geophone sensors were used for monitoring.

CO2↗

DOE OSTI2019

Dynamics of geologic CO 2 storage and plume motion revealed by seismic coda waves

Significance The sequestration of CO 2 into geological formations as a strategy for reducing atmospheric greenhouse gases requires accurate monitoring of CO 2 plume for safe long-term storage. However, imaging CO 2 plume migration in the subsurface is a challenging problem for existing seismic monitoring methods. Here, we present an approach for CO 2 monitoring based on seismic coda waves and apply it to the 3-d period of CO 2 injection in a pilot experiment. We find that velocity reduction is nonlinearly correlated with the cumulative CO 2 mass inside the reservoir, and that coda waves can effectively monitor the spatiotemporal evolution of CO 2 plumes in the subsurface. Our findings suggest approaches for using seismic data in long-term monitoring of subsurface CO 2 plume evolution.

58 GEOSCIENCES↗

DOE OSTI2018

Pressure transient analysis during CO 2 push-pull tests into faults for EGS characterization

Here, with the goal of detecting and characterizing faults and fractures in enhanced geothermal systems (EGS), a new technology involving CO 2 push-pull testing, active-source geophysical imaging, and well logging has recently been proposed. This technique takes advantage of (1) the contrasting properties of supercritical CO 2 and water which cause CO 2 to appear distinct from surrounding brine in seismic and other geophysical logging approaches, (2) the non-wetting nature of CO 2 which keeps it localized to the faults and fractures to create contrast potentially sufficient for active seismic and well-logging approaches to image faults and fracture zones at EGS sites. In this study, we evaluate the feasibility of using pressure transient monitoring during CO 2 push-pull tests to complement active seismic and wireline well logging for EGS characterization. For this purpose, we developed a 2D model of a prototypical geothermal site (Desert Peak, NV) that includes a single fault. The fault zone consists of a slip plane, fault gouge, and damage zone, and is bounded by the surrounding matrix of the country rock. Through numerical simulation using iTOUGH2, we found that the pressure transient at the monitoring wells in the fault gouge shows unique traits due to the multiphase flow conditions developed by CO 2 injection, and varies sensitively on the arrival of the CO 2 plume and the degree of CO 2 saturation. A sensitivity analysis shows the pressure transient is most sensitive to the fault gouge permeability, but also depends on multiphase flow parameters and the boundary conditions of the fault. Lastly, an inversion study reveals that the fault gouge permeability can be best estimated with the pressure transient data, whereas additional CO 2 saturation data do not improve the accuracy of the inversion significantly.

58 GEOSCIENCES↗

DOE OSTI2018

Simulations of carbon dioxide push-pull into a conjugate fault system modeled after Dixie Valley—Sensitivity analysis of significant parameters and uncertainty prediction by data-worth analysis

Characterizing the faults and fractures that provide flow pathways for efficient geothermal energy production is critical for design of sustainable geothermal energy production. Both natural faults and stimulated fractures in enhanced geothermal systems (EGS) are difficult to image and map by seismic methods because hot brine filling the fractures and faults does not create a strong seismic property contrast relative to surrounding rock. We investigate here the technical feasibility of using supercritical CO 2 (scCO 2 ) injection into faults in a single-well push-pull scenario to characterize the hydraulic properties of the fault zone by emplacing scCO 2 that can serve as a contrast fluid for seismic monitoring. We develop a conceptual and numerical reservoir model of two intersecting faults based on the Dixie Valley geothermal system in Nevada, USA.

15 GEOTHERMAL ENERGY↗

DOE OSTI2017

CO2 Push-Pull Single Fault Injection Simulations

ASCII text files containing grid-block name, X-Y-Z location, and multiple parameters from TOUGH2 simulation output of CO2 injection into an idealized single fault representing a dipping normal fault at the Desert Peak geothermal field (readable by GMS). The fault is composed of a damage zone, a fault gouge and a slip plane. The runs are described in detail in the following: Borgia A., Oldenburg C.M., Zhang R., Jung Y., Lee K.J., Doughty C., Daley T.M., Chugunov N., Altundas B, Ramakrishnan T.S., 2017. Carbon Dioxide Injection for Enhanced Characterization of Faults and Fractures in Geothermal Systems. Proceedings of the 42st Workshop on Geothermal Reservoir Engineering, Stanford University, Stanford, California, February 13-17.

15 GEOTHERMAL ENERGY↗

DOE OSTI2017

Spatiotemporal changes of seismic attenuation caused by injected CO 2 at the Frio-II pilot site, Dayton, TX, USA

A continuous active source seismic monitoring data set was collected with crosswell geometry during CO 2 injection at the Frio-II brine pilot, near Liberty, TX. Previous studies have shown that spatiotemporal changes in the P wave first arrival time reveal the movement of the injected CO 2 plume in the storage zone. To further constrain the CO 2 saturation, particularly at higher saturation levels, we investigate spatial-temporal changes in the seismic attenuation of the first arrivals. The attenuation changes over the injection period are estimated by the amount of the centroid frequency shift computed by local time-frequency analysis. We observe that (1) at receivers above the injection zone seismic attenuation does not change in a physical trend; (2) at receivers in the injection zone attenuation sharply increases following injection and peaks at specific points varying with distributed receivers, which is consistent with observations from time delays of first arrivals; then, (3) attenuation decreases over the injection time. The attenuation change exhibits a bell-shaped pattern during CO 2 injection. Under Frio-II field reservoir conditions, White's patchy saturation model can quantitatively explain both the P wave velocity and attenuation response observed. We have combined the velocity and attenuation change data in a crossplot format that is useful for model-data comparison and determining patch size. Our analysis suggests that spatial-temporal attenuation change is not only an indicator of the movement and saturation of CO 2 plumes, even at large saturations, but also can quantitatively constrain CO 2 plume saturation when used jointly with seismic velocity.

58 GEOSCIENCES↗

DOE OSTI2017

In situ measurement of velocity-stress sensitivity using crosswell continuous active-source seismic monitoring

The ability to characterize time-varying reservoir properties, such as the state of stress, has fundamental implications in subsurface engineering, relevant to geologic sequestration of CO 2 . Stress variation, here in the form of changes in pore fluid pressure, is one factor known to affect seismic velocity. Induced variations in velocity have been used in seismic studies to determine and monitor changes in the stress state. Previous studies conducted to determine velocity-stress sensitivity at reservoir conditions rely primarily on laboratory measurements of core samples or theoretical relationships. In this paper, we have developed a novel field-scale experiment designed to study the in situ relationship between pore-fluid pressure and seismic velocity using a crosswell continuous active-source seismic monitoring (CASSM) system. At the Cranfield, Mississippi, CO 2 sequestration field site, we actively monitored seismic response for five days with a temporal resolution of 5 min; the target was a 26 m thick injection zone at approximately 3.2 km depth in a fluvial sandstone formation (lower Tuscaloosa Formation). The variation of pore fluid pressure was obtained during discrete events of fluid withdrawal from one of the two wells and monitored with downhole pressure sensors. The results indicate a correlation between decreasing CASSM time delay (i.e., velocity change for a raypath in the reservoir) and periods of reduced fluid pore pressure. The correlation is interpreted as the velocity-stress sensitivity measured in the reservoir. This observation is consistent with published laboratory studies documenting a velocity ( V ) increase with an effective stress increase. A traveltime change ( d t ) of 0.036 ms is measured as the consequence of a change in pressure of approximately 2.55 MPa ( d P e ). For T = 13 ms total traveltime, the velocity-stress sensitivity is d V / V / d P e = d t / T / d P e = 10.9 × 10 - 4 / MPa . Finally, the overall results suggest that CASSM measurements represent a valid technique for in situ determination of velocity-stress sensitivity in field-scale monitoring studies.

58 GEOSCIENCES↗

DOE OSTI2017

CO2 Push-Pull Dual (Conjugate) Faults Injection Simulations

This submission contains datasets and a final manuscript associated with a project simulating carbon dioxide push-pull into a conjugate fault system modeled after Dixie Valley- sensitivity analysis of significant parameters and uncertainty prediction by data-worth analysis. Datasets include: (1) Forward simulation runs of standard cases (push & pull phases), (2) Local sensitivity analyses (push & pull phases), and (3) Data-worth analysis (push & pull phases).

15 GEOTHERMAL ENERGY↗

DOE OSTI2017

Final Scientific/Technical Report for project “Geomechanical Monitoring for CO 2 Hub Storage: Production and Injection at Kevin Dome

After learning that the TDS value in the target injection formation at the Kevin Dome site is too low to qualify for an EPA Class VI CO2 injection permit, the BSCSP project was re-scoped such that injection of CO2 is no longer planned. With no injection planned, the Geomechanics project was closed. In this final report, we describe the objective and approach of the project as proposed, and the limited results obtained before stopping work. The objective of the proposed research was the development & validation of an integrated monitoring approach for quantifying the interactions between large-scale geological carbon storage (GCS) and subsurface geomechanical state, particularly perturbations relevant to reservoir integrity such as fault reactivation and induced fracturing. In the short period of work before knowing the fate of the Kevin Dome project, we (1) researched designs for both the proposed InSAR corner reflectors as well as the near-surface 3C seismic stations; (2) developed preliminary elastic geomechanical models; (3) developed a second generation deformation prediction for the BSCSP Kevin Dome injection site; and (4) completed a preliminary map of InSAR monuments and shallow MEQ wells in the vicinity of the BSCSP injection pad.

58 GEOSCIENCES↗

DOE OSTI2017

Simulations of CO 2 injection into fractures and faults for improving their geophysical characterization at EGS sites

Here, we propose the use of CO 2 in push-pull well tests to improve geophysical identification and characterization of fractures and faults at enhanced geothermal system (EGS) sites. Using TOUGH2/ECO2N, we carried out numerical experiments of push-pull injection-production cycling of CO 2 into idealized vertical fractures and faults to produce pressure-saturation-temperature conditions that can be analyzed for their geophysical response. Our results show that there is a strong difference between injection and production mainly because of CO 2 buoyancy. While the CO 2 -plume grows laterally and upward during injection, not all CO 2 is recovered during the subsequent production phase. Even under the best conditions for recovery, at least 10% of the volume of the pores still remains filled with CO 2 . To improve EGS characterization, comparisons can be made of active seismic methods carried out before and after (time lapse mode) CO 2 injection into the fracture or fault. Here we find that across the CO 2 saturation range, C11 (the normal stiffness in the horizontal direction perpendicular to the fracture plane) varies between maximum and minimum values by about 15%. It reaches a maximum at around 6% gas saturation, decreasing exponentially to a minimum at higher saturations. Finally, our results suggest that CO 2 injection can be effectively used to infiltrate fault and fracture zones reaching about optimal saturation values in order to enhance seismic imaging at EGS sites.

58 GEOSCIENCES↗

DOE OSTI2016

Progress in Monitoring Strategies for Risk Reduction in Geologic CO2 Storage

Abstract: This geophysical monitoring review is intended to lay the ground work for an approach to integrating monitoring strategies with risk assessment and risk reduction and to summarize work conducted by U.S. Department of Energy's National Risk Assessment Partnership (NRAP) participants that addresses key questions related to monitoring strategies. Commercial, demonstration and pilot geologic CO2 storage (GCS) projects have provided a wealth of practical experience in monitoring technologies. In this manuscript we review a few key projects, specific geophysical methods, well-based methods, geophysical workflows and some suggested best practices. These practices are often driven and governed by regulatory requirements (e.g. U.S. Environmental Protection Agency [US-EPA] Class VI underground injection regulation) and the need for effective reservoir management of pressures and volumes as well as the site-specific risks to containment, plume migration, and underground sources of drinking water. Reducing uncertainty in monitoring is likely to lead to reducing uncertainty in risk. One of our conclusions is the need for field experiment testing that is risk-driven. It is notable that GCS pilot projects have been designed for safe storage, and to date they have been successful. Technical challenges at all geologic CO2 storage sites include assuring injectivity and capacity predictions are reliable, the fate and subsurface topology of the CO2 plume is acceptable, regulatory permitting and compliance are accomplished in a timely manner, needed business assurances are supported by quantitative technical data, and the storage operation is acceptable to stakeholders. There is risk associated with all of these challenges necessitating a monitoring program utilizing both direct and indirect monitoring methods. Because of the direct association of risk and monitoring in GCS, geophysical monitoring is viewed as a key component in approaching risk assessment. To address monitoring in the context of risk assessment the U.S. Department of Energy's National Risk Assessment Partnership (NRAP) has undertaken a review of work related to monitoring storage sites. In this review we provide a framework for monitoring and then present some specific monitoring tools that may be useful for regulatory compliance, as well as technologies that are applicable to leakage detection.

Harbert, William↗