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SPE Member Abstract Wet steam, being a two-phase fluid, has complex critical flow properties. Analytical and experimental data were used to investigate the critical steam flux, and the pressure ratio needed to achieve critical flow for a variety of popular flow-rate controlling devices. Three new parameters โ critical steam flux ratio, dimensionless critical steam flux, and the Napier parameter โ are introduced to correlate the critical flow data. Attention was focused on the effects of stagnation pressure, stagnation quality and design of the flow-rate control device on the critical flux. The study covered stagnation pressures from 200 to 2100 psia and stagnation qualities from 20 to 100%. Introduction Critical flow refers to a situation where any further reduction in the downstream pressure of the flow fails to induce a corresponding increase in the mass flow rate. In other words, critical flow is a phenomenon whereby the flow rate has an upper limit for a given flow-controlling device and the fluid's upstream or stagnation condition. In steam-enhanced oil recovery (EOR) operations, the flow rate of steam is usually controlled by a flow controlling device, such as an orifice, nozzle, venturi, choke, adjustable valve, etc. A constant flow rate of such devices can be maintained for a varying downstream pressure when the flow through the devices is under critical flow conditions. Most steam used in EOR operations is a wet steam whose flow properties are more complex than single-phase fluids. In this study, attention was given to the effect of stagnation pressure, quality and the design of the flow controlling device on the critical flow properties. For representative field applications, this study covered steam pressures ranging from 200 to 2100 psia [1378 to 14500 kPa] and steam qualities from 20 to 100%. Flow-controlling devices discussed in the experiments include orifices, nozzles, venturi, static chokes and adjustable chokes. New parameters are proposed to correlate critical flux data. Results from this study offer a better understanding of the critical flow properties of steam so as to improve steam management for steam flooding or stimulation operations, and to explore the properties that can be used as a basis for developing new and innovative controlling and measuring devices for steam quality and steam flow rate. ANALYTICAL RESULTS OF THE CRITICAL FLOW PROPERTIES OF WET STEAM Various models have been proposed to describe the critical flow behavior of steam. The homogeneous equilibrium model (HEM) is a simple model that gives a good representation of the critical flow properties of steam. It is used as the basis of this study. P. 269^
SPE Member Measurement of Steam Injection Tubing Heat Losses Using Pressure-Temperature Survey Data L.D. Wheaton Abstract The steamflooding of deep reservoirs requires the use of insulated tubing to minimize heat losses and maintain high-quality steam at the sandface. In order to evaluate the effectiveness of tubing used. techniques are needed to measure the heat loss in the wellbore and calculate the thermal conductivity of the insulation. This paper presents the results of tubing analysis in a well of 4250 ft depth using pressure-temperature survey data, The problem of determining the bottom-hole steam quality under normal operating conditions was overcome by setting the inlet quality at a level estimated to result in zero quality at the sandface. This allowed the calculation of bottom-hole enthalpy and total heat loss using pressure and temperature measurements. The performance of the insulated tubing was evaluated by adjusting variables in a wellbore simulator to obtain a match of the experimental data recorded at several elevations. Results of the test concluded the heat loss in the injection well was 130% higher than predicted using anticipated tubing properties. The heat loss was uniform through the tubing, and resulted from poor insulation performance. The simulation results eliminated the possibility of heat loss due to refluxing in the tubing annulus. Introduction Heat losses in the steam injection well can be very detrimental to a steamflood project. Unless efforts are made to minimize losses, the economics of the project can be severely impacted by increased energy costs, and, in the case of deep reservoirs, the steam quality can be reduced to an unsatisfactory level. High heat losses can also raise Casing temperatures to a level that risks failure under the stress of thermal expansion. Insulated tubing is frequently used to minimize heat loss in the injection well. and maximize the downhole steam quality. The performance of the tubing is predicted using a computer model of the steam injection well which calculates pressure changes due to static head and friction, and heat losses to the formation using the manufacturer's test data for the thermal conductivity of the insulation. Evaluation of actual performance is made difficult by the lack of methods to determine the steam quality at the bottom of the well under normal operating conditions. This report presents the results of a field test in which the heat loss and insulation performance were evaluated in the steam injection well in the Madison steamflood pilot at the Garland Field. The following steps were used for the evaluation:The quality of steam at the inlet to the injection well was set at a level estimated to result in zero quality above the sandface assuming design-basis heat losses. A pressure-temperature survey was run in the well to determine fluid properties at the bottom of the well and several intermediate points. The heat loss in the wellbore was calculated from the known inlet and bottom-hole conditions. P. 29^
- North America > United States > Wyoming > Park County (0.24)
- North America > United States > Wyoming > Big Horn County (0.24)
- North America > United States > Wyoming > Bighorn Basin > Garland Field (0.99)
- North America > United States > California > Sacramento Basin > 2 Formation (0.99)
- Reservoir Description and Dynamics > Improved and Enhanced Recovery > Thermal methods (1.00)
- Production and Well Operations > Well & Reservoir Surveillance and Monitoring > Production logging (1.00)
Partial-Exclusion Sand Control Technique for Improving the Efficiency of Thermal Operations From Unconsolidated Heavy Oil Formations
Toma, P. (Alberta Research Council) | King, R.W. (Esso Resources Canada Ltd.) | Harris, P. (Alberta Research Council) | Jha, K.N. (CANMET) | Korpany, G. (Alberta Research Council)
This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Write Publications Manager, SPE, P.O. Box 833836, Richardson, Tx 75083-3836. Publications Manager, SPE, P.O. Box 833836, Richardson, Tx 75083-3836. Telex, 730989 SPEDAL. Abstract A sand control device using prepacked metallic wool designed for total exclusion of sand in thermal operations was tested in Lloydminster and Atbabasca unconsolidated sand formations. The results obtained from 20 different applications, which are summarized in this paper, indicate that sand production previously plaguing some locations disappeared after previously plaguing some locations disappeared after the new filter was introduced. However, high pressure drops and reduction in production rate were pressure drops and reduction in production rate were sometimes associated with partial plugging of the filter in fine grained formations. As a result of the field observations, a laboratory investigation was undertaken to design new criteria for the prepacked metallic wool filter and to achieve better control of solids by using a partial filtration strategy - The experimental program presented in the paper includes a laboratory testing presented in the paper includes a laboratory testing method which replicate s open-hole completions - Alteration of filter permeability, including the formation of a filter cake in open-hole conditions, indicates that a different sand control strategy should be designed for set-through and open-hole completions - A filtration model based on laboratory experiments using a prepacked metallic wool filter for sand control in an open hole is suggested - The model assesses the risk of plugging as a function of formation median grain size, filter compression, and the grade of metallic fibers. The model provides practical criteria for designing a prepacked practical criteria for designing a prepacked metallic wool filter for partial exclusion of sand and to avoid a rapid loss of filter permeability in fine-grained, unconsolidated formations. Introduction From 1987 to 1989, a compressed steel wool (SWC) filter that was first assessed in the laboratory, was extensively field tested in thermal applications. The resistance of this prepacked filtration device to corrosion by hot, high-pH fluids and to erosion, while success fully retaining solids, is comparable or superior to other solids-control devices employed under harsh thermal recovery conditions Table 1 summarizes the observed performance of the SWC in several non-thermal and thermal heavy oil applications. The filter has often been used when other sand control methods have been unsuccessful. The success of the SWC has been mixed and the field observations suggest that the SWC in its present design:performs better for lower viscosity fluids; performs better in formations with a relatively uniform sand size or in clean sand; can be eroded by high velocity fluids carryings and but is better able to withstand erosive environments than other sand control devices. changing the filter design criteria to improve the performance of the filter and increase its service performance of the filter and increase its service life are prime objectives of this study. This paper describes experimental results conducted in a laboratory-simulated open-hole flow environment and aimed at the improving of the design of a prepacked metallic wool filter. The experimental prepacked metallic wool filter. The experimental rig was designed to produce information on the mechanism of filter plugging for different oil/sand slurries. First the background of the sand retention and plugging mechanism specific to prepacked filters plugging mechanism specific to prepacked filters used in thermal recovery of unconsolidated formations is outlined. This is followed by a description of the novel experimental apparatus and procedures used to test the SWC in simulated procedures used to test the SWC in simulated open-hole flow, The measured permeability reduction of filters designed with different compressions and grades of metallic wool and exposed to oil emulsion sand-slurry flow is discussed utilizing semi-empirical theory that describes the plugging of multifilament filter media. P. 13
- North America > United States > California (0.46)
- North America > United States > Texas > Dallas County > Richardson (0.44)
- Well Drilling > Drilling Fluids and Materials > Drilling fluid selection and formulation (chemistry, properties) (1.00)
- Well Completion > Sand Control > Sand/solids control (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Oil sand, oil shale, bitumen (1.00)
- (2 more...)
Abstract Heat losses to Over/underburden play an important role in determining the efficiency of a thermal oil recovery process such as cyclic steam stimulation. Thermal process such as cyclic steam stimulation. Thermal conductivity is a key parameter for evaluating heat losses. Since there is generally little information Concerning in situ thermal conductivity values, it is often assumed in reservoir simulation models that the reservoir and its Over/underlying formations possess the same value of thermal conductivity. If the over/underlying formations possess significantly higher values of thermal conductivity compared to the reservoir, the heat losses will be underestimated in calculations based on uniform thermal properties. Systematic procedures to estimate thermal conductivity values from temperature logs and core measurements are presented in this paper and applied to field and laboratory data. Introduction The commercial process employed by Esso Resources Canada Limited to recover the highly viscous bitumen at Cold Lake, Alberta, is cyclic steam stimulation. The injection of steam at high pressures (10-11 MPa, 1450- 1600 psi) and temperatures (311-318 degrees C. 592-604 degrees F) results in heated reservoir zones, from which heat is lost to the formations above and below the reservoir by conduction. It is necessary to estimate the in situ thermal properties of the reservoir and the Over/underlying formations, in order to assess the thermal efficiency of the recovery process by analytical or numerical methods. In particular, in situ thermal conductivity is a key parameter for evaluating over/underburden heat losses. However, typically there is little information concerning in situ thermal conductivity values and it is often assumed in reservoir simulation models that the reservoir and its neighboring geological formations have the same or nearly the same thermal conductivity values (see. e.g., the values used in the simulation work by Boberg and Rotter and Johnson et al.). If the over/underlying formations possess significantly higher values of thermal possess significantly higher values of thermal conductivity than that of the reservoir, the heat losses and potentially the ultimate recovery from the reservoir may be miscalculated by assuming the same values for the thermal conductivity of all the formations. This paper presents a systematic procedure for estimating thermal conductivity values from temperature logs and laboratory measurements on cores. Anisotropy of thermal conductivity will be ignored here. From temperature logs, in situ thermal conductivity ratios between geological formations can be determined. If the in situ thermal conductivity of one formation is known, then the in situ thermal conductivity values of the entire stratigraphic column can be determined by using the ratios. By using core measurements to estimate the thermal conductivity of one formation (say the reservoir), the in situ thermal conductivity of the various formations may be determined from the log-derived ratios, This estimation procedure is illustrated by application to two initial temperature logs from Cold Lake and data from measurements on cores from the Athabasca oil sands deposit in Alberta. P. 179
- Europe (1.00)
- North America > Canada > Alberta > Athabasca Oil Sands (0.25)
- Geology > Petroleum Play Type > Unconventional Play > Heavy Oil Play (1.00)
- Geology > Rock Type > Sedimentary Rock (0.96)
- Geology > Geological Subdiscipline (0.68)
- North America > United States > California > San Joaquin Basin > Kern River Field (0.99)
- North America > Canada > Alberta > Western Canada Sedimentary Basin > Alberta Basin > Clearwater Formation (0.99)
- North America > Canada > Alberta > Athabasca Oil Sands > Western Canada Sedimentary Basin > Alberta Basin (0.99)
- North America > Canada > Alberta > Western Canada Sedimentary Basin > Alberta Basin > Cold Lake Oil Sands Project > Clearwater Formation (0.98)