Jet lift systems have earned a strong reputation as an effective artificial lift method for unconventional oil well production across the most prolific hydrocarbon-producing regions in the United States of America. In prolific reservoirs such as the Permian Basin, Eagle Ford, and Bakken, operators have successfully utilized jet lift as the primary lifting method for challenging oil wells. Additionally, operators in the Eagle Ford Basin have consistently employed jet lift as the main production technique for their wells.

Like any other artificial lift system used in unconventional oil well production, jet lift has its strengths and weaknesses. Its most notable advantage over other powered production methods is its ability to handle a wide range of flow rates, from 10 barrels of fluid per day (bfpd) up to 5,000 bfpd, using the same jet pump size. The jet pump “free pump” feature, which allows the operator to hydraulically retrieve and reinstall the jet pump without the need for workover or wireline using only reverse power fluid circulation; and is also widely recognized as critically important in the artificial lift selection matrix.

The most common problems that need to be addressed during the implementation of jet lift systems typically include: uncertainty regarding the placement of the jet pump cavity or the optimal depth for the deviation seating point; determining the right moment to start producing the well using the jet pump after the early flowing-well production stage; identifying the most effective initial nozzle-throat combination; selecting the most cost-effective surface equipment capacity (horsepower) for the user; managing the well's transient behavior by resizing the jet pump nozzle-throat combination; preventing cavitation in the jet pump during both early and late production stages; and, finally, developing a properly designed strategy to convert from jet lift to rod lift.

This paper provides a clear discussion of the issues and challenges associated with jet lift operations, along with field-proven solutions successfully implemented in the Eagle Ford formation across approximately 150 jet-pumped wells.
 

During the hydraulic fracturing age, hydraulic jet pumps have seen an increase of installation numbers across the most prolific unconventional well fields in the United States of America, as well as in overseas oil and gas fields. Its simplicity, reliability, robustness, and adaptability have made the jet pump one of the known artificial lift systems on the production of unconventional wells, specially on the early stage of production. During this stage production rates are high, and solids (proppant) are produced; this can be a challenging combination to deal with. When correctly operated, jet pumps can be a useful and effective solution for this unconventional well production cases. Jet pumps can and it have been used to continue to produce an unconventional well through its producing life to depletion, until a transition to a different method is needed, mainly because of the minimum required pump intake pressure that a jet pump needs to operate. Jet pumps require a minimum suction pressure to function, otherwise a phenomenon called “power fluid cavitation” or “low intake pressure cavitation” will occur. When the down-hole pressure of an unconventional well that is operated with jet pump declines to lower levels, specific operating and optimization strategies have to be implemented, in order to maintain acceptable production rate levels, and to optimized the usage of the available surface equipment capacity. During the late stage of production of an unconventional well , a successfully operated jet pump strategy includes several good practices that include: Well completion configuration, surface equipment selection, suction and discharge piping, production data processing and analysis, nozzle and mixing tube resizing and power fluid pressure schedule. The correct application of the previously mentioned actions, increase the possibilities to approach to a trouble free operation, and to a continuous jet pump system implementation from its installation, on the early production stage, to a point where the well flowing pressure is too low that a change of system is required, to a low rate – low pressure production system. This paper presents a straightforward discussion on the operation of jet pump systems during the late production stage of unconventional wells, recommended practices, troubleshooting and procedures to keep the well producing, even when the pump intake pressures are relatively low. 
 

The addition of a sliding sleeve door (SSD) to the tubing string, installed between the deepest gas lift mandrel and the annular packer, will allow the deployment of a wireline-set jet pump. The backup jet pump provides a valuable and cost-effective alternative in several potential scenarios: when unloading fracking fluids before beginning gas-lift production, when restoring production after an unpredicted shutdown of the gas-lift compression system, and when the producing water cut becomes higher than expected.

This simple but ingenious dual-purpose completion approach has already proved to solve the problem of unconventional well production load-up during the early production stage of gas lifted systems. The information provided in this paper will help operators plan, design, deploy, and operate a dual-purpose gas lift-jet pump well completion.

The cavitation phenomenon has been extensively studied for many years, however, guidelines on how to implement this existing knowledge to the actual operation of the jet pumping systems in the oilfield are not abundant and, as per the author can see it, not yet being presented in such way that the people that operate these systems in the oilfield could implement on a straight forward way. It has been proven that using a scientific and easy to follow methodology, it is possible to prevent jet pump operating problems related to cavitation, during the early, middle and late stage of the well production life. Preventative and Corrective methodologies are based on: Measured production rates, power fluid rate and pressure, gas to liquid ratio, jet pump seating depth and jet pump nozzle/throat combination.

This paper presents a straight forward discussion on the jet pump cavitation, its hydrodynamics, causes, identification, potential damage, consequences on the jet pump performance and methods to predict it and avoid it.