Layer | Fill | Outline |
---|
Map layers
Theme | Visible | Selectable | Appearance | Zoom Range (now: 0) |
---|
Fill | Stroke |
---|---|
Collaborating Authors
Results
Cost Analysis Of Current In-Situ Bitumen Production โ Optimum Production Strategies And Priority R&D Needs
Wong, S. (Alberta Research Council) | Toma, P. (Alberta Research Council) | Singh, S. (Alberta Research Council) | DuPlessis, M.P. (Alberta Research Council) | Quon, D. (University of Alberta)
Abstract The survival and growth of Alberta's bitumen industry during the continuing world oil price uncertainty will, to a large extent, depend on the development of improved technologies and enhanced cost effectiveness. It is first necessary to identify key parameters that impact production costs and to determine their relative cost sensitivities. Research can be focused on these targeted areas and production strategies can be developed which could potentially provide significant cost reductions. This paper describes how energy models developed at the Alberta Research Council are used to identify key areas and to determine their cost sensitivity. Current technologies for in situ extraction of bitumen from Alberta's deposits are reviewed, and the implications of different world oil price scenarios are analyzed. The economic impact of a number of promising operating strategies and processes are presented and analyzed. Introduction Five large bitumen and heavy oil deposits with resource estimated at 400 ร 10 m of hydrocarbon are located in Alberta. Defined by UNITAR as a liquid hydrocarbon with a viscosity greater than 10 mPa โขs and an API gravity less than 10 degrees, bitumen found in most of Alberta's reservoirs cannot be produced unless heated. There are various degrees of success of applying thermal recovery methods to Alberta's bitumen deposits โ good results are reported in Cold Lake (Esso) and Peace River (Shell), while others are not that encouraging, especially in the Athabasca deposit. Even so, in the past five years, bitumen production increased six fold from less than 3400 m/D in 1983 to about 20,000 m/D in 1988. In the early years the production came largely from sizable piloting activity. In 1988, there were six commercial projects and 22 bitumen pilot projects operating in Alberta. Most of these projects were started during the 1983โ85 era. Market opportunity, improved fiscal regimes and the high oil price prior to 1986 allowed this aggressive development. Since the precipitous price drop in 1986, the prevailing low oil price has put most new bitumen projects on hold. The bitumen production industry is at a crossroad. Its survival during the continuing world oil price uncertainty will, to a large extent, depend on the development of improved technologies and enhanced cost effectiveness. This paper analyzes the cost of bitumen production and uses a simplified Oil-Steam Ratio (OSR) model to evaluate a number of potential production strategies. A Liquid Fuel Model (ALF01), developed at the Alberta Research Council (ARC) is used to examine how, over the next 40 years, different oil price scenarios and improved technologies would impact on bitumen production. It is used to provide a basis for assessing the potential benefits of R&D in this area. Current In-Situ Commercial Technologies At normal reservoir temperature, bitumen is totally immobile. Mobilization of bitumen through the application of heat requires efficient convection and conduction of hot fluid into the formation. This involves a good distribution of heating sources and an increase of contact areas between the injected hot fluids and the reservoir.
Abstract In the next 30 โ 40 years, Alberta will be one of the few places where liquid hydrocarbon fuels can be economically produced from: conventional sources; oil sands, both mined and in-situ; coal, via liquefaction technologies. In order to make meaningful comparisons between alternative sources and alternative technologies, two large-scale mathematical models, AERAM and AREF, were used for the analysis. In the reference case scenario, the following assumptions were made: a drop in real world oil prices from 1983 to 1985, a small increase until the end of the decade and a real rise of slightly under 2% annually to the end of the century and thereafter; continuing low natural gas prices for industrial users in Alberta, at a substantial discount to the projected Alberta Border Prices; some technological progress in oil sands and coal liquefaction technologies. The results suggest that no new conventional refineries will be built but that considerabler etrofitting will be necessary, in order to increase the diesel fuel yield relative to the gasoline yield. With respect to synthetic fuels, in-situ oil sands projects using high-quality deposits are expected to dominate the new projects in the 1980s and 1990s but as these high quality sites become fully committed during the 90s, mined oil sands will re-emerge. Given the projected fuel prices, coal liquids are projected to be competitive in the export market by the year 2010. From then on, Alberta should have several economically viable synthetic fuel options. Introduction The province of Alberta is in an enviable position of having not only significant reserves of conventional crude oil, but also immense reserves of oil sands and coal, potential sources of future liquid fuels. The Department of Energy and Natural Resources (ENR), Province of Alberta, wanted to have an analytical framework to assess the relative economic significance of different fossil fuel resources, in particular, the relative importance of liquid fuels derived from oil sands and coal. Toward that end, ENR contracted with the Technical and Economic Evaluations group of the Alberta Research Council to develop a formal mathematical model of the liquid fuels sector in Alberta. The rationale was that no "stand-alone" process economics analysis of a particular coal liquefaction technology would be adequate without taking into account alternative competitive liquid fuel technologies, over-all energy prices, market trends and discount rates. A brief description of AREF is given in Appendix A. Although the Alberta Research Council has in existence a comprehensive energy supply model called ABRAM, it was decided to develop a new model, focussing specifically on liquid fuels and capable of describing the coal liquefaction technologies in detail. This model, called AREF, is now operational and is described fully elsewhere. As will be shown later, there are strong linkages between liquid fuels and other energy forms, particularly natural gas, and we have had to use results from the more comprehensive model AERAM as input data to AREF. This paper presents the results from some analyses using both AREF and ABRAM.
Abstract The present period marks a turning point in OHT utilization of energy in which we will shortly see the maturation of the petroleum and natural gas consumption patterns and the emergence of a new energy form, namely nuclear energy. In Order to put this displacement of one energy form by another into the proper perspective it is important to realize that this has happened twice before in the last 100 years, and that the modern industrial society has an enormous capacity to adapt to such changes. Furthermore, our potential energy resources, whether measured in terms of the static reserves life index or in terms of an exponential reserve index, are probably greater now than at any previous time since tire beginning of the industrial revolution. Analysis of past consumption and discovery patterns is used to substantiate this claim. In the transition period, in which a particular energy reserves such as oil or natural gas may become scarce regionally, public policy must recognize the intergenerational externality caused by the usage of a depleting resources. Measure to assure security of supply of energy are suggested. Introduction ANY DISCUSSION of energy resources or, for that matter, any other kind of non-renewable natural resource involves questions not only of technology and economics, but also of social and political value systems. Hence, this paper, in addition to having technological and economic components, will also have an ideological component. There are two extreme views on non-renewable resources the essentially gloomy view of the Malthusian camp who foresee disaster unless we change our ways, and the more optimistic view of the economic determinists who believe that the normal market mechanism together with expected technological progress will keep our problems at a manageable level. The modern Malthusians are perhaps best typified by the Club of Rome, who sponsored Professor Meadows' study on "The Limits of Growth". In accordance with this view, both population and industrial capacity tend to grow exponentially, putting pressure on scarce natural resources, on arable land and on the capacity of the environment to absorb pollution. The standard scenario is for population and capital to overshoot the limits imposed by finite resources, and to subsequently collapse. The question of limits resolves ultimately to a consideration of energy supply โ because with abundant energy, the other material resources can be recycled and pollution can be abated to desired levels. The economic determinists and the technological optimists believe that the market system, despite all its imperfection, will allocate sufficient capital, technology and labour to alleviate the shortage of any commodity, including energy. They further believe that the growth of population and capital will trigger negative feedback mechanisms which will ultimately stabilize these quantities, particularly in societies where there exists a system of pluralistic, informed, decentralized decision-making, as is true of western democracies. Our position is an intermediate one, with perhaps a bias toward the optimists.
Abstract A two-dimensional mathematical model was formulated to describe the injection or steam into an oil reservoir assuming that a step-function satisfactorily approximates the actual temperature profile within the permeable sand. The model was applied to a homogeneous isotropic reservoir to calculate the temperature in the surrounding strata and the thermal efficiency of the injection process. For a particular set of reservoir conditions, the comparison of the results with a published analytical solution for the one-dimensional case showed that there exists a particular injection rate and pay thickness below which the one-dimensional heat transfer model may not be valid. A second model was formulated to describe the backflow period. The thermal behaviour of the non-permeable strata was accounted for by dividing the surrounding formation into two sets of semi-infinite concentric cylinders and applying the one-dimensional heat flow equation to each shell. The fluid mechanics aspect was described by applying Darcy's equation under plug-fluid flow conditions. With the exception of viscosity, all physical properties were assumed to be independent of temperature and were calculated at an average temperature. The trend of the results of two example calculations is consistent with that generally observed from pilot tests reported in Western Canada.
- North America > United States (1.00)
- North America > Canada > Alberta (0.47)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Thermal methods (1.00)
- Reservoir Description and Dynamics > Reservoir Characterization > Exploration, development, structural geology (0.84)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (0.68)
Abstract There has been a growing interest in the use of two-dimensional mathematicalmodels to simulate the transient behaviour of oil and gas fields. Until very recently, the standard numerical technique used the alternating direction implicit procedure (ADIP) to integrate the basic partial differential equation describing flow through porous media. However, the computational problem, evenon high-speed computers, remained a form idable one. A new method for solving the conduction equations, first suggested by Saul'ev and later extended by Larkin, makes ingenious use of the known boundary conditions to permit an explicit point-by-point sequential evaluation of all interior grid points. A reverse sweep is used to minimize the over-all errors. The method, which may becalled an alternating direction explicit procedure (ADEP), combines thestability of the implicit methods with the computational ease of the explicit methods. By examining the structure of the computational models and noting their physical significance, it is shown that ADEP is a logical extension of ADIP and should have about the same accuracy. The new method is applied to anexample problem involving a volumetric under saturated oil reservoir, mathematically represented by several hundred grid points. The results indicatea possible order of magnitude saving in computer time for problems of this typeas compared to an ADIP solution. This suggests that three-dimensional models might now very well be practicable. Introduction The present paper is a preliminary report on a new numerical method, firstproposed by Saul'ev (1) and later extended by Larkin (2), for solving the basicpartial differential equation describing the flow of a slightly compressiblefluid through porous media. As it involves an alternating direction explicitprocedure, it may be referred to as ADEP. Because of limitations of computational machinery and costs, existingmethods have been largely limited to the two-dimensional case. The mostefficient of these methods is the alternating direction implicit procedure, or ADIP, developed by Peaceman and Rachford (3). By examining the proposed methodin the mathematical context of earlier computational models, we can drawcertain, hopefully valid conclusions about its accuracy, its stability and itscalculational requirements. No attempt will be made here to give formalmathematical proofs of stability or to present a detailed error analysis -important considerations which have been examined elsewhere (4).
Abstract Although a number of solutions to the equations describing steady compressible flow in pipes exist, even the most rigorous of these make simplifying assumptions concerning thermal effects; i.e., either that the flowis isothermal or that the gas assumes identically the temperature of the surroundings. There are, however, instances where these assumptions may not be warranted. This paper examines the differential equations which characterize momentum and heat transfer, rearranges them so as to make them amenable to numericalsolution and proposes a computational technique suitable for use on digital computers. The approach represents an improved and generalized method ofhandling gas well calculations as well as pipeline design problems. Introduction The flow of fluids, in general can be described by a set of partial differential equations โ comprising the equation of continuity, aforce-momentum balance for each of the three dimensions and a total energy balance. A general solution of this set of five partial differential equations involving four independent variables โ three geometric, one time โ is currently beyond our capabilities. Fortunately, in many cases of gas flow, the flow ishighly turbulent, steady and occurs in circular conduits. In such cases, the system may be described by two ordinary differential equations, namely, aforce-momentum and a total energy balance. These two equations may be writtenin terms of one independent variable, length, and two dependent variables, which may be two fluid properties. Although any two independent properties willdefine the state of a fluid, temperature and pressure are the obvious choices, as they are the ones usually measured in practice. Until recently, the solution of simultaneous nonlinear differential equations has been too time-consuming to find wide engineering acceptance. Consequently, further simplifying assumptions have been made. It has been assumed that the gas temperature is either constant or an explicit function of length, thereby reducing the number of differential equations to one, viz., theforce-momentum balance. It should be pointed out, however, that the assumption of isothermal flow is normally not defensible on physical grounds. With regardto the alternate proposed assumption, while the temperature of the surroundings may be known, the assumption that the fluid assumes identically the temperature of the surroundings implies that the overall heat transfer coefficient between the fluid and the surroundings is infinite - a questionable hypothesis.