A New Model to Predict Average Pressure Difference of Liquid Droplet in Gas Well

2013 ◽  
Author(s):  
Zhong Hai-Quan ◽  
Liu Zhong-Neng ◽  
Liu Tong ◽  
Liang Kai ◽  
Ren Yong
Keyword(s):  
Pressure Difference ◽  
Liquid Droplet ◽  
Average Pressure ◽  
Gas Well ◽  
New Model

A New Model for Predicting Gas-Well Liquid Loading

2010 ◽  
Vol 25 (02) ◽  
pp. 172-181 ◽  
Author(s):  
Desheng Zhou ◽  
Hong Yuan
Keyword(s):  
Liquid Loading ◽  
Gas Well ◽  
New Model

scholarly journals On the One-Point Model for the Productivity Evaluation in Jingbian Sector of Yan’an Gas Field

2021 ◽  
Vol 9 ◽  
Author(s):  
Liu Er-hu ◽  
Liu Yang-yang ◽  
Gao Li-jun ◽  
Zhou De-sheng ◽  
Liu Xiong ◽  
...  
Keyword(s):  
Pressure Difference ◽  
Single Point ◽  
Final Analysis ◽  
Test Point ◽  
Future Application ◽  
Productivity Analysis ◽  
Well Test ◽  
Gas Field ◽  
Gas Well ◽  
The One

The productivity equation of a gas well is, in the final analysis, an expression that describes the relationship between the production of a gas well and its bottom-hole flowing pressure. There are two kinds of productivity equations in common use at present: binomial productivity equation and exponential productivity equation. Combined with the modified isochronal well test, the test data are interpreted, and it is found that the open flow rates calculated by the two productivity equations are basically the same when the pressure difference at the test point is large, and the deviation of the exponential productivity equation is large when the pressure difference at the test point is small. Using binomial productivity equation and modifying isochronous well test, we established the single-point deliverability formula for the Jingbian sector of the Yan’an gas field. The field experience formula and production data are used to verify it. Their average errors are 2.59% and 7.12%, respectively; and the coincidence rate of productivity evaluation is 90%. The one-point productivity formula established has high precision and is suitable for productivity analysis of gas wells in paleozoic reservoirs in the Jingbian sector of the Yan’an gas field. This paper provides insights into the one-point productivity evaluation and its future application in the gas field.

scholarly journals Dust Eruptions

2021 ◽  
Author(s):  
◽  
Harpreet Singh
Keyword(s):  
Shock Tube ◽  
Pressure Difference ◽  
Momentum Conservation ◽  
Expansion Wave ◽  
Wall Friction ◽  
Good Match ◽  
New Model ◽  
Bead Diameter ◽  
Pressure Changes

<p>We present a new model for the fragmentation of dust beds in laboratory shock tube experiments. The model successfully explains the formation of layers in the bed using mass and momentum conservation. Our model includes the effect of wall friction, inherent cohesion, and gravitational overburden. We find that the pressure changes caused by the expansion wave take time to penetrate into the bed, while simultaneously increasing in magnitude. By the time the pressure difference is large enough to overcome wall friction, the overburden and the intrinsic cohesion of the bed, it has penetrated ~8-15 bead diameters into the bed, thus causing a layer of dust to be lifted off. We have found the dependence of layer size upon bead diameter and found a good match to experiment. We have also predicted the dependence of layer size and fragmentation time on bead density.</p>

Contact Line Pinning and Depinning Prior to Rupture of an Evaporating Droplet in a Simulated Soil Pore

2020 ◽  
Author(s):  
Partha P. Chakraborty ◽  
Melanie M. Derby
Keyword(s):  
Contact Line ◽  
Pressure Difference ◽  
Liquid Droplet ◽  
Liquid Droplets ◽  
Water Contact ◽  
Marginal Rate ◽  
Vapor Interface ◽  
Hydrophobic Pore ◽  
Contact Line Pinning ◽  
Liquid Vapor

Abstract Altering soil wettability by inclusion of hydrophobicity could be an effective way to restrict evaporation from soil, thereby conserving water resources. In this study, 4-μL sessile water droplets were evaporated from an artificial soil millipore comprised of three glass (i.e. hydrophilic) and Teflon (i.e. hydrophobic) 2.38-mm-diameter beads. The distance between the beads were kept constant (i.e. center-to-center spacing of 3.1 mm). Experiments were conducted in an environmental chamber at an air temperature of 20°C and 30% and 75% relative humidity (RH). Evaporation rates were faster (i.e. ∼19 minutes and ∼49 minutes at 30% and 75% RH) from hydrophilic pores than the Teflon one (i.e. ∼24 minutes and ∼52 minutes at 30% and 75% RH) due in part to greater air-water contact area. Rupture of liquid droplets during evaporation was analyzed and predictions were made on rupture based on contact line pinning and depinning, projected surface area just before rupture, and pressure difference across liquid-vapor interface. It was observed that, in hydrophilic pore, the liquid droplet was pinned on one bead and the contact line on the other beads continuously decreased by deforming the liquid-vapor interface, though all three gas-liquid-solid contact lines decreased at a marginal rate in hydrophobic pore. For hydrophilic and hydrophobic pores, approximately 1.7 mm2 and 1.8–2 mm2 projected area of the droplet was predicted at 30% and 75% RH just before rupture occurs. Associated pressure difference responsible for rupture was estimated based on the deformation of curvature of liquid-vapor interface.

New Model for Gas Well Loading Prediction

2009 ◽  
Author(s):  
Desheng Zhou ◽  
Hong Yuan
Keyword(s):  
Gas Well ◽  
New Model

A New Model for Predicting Liquid Loading in Shale Gas Horizontal Wells

2021 ◽  
Author(s):  
Chao Zhou ◽  
Zuqing He ◽  
Yashu Chen ◽  
Zhifa Wang ◽  
Amol Mulunjkar ◽  
...  
Keyword(s):  
Flow Rate ◽  
Shale Gas ◽  
Liquid Flow Rate ◽  
Liquid Droplet ◽  
Case Analysis ◽  
Horizontal Wells ◽  
Critical Flow ◽  
Liquid Loading ◽  
Critical Flow Rate ◽  
New Model

Abstract Current critical flow rate models fail to accurately predict the liquid loading statuses of shale gas horizontal wells. Therefore, a new critical flow rate model for the whole wellbore of shale gas horizontal wells is established. The results of the new model are compared to those of current models through the field case analysis. The new model is based on the dynamic analysis and energy analysis of the deformed liquid-droplet, which takes into account the liquid flow rate, the liquid-droplet deformation and the energy loss caused by the change of buildup rate. The major axis of the maximum stable deformed liquid-droplet is determined based on the energy balance relation. Meanwhile, the suitable drag coefficient equation and surface tension equation applied to shale gas horizontal wells are chosen. Finally, the critical flow rate equation is established and the maximum critical flow rate of the whole wellbore is chosen as the criterion for liquid loading prediction. The precision of liquid loading prediction of the new model is compared to those of the four current models, including Belfroid's model, modified Li's model, liquid film model and modified Wang's model. Field parameters of 29 shale gas horizontal wells are used for the comparison, including parameters of 18 unloaded wells, 2 near loaded-up wells and 9 loaded-up wells. Field case analysis shows that the total precision of liquid loading prediction of the new model is 93.1%, which is higher compared to those of the current four models. The new model can accurately predict the liquid loading statuses of loaded-up wells and near loaded-up wells, while the prediction precision for unloaded wells is high enough for the field application, which is 88.9%. The new model can be used to effectively estimate the field liquid loading statuses of shale gas horizontal wells and choose drainage gas recovery technologies, which considers both the complex wellbore structure and the variation of flowback liquid flow rate in shale gas horizontal wells. The results of the new model fill the gap in existing studies and have a guiding significance for liquid loading prediction in shale gas horizontal wells.

scholarly journals Dust Eruptions

2021 ◽  
Author(s):  
◽  
Harpreet Singh
Keyword(s):  
Shock Tube ◽  
Pressure Difference ◽  
Momentum Conservation ◽  
Expansion Wave ◽  
Wall Friction ◽  
Good Match ◽  
New Model ◽  
Bead Diameter ◽  
Pressure Changes

<p>We present a new model for the fragmentation of dust beds in laboratory shock tube experiments. The model successfully explains the formation of layers in the bed using mass and momentum conservation. Our model includes the effect of wall friction, inherent cohesion, and gravitational overburden. We find that the pressure changes caused by the expansion wave take time to penetrate into the bed, while simultaneously increasing in magnitude. By the time the pressure difference is large enough to overcome wall friction, the overburden and the intrinsic cohesion of the bed, it has penetrated ~8-15 bead diameters into the bed, thus causing a layer of dust to be lifted off. We have found the dependence of layer size upon bead diameter and found a good match to experiment. We have also predicted the dependence of layer size and fragmentation time on bead density.</p>

scholarly journals Applied pilot-scale studies on ceramic membrane processes for the treatment of wastewater streams

2013 ◽  
Vol 8 (1) ◽  
pp. 23-30
Keyword(s):  
Pore Size ◽  
Pressure Difference ◽  
Membrane Surface ◽  
Free Water ◽  
Pilot Scale ◽  
Solid Particles ◽  
Average Pressure ◽  
Pore Sizes ◽  
Solid Suspension ◽  
Feed Volume

Asymmetric multilayer Al2O3 ceramic membranes with pore sizes ranging from 3 to 500 nm are synthesized in tubular form with external diameter of 14mm, internal diameter of 8mm and length of 340mm. The membrane synthesis took place on commercially available supports, with the dip-coating technique either from aloumina particle suspensions or from boehmite sols. The membranes are subsequently mounted in a pilot-scale module able to accept six specimens, and used in micro- and ultra- filtration experiments for the purification of aqueous streams from suspended solids. The experimental module is equipped with a back-flushing circuit that can be activated on demand to prevent the fouling of the membranes and the associated reduction in permeability. For the microfiltration experiments membranes with 100nm pore size are used. In the case of an aqueous solid suspension with a concentration of 0.1 to 1 wt.% consisting of solid particles with an average size of 0.5 μm, complete solid rejection is observed. The process has a capability of treating 0.8 m3 of feed per hour per square meter of membrane surface under an average pressure difference of 3 x 105 Nt m-2. The fouling of the membranes can be quite effectively reduced by back flushing at regular time intervals. Under complete retentate recycling conditions, more than 95% of the feed volume can be recovered as microparticle free water. For the ultrafiltration experiments membranes with 3 nm pore sizes are used. In the case of an aqueous solid suspension of nanoparticles with a concentration of 0.1 to 1 wt.% consisting of solid particles with sizes of 20-30 nm the rejection was also almost complete. The process has in this case a capability of treating 0.16 m3 of feed per hour per square meter of membrane surface under an average pressure difference of 3 x 105 Nt m-2. Fouling appears not to cause serious permeability drop in this case probably because even after the nanoparticle deposition the membrane hydraulic resistance is the permeability determining step. Almost the entire feed volume can be recovered as nanoparticle free water under complete retentate recycling conditions. Purification experiments are also performed in olive oil mill wastewater. Best results are achieved by using a two step membrane process with gradually decreasing pore size. Although complete rejection of solids and significant reduction of the BOD5 and phenol content of the wastes is achieved, the very low permeability is the main draw back of the process.

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