Uncertainty quantification for CO2 sequestration and enhanced oil recovery

This study develops a statistical method to perform uncertainty quantification for understanding CO2 storage potential within an enhanced oil recovery (EOR) environment at the Farnsworth Unit of the Anadarko Basin in northern Texas. A set of geostatistical-based Monte Carlo simulations of CO2-oil-water flow and reactive transport in the Morrow formation are conducted for global sensitivity and statistical analysis of the major uncertainty metrics: net CO2 injection, cumulative oil production, cumulative gas (CH4) production, and net water injection. A global sensitivity and response surface analysis indicates that reservoir permeability, porosity, and thickness are the major intrinsic reservoir parameters that control net CO2 injection/storage and oil/gas recovery rates. The well spacing and the initial water saturation also have large impact on the oil/gas recovery rates. Further, this study has revealed key insights into the potential behavior and the operational parameters of CO2 sequestration at CO2-EOR sites, including the impact of reservoir characterization uncertainty; understanding this uncertainty is critical in terms of economic decision making and the cost-effectiveness of CO2 storage through EOR.Comment: 9 pages, 6 figures, in press, Energy Procedia, 201

A STOCHASTIC SIMULATION-BASED HYBRID INTERVAL FUZZY PROGRAMMING APPROACH FOR OPTIMIZING THE TREATMENT OF RECOVERED OILY WATER

In this paper, a stochastic simulation-based hybrid interval fuzzy programming (SHIFP) approach is developed to aid the decision-making process by solving fuzzy linear optimization problems. Fuzzy set theory, probability theory, and interval analysis are integrated to take into account the effect of imprecise information, subjective judgment, and variable environmental conditions. A case study related to oily water treatment during offshore oil spill clean-up operations is conducted to demonstrate the applicability of the proposed approach. The results suggest that producing a random sequence of triangular fuzzy numbers in a given interval is equivalent to a normal distribution when using the centroid defuzzification method. It also shows that the defuzzified optimal solutions follow the normal distribution and range from 3,000-3,700 tons, given the budget constraint (CAD 110,000-150,000). The normality seems to be able to propagate throughout the optimization process, yet this interesting finding deserves more in-depth study and needs more rigorous mathematical proof to validate its applicability and feasibility. In addition, the optimal decision variables can be categorized into several groups with different probability such that decision makers can wisely allocate limited resources with higher confidence in a short period of time. This study is expected to advise the industries and authorities on how to distribute resources and maximize the treatment efficiency of oily water in a short period of time, particularly in the context of harsh environments

Estimation of Costs of Phosphorus Removal In Wastewater Treatment Facilities: Adaptation of Existing Facilities

As part of a wider enquiry into the feasibility of offset banking schemes as a means to implement pollutant trading within Georgia watersheds, this is the second of two reports addressing the issue of estimating costs for upgrades in the performance of phosphorus removal in point-source wastewater treatment facilities. Earlier, preliminary results are presented in Jiang et al (2004) (Working Paper # 2004-010 of the Georgia Water Planning and Policy Center). The present study is much more detailed and employs an advanced software package (WEST®, Hemmis nv, Kortrijk, Belgium) for simulating a variety of treatment plant designs operating under typical Georgia conditions. Specifically, upgrades in performance, in a single step, from a plant working at an effluent limit of less than 2.0 mg/l phosphorus to one working with limits variously ranging between less than 1.0 mg/l to less than 0.05 mg/l phosphorus are simulated and the resulting costs of the upgrade estimated.Five capacities of plant are considered, from 1 MGD to 100 MGD. Three strategic, alternative designs for the facility are considered: the basic activated sludge (AS) process with chemical addition, the Anoxic/Oxic (A/O) arrangement of the AS process, and the Anaerobic/Aerobic/Oxic (A/A/O) arrangement of the AS process. Upgrades in performance are consistent with the logical alternatives for adapting these options. Cost comparisons are made primarily on the basis of the incremental cost of the upgrade, i.e., from the base-case, reference plant to that performing at the higher level, as expressed through the incremental Total Annual Economic Cost (TAEC; in $) and the marginal unit cost of phosphorus removal, expressed in ($/kg).For the most stringent upgrade, for example, to a plant generating an effluent with less than 0.05 mg/l phosphorus, these marginal costs -- the cost of the additional phosphorus removed as a result of the upgrade -- amount to something of the order of 150-425 $/kg, with the upper bound being associated with the smallest plant configuration (1 MGD). Working Paper Number 2005-001

Preparation, Proximate Composition and Culinary Properties of Yellow Alkaline Noodles from Wheat and Raw/Pregelatinized Gadung (Dioscorea Hispida Dennst) Composite Flours

The steady increase of wheat flour price and noodle consumptions has driven researchers to find substitutes for wheat flour in the noodle making process. In this work, yellow alkaline noodles were prepared from composite flours comprising wheat and raw/pregelatinized gadung (Dioscorea hispida Dennst) flours. The purpose of this work was to investigate the effect of composite flour compositions on the cooking properties (cooking yield, cooking loss and swelling index) of yellow alkaline noodle. In addition, the sensory test and nutrition content of the yellow alkaline noodle were also evaluated for further recommendation. The experimental results showed that a good quality yellow alkaline noodle can be prepared from composite flour containing 20% w/w raw gadung flour. The cooking yield, cooking loss and swelling index of this noodle were 10.32 g, 1.20 and 2.30, respectively. Another good quality yellow alkaline noodle can be made from composite flour containing 40% w/w pregelatinized gadung flour. This noodle had cooking yield 8.93 g, cooking loss 1.20, and swelling index of 1.88. The sensory evaluation suggested that although the color, aroma and firmness of the noodles were significantly different (p ≤ 0.05) from wheat flour noodle, but their flavor remained closely similar. The nutrition content of the noodles also satisfied the Indonesian National Standard for noodle. Therefore, it can be concluded that wheat and raw/pregelatinized gadung composite flours can be used to manufacture yellow alkaline noodle with good quality and suitable for functional food

New insights into transport phenomena involved in carbonated water injection: effective mathematical modeling strategies

Carbonated water injection (CWI) is a promising enhanced oil recovery (EOR) method that provides an efficient and a more environmentally friendly alternative to meet the ever-increasing demand for energy. An additional benefit from the implementation of CWI is the storage of anthropogenic CO₂ and this has made it even more attractive. Over the years, several attempts have been made to model CWI as an EOR process but have been of very little success due to the underlying assumptions used or the modelling strategy. There are several multi-physics involved during CWI and to have an accurate model to investigate CWI, these physics need to be adequately captured. In this thesis, we have attempted to model CWI adequately by using more realistic and practical assumptions to present a novel modeling strategy. This thesis shows our research in a manuscript-based format which is presented in each chapter as major contributions. Firstly, a comprehensive review of CWI where the behavior of fluids, fluid-rock interactions and challenges associated with CWI technique have been thoroughly discussed. Secondly, the modelling investigation to capture the critical salinity which plays an important role in EOR techniques for sandstones and carbonate as well as the solubility of CO₂ during CWI is presented. Thirdly, a 3-D modeling method to investigate CWI which considers important terms such as gravity, non-instantaneous equilibrium, heterogeneity, anisotropy and well orientation is presented. Fourthly, a 1-D core modelling approach which considers the reaction term and rock dissolution in an improved attempt to capture CWI is presented. Finally, a deterministic approach is presented to effectively predict oil recovery factor based on pattern recognition and artificial intelligence. To facilitate this, the use of artificial neural network (ANN), least square support vector machine (LSSVM) modelling and gene expression programming (GEP) are adopted

Case study on CO₂ transport pipeline network design for Humber region in the UK

Reliable, safe and economic CO₂ transport from CO₂ capture points to long term storage/enhanced oil recovery (EOR) sites is critical for commercial deployment of carbon capture and storage (CCS) technology. Pipeline transportation of CO₂ is considered most feasible. However, in CCS applications there is concern about associated impurities and huge volumes of high pressure CO₂ transported over distances likely to be densely populated areas. On this basis, there is limited experience for design and economic assessment of CO₂ pipeline. The Humber region in the UK is a likely site for building CO₂ pipelines in the future due to large CO₂ emissions in the region and its close access to depleted gas fields and saline aquifers beneath the North Sea. In this paper, various issues to be considered in CO₂ pipeline design for CCS applications are discussed. Also, different techno-economic correlations for CO₂ pipelines are assessed using the Humber region as case study. Levelized cost of CO₂ pipelines calculated for the region range from 0.14 to 0.75 GBP per tonne of CO₂. This is a preliminary study and is useful for obtaining quick techno-economic assessment of CO₂ pipelines

Development of free water knock-out tank by using internal heat exchanger for heavy crude oil

Reactivation of an old oil well can be explicitly calculated to maximize crude oil production. The biggest challenge with the activation process is the crude oil content in old wells, which is not feasible to meet the specified minimum standards. In the case of the Bunian oil field, Indonesia, the crude oil produced has high water content. It causes a decrease in the quality of production and also hinders production capacity. The production scheme applied to the Bunian field has a storage tank that functions to reduce water content using the gravity method, but this is less effective. Let’s modify the storage tank into a heat exchanger tank through the engineering design process and labeled it as a free water knockout tank (FWKO). The FWKO is made of a multi-pass tube heat exchanger. The experiments are conducted through three phases’ tests before deciding the final design. From the test, the change in water content is varied with temperature differences of the working fluid and crude oil. The lowest water content is obtained at 0.5 % at final tests. After analyzing the characteristic of each test result, the final design is taken by adjusting the suitable working fluid temperature and pressure. Finally, by using suitable parameters, the average water content of crude oil is decreased up to the minimum requirement (<0.1 %). The design of FWKO is considered simple with an excellent performance and can adapted easily. The FWKO able to process crude oil with water content <20 %, where it suitable for waxy oil well. The working fluid can be processed both in liquid and gas state. Furthermore, the heating source for the working fluid is gained from the gas flare by using thermic heater. Thus, it does not require an extra heating source for the heat exchange

Thermo-economic assessment of a olive pomace gasifier for cogeneration applications

A thermo-economic analysis of a combined heat and power (CHP) plant fed by syngas produced through the gasification of dry olive pomace is presented. The plant is composed by a 800 kWtdowndraft gasifier, a gas clean-up system, a 200 kWemicroturbine (MGT) and a heat recovery system to cogenerate hot water. Surplus heat is used to dry olive pomace from 50% to 17% wb moisture content. The plant is modeled in ASPEN Plus. Real data from experimental tests are used to calibrate the gasifier model, while the technical specification and performance of the CHP plant are collected from commercial plants in operation and data from manufacturers. Mass and energy balances are reported throughout the paper. The thermodynamic simulation of the biomass gasifier coupled to the MGT, the thermal and electrical conversion efficiency and temperature of cogenerated heat available are also presented. A thermo-economic assessment is then proposed, to investigate the economic profitability of this small scale CHP plant in the Italian energy policy scenario and considering the subsidies available for renewable electricity in the form of feed-in tariffs. For this purpose, the case study of base load CHP plant operation and heat supplied to different typologies of energy end user is assumed. The results allow quantifying the most influencing economic and technical factors that affect the performance and profitability of such investment and the bottlenecks that should be faced to facilitate a broader implementation of such CHP schemes for on site generation