Timothy A. Meckel

The cross-scale science of CO2 capture and storage: from pore scale to regional scale

We describe state-of-the-art science and technology related to modeling of CO2 capture and storage (CCS) at four different process scales: pore, reservoir, site, and region scale. We present novel research at each scale to demonstrate why each scale is important for a comprehensive understanding of CCS. Further, we illustrate research linking adjacent process scales, such that critical information is passed from one process scale to the next adjacent scale. We demonstrate this cross-scale approach using real world CO2 capture and storage data, including a scenario managing CO2 emissions from a large U.S. electric utility. At the pore scale, we present a new method for incorporating pore-scale surface tension effects into a relative permeability model of CO2-brine multiphase flow at the reservoir scale. We benchmark a reduced complexity model for site-scale analysis against a rigorous physics-based reservoir simulator, and include new system level considerations including local site-scale pipeline routing analysis (i.e., reservoir to site scale). We also include costs associated with brine production and treatment at the site scale, a significant issue often overlooked in CCS studies. All models that comprise our total system include parameter uncertainty which leads to results that have ranges of probability. Results suggest that research at one scale is able to inform models at adjacent process scales, and that these scale connections can inform policy makers and utility managers of overall system behavior including the impacts of uncertainty.

Influence of cumulative convergence on lithospheric thrust fault development and topography along the Australian‐Pacific plate boundary south of New Zealand

The development of faulting and topography resulting from initial convergence within oceanic lithosphere is largely unknown. We explore relationships among convergence, structural development, and topography along ?1500 km of the submarine Australian-Pacific plate boundary south of New Zealand, the Macquarie Ridge Complex (MRC). Due to the variable orientation of the boundary and close proximity of the Australian-Pacific poles of rotation, individual segments of the plate boundary have experienced different convergence histories since ?10.95 Ma (Chron 5o). Because interaction along the oceanic extent of the boundary involves oceanic lithosphere of broadly the same age and therefore thermal structure, structural and morphologic differences can be attributed primarily to variations in angles and rates of convergence with respect to the plate boundary orientation since 10.95 Ma. We relate plate boundary-normal convergence determined from stage pole rotations to structural development, focusing on transitions from purely strike-slip faulting to partitioned thrust and strike-slip faulting between 47°S and 60°S since 10.95 Ma. Our results indicate that boundary-normal convergence of ?100 km marks the transition from strike-slip dominated faulting to partitioned underthrusting and strike-slip faulting (incipient subduction). Establishment of subduction at the Puysegur Trench and incipient subduction at the Hjort Trench corresponds to convergence at rates between ?2 and 4 cm/yr, angles >30°, and with durations of at least 10 m.y., resulting in >100 km of boundary-normal convergence. Anomalous topographic volumes resulting from tectonic deformation are quantified from swath bathymetry and compared to convergence history. Results from analysis of the central MRC suggest that prior to lithospheric-scale thrust faulting, ?100 km of boundary-normal convergence can be accommodated by crustal deformation (6 km relief from ridge crest to adjacent trough) and strike-slip faulting. Our research supports induced/forced intraoceanic initiation of subduction.

Tectonic implications of fault-scarp-derived volcaniclastic deposits on Macquarie Island : sedimentation at a fossil ridge-transform intersection?

Upper Miocene to lower Pliocene sedimentary rocks on Macquarie Island are dominantly volcaniclastic breccia, sandstone, and siltstone produced by the physical disintegration and tectonic abrasion of oceanic crust in fault zones and mass wasting of these tectonic features. They represent small debris fans and small-scale turbidites deposited at the base of active fault scarps, related to Late Miocene to Early Pliocene seafloor spreading. Most of the sediment is derived from basalts, but diabase and gabbro clasts in some sedimentary rocks indicate that middle and lower oceanic crust was exposed to erosion on the sea floor. A lack of exotic clasts and a low degree of clast roundness are consistent with a local source for the sediment and no input from continental rocks. Spatial relationships between sedimentary rocks and major faults associated with seafloor spreading on the island and correlation between sedimentary clast and adjacent up-thrown block compositions allow us to infer paleotectonic relief for Macquarie Island crust during deposition. Our data support a model involving the deposition of these rocks at the inside corner of a ridge-transform intersection. Furthermore, a tectonic reconstruction of the Australian-Pacific plate boundary for the approximate time that Macquarie Island crust formed (10.9 Ma) also shows that Macquarie Island crust most likely formed near a ridge-transform intersection. This paper describes sedimentation associated with active faulting at a ridge-transform intersection that has been uplifted in situ above sea level along with the surrounding oceanic crust, and demonstrates that high-angle faults have the most pronounced influence, compared with low-angle faults, on sedimentation in this tectonic environment.

Use of novel high-resolution 3D marine seismic technology to evaluate Quaternary fluvial valley development and geologic controls on shallow gas distribution, inner shelf, Gulf of Mexico

The first deployment of the P-Cable™ high-resolution 3D (HR3D) seismic acquisition system in the Gulf of Mexico has provided unprecedented resolution of depositional, architectural, and structural features related to relative sea-level change recorded in the Quaternary stratigraphy. These details are typically beyond conventional 3D seismic resolution and/or excluded from commercial surveys, which are generally optimized for deeper targets. Such HR3D data are valuable for detailed studies of reservoir analogs, sediment delivery systems, fluid-migration systems, and geotechnical hazard assessment (i.e., drilling and infrastructure). The HR3D survey (31.5 km 2 ) collected on the inner shelf (<15 m water depth) offshore San Luis Pass, Texas, imaged the upper 500 m of stratigraphy using peak frequency of 150 Hz and 6.25 m 2 bin size. These data provided an exceptionally well-imaged example of shallow subsurface depositional system and stratigraphic architecture development during a lowstand period. The system evolved from a meandering channel with isolated point-bar deposits to a transgressive estuary characterized by dendritic erosional features that were eventually flooded. In addition, HR3D data have identified a previously unidentified seismically discontinuous zone interpreted to be a gas chimney system emanating from a tested (drilled) nonproductive, three-way structure in the lower Miocene (1.5 km depth). Within the shallowest intervals (<100 m) and at the top of the chimney zone, seismic attribute analysis revealed several high-amplitude anomalies up to 0.5 km 2 . The anomalies were interpreted as reaccumulated thermogenic gas, and their distribution conforms to the stratigraphy and structure of the Quaternary interval, in that they occupy local fault-bounded footwall highs within remnant coarser-grained interfluvial zones, which are overlain by finer grained, transgressive deposits.

7 – Capillary seals for trapping carbon dioxide (CO2) in underground reservoirs

Abstract: Pore -scale capillary processes within geologic reservoirs and seals influence buoyancy-driven fluid migration. This chapter reviews these processes and considers their relevance to CO 2 sequestration. The ability of membrane seals in water/brine -wet rocks to retard buoyant fluid migration (including CO 2 ) relates to the capillary pressures and pore throat diameters of the seal rock. An attempt is made here to calculate anticipated ambient capillary pressures in the lowest portions of the seal, using existing laboratory data on the petrophysical properties of the CO 2 -brine-reservoir system as the basis and calculations carried out using a Monte Carlo approach. The values thus reached can then be used to constrain minimum seal capacities, offering the potential to predict containment capacities. The chapter concludes with a discussion of some aspects of capillary sealing which have been consdiered for hydrocarbon systems but not yet discussed for CO 2 systems.

Time-lapse seismic signal analysis for enhanced oil recovery at Cranfield CO2 sequestration site, Cranfield field, Mississippi

AbstractThe Cranfield field in southwest Mississippi has been under continuous CO2 injection by Denbury Onshore LLC since 2008. Two 3D seismic surveys were collected in 2007 and 2010. An initial 4D seismic response was characterized after three years of injection, where more than three million tons of CO2 remain in the subsurface. This interpretation showed coherent seismic amplitude anomalies in some areas that received large amounts of CO2 but not in others. To understand these effects better, we performed Gassmann substitution modeling at two wells: the 31F-2 observation well and the 28-1 injection well. We aimed to predict a postinjection saturation curve and acoustic impedance (AI) change through the reservoir. Seismic volumes were cross-equalized, well ties to seismic were performed, and AI inversions were subsequently carried out. Inversion results showed that the change in AI is higher than Gassmann substitution predicted for the 28-1 injection well. The time-lapse AI difference predicted by the i...

Best Management Practices for subseabed geologic sequestration of carbon dioxide

A team led by the Gulf Coast Carbon Center at the Bureau of Economic Geology, Jackson School of Geosciences at The University of Texas at Austin, has been funded by the National Oceanographic Partnership Program (NOPP) through and in cooperation with the U.S. Department of Interior (DOI), Bureau of Ocean Energy Management (BOEM) to generate a Best Management Practices (BMPs) document on sub-seabed geologic sequestration of carbon dioxide (CO2) below the U.S. outer continental shelf. The team consists of scientists, engineers, lawyers, and business managers from academia, private industry, and State of Texas government from the following institutions: (1) Gulf Coast Carbon Center at the Bureau of Economic Geology (BEG), (2) Det Norske Veritas (USA) Inc (DNV), (3) Wood Group Mustang and sister company Wood Group Kenny (Wood Group), (4) Texas General Land Office (GLO), (5) Harte Research Institute for Gulf of Mexico Studies at Texas A&M University-Corpus Christi (HRI), and (6) The University of Houston Law Center. Individual team members have expertise in carbon sequestration monitoring, CO2-pipeline design and construction, and domestic and international offshore environmental policy. The BMPs will be reviewed by external experts after it is generated and before being submitted to BOEM. The purpose of the BMPs will be to provide technical guidance to BOEM and BSEE (U.S. DOI Bureau of Safety and Environmental Enforcement) to establish regulatory guidelines for offshore components of future U.S. Carbon Capture and Storage, which is sometimes referred to as sequestration, (CCS) industry. Sub-seabed geologic sequestration (GS) is the process whereby CO2 captured from large volume industrial sources (e.g., power plants, oil refineries) will be (1) compressed to supercritical state and transported via pipeline to offshore injection wells, and (2) injected into geologic strata deep (thousands of feet) below the seafloor. Objectives of the CO2 injection will be for “pure sequestration” (i.e., long-term storage of CO2 in subseafloor saline reservoirs) or sequestration combined with enhanced oil recovery (EOR). Sub-seabed geologic sequestration is very different from ocean dumping (i.e. dissolution of CO2 into circulating seawater) or injection of CO2 into deep water, shallow sub-seabed sediments. Some researchers proposed in the past that shallow subseafloor depths (<; 1,000 ft) were sufficient for permanent CO2 storage in deep marine environments (>; 11,000 ft water depth) (e.g., House et al., 2006). However, the shallow sedimentary subseafloor environment could become unstable and allow release of CO2 into ocean water, the end result of which would be ocean dumping. One mechanism of seafloor instability could be the release of gas from hydrates owing to pressure and temperature perturbations that may be introduced by shallow drilling and CO2 injection. Furthermore, the logistics of transporting CO2 hundreds of miles offshore to areas with sufficient water depths for storage in shallow subsea sediments would probably not be economically feasible. We want to emphasize that subseabed GS of CO2 is not ocean dumping. One of the biggest concerns for onshore GS is the potential to impact shallow drinking water resources. Injecting CO2 deep below the seafloor will avoid this potential consequence. But there are sensitive marine environments of concern in offshore settings, protection of which is critical. Environmental monitoring of marine ecosystems (nearshore, along CO2 pipeline corridors, and outer continental shelf) and subseafloor geological strata in which CO2 will be injected will be a large component of the BMPs. Topics being included in the BMPs, a draft of which will be submitted to BOEM in June of 2013, are: (1) site selection and characterization, (2) risk analysis, (3) project planning and execution, (4) environmental monitoring, (5) mitigation, (6) inspection and auditing, (7) reporting requirements, (8) emergency response and contingency planning, (9) decommissioning and site closure, and (10) legal issues. Where possible, we are using existing regulatory, policy, and technical guidance documents as a starting point for the BMPs. We think the most likely location for initiation of U.S. offshore geologic sequestration of CO2 will be in the western or central sectors of the Gulf of Mexico where extensive offshore oil and gas infrastructure already exists. Academic members of our project team are actively working on criteria for site selection [1]. However, private industry is also assessing the feasibility of offshore geologic sequestration below the Atlantic seafloor [2].

Potential Sinks for Geologic Storage of CO2 Generated in the Carolinas

Duke Energy, Progress Energy, Santee Cooper Power, South Carolina Electric and Gas, Electric Power Research Institute (EPRI), Southern States Energy Board (SSEB)