The availability of industrial alkalinity sources is investigated to determine their potential for the mineral carbonation of CO 2 from point-source emissions in the United States. The available aggregate markets are ...
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The availability of industrial alkalinity sources is investigated to determine their potential for the mineral carbonation of CO 2 from point-source emissions in the United States. The available aggregate markets are investigated as potential sinks for the mineralized CO 2 products. Additionally, a life-cycle assessment of aqueous mineral carbonation suggests that a variety of alkalinity sources and process configurations are capable of net CO 2 reductions. The CO 2 storage potential of mineral carbonation was estimated using the life-cycle assessment results and alkalinity source availability.
Most undergraduate engineering economics textbooks and related curricula include elements of decision analysis, and decision trees are often introduced and promoted as a decision making tool. The teaching of value of ...
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The axial-load-displacement-capacity response of drilled shaft foundations can be analyzed efficiently using the results of seismic piezocone tests (SCPTu) which provide four independent readings in the ground: cone t...
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The axial-load-displacement-capacity response of drilled shaft foundations can be analyzed efficiently using the results of seismic piezocone tests (SCPTu) which provide four independent readings in the ground: cone tip stress (q t), sleeve friction (fs), penetration porewater pressure (ub), and downhole shear wave velocity (Vs). The penetration data are used in a direct CPT method to assess side resistance and end-bearing capacity components, while the shear wave provides the initial stiffness for an elastic continuum analysis of vertical displacements and axial load transfer distributions. Results from instrumented drilled shaft load tests conducted at the national geotechnical experimentation sites at College Station, Texas and Opelika, Alabama are utilized to illustrate the methodology.
This paper summarizes an effort, ongoing for the last eight years, to develop a predictive theory of mudcake buildup and filtrate invasion practical enough to be utilized in everyday drilling operations. During that t...
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This paper summarizes an effort, ongoing for the last eight years, to develop a predictive theory of mudcake buildup and filtrate invasion practical enough to be utilized in everyday drilling operations. During that time, extensive filtration measurements have been made on about 100 water-base muds, about 2/3 being lab-mixed and 1/3 field muds. With this data base we have arrived at a mathematical model, and developed a corresponding numerical simulator, which allows determination of the necessary mudcake parameters and which quantitatively reproduces virtually every aspect of filtration seen in the laboratory. Extension of the model to predict filtration downhole is planned and will be presented at a later time. We find that a minimum of three and a maximum of six parameters are required to characterize a mudcake. The basic three are porosity, permeability and a compressibility exponent that describes the dependence of the first two on pressure across the mudcake. If the mudcake exhibits negligible hyst eresis when pressure across it is first cycled a single compressibility factor suffices. If it does exhibit hysteresis a second compressibility factor is required. The three (or four) parameters can be determined from a static filtration test, which could be performed at the wellsite. For those mudcakes which erode, two additional parameters, which define the shear strength of the mudcake under zero pressure and with applied pressure, must be determined. This requires a dynamic filtration test, best performed in a regional mud lab. Examples are shown utilizing muds covering a wide range of compositions and weights. Derivation of mudcake parameters is illustrated and comparison between simulated and measured filtration sequences is presented.
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