A Model To Calculate the Theoretical Critical Flow Rate Through Venturi Gas Lift Valves

Abstract

A model to calculate the theoretical critical flow rate of nitrogen (N 2 ) or natural gas through a Venturi gas lift valve is described herein. This new model considers real-gas effects not only in density calculations but also in other thermodynamic properties that are relevant during gas isentropic evolution.For the properties of N 2 , the Bennedict, Webb, and Rubin (BWR) equation of state and an accurate correlation for the idealgas isobaric heat capacity were used. For natural gas, the Dranchuk and Abou-Kassem equation, which reproduces the well-known Standing and Katz chart, was used, and, for the ideal-gas isobaric heat capacity, it was assumed that the natural gas was a mixture of methane and ethane only, their individual ideal-gas heat capacity being calculated by updated correlations.To validate the use of the proposed equations of state, a comparison of calculated with experimental or reference data on properties of N 2 and natural gas (including pure methane and some relevant mixtures) was performed with very good results for N 2 and for natural-gas compositions usual in gas lift operations (dry gas with very small amounts of contaminants). For natural gas with moderate amounts of N 2 and carbon dioxide (CO 2 ), accurate results were obtained after correction of critical conditions and of ideal heat capacity. The model was also compared with other theoretical models found in the literature, which use compositional approaches for natural gas, with excellent results. Some experimental results obtained with commercial Venturi valves manufactured in Brazil are also presented.

Investigating effects of ball size on the performance of gas lift valve for both modified and optimized seats

“…A GLV acts as a fixed orifice only when the valve is fully open which rarely happens. Consequently, using the T-C equation would produce erroneous results as indicated by Decker (2008) and Almeida (2011).…”

Design of flow control devices in steam-assisted gravity drainage (SAGD) completion

“…For multiple industries, it is a common practice to flow liquid and gas mixtures through restriction-style chokes (Ajienka et al 1994;Alimonti et al 2010;Almeida 2013;Campos et al 2014;Elgibaly and Nashawi 1998;Grose 1985;Kojasoy et al 1997;Perkins 1993;Schüller et al 2003;Zhang and Cai 1999). Specifically, within the oil and gas industry, restriction-style FCDs are heavily used as wellhead chokes to control production from wells, as a critical part of single or multiphase flow measurement valves, and within gas lift valves (Ajienka et al 1994;AlAttar 2013;Almeida 2013;Surbey et al 2013).…”

“…Specifically, within the oil and gas industry, restriction-style FCDs are heavily used as wellhead chokes to control production from wells, as a critical part of single or multiphase flow measurement valves, and within gas lift valves (Ajienka et al 1994;AlAttar 2013;Almeida 2013;Surbey et al 2013). In SAGD operations, restriction-style FCDs have been used in injection wells as a ''steam splitter,'' a tool to both mechanically divert steam down the wellbore, add additional points of steam injection, and control the rate of injection into particular reservoir zones to equalize steam delivery along the lateral length (Ghesmat and Zhao 2015;Medina 2015).…”

Flow Control Devices in SAGD Completion Design: Enhanced Heavy Oil/Bitumen Recovery Through Improved Thermal Efficiencies

“…For multiple industries, it is a common practice to flow liquid and gas mixtures through restriction-style chokes (Ajienka et al 1994;Alimonti et al 2010;Almeida 2013;Campos et al 2014;Elgibaly and Nashawi 1998;Grose 1985;Kojasoy et al 1997;Perkins 1993;Schüller et al 2003;Zhang and Cai 1999). Specifically within the oil and gas industry, restriction-style FCDs are heavily used as wellhead chokes to control production from wells, as a critical part of single or multiphase flow measurement valves, and within gas lift valves (Ajienka et al 1994;Al-Attar 2013;Almeida 2013;Surbey et al 2013).…”

“…Specifically within the oil and gas industry, restriction-style FCDs are heavily used as wellhead chokes to control production from wells, as a critical part of single or multiphase flow measurement valves, and within gas lift valves (Ajienka et al 1994;Al-Attar 2013;Almeida 2013;Surbey et al 2013). In SAGD operations, restriction-style FCDs have been used in injection wells as a "steam splitter", a tool to both mechanically divert steam down the wellbore, add additional points of steam injection, and control the rate of injection into particular reservoir zones to equalize steam delivery along the lateral length (Ghesmat and Zhao 2015;Medina 2015).…”