In this paper is described an experimental investigation of properties and some developments in the utilization of hydrodynamic-type gas-lubricated bearings, of both journal and thrust types, as distinct from hydrostatic bearings. Two specific developments are described, the one a pump for circulating carbon dioxide gas at 100 lb. per sq. in. gauge and 150 deg. C. through a loop in a nuclear reactor, the other a gas-bearing motor driving a pump for molten radioactive bismuth, the whole within a hermetically-sealed container. The simple machining requirements and special design principles are described. The performance of gas bearings may be predicted from normal liquid bearing theory if the loading is so small that the pressure rise within the bearing is a small fraction (for example, 10 percent) of the ambient pressure. For higher pressure ratios compressibility effects must be taken into account. The experimental results and techniques used are reported, those for plain journal bearings embracing a wide range of working conditions and absolute size including compressible flow operation. An explanation of the physical reasons for the change in performance in compressible flow bearings is given. The dynamic instability sometimes encountered in journal bearings and methods of avoiding it is also discussed.

The induction motor has dominated the global ESP market for decades; however permanent magnet motors (PMM) are gaining acceptance for use in artificial lift. Some PMM vendors have made claims of 20% - 30% reduction in electric operating costs, improved efficiency, and wider applications for today's challenging wells. This paper describes a testing program conducted to understand the characteristics of PMM's, to verify vendor claims and evaluate how to leverage this downhole motor technology to reduce operating expenses. Two International Oil Companies (IOC's) partnered to sponsor a Motor Evaluation Test (MET) program from 2014 - 2015. A motor test protocol was drafted, and ESP motor sizes of 100 HP 450 series were targeted for evaluation. Six ESP vendors agreed to participate, contributing their motor and variable frequency drives (VFD). Four induction motors and four permanent magnet motors, each partnered with the vendor supplied VFD, were evaluated. The objective of the testing was not to differentiate the vendor's products, but to understand the differences in the motor technologies. An independent third-party witness was selected from industry experts to supervise the testing, ensuring to follow the test protocols, manage data security, and test validation. The results were analyzed, documented and reported to vendors by the sponsor companies. The PMM was found to be a cost competitive alternative to the IM for equivalent ESP installations with a VFD. In existing fields, a phased-in approach to replace failed IM with PMM may be economic. For new field developments the PMM offers the benefits of power savings and use in challenging well bore configurations. Alternatively deployed (AD) ESP with PMM may offer reduced well intervention cost as well an improved ability to pass through build angles that would challenge the longer IM system.

A new technology, Magnetic Drive System (MDS), to increase reliability and retrievability of electrical submersible pumps (ESPs) is described. With the improved reliability and retrievability, the production uptime of oil wells with artificial lift and the total cost of ownership of ESPs are improved significantly. An industry survey and literature review were conducted to identify the aspects of the ESP and the failure-prone ESP subsystems to improve upon. Based on the findings, the MDS technology is developed to improve ESP reliability by isolating the failure modes and to improve ESP retrievability by enabling fast deployments and retrievals from wells. Mean Time Between Failure (MTBF) models based on field observed failure mechanisms are applied to identify the impacts of isolating various failure modes on ESP reliability. The total cost of ownership (TCO) is calculated to illustrate the advantages of the MDS system to increase production gains and reduce costs. Analysis on ESP reliability shows that the electrical system is the primary ESP failure mode, covering more than 50% of the failures. Models based on field data from the literature review shows that MTBF can be more than tripled if these failures are eliminated. The MDS topology places all the electrical components, including motor stators, cables and penetrators, of an ESP in the isolated annulus space between the permanent completion and tubing, leaving only the mechanical components, including the permanent magnet motor rotors and pump stages, inside the production tubing. In this case, the electrical components are well protected from the hostile produced fluids, so that the failures modes of the electrical system are eliminated. Since the retrievable string has no electrical components, such as thousands of feet of power cable, the deployments and retrievals of the retrievable string can be easily done by slickline. The larger motor stator and higher power density enabled by enhanced heat dissipation of the MDS topology dramatically increase the motor horsepower and shorten the motor length, thus increasing the production gains of the ESP. Reliability and retrievability are further improved due to the elimination of motor protectors and replaced by the "built-in" magnetic coupling between the MDS motor stator and rotor. With the improved reliability, retrievability, and motor performance simultaneously, MDS reduces the total cost of ownership by more than 70% in some cases compared with the conventional tubing-hung ESP, enables live well deployment and retrieval, reduces production downtime and intervention complexity, and protects reservoir productivity.

As Permanent Magnet Motors (PMMs) become more widely used because of their many benefits, awareness of the potential safety hazards arising from their differences from Induction Motors (IMs) is important. Due to their construction, the magnetic field presence is always "on" with PMM – even when not under energized electrical energy. PMMs are AC generators when freely rotating forward or backward. Elevated safety consciousness is needed to avoid serious injury or fatality when working with PMMs. This paper presents operational procedures for installing, pulling, troubleshooting, and handling PMMs with a focus upon safety. Hazards have been identified, and some mitigations are recommended to eliminate the potential danger and bring awareness to the petroleum industry (and others) to ensure that all workers go home safely. The observations presented in this paper came directly from field experience with operators, equipment manufacturers, and service providers.

Selecting artificial lift papers for the Tech Focus feature of JPT can be a daunting exercise when technologies and innovations abound, more so post-pandemic, with 157 submitted abstracts covering 2021–2022. In narrowing the offerings to three, the criteria of conformance to guidelines and novelty of information, technical equipment, and application were considered. Industry indicators and interest were also factors. Gas lift remains of high global interest, whether in long horizontal shale oil wells or vertical ones because of the cost to operate lower lifting. Declining production and high gas/oil ratios (GORs) present a challenge for conversion to secondary lift forms. Paper SPE 209721 provides an innovative solution combining gas lift with sucker rod lift to enhance and exploit low-productivity wells in high-GOR fields. Permanent magnet motors (PMMs) have made quite the technical splash in the industry over the past decade. PMMs are one-third shorter and result in higher power densities and power savings of up to 18% just by changing out the induction motor. PMMs are again grabbing attention for the direct 1:1 ratio of electrical to carbon footprint. Current environmental, social, and governance concerns are placing demands on all operators, and PMMs are positioned to help with carbon reduction as a low-hanging fruit in paper SPE 209736. In paper SPE 209763, we look at all-metal progressing cavity pumps (aka M2M), which consist of a metal rotor and metal stator. Incremental advances in geometry and materials continue to see operators use high-temperature fluids with low operational expenditure in mind. Reliability is always a concern, and now a novel condition indicator has been developed and tested that offers a better indicator than pump efficiency alone. Recommended additional reading at OnePetro: www.onepetro.org. SPE 206909 Successful Progressing Cavity Pump Reliability Improvement Project in an Oman Steamflood by Shauna Noonan, Oxy, et al. SPE 211782 Maximizing Marginal Fields Profitability Through Drilling Multilateral Wells To Reduce Well Count and Well Cost: Dual Lateral Well With Single ESP and Smart Lower Completion by Mahmoud Mohamed Abdelhay Mostafa, ADNOC, et al. SPE 209748 Gas Pump—A Gas-Driven Positive Displacement Pump Artificial Lift System by Stephen W. Turk, ELC Energy Services, et al.