CHAPTER 3
Review of Central Research Efforts Within the Methane Hydrate Research and Development Program

Since the start of fiscal year 2006, the Department of Energy (DOE) Methane Hydrate Research and Development Program has supported 27 new research projects and has continued to support an additional 11 projects that had begun between 2000 and the end of fiscal year 2005. Of these new or continuing projects, 25 remain active through the end of fiscal year 2009 or beyond (Appendix F). The projects supported by the Program cover several focus areas and have included discipline-specific research activities proposed by investigators at academic institutions and national laboratories as well as large, multidisciplinary projects conducted jointly with industry and/or other federal agencies, national laboratories, and academic institutions. DOE and some of its federal partners, at the U.S. Geological Survey (USGS), for example, have also participated in internationally organized projects.

This chapter provides a topical review of the Program’s scientific projects and major achievements and an assessment of knowledge gaps for research areas that the committee has determined are central to the Program’s mission and success (e.g., Appendix A) and follow naturally



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CHAPTER 3 Review of Central Research Efforts Within the Methane Hydrate Research and Development Program Since the start of fiscal year 2006, the Department of Energy (DoE) Methane Hydrate Research and Development Program has supported 27 new research projects and has continued to support an additional 11 projects that had begun between 2000 and the end of fiscal year 2005. of these new or continuing projects, 25 remain active through the end of fiscal year 2009 or beyond (Appendix F). The projects supported by the Program cover several focus areas and have included discipline-specific research activities proposed by investigators at academic institutions and national laboratories as well as large, multidisciplinary projects conducted jointly with industry and/or other federal agencies, national laboratories, and academic institutions. DoE and some of its federal partners, at the U.S. Geological Survey (USGS), for example, have also participated in internationally organized projects. This chapter provides a topical review of the Program’s scientific projects and major achievements and an assessment of knowledge gaps for research areas that the committee has determined are central to the Program’s mission and success (e.g., Appendix A) and follow naturally 

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . from the “state of the science” and broad challenges in methane hydrate research outlined in Chapter 2. Thus, field projects with aims toward pro- duction tests and drilling, reservoir simulation modeling, geomechanics, remote sensing, and environmental and geohazard-related research are examined here. Although the focus is on research conducted since the last review of the Program (NRC, 2004), background information prior to 2004 is provided where appropriate (Appendix F contains a com- plete inventory of ongoing and completed projects supported by the Program).1 FIELD STUDIES WITH AIMS ToWARD DRILLING AND PRoDUCTIoN TESTS The Program’s field studies2 have focused in the Gulf of Mexico and on the Alaska North Slope. Research projects in both regions have been important cornerstones of the Program’s portfolio since 2001 and have been oriented toward improving exploration methods and quantifying the hydrate resource, and more recently, toward evaluating the challenges of methane hydrate production (Appendix F).3 other research specific to the geologic and physical conditions of each region has also been conducted. An important component of the research in both regions has been their coordination with significant input to research coordination, resources, and execution from industry, other federal agencies, national laboratories, and the academic community, in addition to DoE (and the National Energy and Technology Laboratory [NETL]). Project listings and information, including publications and reports, are catalogued on - 1 line at http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/projects/ DoEProjects/DoE-Project_toc.html. In this review “field studies” refers to those research projects within the DoE portfolio with 2 active orientation toward production testing (see Appendix F). In Appendix F, Project Category “Field studies—Production and drilling projects,” Report 3 identifiers 1 through 4. 

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Review of Central Research Efforts Alaska North Slope Field Projects: Investigating Methane Hydrate Occurrences and Production Response The undertaking of methane hydrate field studies in northern Alaska has many practical advantages including a long history of scientific investiga- tion in the area, a wealth of conventional hydrocarbon drilling and pro- duction experience, and access to logistics infrastructure. Recognizing the efficiencies of working in the Arctic and that the knowledge gained there can have broad applications to other settings, DoE has supported several field programs to date and is working closely with partners in the hydro- carbon industry to develop a number of new initiatives. The geologic setting of methane hydrate in the Alaska North Slope is well described with a geothermal environment conditioned by thick occur- rences of terrestrial permafrost (osterkamp and Payne, 1981; Lachenbruch et al., 1988; Clow and Lachenbruch, 1998). Regional studies initiated in the 1980s (Collett, 1993, 1995), based mainly on well-log interpretations and data from a coring project carried out in 1972, indicate that evidence for the occurrence of methane hydrate is most commonly found in the vicinity of the Kuparuk River, Milne Point, and Prudhoe Bay oil fields (Figure 3.1; see also Figure 2.3). occurrences of methane hydrate are thought to be primarily within coarse-grained clastic sediments often overlying deeper conventional oil and gas occurrences. ALASKA NORTH SLOpE METHANE HYdRATE RESERvOIR CHARACTERIzATION Initiated in 2001, this project, managed by BP Exploration Alaska, Inc. (BPXA) with participation of 16 different research groups has had over- arching goals to (1) characterize the in-place methane hydrate resource on the Alaska North Slope and (2) conduct field and laboratory studies to evaluate the commercial potential for its production. The focus of the four-phase study (Phases 1, 2, and 3A) has been BPXA’s Milne Point production unit (Figure 3.1). Completion of Phases 1 and 2 (in 2005) resulted in seismic and well-log characterization, structural mapping, and 

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 MilnePoint 3D Alaska State waters o 149 o 00' 150 o 00' 148 00' 151o 00' (outer limit) seismic survey Free gas N MilnePoint Tarn accumulation 70 o 30' Mt Elbert Kuparuk River Prudhoe By a 70 o 15' Eileen accumulation Index map Methane hydrate Canada U.S.A. Methane hydrate 0 30000 ft 0 9000 m 70 o 00' EXPLANATION Zone of free gas (not in methane hydrate) Producing oil fields Conventional oil and gas wells Eileen methane hydrate accumulation Tarn methane hydrate accumulation FIGURE 3.1 Map of northern Alaska near the Kuparuk, Milne Point, and Prudhoe Bay oil fields. Location of the Mount Elbert stratigraphic test well is also shown. Analysis ofigure 3.1.epshydrate reservoir and resource characterization relies F the methane upon access to subsurface data including industry seismic and well-log information. Data coverage decreases away from the landscape Prudhoe Bay well cluster (see regional well distribution also in Figure 2.3). SOURCE: U.S. Geological Survey.

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Review of Central Research Efforts geophysical and reservoir modeling of the Milne Point area to calculate the regional in-place reservoir potential of a specific structural trend, and to allow economic analysis of field development scenarios. Phase 3A focused on planning, drilling, and analysis of a stratigraphic test well at the Mount Elbert prospect at Milne Point.4 Field work was completed in February 2007 with extensive methane hydrate coring, advanced open-hole well logging, in situ formation testing, and a com- prehensive post-field laboratory and modeling effort (Boswell et al., 2008; Hunter et al., 2008). This program was effectively managed with special attention to site selection and completion of a state-of-the-art research and development program that for the first time documented the in situ formation properties of a concentrated methane hydrate deposit on the North Slope. Methane hydrate was recovered from two sandstone inter- vals, each approximately 43-44 feet thick (Figure 3.2) with about 65 per- cent methane hydrate saturation. Saturation refers to the percentage of the pore space between sand grains that is occupied by methane hydrate. By integrating detailed core investigations, well-log attributes, and regional three-dimensional (3D) seismic interpretations, the project successfully developed a petroleum system model for the methane hydrate occurrences which established the geothermal setting, gas source, migration and trap- ping mechanisms, and the in situ properties of reservoir sands and enclos- ing sediments above and below them. These concepts were subsequently extended by the USGS in their assessment of the resource potential of the entire Alaska North Slope (Collett et al., 2008; Lee et al., 2008; USGS, 2008; see also Chapter 2). The Mount Elbert methane hydrate stratigraphic test well also ad- vanced research pertinent to evaluating the production response of methane hydrate. Small-scale in situ formation testing was undertaken using Schlumberger’s wireline Modular Dynamic Formation Tester (MDT) tool (Boswell et al., 2008; Hunter et al., 2008; see also Chapter 2). With this tool, a 1-meter formation interval was isolated and the formation pressures Note throughout this report that Mount Elbert refers to the actual prospect—and test well— 4 within the Milne Point area. Milne Point is a more regional name referring to an oil field in which the Mount Elbert prospect was drilled. 

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . Compressional Shear Zonation and Velocity Velocity Gamma Ray Density Resistivity Fluid Contacts m/sec 1.6 1.0 1000 1500 m/sec 1700 API g/cm3 ohm-m 3500 500 0 100 2.5 1800 Top Unit D 2000 Unit D hydrate Top Unit C Unit C hydrate 2200 Core Depth (ft below KB) 2400 Top Unit B 2600 Top Unit A 2800 ~ Base Hydrate Stability Zone 3000 FIGURE 3.2 Geophysical wireline log data with gamma-ray, density, resistivity, compressional, and shear velocity values from the Mount Elbert-01 stratigraphic test well. The well was drilled to 1,987 feet and cored to 2,492 feet below kelly bushing (BKB). Core and logs revealed methane3.2.eps in two clastic sand intervals within the Figure hydrate Sagavanirktok formation “Unit C” andtrait D.” The methane hydrate intervals have por “Unit distinct geophysical signatures on the well logs, including high resistivity and velocity relative to the surrounding sedimentary units. The base of the methane hydrate stability zone is interpreted at about 2,854 feet BKB. The KB references the elevation of the “kelly bushing” at the rig floor and is 55 feet at this location; log depths are in measured depth, which in this approximately vertical well are about 55 feet deeper than sub- sea depths. SOURCE: http://www.netl.doe.gov/ technologies/oil-gas/publications/ Hydrates/2009Reports/NT41332_BPXA-Hunter.pdf. manipulated. Surface readout of the subsequent pressure response, quan- tification of the inflowing material (formation water, gas, and sediment), and sampling capability permitted detailed interpretation of the formation response to reducing the pressure regime at the site. This technique had been successfully used in a cased-hole configuration at the Mallik site in 2002 (Dallimore and Collett, 2005; see also Chapter 2) and offshore in the Nankai Trough (Fujii et al., 2008). 

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Review of Central Research Efforts At Mount Elbert, the MDT yielded the first tests in the open-hole configuration to enable more accurate formation testing without the influ- ence of casing and cement (Boswell et al., 2008). Although interpretation of the MDT results proved complex (Anderson et al., 2008; Hunter et al., 2008), when combined, the MDT and nuclear magnetic resonance log data from Mount Elbert enabled accurate assessments of the in situ and relative permeability of methane hydrate intervals. Methane hydrate dis- sociation and free-gas production were observed in the later stages of each test when the formation pressure was reduced below methane hydrate equi- librium conditions. Complex pressure buildups were also observed when the methane hydrate dissociated, perhaps indicating more complicated behavior of the methane hydrate or formation of ice (Hunter et al., 2008). Developing a better understanding of the behavior of methane hydrate during pressure drawdown and the efficiency of pressure drawdown in pro- ducing methane hydrate remains important for future work at this site. Within the context of these substantial gains in knowledge, three main challenges and needs remain with regard to understanding the potential to produce methane from methane hydrate reservoirs on the Alaska North Slope. These include 1. Further research to ascertain the detailed ground temperature regime of the in situ methane hydrate occurrences; 2. Investigation of the significance and detailed associations of free methane and methane hydrate, especially within the context of identification of geohazards; and 3. Long-term production testing. NEw ALASKA NORTH SLOpE FIELd STUdIES Phase 3B of Alaska North Slope project Building upon the considerable progress made to date in Phases 1, 2, and 3A of the cooperative agreement between DoE and BPXA on the Alaska North Slope, the participant group has expressed interest in continu- ing the work with increased focus on production testing. In particular, the 

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . group agrees that the small-scale MDT testing is not sufficient to assess the production response of a methane hydrate reservoir. The results of this project to date are important, particularly with regard to verification of a proposed geologic model for methane hydrate occurrence. At present, the results of the initial phases of the project are being used to evaluate and rank locations for the development of a long-term production test site in the Prudhoe Bay area. Several sites are under examination by BPXA man- agement for consideration to proceed to Phase 3B. Land ownership and access issues are also part of this process. A decision by BPXA to move to Phase 3B—production testing—is anticipated by the end of March 2010. North Slope Borough Project The DoE reached agreement in December 2008 with the North Slope Borough to assess drilling and long-term production testing opportunities to evaluate the methane hydrate resource potential associated with the Barrow Gas Fields (see location in Figure 2.3) where free-gas occurrences have already been developed as an energy source for the community of Barrow. This project is the second-phase follow-on of a 2-year project (“Phase 1”) with the North Slope Borough (conducted from 2006 to 2008) to character- ize and quantify the methane hydrate resource potential of the Barrow Gas Fields. During Phase 1, methane hydrate stability modeling was conducted to identify the base of the hydrate stability zone in three areas; the aim was to identify areas where a hydrate-stable zone exists in an up-dip position relative to known gas reservoir sands (free gas). Further analysis during Phase 1 defined two locations for potential hydrate test wells. Research during Phase 2 will include (1) geologic studies to verify this accumulation model of methane hydrate occurrences up-dip and in contact with the free gas and (2) the design, drilling, logging, coring, and continu- ous monitoring of a production well to test the commercial potential of producing gas through depressurization dissociation from the free-gas zone underlying the hydrate deposits. Although methane hydrate accumulations with lower contacts to free gas have in the past been proposed as a common occurrence, recent field studies around the world have suggested that the free gas may often exist in low concentrations. The Barrow project will pro- 0

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Review of Central Research Efforts vide field verification of this type of accumulation model and allow assess- ment of the degree of the porous media associations of methane hydrate and free gas. Success with the project will increase industry’s understanding of the role of methane hydrate in the recharge of producing conventional gas fields and of how dissociation of methane hydrate may improve field performance. Methane Hydrate Production Trial Using Carbon Dioxide–Methane Exchange In fall 2008, ConocoPhillips and DoE agreed to pursue a field re- search project on the Alaska North Slope with a stated goal to define, plan, and conduct a field trial of a methane hydrate production methodol- ogy whereby carbon dioxide molecules can be exchanged in situ for the methane molecules within a hydrate structure, thus releasing the methane for production. The purpose of the project is to evaluate the viability of this hydrate production technique and to understand the implications of the process at a field scale (Farrell and Howard, 2009). Conceptually, this novel production scheme has the very desirable attribute that it could reduce the greenhouse gas footprint of methane hydrate production by sequestering carbon dioxide while producing methane. However, achieving this goal presents several significant challenges because the concept is based largely on small-scale laboratory experiments conducted on artificial media (Stevens et al., 2008), and no experiments have been performed to date on fully representative, unconsolidated samples. Scaling these experiments to a full-sized field trial will likely present significant technical challenges including complex well completions and operational procedures. The project is divided into three phases, with work completed under Phase 1 that included developing a ranked set of possible field sites on the Alaska North Slope. Final field site selection occurred during Phase 2, which began in May 2009. Phase 2 work will include both experimental and well-design components. The third phase of the project, assuming successful completion of Phase 2, aims to validate the laboratory tests in the field. At the time of preparation of this report, the project will initiate Phase 3 in January 2010. 1

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . Gulf of Mexico Project Overview The joint industry project ( JIP) in the Gulf of Mexico is a collaborative undertaking led by Chevron Energy Technology Company with a central goal in the initial phases to address critical questions in marine methane hydrate exploration and geohazard assessment. The project has involved 18 industry partners, federal agencies (including DoE, the Minerals Manage- ment Service [MMS], and the USGS), national laboratories, and university research groups.5 During the first two phases of the project (2001-2007) the JIP made several contributions to the overall understanding of marine methane hydrate, as well as of detailed aspects of local methane hydrate occurrences in the Gulf of Mexico. Phases 1 and 2 culminated in the first successful Gulf of Mexico drilling and coring expedition for methane hydrate in May 2005 at two sites (Atwater Valley and Keathley Canyon; Figure 3.3) during which a substantial quantity of well logs, cores, and borehole seismic data were acquired. Laboratory analyses of the cores included analysis of the physical and mechanical properties of fine-grained hydrate-bearing sedi- ments. New tools specific to the shipboard drilling environment were also tested for acquiring and analyzing field samples. Among the notable, specific contributions from the project’s first two phases were the development of laboratory equipment for making the first physical property measurements on pressure cores under in situ pressure conditions and developing a procedure of predrilling site-survey and site- selection efforts. The site-selection process was based on substantial in- dustry 3D seismic datasets, normally unavailable for academic research. The data and results from these phases (summarized in a special volume of Marine and Petroleum Geology6) were used to develop the third phase of http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/projects/ 5 DoEProjects/CharHydGoM-41330.html; members include Chevron Energy Technology Com- pany, Schlumberger oilfield Services, Halliburton Energy Services, ConocoPhillips, Total, Japan oil, Gas and Metals National Corporation, Reliance Industries Ltd., StatoilHydro, Korean National oil Company, MMS, Naval Research Lab, USGS, Rice University, Aumann & Associates Inc., Scripps Institute of oceanography, Georgia Institute of Technology, AoA Geophysics, and Geotek Ltd. Marine and Petroleum Geology, Volume 25, Issue 9, November 2008. 6 

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FIGURE 3.3 Bathymetric map of the northern Gulf of Mexico. The outline of the southeastern tip of Louisiana is visible between 89°W and 92°W. Bathymetric contours are in meters below sea level. Sites considered for drilling during Phases 1 and 2 (JIP Figure 3.3.eps 2005) and Phase 3A (2009) are indicated. Three sites fixed image logging-while-drilling JIP expedition in spring 2009 bitmap, selected for the (shown in red) were in the Alaminos Canyon (21) (which is also referred to as the “East Breaks” site), Green Canyon (955), landscape and Walker Ridge (313). In water depths of about 1,600 to 2,200 meters (5,250 to 7,218 feet), a semi-submersible rig was used to drill seven wells at these three sites. AC = Alaminos Canyon, KC = Keathley Canyon, WR = Walker Ridge, GC = Green  Canyon, AT = Atwater Valley. Isobaths are in meters. SOURCE: Deborah Hutchinson, U.S. Geological Survey.

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . parison study in which the leading methane hydrate reservoir simulators (CMG STARS, HydrateResSim, MH21, HyDRES, SToMP-HyD, and ToUGH+HyDRATE; see Chapter 2, Table 2.1) were used to predict hydrate production rates and to characterize the natural hydrate-bearing sediments. This code comparison study has been ongoing since late 2004. The DoE-supported reservoir modeling results have produced a num- ber of experience-based techniques, or heuristics, which may be valuable during the field tests/production assessments. Despite the progress made by the modeling projects to assess the production potential of methane hydrate reservoirs, the accuracy of the results is still uncertain because the models have not been validated against ground-truthing field data because of the lack of data from long-term production field tests. The state-of-the-art advanced simulator from Lawrence Berkeley National Laboratory ToUGH+HyDRATE code (see also Chapter 2) has also been applied to aid in the interpretation of laboratory experimental data, such as in reverse-modeling of computed tomography x-ray data to determine the physical property parameters (e.g., thermal conductivity and relative permeability data for heterogeneous hydrated sediment samples) (Figure 3.4). Recently, the ToUGH+HyDRATE code has been coupled with a commercial geomechanical code, FLAC3D, to assess the yield (fail- ure) distribution during production of hydrate-bearing sediments. Again, experimental data are critical to validate the geomechanical predictions. REMoTE SENSING The Program has supported 7 remote-sensing–related projects since 2006, of which four have focused on the Gulf of Mexico (Appendix F).9 This emphasis is logical given that the JIP project in the Gulf of Mexico re- quires predrilling site evaluations, including assessing existing industry geophysical data, collecting new geophysical data, and processing these datasets for the specific needs of shallow-drilling and shallow-hazard In Appendix F: Project Category “Resource characterization and remote sensing,” Report identi- 9 fiers 5 through 10 and 21 . 

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Review of Central Research Efforts FIGURE 3.4 Computed tomography x-ray core images showing significant heteroge- Figure 3.4.eps neity in hydrate-bearing sediment cores fixed images the laboratory (bottom left), and bitmaps, 6 synthesized in por trait in recovered natural cores from the ocean floor (top left), Mt. Elbert well (middle), and the Indian National Gas Hydrage Program expedition (far right). The color scales for all natural cores represent the bulk density distribution (in grams per cubic centimeter), and for the synthetic hydrate core the color scale represents methane hydrate saturation (%). SOURCE: Kneafsey (2009). surveys. The result, with the exception of the USGS-related interagency collaboration activities, which include the Alaska North Slope and off- shore India, is that remote-sensing–related projects are marine oriented. The research is conducted by various university groups, federal agencies, national laboratories, and industry partners and concentrates on two main types of remote-sensing techniques: (1) seismic and/or acoustic techniques and (2) controlled-source electromagnetic (CSEM) imaging. 

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . Seismic Techniques A major goal of the Program is to stimulate the development of new geo- physical tools and techniques to detect and quantify methane hydrate in na- ture, primarily using seismic reflection profiling techniques. Some projects attempt to also link this general theme to geomechanical and geohazard issues by coupling with the development of rock physics models to help understand the physical properties (particularly seismic velocities) of the sediments that may contain methane hydrate. Among the seismic-related projects supported by the Program, one in particular has achieved notable success in combining multicomponent seis- mic attributes, new rock physics models, and in situ data to estimate meth- ane hydrate concentrations in deepwater, near-seafloor strata of the Gulf of Mexico. This project has also advanced the use of other, or nonstandard, seismic techniques such as ocean-bottom cables or ocean-bottom seismom- eters in understanding methane hydrate in marine sediments10 (see Chapter 2) (e.g., Hardage et al., 2009; Figure 3.5). Increasing use in the DoE-supported remote-sensing projects is being made of available industry 3D seismic data, which provide an opportunity to better delineate the prospective methane hydrate deposits within the framework of the petroleum-system concept. one shortcoming of using industry seismic data for methane hydrate detection and quantification is that these data typically were acquired with a deeper target depth in mind, and thus the resulting vertical and horizontal resolution within the methane hydrate stability zone is significantly less than could be obtained if the surveys were optimized for methane hydrate targets. Lack of dedicated seismic surveys for (shallow) methane hydrate targets, particularly those across sites with high-quality LWD data such as those recently acquired during Phase 3A of the Gulf of Mexico JIP (see section Field Studies with Aims Toward Drilling and Production Tests), compromises identification and quantification of the methane hydrate resource. http://www.netl.doe.gov/technologies/oil-gas/FutureSupply/MethaneHydrates/projects/ 10 DoEProjects/MH_ 42667GoMSeismic.html; see also Appendix X. 100

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Review of Central Research Efforts FIGURE 3.5 New technology was developed for imaging near-seafloor geology with four-component ocean-bottom cable (OBC) data. This figure shows hydrate concentra- Figure 3.5.eps tions estimated along one of the study’s OBC profiles in the Gulf of Mexico. The units bitmap, fixed image are “percent of pore space occupied by methane hydrate.” (Cgh = color scale from 0 to por trait 35 percent on the right-hand side of the figure). Methane hydrate concentrations were estimated for layers identified by the numbers 2 through 5 (left side of the diagram). Con- centrations were not estimated for Layer 1 because no log data were available across this shallowest interval immediately below the seafloor. The calculated hydrate concentrations exhibit considerable lateral variation within each velocity layer and considerable vertical variability from layer to layer. The maximum methane hydrate concentration found along this OBC profile was in the left-hand side of the line where methane hydrate occupied a little more than 30 percent of the pore space of the host sediment (red colors). At the south end (left-hand side) of the line, the base of the hydrate stability zone (BHSZ) boundary is defined by a reversal of VP velocity. At the north end, a published thermal constraint is used to define the BHSZ. The concepts established through this study allowed the research- ers to conclude that evaluating deepwater hydrate systems with multicomponent seismic data is highly desirable. SOURCE: Hardage et al. (2009). 101

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . CSEM Two projects in the DoE Program’s remote-sensing portfolio have focused on developing new tools, approaches, and equipment to use CSEM tech- niques as a method for methane hydrate detection. Although CSEM techniques are widely used in exploration for conventional marine hydro- carbons, the technique has not yet attracted significant use in methane hydrate research. However, CSEM techniques hold considerable promise for methane hydrate detection because of the electrical resistivity contrasts between methane hydrate–bearing and water-saturated rocks (Chave et al., 1985; Edwards, 2005; Ruppel, 2009). Research Challenges At present, both seismic and CSEM methods as applied specifically to exploration for methane hydrate require additional research and devel- opment. Although exploratory drilling and production tests have been conducted in both Alaska and the Gulf of Mexico areas with success (see section Field Studies with Aims Toward Drilling and Production Tests), a critical contribution to advancing the research in these areas involves acquisition of dedicated, new seismic surveys specifically focused on methane hydrate detection. The combined use of seismic and CSEM in remote sensing for methane hydrate has the potential to minimize ambiguity and resolution limits compared to the use of either technique alone. As outlined in Chapter 2, exploration for methane hydrate occur- rences requires detailed assessment of the temperature and pressure regime within the potential methane hydrate–bearing sediment section to make better predictions of the depth to the base of methane hydrate stability. At this point, the Program’s research portfolio does not include tempera- ture (and, if possible, pressure) surveys, either through marine heat-probe deployments or through assessment of existing well data. Results from such studies could narrow the uncertainty in regional methane hydrate assessments and site-specific analyses, for example, through installation 10

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Review of Central Research Efforts of fiber-optic distributed temperature sensors, similar to those used in the Mallik program (Henninges et al., 2005). ENVIRoNMENTAL AND GEoHAzARD RESEARCH RELATED To METHANE HyDRATE DEGASSING THRoUGH GEoLoGIC TIME The Methane Hydrate Research and Development Act of 2000 (Appen- dix A) specifically encourages DoE to support basic and applied research “to assess and mitigate the environmental impact of hydrate degassing (including both natural degassing and degassing associated with commer- cial development).” To this end, the Program has supported a variety of projects from national laboratories, industry, and academic institutions that address many aspects of the environmental consequences of the degassing of methane hydrate. The Program has thus provided an opportunity for investigators to obtain fundamental information concerning the environ- mental impacts of methane hydrate degassing through geologic time, in- cluding impacts caused by current human activities and those predicted for the future. of 14 environmental impact projects supported by the Program since 2005, 10 have focused on some aspect of environmental impacts resulting from the natural degassing of methane hydrate (Appendix F).11 Different approaches have been taken in these 10 projects to obtain relevant informa- tion. Some projects deal mainly with methane oxidation, another focuses on the biological origins of methane, some use modeling of methane hydrate geodynamics, and still others consider rates of methane seepage (methane flux) (a) in thermokarst lakes of the Arctic, (b) in the water column of the Gulf of Mexico, (c) inferred in sediment of the Bering Sea, (d) from the stratigraphy of carbonates, and (e) in oceanic sediment based on sulfate profiles. The Gulf of Mexico serves as the field site for five of the 14 projects (Figure 3.6). In Appendix F: Project Category “Environmental studies,” Report identifiers 4, 11 through 11 19, and 24 through 27. 10

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R E A L I Z I N G M E T H A N E H y D R A T E P R O D U C T I O N I N T H E U .S . FIGURE 3.6 Gulf of Mexico methane hydrate deposit on the seafloor. A remotely operated vehicle was used to takeFigure 3.6.eps 350-day time series to document photographs over a methane hydrate occurrences and the drivers for their stability, including bottom water temperatures and the water temperaturefixed image MacDonald (2009). bitmap, profile. SOURCE: Most projects specifically proposed to generate new information re- garding the role of methane hydrate in the global carbon cycle and/or in global climate change. Research aimed toward placing methane hydrate degassing into a global context relative to the carbon cycle and climate change is ambitious. As yet no major breakthroughs have appeared from this research in the understanding of possible global roles for methane hydrate resulting from its natural degassing. To date, none of the Program’s projects have substantially addressed the potentially enhanced impacts expected from the commercial exploi- tation of methane hydrate although four of the projects in the environ- 10

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Review of Central Research Efforts mental portfolio have described some research goals that address geo- hazards and environmental issues associated with drilling and production. Also, no project to date has considered the mitigation of the environ- mental impacts of natural degassing and degassing associated with com- mercial development as specified in the enabling legislative language. These latter kinds of studies are critical for the development of strategies to minimize the environmental impacts resulting from any future commercial production of methane from methane hydrate. REFERENCES Anderson, B. J., J. W. Wilder, M. Kurihara, M. D. White, G. J. Moridis, S. J. Wilson, M. Pooladi- Darvish, y. Masuda, T. S. Collett, R. B. Hunter, H. Narita, K. Rose, and R. Boswell. 2008. Analysis of modular dynamic formation test results from the Mount Elbert-01 stratigraphic test well, Milne Point Unit, North Slope Alaska. In P roceedings of the Sixth International Conference on Gas Hydrates (ICGH 00), July 6-10, Vancouver, BC, Canada. Available online at http://www. fekete.com/resources/papers/analysis_modular_dynamic_paper.pdf. Accessed January 2, 2010. Birchwood, R., S. Noeth, M. Tjengdrawira, S. Kisra, F. Elisabeth, C. Sayers, R. Singh, P. Hooyman, R. Plumb, E. Jones, and B. Bloys. 2007. Modeling the mechanical and phase change stability of wellbores drilled in gas hydrates by the Joint Industry Program ( JIP) gas hydrates project Phase II. SPE Annual Technical Conference. November 11-14, Anaheim, CA. SPE 110796; doi:102118/110796-MS. Boswell, R., R. Hunter, T. S. Collett, S. Digert, S. Hancock, M. Weeks, and Mount Elbert Science Team. 2008. Investigation of gas hydrate bearing sandstone reservoirs at the Mount Elbert stratigraphic test well, Milne Point, Alaska. In P roceedings of the Sixth International Conference on Gas Hydrates (ICGH 00), July 6-10, Vancouver, BC, Canada. Available online at http://circle. ubc.ca/handle/2429/1167. Accessed January 2, 2010. Chave, M. R., J. L. Ribeiro, A. Selmi, P. Gibart. 1985. Electrical resistivity and seebeck effect in HgCr2Se4. Physica status solidi (a) 92(1):263-271. Available online at http://adsabs.harvard. edu/cgi-bin/nph-abs_connect��fforward=http://dx.doi.org/10.1002/pssa.2210920126. Accessed January 2, 2010. Clow, G., and A. Lachenbruch. 1998. Borehole locations and permafrost depths, Alaska, USA. In Inter- national Permafrost Association, Data and Information Working Group, comp. Circumpolar Active- Layer Permafrost System (CAPS), version 1.0. CD-RoM available from National Snow and Ice Data Center, nsidc@kryos.colorado.edu. Boulder: NSIDC, University of Colorado. Collett, T. S. 1993. Natural gas hydrates of the Prudhoe Bay and Kuparuk River area, North Slope, Alaska. American Association of Petroleum Geologists Bulletin 77(5):793-812. Collett, T. S. 1995. Gas hydrate resources of the United States. In National Assessment of United States Oil and Gas Resources (on CD-RoM), D. L. Gautier, ed. Digital Data Series, Vol. 30. Reston, VA: U.S. Geological Survey. 10

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Review of Central Research Efforts MacDonald, I. 2009. Remote Sensing Detection of Active Hydrocarbon Seeps: Implications For Methane in the Sea. Presentation to the Committee on Assessment of the Department of En- ergy’s Methane Hydrate Research and Development Program: Evaluating Methane Hydrate as a Future Energy Resource. Washington, DC, March 5. NRC (National Research Council). 2004. Charting the Future of Methane Hydrate Research in the United States. Washington, DC: The National Academies Press. 202 pp. osterkamp, T. E., and M. W. Payne. 1981. Estimates of permafrost thickness from well logs in northern Alaska: Cold Regions Science and Technology 5:13-17. Ruppel, C. 2009. Prospecting for Hydrates—Evolution of Detection and Evaluation Approaches. Presentation to the Committee on Assessment of the Department of Energy’s Methane Hydrate Research and Development Program: Evaluating Methane Hydrate as a Future Energy Resource, Washington, DC, March 5. Stevens, J., J. Howard, B. Baldwin, G. Ersland, J. Husebø, and A. Graue. 2008. Experimental hydrate formation and production scenarios based on Co2 sequestration. In P roceedings of the Sixth Inter- national Conference on Gas Hydrates, July 6-10, Vancouver, BC. Available online at http://www. netl.doe.gov/technologies/oil-gas/publications/hydrates/2009Reports /NT06553_StevensEtAl. pdf. Accessed october 15, 2009. USGS (U.S. Geological Survey). 2008. Assessment of Gas Hydrate Resources on the North Slope, Alaska Fact Sheet 2008-3073. october. Waite, W. F., J. C. Santamarina, D. D. Cortes, B. Dugan, B. N. Espinoza, J. Germaine, J. Jang, J. W. Jung, T. J. Kneafsey, H. Shin, K. Soga, W. J. Winters, and T. S. yun. 2009. Physical properties of hydrate-bearing sediments. Reviews of Geophysics 47:RG4003; doi:10.1029/2008RG000279. 10

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