A Field Test and Analytical Study of Intermittent Gas Lift

1974 ◽  
Vol 14 (05) ◽  
pp. 502-512 ◽  
Author(s):  
A.B. Neely ◽  
J.W. Montgomery ◽  
J.V. Vogel
Keyword(s):  
Montgomery County ◽  
Pressure Gradients ◽  
Time Decay ◽  
Controlled Experiments ◽  
Gas Velocity ◽  
Liquid Slug ◽  
Valve Stem ◽  
Casing Pressure ◽  
Solid Liquid ◽  
Gas Lift

Abstract A series of controlled experiments of intermittent gas life were carried out in an instrumented well in the Conroe field, Montgomery County, Tex. The well was equipped with seven pressure transducers over the length of the tubing string so that progress of the lifted slug of liquid could be followed up the tubing. Unique to the experimental setup was a surface-controlled, bottom-hole hydraulic valve that allowed for letting a liquid load into the tubing, closing the valve, and isolating the well from the controlled test. Thus, individual intermittent slugs could be studied independent of the well performance. A wide range of slug sizes and injection gas volumes was covered in the 52 test runs.Understanding the action of the gas-life valve is quite important in predicting intermittent-gas-lift performance. Gas-Lift valve action depends somewhat performance. Gas-Lift valve action depends somewhat on the pressure and forces acting upon the stem of the valve. Gas-life literature has assumed that this pressure is equal to the pressure in the casing once pressure is equal to the pressure in the casing once the valve opens. Tests carried out as a result of valve action seen in the instrumented well clearly indicate that this assumption is not valid. Some pressure between the casing pressure and the tubing pressure between the casing pressure and the tubing pressure will exist on the valve stem when the valve pressure will exist on the valve stem when the valve is open; and it is extremely important to be aware of this in predicting valve action. Some design techniques predict the amount of solid liquid slug that will be predict the amount of solid liquid slug that will be brought to the surface and assume that any additional liquid produced in the afterflow of gas will be negligible. It was observed in these tests that a significant portion of the liquid produced at the surface sometimes as much as 50 percent was contributed by this afterflow there will be a considerable discrepancy between predicted and actual results.Liquid recovery from individual runs did not correlate directly with any of the measured parameters. However, it appears that the amount of the liquid slug that is not produced can be correlated with the average gas velocity produced can be correlated with the average gas velocity below the slug. Since the starting slug size is known, the correlation can be used as a predictive technique in intermittent-gas-lift design. The design method has been compared with a field test. Introduction Although intermittent gas lift has been used for artificial lift in oil wells for many years, little concrete technology has been developed for it. Design methods and behavior predictions are as much an art as a science. There have predictions are as much an art as a science. There have been two major attempts to remedy the situation. White et al. attempted to analyze the motion of a finite slug of liquid propelled to the surface by gas injected at high pressure underneath. Supporting their premise by a modicum pressure underneath. Supporting their premise by a modicum of experimentation, they published results in the form of design curves. Brown and Jessen, on the other hand, attempted no analytical solution, but did extensive field testing to develop an empirical foundation for intermittent-gas-lift technology. Unfortunately, there was considerable discrepancy in the results of the two studies.To improve the technology in intermittent gas lift, Shell Oil Co, ran a series of controlled experiments in a gas-life well in the Conroe Field, Montgomery County, Tex. The well instrumentation necessary to carry out the tests is shown in Figs. 1 and 2. (The instrumentation technology was provided by B. C. Sheffield of Shell Development Co.)To predict intermittent-lift behavior, analytical methods are needed to calculate the time rate behavior of the casing gas pressure and volume, the flow of gas through a gas-lift valve, the velocity with which a liquid slug will be raised to the surface by this gas, the amount of liquid that will be produced at the surface and the amount left behind, the pressure gradients during the process, and the time decay pressure gradients during the process, and the time decay curve for the blowdown of gas pressure after the slug has surfaced. None of these functions is independent of the others and all must be considered simultaneously in predicting lift behavior. SPEJ p. 502

Utilization of Gas-Liquid Cylindrical Cyclone (GLCC©) Compact Separator for Solids Removal—Part I: Minimum Required Liquid Injection Rate

2009 ◽  
Author(s):  
R. Arismendi ◽  
L. Gomez ◽  
S. Wang ◽  
R. Mohan ◽  
O. Shoham ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mechanistic Model ◽  
Injection Rate ◽  
Gas Velocity ◽  
Horizontal Section ◽  
Injection Point ◽  
Solids Transport ◽  
Liquid Injection ◽  
Injection Line ◽  
Solid Liquid

The hydrodynamic behavior of gas-liquid-solids in a modified GLCC© has been studied for the first time experimentally and theoretically. A GLCC© experimental facility has been designed, constructed and utilized to acquire data on gas-solid-liquid flow in both upstream 2-inch injection line horizontal section and in the 3-inch GLCC©. Experimental data have been acquired for the minimum gas velocity required to transport the solids up to the liquid injection point, and for the minimum liquid injection rate necessary to wet the solids and capture them in the liquid phase. The data have been acquired for 4 solid particle sizes of 5 μm, 25 μm, 50 μm and 150 μm. A mechanistic model has been developed or modified for solids transport/ separation, for the prediction of the minimum transport gas velocity, and the required minimum liquid injection rate. A comparison between the model prediction and the acquired experimental data shows good agreement. The average relative error for minimum transport gas and liquid velocities are, 4.3% and 9.55%, respectively.

Increasing Oil Production by Gas Lift Injection Point Detection Based on Well Test Data: Field Experience in the Handil Field

2020 ◽  
Author(s):  
A. M. Andari
Keyword(s):  
Computational Simulation ◽  
Oil Production ◽  
Pressure Profile ◽  
Well Testing ◽  
Well Test ◽  
Success Rates ◽  
Injection Point ◽  
East Kalimantan ◽  
Casing Pressure ◽  
Gas Lift

The Handil field is one of the mature fields in the Mahakam Delta, East Kalimantan, Indonesia. This field is widely known as an oil producer for more than 40 years with peak production of 180,000 BOPD in 1977 and has been challenging in terms of oil production decline ever since. Today, this field delivers ~16,000 BOPD from 115 active wells with more than 90% of oil production coming from gas lifted wells. Therefore, evaluating gas lift performance is very crucial to maintain hydrocarbon production of the field. As a gas lift well is produced, it is common to find gas lift unloader damage, sealing element problems, or even leaks at the tubing due to aging of equipment that degrades the gas lift performance. This paper explains the use of well testing data on investigating the performance of gas lift by estimating gas lift injection depth. The best fit vertical lift correlation should be chosen to represent actual pressure profile of the wells inside the tubing and annulus casing pressure. Estimated injection point is derived from gas lift unloader valve opening status or meeting point between tubing and casing pressure profile. The calculation was done using computational simulation and was applied for every flowing gas lifted well in an integrated module. Based on the simulation, wells that were found to encounter behavior anomalies requested to perform P-T (pressure temperature) + spinner surveys to confirm leak points prior to leak isolations. Based on 3 proven leak cases, it is confirmed that estimated gas lift injection point from simulation versus production logging survey are in line. In 2019, we had 6 gas lift well cases that were confirmed to have a leak and continued with a leak isolation program. After these wells were put back into production, it gave cumulative oil production of up to almost 100,000 Bbls oil. The high success rates of this method verifies the applicability of this effective approach to maintain gas lift performance and is easy to replicate for others PSC companies.

scholarly journals Determining the Effective Mass Transfer Area in Three-Phase Fluidized Bed with Low Density Inert Solids

2019 ◽  
Vol 70 (11) ◽  
pp. 4040-4046
Author(s):  
Simion Dragan
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Effective Mass ◽  
Fluidized Bed ◽  
Internal Diameter ◽  
Gas Velocity ◽  
Mathematical Correlation ◽  
Liquid Load ◽  
Three Phase ◽  
Solid Liquid

The absorption process is strongly influenced by the effective mass transfer area. In this study the effective mass transfer area in gas-solid-liquid three-phase fluidized bed was determined, in a fluidizing column having an internal diameter of 0.14 m and a height of 1.10 m. The solid packing is made of plastic hollow spheres of 0.01 m diameter, with 415 m2/m3 geometric area and a density of 170 Kg/m3. The absorption of carbon dioxide from the air-carbon dioxide mixture with molar concentration of 0.05M, 0.08M and 0.1M CO2 into sodium hydroxide aqueous solutions of 0.5N and 1.0 N has been employed as test reaction. The experiments were conducted with liquid load changing from 6.49 to 16.24 m�/(m� h) and gas velocity of 1.1 m/s and 2.1 m/s. It was found that the effective mass transfer area increased both with the increase of the gas velocity and the increase of the liquid spray density. It has been observed that the effective mass transfer area in gas-solid-liquid three-phase fluidized bed absorber is from three to eight times higher than the geometric area of the solid packing. A mathematical correlation has been established in order to predict the effective mass transfer area,under the specified conditions, with a deviation of less than 5%.

Solid suspension and gas dispersion in gas-solid-liquid agitated systems

2010 ◽  
Vol 64 (2) ◽  
Author(s):  
Anna Kiełbus-Rąpała ◽  
Joanna Karcz
Keyword(s):  
Residence Time ◽  
Experimental Studies ◽  
Gas Bubbles ◽  
High Energy ◽  
Gas Velocity ◽  
Solids Concentration ◽  
Three Phase ◽  
Phase Systems ◽  
Superficial Gas Velocity ◽  
Solid Liquid

AbstractThe aim of the research work was to investigate the effect of superficial gas velocity and solids concentration on the critical agitator speed, gas hold-up and averaged residence time of gas bubbles in an agitated gas-solid-liquid system. Experimental studies were conducted in a vessel of the inner diameter of 0.634 m. Different high-speed impellers: Rushton and Smith turbines, A 315 and HE 3 impellers, were used for agitation. The measurements were conducted in systems with different physical parameters of the continuous phase. Liquid phases were: distilled water (coalescing system) or aqueous solutions of NaCl (non-coalescing systems). The experiments were carried out at five different values of solids concentration and gas flow rate. Experimental analysis of the conditions of gas bubbles dispersion and particles suspension in the vessel with a flat bottom and four standard baffles showed that both gas and solid phases strongly affected the critical agitation speed necessary to produce a three-phase system. On the basis of experimental studies, the critical agitator speed for all agitators working in the gas-solid-liquid systems was found. An increase of superficial gas velocity caused a significant increase of the gas hold-up in both coalescing and non-coalescing three-phase systems. The type of the impeller strongly affected the parameters considered in this work. Low values of the critical impeller speed together with the relatively short average gas bubbles residence time tR in three phase systems were characteristic for the A 315 impeller. Radial flow Rushton and Smith turbines are high-energy consuming impellers but they enable to maintain longer gas bubbles residence time and to obtain higher values of the gas hold-up in the three-phase systems. Empirical correlations were proposed for the critical agitator speed, mean specific energy dissipated and the gas hold-up prediction. Its parameters were fitted using experimental data.

scholarly journals Monostable superrepellent materials

2017 ◽  
Vol 114 (13) ◽  
pp. 3387-3392 ◽  
Author(s):  
Yanshen Li ◽  
David Quéré ◽  
Cunjing Lv ◽  
Quanshui Zheng
Keyword(s):  
Phase Space ◽  
Surface Chemistry ◽  
Energy Input ◽  
Dramatic Reduction ◽  
Controlled Experiments ◽  
Extreme Situation ◽  
Environmental Disturbances ◽  
Cassie State ◽  
Hydrodynamic Slip ◽  
Solid Liquid

Superrepellency is an extreme situation where liquids stay at the tops of rough surfaces, in the so-called Cassie state. Owing to the dramatic reduction of solid/liquid contact, such states lead to many applications, such as antifouling, droplet manipulation, hydrodynamic slip, and self-cleaning. However, superrepellency is often destroyed by impalement transitions triggered by environmental disturbances whereas inverse transitions are not observed without energy input. Here we show through controlled experiments the existence of a “monostable” region in the phase space of surface chemistry and roughness, where transitions from Cassie to (impaled) Wenzel states become spontaneously reversible. We establish the condition for observing monostability, which might guide further design and engineering of robust superrepellent materials.

Determining the Effective Mass Transfer Area in Three-Phase Fluidized Bed with Low Density Inert Solids

2018 ◽  
Vol 70 (11) ◽  
pp. 4040-4046
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Effective Mass ◽  
Fluidized Bed ◽  
Internal Diameter ◽  
Low Density ◽  
Gas Velocity ◽  
Liquid Load ◽  
Three Phase ◽  
Solid Liquid

The absorption process is strongly influenced by the effective mass transfer area. In this study the effective mass transfer area in gas-solid-liquid three-phase fluidized bed was determined, in a fluidizing column having an internal diameter of 0.14 m and a height of 1.10 m. The solid packing is made of plastic hollow spheres of 0.01 m diameter, with 415 m2/m3 geometric area and a density of 170 Kg/m3. The absorption of carbon dioxide from the air-carbon dioxide mixture with molar concentration of 0.05M, 0.08M and 0.1M CO2 into sodium hydroxide aqueous solutions of 0.5N and 1.0 N has been employed as test reaction. The experiments were conducted with liquid load changing from 6.49 to 16.24 m³/(m² h) and gas velocity of 1.1 m/s and 2.1 m/s. It was found that the effective mass transfer area increased both with the increase of the gas velocity and the increase of the liquid spray density. It has been observed that the effective mass transfer area in gas-solid-liquid three-phase fluidized bed absorber is from three to eight times higher than the geometric area of the solid packing. A mathematical correlation has been established in order to predict the effective mass transfer area,under the specified conditions, with a deviation of less than 5%. Keywords: Effective mass transfer area, three-phase fluidized bed with low density inert solid packing, mass transfer model, chemical method, reaction regime

Characteristics of Radial Transport in Solid-Liquid Slug Flow

1978 ◽  
Vol 17 (1) ◽  
pp. 39-45 ◽  
Author(s):  
James S. Vrentas ◽  
J. Larry Duda ◽  
George D. Lehmkuhl
Keyword(s):  
Slug Flow ◽  
Liquid Slug ◽  
Radial Transport ◽  
Solid Liquid

Prediction of Pressure Gradients for Multiphase Flow in Tubing

1963 ◽  
Vol 3 (01) ◽  
pp. 59-69 ◽  
Author(s):  
George H. Fancher ◽  
Kermit E. Brown
Keyword(s):  
Multiphase Flow ◽  
Pressure Gradient ◽  
Field Data ◽  
Empirical Method ◽  
Low Flow ◽  
Pressure Gradients ◽  
Liquid Ratio ◽  
Flow Rates ◽  
Flow Through ◽  
Gas Lift

Abstract An 8,000-ft experimental field well was utilized to conduct flowing pressure gradient tests under conditions of continuous, multiphase flow through 2 3/8-in. OD tubing. The well was equipped with 10 gas-lift valves and 10 Maihak electronic pressure recorders, as well as instruments to accurately measure the surface pressure, temperature, volume of injected gas and fluid production.These tests were conducted for flow rates ranging from 75 to 936 B/D at various gas-liquid ratios from 105 to 9,433 scf/bbl. An expanding-orifice gas-lift valve allowed each flow rate to be produced with a range of controlled gas-liquid ratios. From these data an accurate pressure traverse has been constructed for various flow rates and for various gas-liquid ratios.A comparison of these tests to Poettmann and Carp enter's correlation indicates that deviations occur for certain ranges of flow rates and gasliquid ratios. Numerous curves are presented illustrating the comparison of this correlation with the field data. Poettmann and Carpenter's correlation deviates some for low flow rates and, in particular, for gas-liquid ratios in excess of 3,000 scf/bbl. These deviations are believed to be mainly due to the friction-factor correlation. However, Poettmann and Carpenter's correlation gives excellent agreement in those ranges of higher density. This was as expected and predicted by Poettmann. He pointed out that their method was not intended to be extended to those ranges of low densities whereby an extreme reversal in curvature occurs.As a result of these experimental tests, correlations using Poettmann and Carpenter's method were established between the friction factors and mass flow rates which are applicable for all gasliquid ratios and flow rates. Definite changing flow patterns do not allow any one correlation to be accurate for all ranges of flow. Introduction The ability to analytically predict the pressure at any point in a flow string is essential in determining optimum production string dimensions and in the design of gas-lift installations. This information is also invaluable in predicting bottom-hole pressures in flowing wells.Although this problem is not new to industry, it has by no means been solved completely for all types of flow conditions. Versluys, Uren, et al, Gosline, May, and Moore, et al, were all early investigators of multiphase flow through vertical conduits. However, all of these investigations and proposed methods were very limited as to their range of application. Likewise, many are extremely complicated and therefore not very useful in the field.Only in the last decade have any significant methods been proposed which are generally applicable. The most widely accepted procedure in industry at the present time is a semi-empirical method developed from an energy balance, proposed by Poettmann and Carpenter in 1952. Their correlation is based on actual pressure measurements from field wells. Accurate predictions from this correlation are limited to high flow rates and low gas-liquid ratios.Although this method will he discussed in detail later, it should be pointed out that two important parameters, namely the gas-liquid ratio and the viscosity, were omitted in their correlation. The viscosity was justifiably omitted since their data was in the highly turbulent flow region for both phases, and most wells fall in this category. The gas-liquid ratio was incorporated to some extent in the gas-density term. In 1954, Gilbert presented numerous pressure gradient curves obtained from field data for various flow rates and gas-liquid ratios for the determination of optimum flow strings. However, no method is presented for predicting pressure gradients except by comparison to these curves. SPEJ P. 59^

The investigation of a standing wave due to gas blowing upwards over a liquid film; its relation to flooding in wetted-wall columns

1965 ◽  
Vol 22 (2) ◽  
pp. 321-335 ◽  
Author(s):  
C. J. Shearer ◽  
J. F. Davidson
Keyword(s):  
Liquid Film ◽  
Standing Wave ◽  
Gas Flow ◽  
Wave Amplitude ◽  
Volume Flow Rate ◽  
Vertical Surface ◽  
Liquid Volume ◽  
Pressure Gradients ◽  
Gas Velocity ◽  
Gas Blowing

A theory is given to predict the shape and amplitude of a standing wave formed on a liquid film running down a vertical surface, and due to an upward flow of gas over the liquid surface. The wave is maintained in position by the pressure gradients induced within the gas stream by acceleration over the windward part of the wave; over the leeward part of the wave, the gas pressure is roughly constant due to breakaway of the gas flow.The wave amplitude is found to be very sensitive to gas velocity so that the theory predicts a critical gas velocity beyond which the wave amplitude becomes very large; this critical velocity is confirmed by experiment, and the experiments confirm the predicted wave shape. The critical gas velocity also agrees reasonably well with published values of the flooding velocity in empty wetted-wall tubes; this velocity is defined as the point at which countercurrent flow of gas and liquid becomes unstable. The phenomenon of flooding, which has puzzled chemical engineers for many years, may thus be due to wave formation on the liquid film.From the theory are derived three dimensionless groups, namely, Weber number $We \equiv \rho_g U_c^2t_0|T$, liquid-film Reynolds number $Re \equiv 4\rho_l Q|\mu, and Z \equiv T(\rho_l|\mu g)^{1/3}|\mu$. Here Uc is the critical gas velocity, Q is the liquid volume flow rate per unit wetted perimeter, ρg and ρl are the gas and liquid densities, μ is the liquid viscosity and T is its surface tension; $t_0 = (3\mu Q|\rho_lg)^{1/3}$ is the liquid film thickness in the absence of gas flow. We, Re and Z are uniquely related at the flooding point, and a diagram is presented to show this relation. This diagram will enable designers to predict flooding in wetted-wall tubes, though more experimental verification is required.

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