8 Matching Results

Search Results

Advanced search parameters have been applied.

Options for gas-to-liquids technology in Alaska

Description: The purpose of this work was to assess the effect of applying new technology to the economics of a proposed natural gas-to-liquids (GTL) plant, to evaluate the potential of a slower-paced, staged deployment of GTL technology, and to evaluate the effect of GTL placement of economics. Five scenarios were economically evaluated and compared: a no-major-gas-sales scenario, a gas-pipeline/LNG scenario, a fast-paced GTL development scenario, a slow-paced GTL development scenario, and a scenario which places the GTL plant in lower Alaska, instead of on the North Slope. Evaluations were completed using an after-tax discounted cash flow analysis. Results indicate that the slow-paced GTL scenario is the only one with a rate of return greater than 10%. The slow-paced GTL development would allow cost saving on subsequent expansions. These assumed savings, along with the lowering of the transportation tariff, combine to distinguish this option for marketing the North Slope gas from the other scenarios. Critical variables that need further consideration include the GTL plant cost, the GTL product premium, and operating and maintenance costs.
Date: December 1, 1999
Creator: Robertson, E.P.
Partner: UNT Libraries Government Documents Department

Conversion economics for Alaska North Slope natural gas

Description: For the Prudhoe Bay field, this preliminary analysis provides an indication that major gas sales using a gas pipeline/LNG plant scenario, such as Trans Alaska Gas System, or a gas-to-liquids process with the cost parameters assumed, are essentially equivalent and would be viable and profitable to industry and beneficial to the state of Alaska and the federal government. The cases are compared for the Reference oil price case. The reserves would be 12.7 BBO for the base case without major gas sales, 12.3 BBO and 20 Tcf gas for the major gas sales case, and 14.3 BBO for the gas-to-liquids conversion cases. Use of different parameters will significantly alter these results; e.g., the low oil price case would result in the base case for Prudhoe Bay field becoming uneconomic in 2002 with the operating costs and investments as currently estimated.
Date: July 1, 1995
Creator: Thomas, C.P. & Robertson, E.P.
Partner: UNT Libraries Government Documents Department

Permeability Modification Using a Reactive Alkaline-Soluble Biopolymer

Description: Polymer injection has been used in reservoirs to alleviate contrasting permeability zones. Current technology relies on the use of cross-linking agents to initiate gelation. The use of biological polymers are advantageous in that they can block high permeability areas, are environmentally friendly, and have potential to form reversible gels without the use of hazardous cross-linkers. Recent efforts at the Idaho National Engineering and Environmental Laboratory (INEEL) have produced a reactive alkaline-soluble biopolymer from Agrobacterium sp. ATCC no. 31749 that gels upon decreasing the pH of the polymeric solution. The focus of this study was to determine the impact an alkaline-soluble biopolymer can have on sandstone permeability. Permeability modification was investigated by injecting solubilized biopolymer into Berea sandstone cores and defining the contribution of pH, salt, temperature, and Schuricht crude oil on biopolymer gelation. The biopolymer was soluble in KOH at a pH greater than 11.4 and gelled when the pH dropped below 10.8. The Berea sandstone core buffered the biopolymer solution, decreasing the pH sufficiently to form a gel, which subsequently decreased the permeability. The effluent pH of the control cores injected with 0.01 {und M} KOH (pH 12.0) and 0.10{und M} KOH (pH 13.0) decreased to 10.6 and 12.7, respectively. The permeability of the sandstone core injected with biopolymer was decreased to greater than 95% of the original permeability at 25 C in the presence of 2% NaCl, and Schuricht crude oil; however, the permeability increased when the temperature of the core was increased to 60 C. Residual resistance factors as high as 792 were seen in Berea cores treated with biopolymer. The buffering capacity of sandstone has been demonstrated to reduce the pH of a biopolymer solution sufficiently to cause the polymer to form a stable in-situ gel. This finding could potentially lead to alternate technology for permeability ...
Date: October 1, 2003
Creator: Fox, Snadra L.; Xie, X.; Schaller, K. D.; Robertson, E. P. & Bala, G. A.
Partner: UNT Libraries Government Documents Department

A Mechanistic Model for CO2 Sequestration in Tiffany Coal Bed Methane Field

Description: The objective of this project is to develop mechanistic models specific to CO2 sequestration in BP's Tiffany coal bed methane (CBM) field. In this study, the original field model was modified to match the field performance of a 5-spot pattern in the northern part of the Tiffany Field where BP plans to perform a micro-pilot test. The modified model consists of one high-permeability fast layer sandwiched between two low-permeability slow layers. In this mechanistic model, the fast layer represents well-cleated and fractured coal from all geological layers while the slow layers represent coal with little or no fracture development from the same geological layers. The model successfully matched the performance of the 5-spot pattern during the enhanced recovery period. However, in order to match nitrogen breakthrough times and nitrogen cut the vertical transmissibility between layers had to be set to zero. During gas injection, nitrogen was allowed to enter all three layers, not just the high-permeability fast layer. However, because the permeabilities of the slow layers were low and there is no communication between the fast and the slow layers, most of the injected nitrogen entered the high-permeability fast layer. This suggests that the future gas injection and CO2 sequestration may be restricted to only one third of the total available pay.
Date: May 1, 2003
Creator: Liang, J.; Raterman, K.T. & Robertson, E.P.
Partner: UNT Libraries Government Documents Department

Laboratory methods for enhanced oil recovery core floods

Description: Current research at the Idaho National Engineering Laboratory (INEL) is investigating microbially enhanced oil recovery (MEOR) systems for application to oil reservoirs. Laboratory corefloods are invaluable in developing technology necessary for a field application of MEOR. Methods used to prepare sandstone cores for experimentation, coreflooding techniques, and quantification of coreflood effluent are discussed in detail. A technique to quantify the small volumes of oil associated with laboratory core floods is described.
Date: March 1, 1994
Creator: Robertson, E.P.; Bala, G.A. & Thomas, C.P.
Partner: UNT Libraries Government Documents Department

An overview of field specific designs of microbial EOR

Description: The selection and design of a microbial enhanced oil recovery (MEOR) process for application in a specific field involves geological, reservoir, and biological characterization. Microbially mediated oil recovery mechanisms (biogenic gas, biopolymers, and biosurfactants) are defined by the types of microorganisms used. The engineering and biological character of a given reservoir must be understood to correctly select a microbial system to enhance oil recovery. The objective of this paper is to discuss the methods used to evaluate three fields with distinct characteristics and production problems for the applicability of MEOR technology. Reservoir characteristics and laboratory results indicated that MEOR would not be applicable in two of the three fields considered. The development of a microbial oil recovery process for the third field appeared promising. Development of a bacterial consortium capable of producing the desired metabolites was initiated and field isolates were characterized.
Date: December 1, 1995
Creator: Robertson, E.P.; Bala, G.A.; Fox, S.L.; Jackson, J.D. & Thomas, C.P.
Partner: UNT Libraries Government Documents Department

INEEL Biotechnology for Oilfield Application--Microbial Enhanced Oil Recovery FY-03 Report

Description: The Idaho National Engineering and Environmental Laboratory (INEEL) Biotechnology for Oilfield Operations program supports development, engineering, and application of biotechnology for exploration and production. This continuing INEEL program also supports mitigation of detrimental field conditions. The program is consistent with the United States Department of Energy mission to ¡§promote activities and policies through its oil technology and natural gas supply programs to enhance the efficiency and environmental quality of domestic oil and natural gas exploration, recovery, processing, transport, and storage.¡¨ In addition, the program directly supports the focus areas of Reservoir Life Extension; Advanced Drilling, Completion and Stimulation Systems; Effective Environmental Protection; and Cross Cutting Areas. The program is enhanced by collaborative relationships with industry and academia. For fiscal year 2003, the program focused on production and characterization of biological surfactants from agricultural residuals and the production and application of reactive microbial polymers. This report specifically details: 1. Use of a chemostat reactor operated in batch mode for producing surfactin, with concomitant use of an antifoam to prevent surfactant loss. The program achieved production and recovery of 0.6 g/L of surfactin per 12 hr. 2. Characterization of surfactin produced from agricultural residuals with respect to its ability to mediate changes in surface tension. Conditions evaluated were salt (as NaCl) from 0 to 10% (w/v), pH from 3 to 10, temperature from 21 to 70¢XC, and combinations of these conditions. When evaluated singularly, pH below 6 and salt concentrations above 30 g/L were found to have an adverse impact on surfactin. Temperatures of 70¢XC for 95 days had no effect. When the effect of temperature was added to the pH experiment, there were no significant changes, and, again, surface tension, at any temperature, increased at pH below 6. When temperature (70¢XC) was added to the experiments with salt, the impacts of ...
Date: November 1, 2003
Creator: Bala, G. A.; Bruhn, D. F.; Fox, S. L.; Noah, K. S.; Schaller, K. D.; Robertson, E. P. et al.
Partner: UNT Libraries Government Documents Department

Economics of Alaska North Slope gas utilization options

Description: The recoverable natural gas available for sale in the developed and known undeveloped fields on the Alaskan North Slope (ANS) total about 26 trillion cubic feet (TCF), including 22 TCF in the Prudhoe Bay Unit (PBU) and 3 TCF in the undeveloped Point Thomson Unit (PTU). No significant commercial use has been made of this large natural gas resource because there are no facilities in place to transport this gas to current markets. To date the economics have not been favorable to support development of a gas transportation system. However, with the declining trend in ANS oil production, interest in development of this huge gas resource is rising, making it important for the U.S. Department of Energy, industry, and the State of Alaska to evaluate and assess the options for development of this vast gas resource. The purpose of this study was to assess whether gas-to-liquids (GTL) conversion technology would be an economic alternative for the development and sale of the large, remote, and currently unmarketable ANS natural gas resource, and to compare the long term economic impact of a GTL conversion option to that of the more frequently discussed natural gas pipeline/liquefied natural gas (LNG) option. The major components of the study are: an assessment of the ANS oil and gas resources; an analysis of conversion and transportation options; a review of natural gas, LNG, and selected oil product markets; and an economic analysis of the LNG and GTL gas sales options based on publicly available input needed for assumptions of the economic variables. Uncertainties in assumptions are evaluated by determining the sensitivity of project economics to changes in baseline economic variables.
Date: August 1, 1996
Creator: Thomas, C.P.; Doughty, T.C.; Hackworth, J.H.; North, W.B. & Robertson, E.P.
Partner: UNT Libraries Government Documents Department