An 8,000-ft experimental field well was utilized to conduct flowing pressure gradient tests under conditions of continuous, multiphase flow through 2 3/8-in. OD tubing. The well was equipped with 10 gas-lift valves and 10 Maihak electronic pressure recorders, as well as instruments to accurately measure the surface pressure, temperature, volume of injected gas and fluid production.These tests were conducted for flow rates ranging from 75 to 936 B/D at various gas-liquid ratios from 105 to 9,433 scf/bbl. An expanding-orifice gas-lift valve allowed each flow rate to be produced with a range of controlled gas-liquid ratios. From these data an accurate pressure traverse has been constructed for various flow rates and for various gas-liquid ratios.A comparison of these tests to Poettmann and Carp enter's correlation indicates that deviations occur for certain ranges of flow rates and gasliquid ratios. Numerous curves are presented illustrating the comparison of this correlation with the field data. Poettmann and Carpenter's correlation deviates some for low flow rates and, in particular, for gas-liquid ratios in excess of 3,000 scf/bbl. These deviations are believed to be mainly due to the friction-factor correlation. However, Poettmann and Carpenter's correlation gives excellent agreement in those ranges of higher density. This was as expected and predicted by Poettmann. He pointed out that their method was not intended to be extended to those ranges of low densities whereby an extreme reversal in curvature occurs.As a result of these experimental tests, correlations using Poettmann and Carpenter's method were established between the friction factors and mass flow rates which are applicable for all gasliquid ratios and flow rates. Definite changing flow patterns do not allow any one correlation to be accurate for all ranges of flow. Introduction The ability to analytically predict the pressure at any point in a flow string is essential in determining optimum production string dimensions and in the design of gas-lift installations. This information is also invaluable in predicting bottom-hole pressures in flowing wells.Although this problem is not new to industry, it has by no means been solved completely for all types of flow conditions. Versluys, Uren, et al, Gosline, May, and Moore, et al, were all early investigators of multiphase flow through vertical conduits. However, all of these investigations and proposed methods were very limited as to their range of application. Likewise, many are extremely complicated and therefore not very useful in the field.Only in the last decade have any significant methods been proposed which are generally applicable. The most widely accepted procedure in industry at the present time is a semi-empirical method developed from an energy balance, proposed by Poettmann and Carpenter in 1952. Their correlation is based on actual pressure measurements from field wells. Accurate predictions from this correlation are limited to high flow rates and low gas-liquid ratios.Although this method will he discussed in detail later, it should be pointed out that two important parameters, namely the gas-liquid ratio and the viscosity, were omitted in their correlation. The viscosity was justifiably omitted since their data was in the highly turbulent flow region for both phases, and most wells fall in this category. The gas-liquid ratio was incorporated to some extent in the gas-density term. In 1954, Gilbert presented numerous pressure gradient curves obtained from field data for various flow rates and gas-liquid ratios for the determination of optimum flow strings. However, no method is presented for predicting pressure gradients except by comparison to these curves. SPEJ P. 59^
An 8000 ft. experimental field well was utilized to conduct flowing pressure gradient tests under conditions of continuous, multiphase flow through 2-3/8 in O.D. tubing. The well was equipped with 10 gas lift valves and 10 Maihak electronic pressure recorders as well as instruments to accurately measure the surface pressure, temperature, volume of injected gas and fluid production. These tests were conducted for flow rates ranging from 75 to 936 B/D at various gas-liquid ratios from 105 to 9433 SCF/BBL. An expanding orifice gas lift valve allowed each flow rate to be produced with a range of controlled gas-liquid ratios. From these data an accurate pressure traverse has been constructed for various flow rates and for various gas-liquid ratios. A comparison of these tests to Poettmann and Carpenter's correlation indicates that deviations occur for certain ranges of flow rates and gas-liquid ratios.
Introduction The proration of oil produced in the field frequently is based partially or entirely upon the gas-oil ratio of wells. The measurement of the gas-oil ratio is one of the more important field tests in regulatory and proration work, and the test always should be conducted according to standardized methods and procedure. Obviously, the gas-oil ratio and the volume of gas produced by a well depend upon many factors but should be independent of the method of measurement and of the devices used to measure gas and oil. Consequently, the volume of gas accompanying a barrel of oil produced by a well may be measured by any reliable and accurate device or instrument. Frequently either a critical flow prover or an orifice well tester is used for this purpose, and for a particular well the same rate of flow of gas should be obtained regardless of whether a critical flow prover or an orifice well tester is employed in the test. In Texas, when using either instrument, either Capacity Table 1 or 5 is employed in making the necessary computations. If the tables are used, a discrepancy always is found whenever the two instruments are compared by extrapolation to the same conditions of flow. Clearly, Tables 1 and 5 must be at fault in some respects. The orifice well tester and the Bureau of Mines type of critical flow prover are essentially the same instrument; both devices utilize a square-edged orifice 1/8 in. in diameter as the primary element, and both freely discharge gas to the atmosphere. Tables for the orifice well tester have been published in the ranges of 0 to 15 in. of water and 0 to 40 in. of mercury (Hg) differential in pressure. Coefficients for the critical flow prover have been published for differentials in pressure greater than 75 psia.
Introduction The petroleum industry, and particularly that part of it that is concerned with the production of oil and natural gas, depends upon the ability of these fluids to flow through the porous rocks of the subterranean reservoirs in which they are imprisoned. The ability of fluids to flow through porous rock is expressed in the language of mathematics by Darcy's law, and this mathematical statement is the basis of many petroleum engineering computations. Petroleum engineers have found it the most useful, fruitful, and dependable expression of the pertinent factors which govern the ability of reservoirs to produce oil, gas, and water and of wells to yield these fluids. Consequently, it is not too much to say that Darcy's law is the very basis of the modern petroleum industry. Darcy's law was stated and published just 100 years ago, when Henri Philibert Gaspard Darcy published his classic paper on the flow of water through sand filter beds. It is fitting that this important anniversary be commemorated by the petroleum industry, although no one would be more surprised than Henry Darcy himself that the work to which he devoted his comparatively brief professional career should provide the basis for a gigantic industry which is the bulwark of modern civilization, an industry which began just three years after the first published statement of Darcy's law. Although petroleum engineers make use of Darcy's law daily in the preparation of professional analyses and reports, and executives of the oil industry, bankers and business men, public officials, politicians, and heads of state arrive at decisions on the basis of these analyses and reports the details of the life and work of this humble Frenchman and public servant, Henry Darcy, are known to few. Early Life of Darcy Henri Philibert Gaspard Darcy was born June 10, 1803, in the city of Dijon, chief town in the Department of Cote d'Or and former capital of the old Duchy of Burgundy. Dijon is situated at the confluence of the rivers Ouche and Saone, some 210 miles southeast of Paris by rail (about 160 miles by air line). It is a city of order and discipline, a city of old forts, palaces, bridges, public buildings and worksfactors no doubt of some importance in shaping and molding the lives of its citizens. Deprived at 14 of his father, who was Collector of the Registry and well thought of by his superiors and fellow citizens, Henry Darcy was reared by his mother, a woman of rare merit who, although left a widow at an early age, devoted her energy to the rearing of her two sons and who was responsible for their education.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.