Petroleum engineering calculations

The specific petroleum engineering discipline chapters cover drilling and well completions, reservoir engineering, production, and economics and valuation. These chapters contain information, data, and example calculations related to practical situations that petroleum engineers often encounter. Also, these chapters reflect the growing role of natural gas in industrial operations by integrating natural gas topics and related subjects throughout both volumes. 

Figure 18.25 Observed data and model calculations for initial and converged parameter values for the 2"d SPE problem, (a) Match ofgas-oil ratio and water-oil ratio, (b) Match of bottom-hole pressure and reservoir pressures at layers 7 and 8 [reprinted with permission from the Society of Petroleum Engineers].

Similarly, in 3D-radial geometries of interest for petroleum engineers, an equivalent wellbore radius re is defined. The near-wellbore region, including radially distributed wormholes from rw up to re, is infinitely permeable and therefore becomes a mere radial extension of the wellbore itself. Equation 2 can be used to calculate the pseudodecrease of the skin when an undamaged primary porosity formation of permeability k0 includes wormholes as described hereabove ... 

In most instances, the petroleum engineer is concerned with the viscosity of gases at pressures far removed from one atmosphere, so we must now turn to a method of calculating gas viscosity at high pressure. 

The petroleum engineer needs to be able to estimate the density of the reservoir liquid at reservoir conditions. Then the shrinkage in volume that a reservoir liquid undergoes while progressing from the reservoir to the stock tank can be estimated. There are several methods of calculating the volume occupied by a given mass of liquid at elevated pressures and temperatures. We will consider only one method the method most applicable to the liquids encountered in the oil fields. This. method is based on ideal-solution principles. 

There are no ideal liquid solutions, just as there are no ideal gas mixtures. However, when liquids of similar chemical and physical characteristics are mixed, the behavior of the resulting solution is very much like the behavior of an ideal solution. Fortunately, most of the liquid mixtures encountered by petroleum engineers are mixtures of hydrocarbons with similar characteristics. Thus, ideal-solution principles can be applied to the calculation of the densities of these liquids. 

Differential vaporization calculations of two types interest petroleum engineers. In both cases differential vaporization is at constant temperature, and the composition of the initial liquid is known. In the first case, initial conditions and final pressure are given and the number of moles to be vaporized is calculated. In the second case, the initial conditions and the number of moles, to bevalorized arc given and the final pressure is calculated. Either case requires a trial-and-error solution. 

Attempts have been made to define this third property in several different ways.1 We will look only at convergence pressure, which appears to be the most convenient for the types of calculations required of petroleum engineers. 

Many petroleum engineering and process design calculations dealing with natural gases require knowledge of deviation factors or compressibility Z factors. Experimental data from pressure-volume-temperature (P-V-T) measurements are seldom available. The Z-factors are available in charts [27] or tables as a function of pseudo-reduced temperatures T and pressures P. However, use of these charts is often time consuming and involves complex calculations. 

In chemical, biochemical, environmental and petroleum engineering these models are based on the principles of chemistry, physics, thermodynamics, kinetics and transport phenomena. As most engineering calculations cannot be based on quantum mechanics as of yet, the models contain a number of quantities the value of which is not known a priori. It is customary to call these quantities adjustable parameters. The determination of suitable values for these adjustable parameters is the objective of parameter estimation, also known as data regression. A classic example of parameter estimation is the determination of kinetic parameters from a set of data. 

Figure 3. Combined effects of bubble radius, r, and capillary radius R, on apparent viscosity of foam circles are experimental data, and curves are theoretically calculated. (Reproduced with permission from reference 29. Copyright 1992 Society of Petroleum Engineers.)...

Lohrenz, j. Bray, B. G. 1964. The calculation of bubble points of reservoir fluids from their compositions. Society of Petroleum Engineers Paper 792, Rocky Mountain S.P.E. Meeting, Casper, Wyoming, May 1964. 

Averaging methods. Equivalent resistance calculations in simple electric circuits is based on appropriate use of lumped or averaged properties. Similar results are desired in petroleum engineering, but in three widely used simulators we evaluated, averaging techniques are systematically abused. Formulas that are derived for linear (vs. cylindrical or spherical) flow under constant density, single-phase, identical-block-size assumptions are indiscriminately employed to process intermediate results in compressible, multiphase, variable grid block runs, leading to questionable results. 

Peaceman, D.W., and Rachford, H.H., Numerical Calculation of Multidimensional Miscible Displacement, Society of Petroleum Engineers Journal, Dec. 1962, pp. 327-339. 

A semiempirical model to calculate wormhole growth in carbonate acidizing. Paper SPE 96892, presented at the Society of Petroleum Engineers Annual Technical Conference and Exhibition, Dallas. 

A.O. Garder, D.W. Peaceman, and A.L. Pozzi (1964) Numerical calculation of multidimensional miscible displacement by the method of characteristics. Society of Petroleum Engineers Journal 4, 26-36. 

H.H. Rachford (1966) Numerical calculation of immiscible displacement by a moving reference point method. Society of Petroleum Engineers Journal, June 1966, 87-101. 

Knowledge of physical properties of fluids is essential to the process engineer because it enables him to specify, size or verify the operation of equipment in a production unit. The objective of this chapter is to present a collection of methods used in the calculation of physical properties of mixtures encountered in the petroleum industry, different kinds of hydrocarbon components, and some pure compounds. 

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). 

Dente and Ranzi (in Albright et al., eds.. Pyrolysis Theory and Industrial Practice, Academic Press, 1983, pp. 133-175) Mathematical modehng of hydrocarbon pyrolysis reactions Shah and Sharma (in Carberry and Varma, eds.. Chemical Reaction and Reaction Engineering Handbook, Dekker, 1987, pp. 713-721) Hydroxylamine phosphate manufacture in a slurry reactor Some aspects of a kinetic model of methanol synthesis are described in the first example, which is followed by a second example that describes coping with the multiphcity of reactants and reactions of some petroleum conversion processes. Then two somewhat simph-fied industrial examples are worked out in detail mild thermal cracking and production of styrene. Even these calculations are impractical without a computer. The basic data and mathematics and some of the results are presented. 

Low absolute pressure calculations, 129 Low pressure system, 129 American Petroleum Institute, 399 American Society of Mechanical Engineers, 399 API Codes, 399 API oil field separators, 239 API, heat absorbed from fire, 451-453 Babcock steam formula, 103, 107, 108 Back pressure, 404 Effect of, 407, 408 Baffles, lank mixing, 311 Diagrams, 330 Bag filters/separators, 270 Bag materials, 274 Cleaning, 272, 273 Heavy dust loads, 271 Specifications, 271 Temperature range, 271 Bins, silos, hoppers venting, 516 Blast pressure, 496 Blowdown, 404... 

Trimmell, M. L., 1987, Installation of Hydrocarbon Detection Wells and Volumetric Calculations within a Confined Aquifer In Proceedings of the National Water Well Association of Ground Water Scientists and Engineers and the American Petroleum Institute Conference on Petroleum Hydrocarbons and Organic Chemicals in Ground Water Prevention, Detection and Restoration, November, pp. 255-269. 

Development of solvent extraction processes in the petroleum industry and theoretical aspects of solvent extraction are reviewed. Six extraction processes which have received industrial acceptance are described and performance characteristics of furfural, phenol, and Duosol processes are compared. Data are presented to demonstrate the applicability of adsorption analyses for stock evaluation and prediction of commercial extraction yields. Correlations for predicting solvent requirements and layer compositions and process design and engineering considerations are included. The desirability of further fundamental work to facilitate design calculations from physical data is suggested. 

Specific heats are extremely important engineering quantities in refinery practice because they are used in all calculations on heating and cooling petroleum products. Many measurements have been made on various hydrocarbon... 

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