Numerical Study of Shale Gas Flow Behaviour in Reservoir and Hydraulic Fractures

2017 ◽  
pp. 43-59
Author(s):  
Jebraeel Gholinezhad ◽  
John Senam Fianu ◽  
Mohamed Galal Hassan
Keyword(s):  
Shale Gas ◽  
Gas Flow ◽  
Numerical Study ◽  
Flow Behaviour ◽  
Hydraulic Fractures

scholarly journals History Matching and Forecast of Shale Gas Production Considering Hydraulic Fracture Closure

Energies ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1634 ◽  
Author(s):  
Juhyun Kim ◽  
Youngjin Seo ◽  
Jihoon Wang ◽  
Youngsoo Lee
Keyword(s):  
Shale Gas ◽  
Hydraulic Fracture ◽  
History Matching ◽  
Gas Flow ◽  
Fluid Pressure ◽  
Gas Production ◽  
Hydraulic Fractures ◽  
Gas Reservoirs ◽  
Shale Gas Reservoirs ◽  
Fracture Closure

Most shale gas reservoirs have extremely low permeability. Predicting their fluid transport characteristics is extremely difficult due to complex flow mechanisms between hydraulic fractures and the adjacent rock matrix. Recently, studies adopting the dynamic modeling approach have been proposed to investigate the shape of the flow regime between induced and natural fractures. In this study, a production history matching was performed on a shale gas reservoir in Canada’s Horn River basin. Hypocenters and densities of the microseismic signals were used to identify the hydraulic fracture distributions and the stimulated reservoir volume. In addition, the fracture width decreased because of fluid pressure reduction during production, which was integrated with the dynamic permeability change of the hydraulic fractures. We also incorporated the geometric change of hydraulic fractures to the 3D reservoir simulation model and established a new shale gas modeling procedure. Results demonstrate that the accuracy of the predictions for shale gas flow improved. We believe that this technique will enrich the community’s understanding of fluid flows in shale gas reservoirs.

A Generalized Framework Model for the Simulation of Gas Production in Unconventional Gas Reservoirs

SPE Journal ◽  
2014 ◽  
Vol 19 (05) ◽  
pp. 845-857 ◽  
Author(s):  
Yu-Shu Wu ◽  
Jianfang Li ◽  
Didier-Yu Ding ◽  
Cong Wang ◽  
Yuan Di
Keyword(s):  
Shale Gas ◽  
Gas Flow ◽  
Gas Production ◽  
Unconventional Reservoirs ◽  
Hydraulic Fractures ◽  
Gas Reservoirs ◽  
Unconventional Gas ◽  
Shale Gas Reservoirs ◽  
Framework Model ◽  
Unconventional Gas Reservoirs

Summary Unconventional gas resources from tight-sand and shale gas reservoirs have received great attention in the past decade around the world because of their large reserves and technical advances in developing these resources. As a result of improved horizontal-drilling and hydraulic-fracturing technologies, progress is being made toward commercial gas production from such reservoirs, as demonstrated in the US. However, understandings and technologies needed for the effective development of unconventional reservoirs are far behind the industry needs (e.g., gas-recovery rates from those unconventional resources remain very low). There are some efforts in the literature on how to model gas flow in shale gas reservoirs by use of various approaches—from modified commercial simulators to simplified analytical solutions—leading to limited success. Compared with conventional reservoirs, gas flow in ultralow-permeability unconventional reservoirs is subject to more nonlinear, coupled processes, including nonlinear adsorption/desorption, non-Darcy flow (at both high flow rate and low flow rate), strong rock/fluid interaction, and rock deformation within nanopores or microfractures, coexisting with complex flow geometry and multiscaled heterogeneity. Therefore, quantifying flow in unconventional gas reservoirs has been a significant challenge, and the traditional representative-elementary-volume- (REV) based Darcy's law, for example, may not be generally applicable. In this paper, we discuss a generalized mathematical framework model and numerical approach for unconventional-gas-reservoir simulation. We present a unified framework model able to incorporate known mechanisms and processes for two-phase gas flow and transport in shale gas or tight gas formations. The model and numerical scheme are based on generalized flow models with unstructured grids. We discuss the numerical implementation of the mathematical model and show results of our model-verification effort. Specifically, we discuss a multidomain, multicontinuum concept for handling multiscaled heterogeneity and fractures [i.e., the use of hybrid modeling approaches to describe different types and scales of fractures or heterogeneous pores—from the explicit modeling of hydraulic fractures and the fracture network in stimulated reservoir volume (SRV) to distributed natural fractures, microfractures, and tight matrix]. We demonstrate model application to quantify hydraulic fractures and transient flow behavior in shale gas reservoirs.

Numerical Study on the Removal of Hydrogen and Nitrogen from the Melt of Medium Carbon Steel in Vacuum Tank Degasser

2013 ◽  
Vol 762 ◽  
pp. 253-260 ◽  
Author(s):  
Shan Yu ◽  
Jyrki Miettinen ◽  
Seppo Louhenkilpi
Keyword(s):  
Carbon Steel ◽  
Liquid Steel ◽  
Gas Flow ◽  
Numerical Study ◽  
Vacuum Treatment ◽  
Medium Carbon Steel ◽  
Transfer Coefficients ◽  
Ansys Fluent ◽  
Medium Carbon ◽  
Cell Expression

The steelmaking field has been seeing an increased demand of reducing hydrogen and nitrogen in liquid steel before casting. This is often accomplished by vacuum treatment. This paper focuses on developing a numerical model to investigate the removal of hydrogen and nitrogen from the melt of medium carbon steel in a commercial vacuum tank degasser. An activity coefficient model and the eddy-cell expression are implemented in the ANSYS FLUENT code to compute the activities of related elements and mass transfer coefficients of hydrogen and nitrogen in liquid steel. Several cases are simulated to assess the effect of gas flow rate and initial nitrogen content in liquid steel on degassing process and the calculated results are compared with industrial measured data.

Numerical Study of Methane and Air Combustion Inside Heat-Recirculating Combustors

2013 ◽  
Author(s):  
Yanxia Li ◽  
Zhongliang Liu ◽  
Yan Wang ◽  
Jiaming Liu
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Central Area ◽  
Small Scale ◽  
Inlet Velocity ◽  
Strong Convection ◽  
Simulation Results ◽  
Lean Fuel ◽  
Set Up

A numerical model on methane/air combustion inside a small Swiss-roll combustor was set up to investigate the flame position of small-scale combustion. The simulation results show that the combustion flame could be maintained in the central area of the combustor only when the speed and equivalence ratio are all within a narrow and specific range. For high inlet velocity, the combustion could be sustained stably even with a very lean fuel and the flame always stayed at the first corner of reactant channel because of the strong convection heat transfer and preheating. For low inlet velocity, small amounts of fuel could combust stably in the central area of the combustor, because heat was appropriately transferred from the gas to the inlet mixture. Whereas, for the low premixed gas flow, only in certain conditions (Φ = 0.8 ～ 1.2 when ν0 = 1.0m/s, Φ = 1.0 when ν0 = 0.5m/s) the small-scale combustion could be maintained.

Numerical Study on Characteristics of Real Gas Flow Through a Critical Nozzle

2012 ◽  
Vol 29 (1) ◽  
Author(s):  
Junji Nagao ◽  
Shigeru Matsuo ◽  
Mamun Mohammad ◽  
Toshiaki Setoguchi ◽  
Heuy Dong Kim
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Real Gas ◽  
Critical Nozzle ◽  
Flow Through

scholarly journals Numerical Simulation of Secondary Flow in Gas Turbine Disc Cavities, Including Conjugate Heat Transfer

1996 ◽  
Author(s):  
Y.-H. Ho ◽  
M. M. Athavale ◽  
J. M. Forry ◽  
R. C. Hendricks ◽  
B. M. Steinetz
Keyword(s):  
Heat Transfer ◽  
Secondary Flow ◽  
Conjugate Heat Transfer ◽  
Gas Flow ◽  
Numerical Study ◽  
Labyrinth Seal ◽  
Temperature Fields ◽  
Heat Transfer Analysis ◽  
Flow Rates ◽  
Turbine Disc

A numerical study of the flow and heat transfer in secondary flow elements of the entire inner portion of the turbine section of the Allison T-56/501D engine is presented. The flow simulation included the interstage cavities, rim seals and associated main path flows, while the energy equation also included the solid parts of the turbine disc, rotor supports, and stator supports. Solutions of the energy equations in these problems usually face the difficulty in specifications of wall thermal boundary conditions. By solving the entire turbine section this difficulty is thus removed, and realistic thermal conditions are realized on all internal walls. The simulation was performed using SCISEAL, an advanced 2D/3D CFD code for predictions of fluid flows and forces in turbomachinery seals and secondary flow elements. The mass flow rates and gas temperatures at various seal locations were compared with the design data from Allison. Computed gas flow rates and temperatures in the rim and labyrinth seal show a fair 10 good comparison with the design calculations. The conjugate heat transfer analysis indicates temperature gradients in the stationary intercavity walls, as well as the rotating turbine discs. The thermal strains in the stationary wall may lead to altered interstage labyrinth seal clearances and affect the disc cavity flows. The temperature, fields in the turbine discs also may lead to distortions that can alter the rim seal clearances. Such details of the flow and temperature fields are important in designs of the turbine sections to account for possible thermal distortions and their effects on the performance. The simulation shows that the present day CFD codes can provide the means to understand the complex flow field and thereby aid the design process.

scholarly journals NMR Analysis Method of Gas Flow Pattern in the Process of Shale Gas Depletion Development

Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-7
Author(s):  
Rui Shen ◽  
Zhiming Hu ◽  
Xianggang Duan ◽  
Wei Sun ◽  
Wei Xiong ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Pore Pressure ◽  
Shale Gas ◽  
Gas Flow ◽  
Continuous Medium ◽  
Slip Flow ◽  
Flow Patterns ◽  
Transitional Flow ◽  
Analysis Method ◽  
Adsorbed Gas

Shale gas reservoirs have pores of various sizes, in which gas flows in different patterns. The coexistence of multiple gas flow patterns is common. In order to quantitatively characterize the flow pattern in the process of shale gas depletion development, a physical simulation experiment of shale gas depletion development was designed, and a high-pressure on-line NMR analysis method of gas flow pattern in this process was proposed. The signal amplitudes of methane in pores of various sizes at different pressure levels were calculated according to the conversion relationship between the NMR T 2 relaxation time and pore radius, and then, the flow patterns of methane in pores of various sizes under different pore pressure conditions were analyzed as per the flow pattern determination criteria. It is found that there are three flow patterns in the process of shale gas depletion development, i.e., continuous medium flow, slip flow, and transitional flow, which account for 73.5%, 25.8%, and 0.7% of total gas flow, respectively. When the pore pressure is high, the continuous medium flow is dominant. With the gas production in shale reservoir, the pore pressure decreases, the Knudsen number increases, and the pore size range of slip flow zone and transitional flow zone expands. When the reservoir pressure is higher than the critical desorption pressure, the adsorbed gas is not desorbed intensively, and the produced gas is mainly free gas. When the reservoir pressure is lower than the critical desorption pressure, the adsorbed gas is gradually desorbed, and the proportion of desorbed gas in the produced gas gradually increases.

A Novel Design Method for Optimizing the Diverter Dosage in Hydraulic Fracturing Using Three-Dimensionally Printed Fractures

2021 ◽  
Author(s):  
Meng Wang ◽  
Mingguang Che ◽  
Bo Zeng ◽  
Yi Song ◽  
Yun Jiang ◽  
...  
Keyword(s):  
Shale Gas ◽  
Design Method ◽  
Pressure Rise ◽  
Horizontal Wells ◽  
Optimization Method ◽  
Darcy Law ◽  
Hydraulic Fractures ◽  
Fracture Conductivity ◽  
Fracture Simulation ◽  
3D Printed

Abstract Application of diversion agents in temporarily plugging fracturing of horizontal wells of shale has becoming more and more popular. Nevertheless, the studies on determining the diverter dosage are below adequacy. A novel approach based on laboratory experiments, logging data, rock mechanics tests and fracture simulation was proposed to optimizing the dosage of diversion agents. The optimization model is based on the classic Darcy Law. A pair of 3D-printed rock plates with rugged faces was combined to simulate the coarse hydraulic fractures with the width of 2.0 ~ 7.0 mm. The mixture of the diversion agents and slickwater was dynamically injected to simulate the fracture in Temco fracture conductivity system to mimic the practical treatment to temporarily plugging the fracture. The permeability of the temporary plugging zone in the 3D-printed fractures was measured in order to optimize the dosage of the selected diversion agents. The value of Pnet (also the value of ΔP in Darcy Formula) required for creation of new branched fractures was determined using the Warpinski-Teufel Failure Rules. The hydraulic fractures of target stages were simulated to obtain the widths and heights. The experimental results proved that the selected suite of the diversion agents can temporarily plug the 3D-printed fractures of 2.0 ~ 7.0 mm with blocking pressure up to 15 MPa. The measured permeability of the resulting plugging zones was 0.724 ~ 0.933 D (averaging 0.837 D). The value of Pnet required for creation of branched fractures in shale of WY area (main shale gas payzone of China) was determined as 0.4 ~ 15.6 MPa (averaging 7.9 MPa) which means the natural fractures and/or weak planes with approaching angle less than 70° could be opened to increase the SRV. The typical dosage of the diversion agents used for one stage of the horizontal wells (averaging TVD 3600 m) was calculated as 232 ~ 310 kg. The optimization method was applied to the design job of temporarily plugging fracturing of two shale gas wells. The observed surface pressure rise after injection of diversion agents was 0.6 ~ 11.7 MPa (averaging 4.7 MPa) and the monitored microseismic events of the test stages were 37% more than those of the offset stages.

Shale-gas well in Marcellus Shale with bi-wing hydraulic fractures

2021 ◽  
pp. 89-103
Author(s):  
Sutthaporn Tripoppoom ◽  
Wei Yu ◽  
Kamy Sepehrnoori ◽  
Jijun Miao
Keyword(s):  
Shale Gas ◽  
Marcellus Shale ◽  
Hydraulic Fractures ◽  
Gas Well
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