Thermal recovery

Thermal recovery involves the introduction of heat, for example, by injection of steam, to lower the viscosity or thin the heavy viscous oil and improve its ability to flow 

As the production lives of secondary methods lose their efficiency, further techniques have been tested and found to continue to release additional amounts of oil. These methods are considered tertiary methods and are generally associated with chemical or gaseous recirculation methods of recovery. Some instances of in-situ thermal recovery have been used but not on a large extent. 

Proprietary methods are developed which inject chemical detergent solutions into the oil reservoirs to increase the viscosity of the remaining oil reservoirs. After the chemical detergent solutions are injected, polymer thickened water is provided behind the chemical detergent to drive the oil towards producing wells. 

Underground hydrocarbons are ignited, which creates a flame front or heat barrier that pushes the oil towards the producing well. 

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Thermal Recovery Polymer Flooding Infill Wells... 

Secondary recovery, infill drilling, various pumping techniques, and workover actions may still leave oil, sometimes the majority of the oil, in the reservoir. There are further applications of technology to extract the oil that can be utilized if the economics justifies them. These more elaborate procedures are called enhanced oil recovery. They fall into three general categories thermal recoveiy, chemical processes, and miscible methods. All involve injections of some substance into the reservoir. Thermal recovery methods inject steam or hot water m order to improve the mobility of the oil. They work best for heavy nils. In one version the production crew maintains steam or hot water injection continuously in order to displace the oil toward the production wells. In another version, called steam soak or huff and puff, the crew injects steam for a time into a production well and then lets it soak while the heat from the steam transfers to the resei voir. After a period of a week or more, the crew reopens the well and produces the heated oil. This sequence can be repeated as long as it is effective. 

The three classes of EOR technologies that have been studied extensively are thermal recovery, miscible flooding, and chemical flooding. For each of these methods, the following two basic problems must be overcome if we are to recover a significant part of the remaining oil. 

Thermal recovery methods involve the use of steam and in-situ combustion. Thermal EOR processes add heat to the reservoir to reduce the viscosity of the oil or to vaporize it. In addition, these processes use steam or oil combustion... 

C. H. Moore. Computer simulation of formation damage resulting from thermal recovery. In Proceedings Volume. SPE Int Therm Oper Heavy Oil Symp (Margarita Island, Venezuela, 3/12-3/14), 2001. 

Prats, M. Thermal Recovery, Monograph Volume 7, Society of... 

At a given NaCI concentration, an increase in temperature resulted in an increase in interfacial tension. In contrast, for a narrow range of CaCI concentrations, interfacial tensions decreased with increasing temperatures. Changes of the amphiphile at the oil/water interface accounted for some of the experimental observations. Since the extent of oil desaturation is dependent on interfacial tension, the tension data could be used to assess the ability of surfactants to reduce oil saturations in the reservoir for application of surfactants and foams to thermal recovery processes. 

The decrease in absorbancy of poly U upon irradiation is discussed by Swenson and Setlow.48 Their results are shown in Figure 27. In this figure is also shown the photoinduced dimer splitting. The amount of photorecovery of absorbance for any particular total dose was taken to be a measure of the amount of dimer content at that dose. The amounts of dimer so calculated are shown in Figure 28. The amount of hydrates formed were estimated by measuring the thermal recovery of absorbancy. The results of both thermal and radiation reversal are shown in Figure 29. The total recovery of absorbance for poly U irradiated at 265 nm was 87-90% (after certain corrections, it was estimated that 95% of the absorbance decrease could be accounted for by dimers and hydrates). Of this total reversal of 907o about 67% was effected by the thermal treatment, and presumably this number provides an estimate of the total fraction (0.75) of hydrates in the photoproducts. 

At elevated temperatures, the thermal recovery processes described in Section 5.1.2.3 can occur concurrently with deformation, and both strength and strain hardening are consequently reduced. The latter effect results in decreasing the difference between yield and tensile strengths until at sufficiently high temperatures, they are essentially equal. At lower temperatures, temperature has a marked influence on deformation in crystalline materials. Temperature can affect the number of active slip systems in some... 

Chloride volatilization Thermal recovery Roasting of chloride results in volatilization... 

Bitumen in tar sand deposits represents a potentially large supply of energy. However, many of these reserves are only available with some difficulty and optional refinery scenarios will be necessary for conversion of these materials to low-sulfur liquid products (Chapter 9) because of the substantial differences in character between conventional petroleum and tar sand bitumen (Table 1-6). Bitumen recovery requires the prior application of reservoir fracturing procedures before the introduction of thermal recovery methods. Currently, commercial operations in Canada use mining techniques for bitumen recovery. 

Kawasaki et al.40 disclosed the use of hindered phenols such as 2,6-di(tert-butyl)phenol as stabilizers for spirooxazines in poly (vinyl butyral). The hindered phenols not only improved photochromic durability but also photochromic response, besides accelerating the thermal recovery rate. 

Overall thermal recovery can he enhanced by cogeneration and advanced technologies such as fluidised bed combustion with fuel pre-drying (6, 7). Useful heat conversion efficiency as a performance characteristic has been evaluated for small boilers using wood fuels, which adopted a combustion equation based on oxidation of lignin, cellulose and hemicelluloses including the effect of air, moisture content and the charcoal fraction in the ash (8). 

Meldrum et al. (1999) recently derived an expression to describe the relationship between amorphization dose and temperature based on a composite model involving both direct impact and close-pair recombination processes. This model provides more realistic values for the activation energies of thermal recovery processes, but the curves generated from the expression predict a sharp curvature near Tc. 

The temperature dependence of amorphization dose can also be derived by including the kinetics for thermal recovery in the crystallization efficiency parameter. A, which can be written as (SX Wang 1997, SX Wang et al. 2000e) ... 

Thevuthasan S, Jiang W, Weber WJ, McCready DE (1999) Damage accumulation and thermal recovery in SrTiOs implanted with Au ions. Mat Res Soc Symp Proc 540 373-378. 

The two main thermal recovery processes are steam injection and in situ combustion. In the steam injection process, steam of 80% quality is injected into the reservoir to displace oil. The steam can be injected continuously (called steam drive ) or intermittently (called cyclic steam injection ). In the steam drive process, steam is injected in several injection wells and the oil is produced in several production well. In cyclic injection process, steam is injected in several (previously producing) wells for 2-6 weeks, soaked for 3-7 days, and produced back for a few weeks or months. This cycle can be repeated several times. Often, the steam flood is preceded by cyclic injection. Steam injection has been used commercially for several decades. In fire flooding or in situ combustion process, air is injected and ignited inside the reservoir. A combustion front... 

Thermal recovery in situ combustion—forward dry, wet, Toe-to-Heel Air-Injection (THAI), and CAPRI (i.e., variation of THAI with a catalyst for... 

When alkaline flooding is combined with other methods, such as polymer flooding, surfactant flooding, hydrocarbon gas injection, or thermal recovery, much better effects will be obtained. 

Prats, M., 1982. Thermal Recovery. Society of Petroleum Engineers, Dallas. 

Hutcheon, I. Abercrombie, H.J. (1990) Fluid-rock interaction in thermal recovery of bitumen. Tucker Lake Pilot, Cold Lake, Alberta. In Prediction of Reservoir Quality Through Chemical Modeling (Eds Meshri, I.D. Ortoleva, P.J). Mem. Am. Ass. Petrol. Geol., Tulsa, 49, 161-170. 

Hutcheon, I., Abercrombie, H. Krouse, H.R. (1990) Inorganic origin of carbon dioxide production in low temperature thermal recovery of bitumen chemical and isotopic evidence. Geochim. Cosmochim. Acta, 54,165-171. 

A number of reports on phthalocyanines and porphyrins have been published. Spectral diffusion and thermal recovery of spectral holes burnt into phthalocyanine doped Shpol skii systems has been examined . An absorption, emission, and thermal lensing research on carboxylated zinc phthalocyanine shows the influence of dimerization on these properties. Fourier transformation of fluorescence and phosphorescence spectra of porphine in rare gas matrices has yielded much structural and electronic state data on this compound . Exciton splitting is an effect which is seen in the spectra of covalently linked porphyrins . A ps fluorescence study of the semirigid zinc porphyrin-viologen dyad has provided evidence for two dyad conformers . Spectral diffusion in organic glasses has been measured by observing the hole recovery kinetics over the time scale of 1 to 500 ms for zinc tetrabenzoporphyrin in PMMA . 

Thermal Recovery of Oil from Tar Sands by an Energy-Efficient Process... 

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