Plunger Lift Dynamic Characteristics in Single Well and Network System for Tight Gas Well Deliquification

Abstract

This paper presents a study for plunger lift characteristics to dewater tight-gas wells operated in the Piceance basin of Rocky Mountains with multiple-well pads and surface pipeline network. The wells' TVDs are about 6000 ft with deviated paths, and the water-gas-ratio (WGR) is 40~80 stb/MMscf. The objective is to understand the optimal operating conditions for reasonably controlling deliquification without severe liquid surge while maintaining maximum gas production.The IPR and reservoir depletion are based on tight gas model, which considers the transient IPR due to very low matrix permeability, hydraulic-fractures and drainage radius. A transient dynamic multiphase flow analysis has been performed to investigate the plunger lift effectiveness, performance and optimization for different scenarios. Simulation runs were performed for early, middle and late field life which corresponds to different reservoir pressure and productivity index. It shows that liquid loading becomes severe and production becomes unstable (heading) with decreased reservoir pressure and increased water influx. Eventually the well production can stop due to liquid loading. Plunger lift helps to maintain the production and reduce the instability. A network model with 22 wells on a pad has been built to study the interaction of the system and the liquid surge control strategy.Plunger-lift process for tight gas wells with liquid loading problems needs integrated dynamic modeling for both reservoir and wellbore systems. The philosophy of optimization is that, the reservoir and wellbore system should be the "master" for production optimization, and surface control should serve as a "slave" system.

Shut-in based production optimization of shale-gas systems

“…Gas-lift is rarely applied for dry-gas shale wells due to the installation cost and marginal profit of many wells, whereas plunger-lift seems to be widely used both in shale and tight gas systems, see e.g. Stevenson and O'Shea (2006); Tang (2009); Kravits et al (2011). Plunger-lift is an artificiallift technique, based on installing a metal plunger in the tubing to supply a solid interface between the gas and liquids to be lifted, and using the energy of gas expanding in the annulus during a shut-in to lift to the surface both the plunger and liquids accumulated in the tubing once the well is re-opened.…”

“…Production with a plunger lift system implies an intermittent shut-in and production scheme. Efficient operations with plunger-lift systems rely on good control and optimization of the flowing, after-flowing and shut-in cycle, which may be complex (Tang, 2009;Gasbarri and Wiggins, 2001), particularly for multi-well systems producing to shared surface facilities. From the literature, however, it does not seem to be a common understanding of the actual effect of the solid interface provided by a plunger for increasing the volume of lifted liquids, as most models neglect liquid fallback when the plunger rises (Lea, 1982;Marcano, 1994;Gasbarri and Wiggins, 2001).…”

“…From the literature, however, it does not seem to be a common understanding of the actual effect of the solid interface provided by a plunger for increasing the volume of lifted liquids, as most models neglect liquid fallback when the plunger rises (Lea, 1982;Marcano, 1994;Gasbarri and Wiggins, 2001). Tang (2009), on the other hand, includes this effect in a high fidelity model, and reports that almost no liquid remains in front of the plunger when hitting the wellhead. Whitson et al (2012) develop an alternative cyclic production strategy to plunger lift for eliminating liquid loading in low-permeability tight-gas wells.…”

“…The model objective in this study is simulation of pipeline pressure loss and compressor fuel usage in a system with 1150 wells and many miles of pipelines. Tang (2009) presents a model of tight-gas multi-well pads running simultaneous plunger-lift systems, using a static reservoir inflow model and a dynamic multi-phase wellbore and plunger-lift model. In this application the shut-in lengths are in the range of minutes, hence enhancing the importance of including detailed wellbore dynamics.…”

Evaluation of Liquid Loading in the Pinedale Field: Integration of Smart Plunger Data and Mechanistic Modeling

“…The relationship between plunger-lift cycle operations and maximum hydrocarbon recovery is one important issue that has been the subject of intensive studies (Yang, 2010;Sask et al, 2010;Rowlan et al, 2009;Tang, 2009;Lea et al, 2007;Rowlan et al, 2006;Lea et al, 2003;Maggard, 2000;Chambliss, 2001;Wiggins et al, 1999;Gasbari and Wiggins, 1997;Avery and Evans, 1988;Lea, 1982;Foss and Gaul, 1965). Plunger-lift cycle operation is a complex problem that involves many decision variables and multiple objectives.…”