Gene Kouba

The effects of geometry, fluid properties and pressure on the hydrodynamics of gas–liquid cylindrical cyclone separators

Abstract The hydrodynamic flow behavior in a Gas–Liquid Cylindrical Cyclone (GLCC) compact separator is studied experimentally and theoretically. New experimental data are acquired utilizing a 7.62 cm I.D, 2.18 m high, GLCC separator for a wide range of operating conditions. Investigated parameters include three different inlet geometries (5.08 cm I.D single, 7.62 cm I.D single and 7.62 cm I.D dual inlets), four different liquid viscosities (1, 2.5, 5 and 10 cps), three system pressures (101.3, 273.6 and 487.2 kPa), and the effect of surfactant. The measured data comprise of equilibrium liquid level, zero-net liquid flow holdup and the operational envelope for liquid carry-over. The data are utilized to verify and refine an existing GLCC mechanistic model. Comparison between the modified model predictions and the experimental data show a very good agreement.

Hydrodynamics of Two-Phase Flow in Gas-Liquid Cylindrical Cyclone Separators

This paper presents new experimental data and an improved mechanistic model for the Gas-Liquid Cylindrical Cyclone (GLCC) separator. The data were acquired utilizing a 3” ID laboratory-scale GLCC, and are presented along with a limited number of field data. The data include measurements of several parameters of the flow behavior and the operational envelope of the GLCC. The operational envelope defines the conditions for which there will be no liquid carry-over or gas carry-under. The developed model enables the prediction of the hydrodynamic flow behavior in the GLCC, including the operational envelope, equilibrium liquid level, vortex shape, velocity and holdup distributions and pressure drop across the GLCC. The predictions of the model are compared with the experimental data. These provide the state-of-the-art for the design of GLCC’s for the industry.

Design and performance of passive control system for gas-liquid cylindrical cyclone separators

The performance of gas-liquid cylindrical cyclone (GLCC) separators can be improved by reducing or eliminating liquid carryover into the gas stream or gas carryunder through the liquid stream, utilizing a suitable liquid level control. In this study, a new passive control system has been developed for the GLCC, in which the control is achieved by utilizing only the liquid flow energy. A passive control system is highly desirable for remote, unmanned locations operated with no external power source. Salient features of this design are presented here. Detailed experimental and modeling studies have been conducted to evaluate the improvement in the GLCC operational envelope for liquid carryover with the passive control system. The results demonstrate that a passive control system is feasible for operation in normal slug flow conditions. The advantage of a dual inlet configuration of the GLCC is quantified for comparative evaluation of the passive control system. The results of this study could form the basis for future development of active control systems using a classical control approach.

Performance Improvement of Gas Liquid Cylindrical Cyclone Separators Using Integrated Level and Pressure Control Systems

The performance of gas-liquid cylindrical cyclone (GLCC ©1 ) separators for two-phase flow metering loop can be improved by eliminating liquid overflow into the gas leg or gas blow-out through the liquid leg, utilizing suitable integrated control systems. In this study, a new integrated control system has been developed for the GLCC, in which the control is achieved by a liquid control valve in the liquid discharge line and a gas control valve in the gas discharge line. Simulation studies demonstrate that the integrated level and pressure control system is highly desirable for slugging conditions. This strategy will enable the GLCC to operate at constant pressure so as not to restrict well flow and simultaneously prevent liquid carry-over and gas carry-under. Detailed experimental studies have been conducted to evaluate the improvement in the GLCC operational envelope for liquid carry-over with the integrated level and pressure control system. The results demonstrate that the GLCC equipped with integrated control system is capable of controlling the liquid level and GLCC pressure for a wide range of flow conditions. The experimental results also show that the operational envelope for liquid carry-over is improved twofold at higher liquid flow rate region and higher gas flow rate region. GLCC performance is also evaluated by measuring the operational envelope for onset of gas carry-under. @S0195-0738~00!00804-9#

Control System Simulators for Gas-Liquid Cylindrical Cyclone Separators

The control system performance of gas liquid cylindrical cyclone (GLCC©) 1 separators can be considerably improved by adopting suitable control strategy and optimizing the design of the controller PID settings. Dynamic simulators have been developed in this study, based on Matlab/Simulink® software for evaluation of several different GLCC control philosophies for two-phase flow metering loop and bulk separation applications. Detailed analysis of the GLCC control system simulators indicates that for integrated liquid level and pressure control strategy, the level control loop compliments the operation of the pressure control loop, and vice versa. This strategy is ideal for reducing the pressure fluctuations in the GLCC. At severe slugging conditions, the integrated liquid level control is more desirable because of its faster response. However, there is no control of the GLCC pressure fluctuations. The results also show that the simulators are capable of representing the dynamic behavior of real physical systems.

The Flow of Slugs in Horizontal, Two-Phase Pipelines

The flow characteristics in horizontal slug flow are studied experimentally in a 150-mm-dia pipeline. If a frame of reference is taken as moving with the translational velocity of the slug, measurements of the Froude number in the liquid film ahead of the slug were always greater than unity while the Froude number within the slug was in general less than unity. This illustrates a change in flow from super to subcritical flow and the presence of a hydraulic jump. Different types of flow are noticed using high-speed video equipment and these types closely resemble those reported by open-channel hydraulics tests. The distribution of gas in the slug body is only homogeneous at high-mixture velocities and the effect of buoyancy on the gas is more noticeable at low gas velocities. The liquid fraction in the slug is shown to be directly dependent on the Froude number in the liquid film. The ratio of the translational velocity of the slug to the mixture velocity decreases continuously from 2.0 at low-mixture velocities to 1.25 and a mixture velocity of approximately 3 m/s. After this point, it remains constant at 1.25.

Optimal Control Strategy and Experimental Investigation of Gas/Liquid Compact Separators

This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. Abstract The deployment of the new technology of gas-liquid compact separators such as Gas Liquid Cylindrical Cyclone (GLCC 1) requires dedicated control systems for field applications. The control strategy implementation is crucial for process optimization and adaptation, especially when GLCCs are operated at wide range of liquid and gas flow conditions. In this study, a unique and simple control strategy, which is capable of optimizing the operating pressure and adapting to liquid and gas inflow conditions, has been developed. Detailed simulations and experimental investigations have also been conducted to evaluate the performance of the proposed control systems. The significant advantages of this strategy are: the system can be operated at optimum separator back pressure; the system can adapt to the changes of liquid and gas flow conditions; and the strategy can be easily implemented using simple PID controllers available in the market. This provides the oil and gas industry a simple, robust compact separator control technique which has the potential for offshore and subsea applications. Introduction Compared to conventional separators, compact separators, such as the Gas-Liquid Cylindrical Cyclone (GLCC) are simple, compact, possess low weight, low-cost, require little maintenance, and are easy to install and operate. GLCCs have been used to enhance the performance of multiphase meters,

Wet Gas Separation in Gas-Liquid Cylindrical Cyclone Separator

A novel gas-liquid cylindrical cyclone (GLCC

GAS-LIQUID CYLINDRICAL CYCLONE (GLCC ) COMPACT SEPARATORS FOR WET GAS APPLICATIONS

Gas-Liquid Cylindrical Cyclone (GLCC 1 ) separators are becoming increasingly popular as attractive alternatives to conventional separators as they are simple, less expensive, have low-weight, and require little maintenance. However, present studies focus on GLCC designs and applications at relatively lower gas velocities (below the minimum velocity for onset of liquid carry-over in the form of mist flow). With appropriate modifications GLCCs can be used for wet gas and high gas oil ratio (GOR) applications, characterized by higher gas velocities, to knock out the liquid droplets from the gas core. The objectives of this study are to design a novel GLCC capable of separating liquid from a wet gas stream; conduct experimental investigations to evaluate the GLCC performance improvement in terms of operational envelope for liquid carryover; and, measure the liquid extraction from the gas stream. Specific design guidelines for wet gas GLCC are also formulated based on the experimental studies. This investigation provides new capabilities for compact separators for wet gas and high GOR (exceeding 90%) applications.

Aspect ratio modeling and design procedure for GLCC compact separators

The petroleum industry has recently shown interest in the development of innovative alternatives to the conventional vessel-type separator. One such alternative is the gas-liquid cylindrical cyclone (GLCC) separator, which is simple, compact, and low weight, and has low capital and operational costs. A new mechanistic model is proposed, for the first time, to predict the aspect ratio of the GLCC, based on its complex hydrodynamic multiphase flow behavior. This model incorporates an analytical solution for the gas-liquid vortex interface shape, and a unified particle trajectory model for bubbles and droplets. A simplified GLCC design methodology, based on the foregoing mechanistic model, is developed and specific design criteria are proposed as user guidelines for GLCC design. A summary offour actual field application designs is provided to demonstrate the capability of the aspect ratio modeling and the impact that the GLCC technology may have on the petroleum industry.