John F. Metz, National Oilwell
Printed technical references to jet pumps can be traced as far back as 1852 England. However, consistent mathematical formulas were not published until 1933, when J. E. Gosline and M. P. O"Brien of the University of California at Berkley published The Water Jet Pump. In the same time period, the Jacuzzi Company received a patent for a jet pumping system that was successfully used to lift shallow water wells. Over the years, jet pumps have also been used as vacuum sources in applications such as steam ejectors on large, condensing steam turbines or on a wide variety of process industry vacuum requirements. Low to moderate lift water wells, and process and steam ejectors remain today as common industrial applications of jet pump technology. These applications, however, use liquid as a power source to move liquid, or gas as a power source to move gas. The initial problem in applying jet pumps to lift oil wells was based on the fact that a typical oil well contains a mixture of oil, water, and gas. The mathematical formulas of the 1930's did not produce accurate results in predicting pump performance and, consequently, required considerable modification. Also, jet pump performance calculations require a cycle of a number of repeat calculations, each one "zeroing in," as it were, more closely on the desired result. Making these calculations manually is very time consuming. It was not until the widespread availability of computers and the ability to properly program calculations of this type that the proper application of jet pump lift to oil wells became a practical reality. The first really successful applications were put in service in 1970. The use of this method of artificial lift has grown quite steadily since then. It is not the intent of this paper to discuss in detail the theory of operation or the calculation methods employed to accurately predict jet pump performance. It is suggested that those interested in a detailed presentation of those topics refer to the 1987 edition of The Petroleum Engineering Handbook, published by the Society of Petroleum Engineers. Chapter 6 of this publication, authored by Hal Petrie of National-Oilwell, contains a wealth of excellent information on hydraulic pumping, including both jet and reciprocating pumps. However, in order to discuss the versatility of jet pumping oil wells, a basic discussion of the Hydraulic Lift System and the jet pump's design characteristics is in order, since these are the basis of the jet pump's versatility.