Petroleum evaluation

Finally, not all tests that are applied to the evaluation of conventional petroleum are noted here. It is the purpose of this chapter to enumerate those tests that are regularly applied to the evaluation of the heavier feedstocks. For example, tests such as those used to determine volatility (a characteristic that is not obvious in the heavy, or high boiling, feedstocks) are omitted. The reader is referred to a more detailed discussion of petroleum evaluation for these tests (Speight, 1999 and references cited therein). 

Other factors, such as the Watson characterization factor, are also used. A highly paraffinic crude oil can have a characterization factor as high as 13, whereas a highly naphthenic crude oil can be as low as 10.5, and the breakpoint between the two types of crude oil is approximately 12. Sulfur content, the carbon residue, and distillation data are also valuable in petroleum evaluation (Speight, 2001). 

McCray A.W. 1975. Petroleum Evaluations and Economic Decisions. Prentice Hall, New Jersey. 

Kenney, J.F. Considerations about recent predictions of impending shortages of petroleum evaluated from the perspective of modem petroleum science. Energy World 1996, 240, 16-18. 

Although distillation and elemental analysis of the fractions provide a good evaluation of the qualities of a crude oil, they are nevertheless insufficient. Indeed, the numerous uses of petroleum demand a detailed molecular analysis. This is true for all distillation fractions, certain crude oils being valued essentially for their light fractions used in motor fuels, others because they make quality lubricating oils and still others because they make excellent base stocks for paving asphalt. 

Furthermore, molecular analysis is absolutely necessary for the petroleum industry in order to interpret the chemical processes being used and to evaluate the efficiency of treatments whether they be thermal or catalytic. This chapter will therefore present physical analytical methods used in the molecular characterization of petroleum. 

The flash point measures the tendency of a petroleum material to form a flammable mixture with air. It is one of the properties to be considered when evaluating the flammability of a petroleum cut. 

Even if all of the elements described so far have been present within a sedimentary basin an accumulation will not necessarily be encountered. One of the crucial questions in prospect evaluation is about the timing of events. The deformation of strata into a suitable trap has to precede the maturation and migration of petroleum. The reservoir seal must have been intact throughout geologic time. If a leak occurred sometime in the past, the exploration well will only encounter small amounts of residual hydrocarbons. Conversely, a seal such as a fault may have developed early on in the field s history and prevented the migration of hydrocarbons into the structure. 

Mark Cook is a Reservoir Engineer and Petroleum Economist. He has worked on international assignments mainly in Tanzania, Oman, the Netherlands and the UK. His main focus is in economic evaluation of field development projects, risk analysis, reservoir management and simulation. After 11 years with a multinational company he co-founded TRACS International of which he is Technical Director. 

The octane numbers of many pure compounds have been measured and reported in the Hterature. Probably the most comprehensive project was carried out under the auspices of the American Petroleum Institute (18). Table 2 Hsts RON and MON values for a number of representative compounds. Some aromatic compounds cannot be tested neat in the knock engine, so these are evaluated at levels of 20%, and the equivalent octane number is calculated. The values for oxygenates in Table 2 have been reported elsewhere (19). 

The standard methods (26) of analysis for commercial lecithin, as embodied in the Official and Tentative Methods of the American Oil Chemists Society (AOCS), generally are used in the technical evaluation of lecithin (27). Eor example, the AOCS Ja 4-46 method determines the acetone-insoluble matter under the conditions of the test, free from sand, meal, and other petroleum ether-insoluble material. The phosphoHpids are included in the acetone-insoluble fraction. The substances insoluble in hexane are determined by method AOCS Ja 3-87. 

Surfactants evaluated in surfactant-enhanced alkaline flooding include internal olefin sulfonates (259,261), linear alkyl xylene sulfonates (262), petroleum sulfonates (262), alcohol ethoxysulfates (258,261,263), and alcohol ethoxylates/anionic surfactants (257). Water-thickening polymers, either xanthan or polyacrylamide, can reduce injected fluid mobiHty in alkaline flooding (264) and surfactant-enhanced alkaline flooding (259,263). The combined use of alkah, surfactant, and water-thickening polymer has been termed the alkaH—surfactant—polymer (ASP) process. Cross-linked polymers have been used to increase volumetric sweep efficiency of surfactant—polymer—alkaline agent formulations (265). 

The hterature is hiU of detailed evaluations of recycled petroleum products (2,6,17,18,23,28) and investigations into the environmental ramifications of the recycling processes themselves (30). 

API, In Situ Air Sparging. Evaluation of Petroleum Industy Sites and Considerations for Applicability, Design, and Operation, Pubhcation No. 841-46090, American Petroleum Institute, Washington, D.C., 1995. 

A key feature of this model is that no data for mixtures are required to apply the regular-solution equations because the solubiHty parameters are evaluated from pure-component data. Results based on these equations should be treated as only quaHtative. However, mixtures of nonpolar or slightly polar, nonassociating chemicals, can sometimes be modeled adequately (1,3,18). AppHcations of this model have been limited to hydrocarbons (qv) and a few gases associated with petroleum (qv) and natural gas (see Gas, natural) processiag, such as N2, H2, CO2, and H2S. Values for 5 and H can be found ia many references (1—3,7). 

Sohre, J., Reliability Evaluation for Trouble-Shooting of High-Speed Turbomachinery, ASME Petroleum Mechanical Engineering Conference, Denver, Colorado. 

Lock, Jack A., Techniques for More Accurate Centrifugal Compres. ur Performance Evaluation, ASME 29th Annual Petroleum Mechanical Engineering Conference, New York American Society of Mechanical Engineers, 1974. 

Bultzo, C., Turbomachinery Acceptance Testing for Conformance to Design Criteria and Overall Performance Evaluation, ASME Petroleum Division Conference, New Orleans, LA, September 14, 1972... 

Antioxidants may be assessed in a variety of ways. For screening and for fundamental studies the induction period and rate of oxidation of petroleum fractions with and without antioxidants present provide useful model systems. Since the effect of oxidation differs from polymer to polymer it is important to evaluate the efficacy of the antioxidant with respect to some property seriously affected by oxidation. Thus for polyethylene it is common to study changes in flow properties and in power factor in polypropylene, flow properties and tendency to embrittlement in natural rubber vulcanisates, changes in tensile strength and tear strength. 

These faetors and methods for evaluating their effeets are diseussed in greater detail in Ameriean Petroleum Institute publieations (API RP521) [36], Lees [37], and Wells [38],... 

Based on the equation presented in the problem statement, the mi.xture of butane, cyclohe.xane, ethyl ether and liquid petroleum gas is evaluated in terms of the combined TLV as follows ... 

Figure 10-69. Turbulence correction factor for horizontal multitube banks. Evaluate Ng by solving for ns from Figure 10-68. (Used by permission Devore, A. Petroleum Refiner, V. 38, No. 6, 1959. Gulf Publishing Company, Houston, Texas. All rights reserved.)...

An overall economic evaluation must be made to ensure that the contemplated project for petroleum development will recover sufficient capital to pay for the total cost of development, installation and assembly effort of the company. Further, the capital return must yield a financial return consistent with the overall company risk involved. Thus, it is very important that the petroleum engineer designing a recovery system understand the company s evaluation criteria that will be used by management in judging whether a new project is to go forward. Chapter 7 (Petroleum Economics) has detailed discussions of general engineering economics and product (or project) evaluation criteria. 

Lyons, W. C., et al., Field testing of a downhole pneumatic turbine motor , Geothermal Energy Symposium, ASME/GRC, January 10-13, 1988. Magner, N. J., Air motor drill, The Petroleum Engineer, October 1960. Downs, H. F., Application and evaluation of air-hammer drilling in the Permian Basin, API Drilling and Production Practices, 1960. 

This problem can be cast in linear programming form in which the coefficients are functions of time. In fact, many linear programming problems occurring in applications may be cast in this parametric form. For example, in the petroleum industry it has been found useful to parameterize the outputs as functions of time. In Leontieff models, this dependence of the coefficients on time is an essential part of the problem. Of special interest is the general case where the inputs, the outputs, and the costs all vary with time. When the variation of the coefficients with time is known, it is then desirable to obtain the solution as a function of time, avoiding repetitions for specific values. Here, we give by means of an example, a method of evaluating the extreme value of the parameterized problem based on the simplex process. We show how to set up a correspondence between intervals of parameter values and solutions. In that case the solution, which is a function of time, would apply to the values of the parameter in an interval. For each value in an interval, the solution vector and the extreme value may be evaluated as functions of the parameter. 

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