Subsea boosting of hydrocarbon flow, either directly from the well or from a subsea separator, will typically result in the need of handling some free gas. Pumping moderate gas volume fractions (GVF) in combination with high pressure increase, is typical for boosting flow from deep water wells and represent a challenge in pump design. Aker Solutions has developed such a pump, called a HybridBooster. This paper presents the design process of such a multistage pump from CFD-simulations to the complete full scaled testing. The hybrid pump design is flexible and suitable for a wide range of flow rates and GVF's due to the many stacking possibilities of impellers with different characteristics. This allows for making a pump with the best possible performance and efficiency. The two-phase testing was done with a mixture of water and air at Aker Solutions facility in Tranby. The pump generates a differential pressure in the range of 150 to 240 bar, depending on the rotational speed and flow rate, at 20% GVF with a suction pressure of 12 bar. The pump design is based on a combination of mixed-flow impellers and radial impellers. Test results show that the mixed-flow impeller technology have great potential for moderate GVF at all flow rates and high GVF capability at best efficiency point and above. The strength of the mixed-flow impeller is the internal remixing of gas and liquid that strongly reduces the risk of gas blocking in the flow channel. The behavior of the pump during testing was stable, granting easy pump control. Introduction The Hybrid Pump Project is a Joint Industry Project supported by Demo 2000 The Research Council of Norway and the following companies: Aker Solutions, Statoil ASA, Total E&P Norway, Nexen Exploration Norway AS, ExxonMobil Upstream Research Company USA. The large variety of oil field characteristics demands a range of tooling for a successful production. One of these tools is the subsea HybridBooster. Unlike a conventional single phase (liquid) pump the hybrid pump is able to pump a liquid/gas mixture with a high pressure increase. The HybridBooster will be a well-suited and cost and production-efficient solution in a number of applications. Typical applications are:Pumping liquid from a gas/liquid separator where a risk for gas carry-under existPumping hydrocarbons from fields producing mainly liquid, but with risk of gas break-through over time To meet the challenging requirements of handling an increased fraction of gas combined with high pressure increase a Hybrid pump development project was established. The key specifications for the subsea Hybrid Pump development are:Pressure increase - target: 200 bar, min. 100 barGas tolerance, base case - target: 20% GVFGas tolerance, advanced case - target: >30% GVFInlet Pressure - > 10 bar, < 50 barFlow - within power limit of 2,5 MW The major design criterion was to design a gas tolerant multi-stage pump that could handle 20% GVF at suction condition, with stable operating conditions and predictable behavior.
During a market condition that is characterized by volatile oil price, there is a strong incentive in the Oil & Gas Industry on maximizing the hydrocarbons recovery from existing fields, rather than initiating new field developments. For offshore deep water field applications, subsea boosting technologies are considered to be a solution to improve the field recovery, while also acting as enabling technology that allows for development of deep, harsh and stranded reserves, which otherwise deemed non-accessible. This paper presents the performances and application area of two novel subsea boosting solutions developed by Aker Solutions: The boosting of condensate and oil as well as pressure increase by water injection through high pressure subsea pumpsThe subsea boosting of gas flow with associated liquid, though high performance subsea compression. Special focus is given to the subsea centrifugal pump and compression technologies and how these new solutions can solve the existing challenges represented by providing high performance pressure boosting for both oil production with high gas content, as well as gas production with high liquid content. Highlights on the key features of these novel technologies are provided, with specific focus on the benefits the technology brings to the market, like the high differential pressure generated together with the high efficiency and mechanical stability. These are all game changers for deep water IOR developments.
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.