Remote Sensing Applications for Antrim Shale Fracture Characterization, Michigan Basin

Advanced Research International (ARI) sent seven staff members to the 1997 International Coalbed Methane Symposium, held in Tuscaloosa, Alabama from May 12-17. ARI gave a short course on risk reduction strategies, including remote fracture detection, for coalbed methane exploration and development that was attended by about 25 coalbed methane industry professionals; and presented a paper entitled 'Optimizing coalbed methane cavity completion operations with the application of a new discrete element model.' We met with many potential clients and discussed our fracture detection services. China has vast coalbed methane resources, but is still highly dependent on coal-and wood-burning. This workshop, sponsored by the United Nations, was intended to help China develop its less-polluting energy reserves. ARI is successfully finding new applications for its fracture detection services. Coalbed methane exploration became an important market in this quarter, with the inception of a joint industry/government collaboration between ARI, Texaco and DOE to use remote fracture detection to identify areas with good potential for coalbed methane production in the Ferron Coal Trend of central Utah. Geothermal energy exploration is another emerging market for ARI, where fracture detection is applied to identify pathways for groundwater recharge, movement, and the locations of potential geothermal reservoirs. Ari continued work on two industry/government collaborations to demonstrate fracture detection to potential clients. Also completed the technical content layout for multimedia CD-ROM that describes our remote fracture detection services

Multi-Site Application of the Geomechanical Approach for Natural Fracture Exploration

In order to predict the nature and distribution of natural fracturing, Advanced Resources Inc. (ARI) incorporated concepts of rock mechanics, geologic history, and local geology into a geomechanical approach for natural fracture prediction within mildly deformed, tight (low-permeability) gas reservoirs. Under the auspices of this project, ARI utilized and refined this approach in tight gas reservoir characterization and exploratory activities in three basins: the Piceance, Wind River and the Anadarko. The primary focus of this report is the knowledge gained on natural fractural prediction along with practical applications for enhancing gas recovery and commerciality. Of importance to tight formation gas production are two broad categories of natural fractures: (1) shear related natural fractures and (2) extensional (opening mode) natural fractures. While arising from different origins this natural fracture type differentiation based on morphology is sometimes inter related. Predicting fracture distribution successfully is largely a function of collecting and understanding the available relevant data in conjunction with a methodology appropriate to the fracture origin. Initially ARI envisioned the geomechanical approach to natural fracture prediction as the use of elastic rock mechanics methods to project the nature and distribution of natural fracturing within mildly deformed, tight (low permeability) gas reservoirs. Technical issues and inconsistencies during the project prompted re-evaluation of these initial assumptions. ARI's philosophy for the geomechanical tools was one of heuristic development through field site testing and iterative enhancements to make it a better tool. The technology and underlying concepts were refined considerably during the course of the project. As with any new tool, there was a substantial learning curve. Through a heuristic approach, addressing these discoveries with additional software and concepts resulted in a stronger set of geomechanical tools. Thus, the outcome of this project is a set of predictive tools with broad applicability across low permeability gas basins where natural fractures play an important role in reservoir permeability. Potential uses for these learnings and tools range from rank exploration to field-development portfolio management. Early incorporation of the permeability development concepts presented here can improve basin assessment and direct focus to the high potential areas within basins. Insight into production variability inherent in tight naturally fractured reservoirs leads to improved wellbore evaluation and reduces the incidence of premature exits from high potential plays. A significant conclusion of this project is that natural fractures, while often an important, overlooked aspect of reservoir geology, represent only one aspect of the overall reservoir fabric. A balanced perspective encompassing all aspects of reservoir geology will have the greatest impact on exploration and development in the low permeability gas setting

Methods of estimating shale gas resources - Comparison, evaluation and implications

Estimates of technically recoverable shale gas resources remain highly uncertain, even in regions with a relatively long history of shale gas production. This paper examines the reasons for these uncertainties, focusing in particular on the methods used to derive resource estimates. Such estimates can be based upon the extrapolation of previous production experience in developed areas, or from the geological appraisal of undeveloped areas. The paper assesses the strengths and weaknesses of these methods, the level of uncertainty in the results and the implications of this for current policy debates. We conclude that there are substantial difficulties in assessing the recoverable volumes of shale gas and that current resource estimates should be treated with considerable caution. Most existing studies lack transparency or a rigorous approach to assessing uncertainty and provide estimates that are highly sensitive to key variables that are poorly defined - such as the assumed ratio of gas-in-place to recovered gas (the ‘recovery factor’) and the assumed ultimate recovery from individual wells. To illustrate the uncertainties both within and between different methodological approaches, we provide case studies of resource estimates for the Marcellus shale in the US and three basins in India

Natural Gas Resources of the Greater Green River and Wind River Basins of Wyoming (Assessing the Technology Needs of Sub-economic Resources, Phase I: Greater Green River and Wind river Basins, Fall 2002)

In 2000, NETL conducted a review of the adequacy of the resource characterization databases used in its Gas Systems Analysis Model (GSAM). This review indicated that the most striking deficiency in GSAM’s databases was the poor representation of the vast resource believed to exist in low-permeability sandstone accumulations in western U.S. basins. The model’s databases, which are built primarily around the United States Geological Survey (USGS) 1995 National Assessment (for undiscovered resources), reflected an estimate of the original-gas-inplace (OGIP) only in accumulations designated “technically-recoverable” by the USGS –roughly 3% to 4% of the total estimated OGIP of the region. As these vast remaining resources are a prime target of NETL programs, NETL immediately launched an effort to upgrade its resource characterizations. Upon review of existing data, NETL concluded that no existing data were appropriate sources for its modeling needs, and a decision was made to conduct new, detailed log-based, gas-in-place assessments

Natural Gas Resources of the Greater Green River and Wind River Basins of Wyoming (Assessing the Technology Needs of Sub-economic Resources, Phase I: Greater Green River and Wind river Basins, Fall 2002)

In 2000, NETL conducted a review of the adequacy of the resource characterization databases used in its Gas Systems Analysis Model (GSAM). This review indicated that the most striking deficiency in GSAM’s databases was the poor representation of the vast resource believed to exist in low-permeability sandstone accumulations in western U.S. basins. The model’s databases, which are built primarily around the United States Geological Survey (USGS) 1995 National Assessment (for undiscovered resources), reflected an estimate of the original-gas-inplace (OGIP) only in accumulations designated “technically-recoverable” by the USGS –roughly 3% to 4% of the total estimated OGIP of the region. As these vast remaining resources are a prime target of NETL programs, NETL immediately launched an effort to upgrade its resource characterizations. Upon review of existing data, NETL concluded that no existing data were appropriate sources for its modeling needs, and a decision was made to conduct new, detailed log-based, gas-in-place assessments

Rigorous Screening Technology for Identifying Suitable CO2 Storage Sites II

This report serves as the final technical report and users manual for the 'Rigorous Screening Technology for Identifying Suitable CO2 Storage Sites II SBIR project. Advanced Resources International has developed a screening tool by which users can technically screen, assess the storage capacity and quantify the costs of CO2 storage in four types of CO2 storage reservoirs. These include CO2-enhanced oil recovery reservoirs, depleted oil and gas fields (non-enhanced oil recovery candidates), deep coal seems that are amenable to CO2-enhanced methane recovery, and saline reservoirs. The screening function assessed whether the reservoir could likely serve as a safe, long-term CO2 storage reservoir. The storage capacity assessment uses rigorous reservoir simulation models to determine the timing, ultimate storage capacity, and potential for enhanced hydrocarbon recovery. Finally, the economic assessment function determines both the field-level and pipeline (transportation) costs for CO2 sequestration in a given reservoir. The screening tool has been peer reviewed at an Electrical Power Research Institute (EPRI) technical meeting in March 2009. A number of useful observations and recommendations emerged from the Workshop on the costs of CO2 transport and storage that could be readily incorporated into a commercial version of the Screening Tool in a Phase III SBIR

Effect of sorption induced swelling on gas transport in coal

In this study, an investigation of carbon dioxide sorption induced coal swelling and its effects on gas transport in coal is shown. The model presented is based on an existing coupled thermal, hydraulic, chemical and mechanical (THCM) model. A series of numerical simulations dealing with high pressure carbon dioxide injection in coal sample is presented. In particular, the effect of carbon dioxide sorption induced swelling on permeability evolution and gas breakthrough is investigated. Different cases are considered accounting for the difference in coal seam properties and its sorption characteristics. Under the conditions considered, it is demonstrated that the permeability response of coal to gas is affected by the carbon dioxide sorption induced volumetric strain. The results suggest that medium and high porous coals that swell gradually over the range of pressures considered in this work would lose a smaller portion of injectivity during gas injection, compared to low porous coals that swell significantly at low pressures, allowing quick breakthrough of gas through the domain

Appraisal of the technical and economic potential of U.S. tar sands

reportU.S. tar sands constitute a large, essentially undeveloped resource that could, with technological advances. provide an important source for future liquid supplies of petroleum. The identified resource base, as reported in the update to the 19B3 report by the Interstate Oil Compact Commission (IDCC), is appraised at over 60 billion barrels, and significant additional resources have recently been identified offshore California and in Alaska. This resource is widely distributed and is present in major quantities in each of the key oil producing states