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 Role of Shearing Dispersion and Stripping in Wax Deposition in Crude Oil Pipelines

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4325
Author(s):  
Zhihua Wang ◽  
Yunfei Xu ◽  
Yi Zhao ◽  
Zhimin Li ◽  
Yang Liu ◽  
...  
Keyword(s):  
Crude Oil ◽  
Flow Rate ◽  
Critical Flow ◽  
Wax Deposition ◽  
Dominant Effect ◽  
Critical Flow Rate ◽  
Oil Pipelines ◽  
Oil Flow ◽  
Shearing Mechanism

Wax deposition during crude oil transmission can cause a series of negative effects and lead to problems associated with pipeline safety. A considerable number of previous works have investigated the wax deposition mechanism, inhibition technology, and remediation methods. However, studies on the shearing mechanism of wax deposition have focused largely on the characterization of this phenomena. The role of the shearing mechanism on wax deposition has not been completely clarified. This mechanism can be divided into the shearing dispersion effect caused by radial migration of wax particles and the shearing stripping effect caused by hydrodynamic scouring. From the perspective of energy analysis, a novel wax deposition model was proposed that considered the flow parameters of waxy crude oil in pipelines instead of its rheological parameters. Considering the two effects of shearing dispersion and shearing stripping coexist, with either one of them being the dominant mechanism, a shearing dispersion flux model and a shearing stripping model were established. Furthermore, a quantitative method to distinguish between the roles of shearing dispersion and shearing stripping in wax deposition was developed. The results indicated that the shearing mechanism can contribute an average of approximately 10% and a maximum of nearly 30% to the wax deposition process. With an increase in the oil flow rate, the effect of the shearing mechanism on wax deposition is enhanced, and its contribution was demonstrated to be negative; shear stripping was observed to be the dominant mechanism. A critical flow rate was observed when the dominant effect changes. When the oil flow rate is lower than the critical flow rate, the shearing dispersion effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. When the oil flow rate is higher than the critical flow rate, the shearing stripping effect is the dominant effect; its contribution rate increases with an increase in the oil flow temperature. This understanding can be used to design operational parameters of the actual crude oil pipelines and address the potential flow assurance problems. The results of this study are of great significance for understanding the wax deposition theory of crude oil and accelerating the development of petroleum industry pipelines.

Comprehensive Analysis of Production Loggings in Fuling Shale Gas Play in China

2021 ◽  
Author(s):  
Yaowen Liu ◽  
Wei Pang ◽  
Jincai Shen ◽  
Ying Mi
Keyword(s):  
Shale Gas ◽  
Mineral Content ◽  
Horizontal Wells ◽  
Organic Content ◽  
Gas Production ◽  
Liquid Loading ◽  
Comprehensive Overview ◽  
Gas Field ◽  
Well Trajectory ◽  
Positive Effect

Abstract Fuling shale gas field is one of the most successful shale gas play in China. Production logging is one of the vital technologies to evaluate the shale gas contribution in different stages and different clusters. Production logging has been conducted in over 40 wells and most of the operations are successful and good results have been observed. Some previous studies have unveiled one or several wells production logging results in Fuling shale gas play. But production logging results show huge difference between different wells. In order to get better understanding of the results, a comprehensive overview is carried out. The effect of lithology layers, TOC (total organic content), porosity, brittle mineral content, well trajectory is analyzed. Results show that the production logging result is consistent with the geology understanding, and fractures in the favorable layers make more gas contribution. Rate contribution shows positive correlation with TOC, the higher the TOC, the greater the rate contribution per stage. For wells with higher TOC, the rate contribution difference per stage is relatively smaller, but for wells with lower TOC, it shows huge rate contribution variation, fracture stages with TOC lower than 2% contribute very little, and there exist one or several dominant fractures which contributes most gas rate. Porosity and brittle minerals also show positive effect on rate contribution. The gas rate contribution per fracture stage increases with the increase of porosity and brittle minerals. The gas contribution of the front half lateral and that of latter half lateral are relatively close for the "upward" or horizontal wells. However, for the "downward" wells, the latter half lateral contribute much more gas than the front half lateral. It is believed that the liquid loading in the toe parts reduced the gas contribution in the front half lateral. The overview research is important to get a compressive understanding of production logging and different fractures’ contribution in shale gas production. It is also useful to guide the design of horizontal laterals and fractures scenarios design.

Numerical Simulation of Vibration of Composite Pipelines Conveying Pulsating Fluid

2019 ◽  
Vol 11 (09) ◽  
pp. 1950090 ◽  
Author(s):  
B. A. Khudayarov ◽  
KH. M. Komilova ◽  
F. ZH. Turaev
Keyword(s):  
Internal Pressure ◽  
Galerkin Method ◽  
Flow Rate ◽  
Pulsating Flow ◽  
Integral Model ◽  
Rheological Parameters ◽  
Critical Flow ◽  
Critical Flow Rate ◽  
Weakly Singular ◽  
Pulsating Fluid

Vibration problems of pipelines made of composite materials conveying pulsating flow of gas and fluid are investigated in the paper. A dynamic model of motion of pipelines conveying pulsating fluid flow supported by a Hetenyi’s base is developed taking into account the viscosity properties of the structure material, axial forces, internal pressure and Winkler’s viscoelastic base. To describe the processes of viscoelastic material strain, the Boltzmann–Volterra integral model with weakly singular hereditary kernels is used. Using the Bubnov–Galerkin method, the problem is reduced to the study of a system of ordinary integro-differential equations (IDE). A computational algorithm is developed based on the elimination of the features of IDE with weakly singular kernels, followed by the use of quadrature formulas. The effect of rheological parameters of the pipeline material, flow rate and base parameters on the vibration of a viscoelastic pipeline conveying pulsating fluid is analyzed. The convergence analysis of the approximate solution of the Bubnov–Galerkin method is carried out. It was revealed that the viscosity parameters of the material and the pipeline base lead to a significant change in the critical flow rate. It was stated that an increase in excitation coefficient of pulsating flow and the parameter of internal pressure leads to a decrease in the critical flow rate. It is shown that an increase in the singularity parameter, the Winkler base parameter, the rigidity parameter of the continuous base layer and the Reynolds number increases the critical flow rate.

Effect of Non-Condensible Gas on the Subcooled Water Critical Flow in a Safety Valve

2002 ◽  
Author(s):  
Se Won Kim ◽  
Sang Kyoon Lee ◽  
Hee Cheon No
Keyword(s):  
Flow Rate ◽  
Critical Pressure ◽  
Safety Valve ◽  
Pressure Ratio ◽  
Water Flow Rate ◽  
Critical Flow ◽  
Inlet Temperature ◽  
Nitrogen Gas ◽  
Critical Flow Rate ◽  
Subcooled Water

The effect of non-condensable gas on the subcooled water critical flow in a safety valve is investigated experimentally at various subcoolings with 3 different disk lifts. To evaluate its effect on the critical pressure ratio and critical flow rate, three parameters are considered: the ratios of outlet pressure to inlet pressure, the subcooling to inlet temperature, and the gas volumetric flow to water volumetric flow are 0.15–0.23, 0.07–0.12, and 0–0.8, respectively. It turns out that the critical pressure ratio is mainly dependent on the subcooling, and its dependency on the gas fraction and the pressure drop is relatively small. When the ratio of nitrogen gas volumetric flow to water volumetric flow becomes lower than 20%, the subcooled water critical flow rate is decreased about 10% compare to the water flow rate of without non-condensable gas. However, it maintains a constant value after the ratio of gas volumetric flow to water volumetric flow becomes higher than 20%. The subcooled water critical flow correlation, which considers subcooling, disc lift, backpressure, and non-condensable gas, shows good agreement with the total present experimental data with the root mean square error 8.17%.

Critical flow rate of anode fuel exhaust in a PEM fuel cell system

2006 ◽  
Vol 156 (2) ◽  
pp. 512-519 ◽  
Author(s):  
Wenhua H. Zhu ◽  
Robert U. Payne ◽  
Bruce J. Tatarchuk
Keyword(s):  
Fuel Cell ◽  
Flow Rate ◽  
Pem Fuel Cell ◽  
Cell System ◽  
Critical Flow ◽  
Fuel Cell System ◽  
Critical Flow Rate

Hydraulic Characteristics of Pipelines Transporting Hot Waxy Crudes

2006 ◽  
Author(s):  
Jun Chen ◽  
Jinjun Zhang ◽  
Hongying Li
Keyword(s):  
Flow Rate ◽  
Pour Point ◽  
Friction Loss ◽  
Low Flow ◽  
Critical Flow ◽  
Outlet Temperature ◽  
Hydraulic Characteristics ◽  
Critical Flow Rate ◽  
Waxy Crude ◽  
Oil Pipeline

Waxy crudes are generally pipelined by means of heating. In general, the friction loss of a pipeline decreases with decreasing flow rate. This is the case of isothermal pipeline. However, a hot oil pipeline operated at low flow rate might show a contrary case, i.e. friction-loss increases with decreasing flow rate. This is an unstable operation state and may result in disastrous consequence of flow ceasing if tackled improperly. For a waxy crude pipeline, this may also be exaggerated by the non-Newtonian flow characteristics at temperatures near the pour point. That is to say, there may exist a critical flow rate for pipelines transporting heated waxy crude, and in order to ensure safe operation, the flow rate of a pipeline transporting hot oil should be no less than this critical flow rate. Based on theoretical analysis and can study, the hydraulic characteristics of pipelines transporting hot waxy crudes was investigated, and an empirical model was developed correlating the critical flow rate QC and the pipelining parameters, such as the average overall heat transfer coefficient, the ground temperature, the heating temperature, etc. Another relationship was found between TZC, the outlet temperature of the pipeline corresponding to the critical flow rate, and the critical flow rate. This TZC is also the lowest pipeline outlet temperature that ensures the normal pipelining operation state. Case study on a 720mm O.D. pipeline transporting heated Daqing waxy crude with a pour point of 36 °C showed that the TZC was in a range of 31∼34.2°C.

scholarly journals An analytical solution for critical withdrawal of layered fluid through a line sink in a porous medium

1997 ◽  
Vol 39 (2) ◽  
pp. 271-279 ◽  
Author(s):  
H. Zhang ◽  
G. C. Hocking ◽  
D. A. Barry
Keyword(s):  
Porous Medium ◽  
Analytical Solution ◽  
Flow Rate ◽  
Close Agreement ◽  
Critical Flow ◽  
Hodograph Method ◽  
Critical Flow Rate ◽  
Line Sink ◽  
Surface Profiles ◽  
Layered Fluid

AbstractFluid withdrawn through a line sink from a layered fluid in a vertically confined porous medium is considered. A hodograph method is used to obtain the shape of the interface for a given sink position at the critical flow rate. The analytical solution is compared with a more general numerical solution developed in earlier work. It was found that the surface profiles obtained by the two methods are in close agreement. However, the present work has the advantage that it gives a fully explicit solution.

scholarly journals Prediction of Two-Phase Critical Flow Rate

1965 ◽  
Vol 87 (1) ◽  
pp. 53-57 ◽  
Author(s):  
S. Levy
Keyword(s):  
Flow Rate ◽  
Thermal Equilibrium ◽  
Present Model ◽  
Critical Flow ◽  
Test Results ◽  
Two Phase ◽  
Mean Velocity ◽  
Critical Flow Rate ◽  
Pressure Losses ◽  
Gas Void Fraction

An analytical model to predict two-phase critical flow rate is proposed. The model is based upon thermal equilibrium, a “lumped” treatment of the two-phase velocity (each phase is represented by a single mean velocity), and upon the neglect of frictional and hydrostatic pressure losses. A comparison of the proposed predictions with available test results and previous analyses shows that: (a) The present model agrees very well with the published test data; (b) In contrast to all other analyses, the model requires no assumption about the gas void fraction.

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