Subsidence monitoring is a crucial component to understanding cavern integrity of salt storage caverns. This report looks at historical and current data at the Bayou Choctaw Strategic Petroleum Reserve Site. Data from the most recent land-based annual surveys, GPS, and tiltmeter indicate the subsidence rates across the site are approximately 0.0 ft./yr. Because of this, there is no evidence from the subsidence survey to suggest any of the DOE caverns have been structurally compromised.
Subsidence monitoring is a critical component to understanding the cavern integrity of salt storage caverns. This report looks at historical and recent data from two of the three West Hackberry dome cavern operators. DOE SPR and LA Storage are coordinating subsidence surveys to create a comprehensive understanding of ground movement above the dome. Data from annual level and rod surveys, GPS, and tiltmeter data show the sites are experiencing typical ground movement. The highest subsidence rate is seen in the middle of the DOE SPR site at just under one inch per year with less ground movement around the edge of the site. A GPS and tiltmeter instrument in the northeast areas of the DOE SPR site has not seen any trend change since the devices were installed in 2013. Comparison between recent ground movement data and historical trends suggest that there is no reason to believe that any DOE SPR or LA Storage caverns have been structurally compromised.
This report summarizes the work performed in the prioritization of cavern access wells for remediation and monitoring at the Bayou Choctaw Strategic Petroleum Reserve site. The grading included consideration of all 15 wells at the Bayou Choctaw site, with each active well receiving a separate grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The factors and grading framework used here are the same as those used in developing similar well remediation and monitoring priorities at the Big Hill, Bryan Mound, and West Hackberry Strategic Petroleum Reserve Sites.
The Bryan Mound caprock was subjected to extens ive sulphur mining prior to the development of the Strategic Petroleum Reserve. Undoubtedl y, the mining has modified the caprock integrity. Cavern wells at Bryan Mound have been subject to a host of well integr ity concerns with many likely compromised by the cavernous capro ck, surrounding corrosive environment (H 2 SO 4 ), and associated elevated residual temperatures al l of which are a product of the mining activities. The intent of this study was to understand the sulphur mining process and how the mining has affected the stability of the caprock and how the compromised caprock has influenced the integrity of the cavern wells. After an extensiv e search to collect pert inent information through state agencies, literature sear ches, and the Sandia SPR librar y, a better understanding of the caprock can be inferred from the knowledge gaine d. Specifically, the discovery of the original ore reserve map goes a long way towards modeling caprock stability. In addition the gained knowledge of sulphur mining - subs idence, superheated corrosive wa ters, and caprock collapse - helps to better predict the post mi ning effects on wellbore integrity. This page intentionally left blank
Sandia National Laboratories is evaluating alternative gravity bomb flight test (GBFT) options that might be more cost effective in the 2025 timeframe than the current Tonopah Test Range (TTR) facility. The alternate ranges being considered are White Sands Missile Range (WSMR) and the Nevada National Security Site (NNSS). One of the factors considered in the decision process is if the geology of the alternative sites is suitable for gravity bomb flight testing. The study looked at seven specific sites within the three test ranges, including the TTR. Those seven sites are Main Lake and Antelope Lake at TTR, Trinity Lake at WSMR, and Yucca Lake, an area west of Frenchman Flat, Pahute Mesa, and the Pahute Airstrip all at NNSS. The four lakes studied are playas. In general the findings indicate that the playa lakes (Main, Antelope, Trinity, and Yucca) consist of fine-grained lacustrine sediments with inter-bedded stringers of coarse grains and gravels towards the shorelines. Frenchman Flat and Pahute Airstrip are both located within basins filled with poorly sorted gravel alluviums. Pahute Mesa consists of volcanic tuff. The seven sites are listed in order from the most favorable location to least favorable based on the suitability of the geology for GBFT. An ideal test site would consist of a succession of soft sediments devoid of hard layers. WSMR Lake Trinity is the most suitable site, exhibiting solely find-grained sediments across the study region. The lakes at TTR follow next with Antelope Lake and Main Lake, Antelope lake being finer grained and more homogeneous than Main Lake. The four NNSS sites are considered the least favorable due the heterogenetic character of Yucca Lake, Pahute Airstrip, and Frenchman Flat. The geology of Pahute Mesa is considered the least favorable consisting of volcanic tuff too hard for current test operations.
This report summarizes the work performed in the prioritization of cavern access wells for remediation and monitoring at the West Hackberry Strategic Petroleum Reserve site. The grading included consideration of all 31 wells at the West Hackberry site, with each well receiving a separate grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The factors and grading framework used here are the same as those used in developing similar well remediation and monitoring priorities at the Big Hill and Bryan Mound Strategic Petroleum Reserve Sites.
This report summarizes the work performed in the prioritization of cavern access wells for remediation and monitoring at the Bryan Mound Strategic Petroleum Reserve site. The grading included consideration of all 47 wells at the Bryan Mound site, with each well receiving a separate grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The factors and grading framework used here are the same as those used in developing similar well remediation and monitoring priorities at the Big Hill Strategic Petroleum Reserve Site.
This paper presents a study of operational and abandoned large-diameter caverns and their long-term implications for oil storage facilities in domal salt. Two caverns at the U.S. Strategic Petroleum Reserve’s West Hackberry site, Caverns 6 and 9, present concerns due to their large diameters, unusual shapes and close proximity to each other. The Bryan Mound site has three caverns whose unusual shapes and dimensions have caused concerns about cavern collapse, sinkhole formation, and loss of accessibility to stored oil. This report presents a case study of how historical field data, computational geomechanical analyses, and the implementation of new instrumentation and historical data analyses may be used to develop site operation and monitoring plans for these caverns.
This report summarizes the work performed in developing a framework for the prioritization of cavern access wells for remediation and monitoring at the Big Hill Strategic Petroleum Reserve site. This framework was then applied to all 28 wells at the Big Hill site with each well receiving a grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading framework including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The framework was developed in a way as to be applicable to all four of the Strategic Petroleum Reserve sites.
This report addresses recent well integrity issues related to cavern 114 at the Big Hill Strategic Petroleum Reserve site. DM Petroleum Operations, M&O contractor for the U.S. Strategic Petroleum Reserve, recognized an apparent leak in Big Hill cavern well 114A in late summer, 2012, and provided written notice to the State of Texas as required by law. DM has since isolated the leak in well A with a temporary plug, and is planning on remediating both 114 A- and B-wells with liners. In this report Sandia provides an analysis of the apparent leak that includes: (i) estimated leak volume, (ii) recommendation for operating pressure to maintain in the cavern between temporary and permanent fixes for the well integrity issues, and (iii) identification of other caverns or wells at Big Hill that should be monitored closely in light of the sequence of failures there in the last several years.
The U.S. Department of Energy (DOE) has an interest in large scale hydrogen geostorage, which could offer substantial buffer capacity to meet possible disruptions in supply or changing seasonal demands. The geostorage site options being considered are salt caverns, depleted oil/gas reservoirs, aquifers and hard rock caverns. The DOE has an interest in assessing the geological, geomechanical and economic viability for these types of geologic hydrogen storage options. This study has developed an economic analysis methodology and subsequent spreadsheet analysis to address costs entailed in developing and operating an underground geologic storage facility. This year the tool was updated specifically to (1) incorporate more site-specific model input assumptions for the wells and storage site modules, (2) develop a version that matches the general format of the HDSAM model developed and maintained by Argonne National Laboratory, and (3) incorporate specific demand scenarios illustrating the model's capability. Four general types of underground storage were analyzed: salt caverns, depleted oil/gas reservoirs, aquifers, and hard rock caverns/other custom sites. Due to the substantial lessons learned from the geological storage of natural gas already employed, these options present a potentially sizable storage option. Understanding and including these various geologic storage types in the analysis physical and economic framework will help identify what geologic option would be best suited for the storage of hydrogen. It is important to note, however, that existing natural gas options may not translate to a hydrogen system where substantial engineering obstacles may be encountered. There are only three locations worldwide that currently store hydrogen underground and they are all in salt caverns. Two locations are in the U.S. (Texas), and are managed by ConocoPhillips and Praxair (Leighty, 2007). The third is in Teeside, U.K., managed by Sabic Petrochemicals (Crotogino et al., 2008; Panfilov et al., 2006). These existing H{sub 2} facilities are quite small by natural gas storage standards. The second stage of the analysis involved providing ANL with estimated geostorage costs of hydrogen within salt caverns for various market penetrations for four representative cities (Houston, Detroit, Pittsburgh and Los Angeles). Using these demand levels, the scale and cost of hydrogen storage necessary to meet 10%, 25% and 100% of vehicle summer demands was calculated.
This report evaluates the feasibility of disposing U.S. high-level radioactive waste in granite several hundred meters below the surface of the earth. The U.S. has many granite formations with positive attributes for permanent disposal. Similar crystalline formations have been extensively studied by international programs, two of which, in Sweden and Finland, are the host rocks of submitted or imminent repository license applications. This report is enabled by the advanced work of the international community to establish functional and operational requirements for disposal of a range of waste forms in granite media. In this report we develop scoping performance analyses, based on the applicable features, events, and processes (FEPs) identified by international investigators, to support generic conclusions regarding post-closure safety. Unlike the safety analyses for disposal in salt, shale/clay, or deep boreholes, the safety analysis for a mined granite repository depends largely on waste package preservation. In crystalline rock, waste packages are preserved by the high mechanical stability of the excavations, the diffusive barrier of the buffer, and favorable chemical conditions. The buffer is preserved by low groundwater fluxes, favorable chemical conditions, backfill, and the rigid confines of the host rock. An added advantage of a mined granite repository is that waste packages would be fairly easy to retrieve, should retrievability be an important objective. The results of the safety analyses performed in this study are consistent with the results of comprehensive safety assessments performed for sites in Sweden, Finland, and Canada. They indicate that a granite repository would satisfy established safety criteria and suggest that a small number of FEPs would largely control the release and transport of radionuclides. In the event the U.S. decides to pursue a potential repository in granite, a detailed evaluation of these FEPs would be needed to inform site selection and safety assessment.
The U.S. Department of Energy has an interest in large scale hydrogen geostorage, which would offer substantial buffer capacity to meet possible disruptions in supply. Geostorage options being considered are salt caverns, depleted oil/gas reservoirs, aquifers and potentially hard rock cavrns. DOE has an interest in assessing the geological, geomechanical and economic viability for these types of hydrogen storage options. This study has developed an ecocomic analysis methodology to address costs entailed in developing and operating an underground geologic storage facility. This year the tool was updated specifically to (1) a version that is fully arrayed such that all four types of geologic storage options can be assessed at the same time, (2) incorporate specific scenarios illustrating the model's capability, and (3) incorporate more accurate model input assumptions for the wells and storage site modules. Drawing from the knowledge gained in the underground large scale geostorage options for natural gas and petroleum in the U.S. and from the potential to store relatively large volumes of CO{sub 2} in geological formations, the hydrogen storage assessment modeling will continue to build on these strengths while maintaining modeling transparency such that other modeling efforts may draw from this project.