scholarly journals Temporal Scale Analysis of Gas Flow in Tight Gas Reservoirs considering the Nonequilibrium Effect

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Binglin Li ◽  
Yuliang Su ◽  
Maen Husein ◽  
Roberto Aguilera ◽  
Mingjing Lu
Keyword(s):  
Fractal Geometry ◽  
Gas Flow ◽  
Temporal Scale ◽  
Production Performance ◽  
Darcy Flow ◽  
Scale Analysis ◽  
Nonequilibrium Effect ◽  
Wellbore Pressure ◽  
The Matrix ◽  
The Impact

The fractal geometry, anisotropy, discontinuity, and non-Darcy flow of tight reservoirs exert a significant effect on well production performance. In this study, the reservoir fractal geometry is represented by exponential functions on the basis of microseismic data, while the discontinuity of the fractures is presented as a nonequilibrium effect. The impact of the nonequilibrium effect and the low velocity non-Darcy flow on the temporal scale of the wellbore pressure is predicted herein. Results showed that the time scale analysis accurately simulates gas flow in a tight reservoir. The wellbore pressure gradually increases, whereas the pressure in the matrix lags when the nonequilibrium effect is considered. The wellbore pressure is affected in the early period by the nonequilibrium effect. However, at the later stage, the pressure in the matrix is mainly affected by the non-Darcy flow. When the non-Darcy flow is dominant, the pores without gas flowing through are better presented.

scholarly journals Prediction of Production Performance of Refractured Shale Gas Well considering Coupled Multiscale Gas Flow and Geomechanics

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-21 ◽  
Author(s):  
Zhiqiang Li ◽  
Zhilin Qi ◽  
Wende Yan ◽  
Zuping Xiang ◽  
Xiang Ao ◽  
...  
Keyword(s):  
Shale Gas ◽  
Gas Flow ◽  
Knudsen Diffusion ◽  
Stress Sensitivity ◽  
Production Performance ◽  
Design Parameters ◽  
Production Loss ◽  
Apparent Permeability ◽  
Gas Well ◽  
The Matrix

Production simulation is an important method to evaluate the stimulation effect of refracturing. Therefore, a production simulation model based on coupled fluid flow and geomechanics in triple continuum including kerogen, an inorganic matrix, and a fracture network is proposed considering the multiscale flow characteristics of shale gas, the induced stress of fracture opening, and the pore elastic effect. The complex transport mechanisms due to multiple physics, including gas adsorption/desorption, slip flow, Knudsen diffusion, surface diffusion, stress sensitivity, and adsorption layer are fully considered in this model. The apparent permeability is used to describe the multiple physics occurring in the matrix. The model is validated using actual production data of a horizontal shale gas well and applied to predict the production and production increase percentage (PIP) after refracturing. A sensitivity analysis is performed to study the effects of the refracturing pattern, fracture conductivity, width of stimulated reservoir volume (SRV), SRV length of new and initial fractures, and refracturing time on production and the PIP. In addition, the effects of multiple physics on the matrix permeability and production, and the geomechanical effects of matrix and fracture on production are also studied. The research shows that the refracturing design parameters have an important influence on the PIP. The geomechanical effect is an important cause of production loss, while slippage and diffusion effects in matrix can offset the production loss.

Improving reservoir performance using intelligent well completion sensors combined with surface wet-gas flow measurement

2012 ◽  
Vol 52 (1) ◽  
pp. 181
Author(s):  
Nematollah Tarom ◽  
Mofazzal Hossain
Keyword(s):  
Data Acquisition ◽  
Gas Flow ◽  
Reservoir Management ◽  
Production Performance ◽  
Well Performance ◽  
Reservoir Performance ◽  
Well Completion ◽  
Wet Gas ◽  
Wellbore Pressure ◽  
Reservoir Conditions

Reservoir performance, in addition to day-to-day well performance, needs to be evaluated during the life of a well. The production logging tool (PLT) is conventionally designed to provide a full set of data measurements in producing wells to evaluate well and reservoir performance. Depending on the well conditions and location, running conventional PLTs may be difficult, impossible or expensive. Therefore, an alternative approach that can be applied in lieu of PLT operations—to obtain information similar to PLTs for better reservoir management—and that can optimise reservoir production performance is desireable. Data acquisition techniques such as downhole pressure/temperature gauges, fibre optic sensors at reservoir conditions and wet-gas flow meters at the surface have been considered as a viable alternative. Such data acquisition techniques help to increase flexibility in the field development and reservoir management of problematic wells with well completion technologies such as multi-lateral, horizontal and artificial lift. This study focused on the development of an alternative method of analysing problem well data on the basis of downhole pressure and temperature data collected at reservoir conditions. The proposed model has been based on the Joule-Thomson effect and radial heat and fluid flow equations to solve the transient wellbore pressure and temperature equations. It is expected this model can be used to analyse intelligent wells completed with downhole pressure and temperature sensors, and facilitate the monitoring of wells and reservoir performance without any PLT operation, especially for complex fields.

EDFM-based Multi-Continuum Shale Gas Simulation with Low Velocity Non-Darcy Water Flow Effect

2021 ◽  
Author(s):  
Yu Jiang ◽  
John Killough ◽  
Linkai Li ◽  
Xiaona Cui ◽  
Jin Tang
Keyword(s):  
Water Flow ◽  
Shale Gas ◽  
Gas Flow ◽  
Early Stage ◽  
Knudsen Diffusion ◽  
Gas Production ◽  
Darcy Flow ◽  
Low Velocity ◽  
Water Imbibition ◽  
The Impact

Abstract The exploitation of shale gas has attracted extensive attention in industry and academia. Multi-scale gas transportation mechanisms in matrix and fractures have been well studied. However, due to the presence of water originating from both fracking fluids and connate water, shale gas production is also greatly affected by water imbibition and flowback, of which the processes have not been thoroughly analyzed. This paper aims at presenting a comprehensive multi-continuum multi-component model to characterize the complicated shale gas flow behaviors as well as the impact of non-Darcy water flow on shale gas production. A two-phase numerical simulator is built up with multi-continuum settings. Shale matrix is split into organic and inorganic matters while natural and hydraulic fractures are modeled using an embedded discrete fracture model (EDFM). Fracture closure and elongation are modeled using a dynamic gridding approach. Different transportation mechanisms are considered to describe gas flow in shale, including Knudsen diffusion, ab/desorption, and convection. The low-velocity non-Darcy flow of water is used in inorganic pores to analyze the effect of water flow. A pre-stage model based on pumping history is simulated firstly before production starts. This serves as an initialization step to model fracking fluid imbibition and early-stage water flowback. This pre-stage simulation gives out more precise pressure and saturation profiles than the conventional non-equilibrium initialization method, especially in enhanced pore volumes and fractures. Based upon simulation results from the production period, Langmuir isotherm absorption has shown a massive impact on gas flow in shale, and Knudsen diffusion weights highest among transport mechanisms. Water non-Darcy flow better benefits in simulating both early-stage water flowback and production process compared with Darcy flow, which gives us a new explanation on the low flowback efficiency in real shale gas operations. Studies on early-stage water flowback also show that the flowback affects saturation distribution, which has a strong relationship with gas production and shall not be ignored. This work establishes a novel method to simulate and analyze shale gas production. It considers multiple and complex flow mechanisms and gives out better estimates of water flux. It is also used to initialize a model for pumping water imbibition and early-stage flowback, which can be used as technical resources for analyzing and simulating unconventional plays.

Impact of Shale-Gas Apparent Permeability on Production: Combined Effects of Non-Darcy Flow/Gas Slippage, Desorption, and Geomechanics

2015 ◽  
Vol 18 (04) ◽  
pp. 495-507 ◽  
Author(s):  
HanYi Wang ◽  
Matteo Marongiu-Porcu
Keyword(s):  
Pore Structure ◽  
Shale Gas ◽  
Fracture Network ◽  
Darcy Flow ◽  
Permeability Evolution ◽  
Apparent Permeability ◽  
Gas Slippage ◽  
The Matrix ◽  
Gas Layer ◽  
The Impact

Summary Permeability is one of the most fundamental reservoir-rock properties required for modeling hydrocarbon production. Many shale-gas and ultralow-permeability tight gas reservoirs can have matrix-permeability values in the range of tens to hundreds of nanodarcies. The ultrafine pore structure of these rocks can cause violation of the basic assumptions behind Darcy's law. Depending on a combination of pressure-temperature conditions, pore structure and gas properties, non-Darcy flow mechanisms such as Knudsen diffusion, and/or gas-slippage effects will affect the matrix apparent permeability. Even though numerous theoretical and empirical models were proposed to describe the increasing apparent permeability caused by non-Darcy flow/gas-slippage behavior in nanopore space, few literature sources have investigated the impact of formation compaction and the release of the adsorption gas layer upon shale-matrix apparent permeability during reservoir depletion. In this article, we first present a thorough review on gas flow in shale nanopore space and discuss the factors that can affect shale-matrix apparent permeability, besides the well-studied non-Darcy flow/gas-slippage behavior. Then, a unified shale-matrix apparent-permeability model is proposed to bridge the effects of non-Darcy flow/gas-slippage, geomechanics (formation compaction), and the release of the adsorption gas layer into a single, coherent equation. In addition, a mathematical framework for an unconventional reservoir simulator that was developed for this study is also presented. Different matrix apparent-permeability models are implemented in our numerical simulator to examine how the various factors affect matrix apparent permeability within the simulated reservoir volume. Finally, the impact of a natural-fracture network on matrix apparent-permeability evolution is investigated. The results indicate that, even though the conductive fracture network plays a vital role in shale-gas production, the matrix apparent-permeability evolution during pressure depletion cannot be neglected for accurate production modeling.

A Nano-Pore Scale Gas Flow Model for Shale Gas Reservoir

2014 ◽  
Author(s):  
Y.. Li ◽  
X.. Li ◽  
J.. Shi ◽  
H.. Wang ◽  
L.. Wu ◽  
...  
Keyword(s):  
Gas Flow ◽  
Pore Diameter ◽  
Knudsen Diffusion ◽  
Adsorbed Layer ◽  
Production Performance ◽  
Darcy Flow ◽  
Pore Scale ◽  
Transition Flow ◽  
Gas Reservoirs ◽  
Flow Mechanisms

Abstract Many shale/tight gas reservoirs can have pore scale values in the range from one to hundreds of nanometer. And the flow in nano-scale deviate the Darcy's law. Knudsen diffusion and/or gas slippage effects usually have modeled to character the non-Darcy flow mechanisms by many authors. In this paper, we investigate the non-Darcy flow mechanisms in unconventional gas reservoirs, and classify these various mechanisms based on different pore scale and pressure. Then, based on the change of pore scale and pressure, the models of gas flow that consider the absorption, desorption, slip flow, transition flow, Knudsen diffusion and continuous flow in nano-pore have been proposed to evaluate the flow character. Then, the relationship between the absorbed layers and pressure or Langmuir coefficient has been built and the influences of absorption of gas molecule have been studied on the permeability change. Compared with experimental value, the model could agree with the experimental value very well. And, desorption of the absorbed layers make the pore diameter become larger. When the thickness of the absorbed layers and the pore diameter ratio is larger than 0.1, the effect of adsorbed layer becomes very significant. With this study, the change of permeability and the gas rate on entire long term production performance could be understood better and predicted, and it is very important for the optimization of production performance and adjustment.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

2020 ◽  
Vol 38 (7A) ◽  
pp. 960-966
Author(s):  
Aseel M. Abdullah ◽  
Hussein Jaber ◽  
Hanaa A. Al-Kaisy
Keyword(s):  
Impact Strength ◽  
Wear Rate ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Weight Fraction ◽  
Pure Pmma ◽  
Calcination Process ◽  
The Matrix ◽  
The Impact ◽  
Interface Bond

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

scholarly journals The Interactions between Polyphenols and Microorganisms, Especially Gut Microbiota

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 188
Author(s):  
Małgorzata Makarewicz ◽  
Iwona Drożdż ◽  
Tomasz Tarko ◽  
Aleksandra Duda-Chodak
Keyword(s):  
Intestinal Bacteria ◽  
Research Data ◽  
Bioactive Metabolites ◽  
Human Organism ◽  
Comprehensive Knowledge ◽  
Bidirectional Relationship ◽  
The Matrix ◽  
Intestinal Pathogens ◽  
The Impact

This review presents the comprehensive knowledge about the bidirectional relationship between polyphenols and the gut microbiome. The first part is related to polyphenols’ impacts on various microorganisms, especially bacteria, and their influence on intestinal pathogens. The research data on the mechanisms of polyphenol action were collected together and organized. The impact of various polyphenols groups on intestinal bacteria both on the whole “microbiota” and on particular species, including probiotics, are presented. Moreover, the impact of polyphenols present in food (bound to the matrix) was compared with the purified polyphenols (such as in dietary supplements) as well as polyphenols in the form of derivatives (such as glycosides) with those in the form of aglycones. The second part of the paper discusses in detail the mechanisms (pathways) and the role of bacterial biotransformation of the most important groups of polyphenols, including the production of bioactive metabolites with a significant impact on the human organism (both positive and negative).

scholarly journals The High-Rate Sealed MRPC to Promote Pollutant Exchange in Gas Gaps: Status on the Development and Observations

2021 ◽  
Vol 11 (11) ◽  
pp. 4722
Author(s):  
Botan Wang ◽  
Xiaolong Chen ◽  
Yi Wang ◽  
Dong Han ◽  
Baohong Guo ◽  
...  
Keyword(s):  
Gas Flow ◽  
High Rate ◽  
Stable Operation ◽  
Beam Test ◽  
High Luminosity ◽  
Rate Test ◽  
3D Printed ◽  
Resistive Plate Chambers ◽  
The Impact ◽  
Current Behavior

This work reports the latest observations on the behavior of two Multigap Resistive Plate Chambers (MRPC) under wide high-luminosity exposures, which motivate the development and in-beam test of the sealed MRPC prototype assembled with low-resistive glass. The operation currently being monitored, together with previous simulation results, shows the impact of gas pollution caused by avalanches in gas gaps, and the necessity to shrink the gas-streaming volume. With the lateral edge of the detector sealed by a 3D-printed frame, a reduced gas-streaming volume of ~170 mL has been achieved for a direct gas flow to the active area. A high-rate test of the sealed MRPC prototype shows that, ensuring a 97% efficiency and 70 ps time resolution, the sealed design results in a stable operation current behavior at a counting rate of 3–5 kHz/cm2. The sealed MRPC will become a potential solution for future high luminosity applications.

scholarly journals Reliability Assessment of a Multi-State HVDC System by Combining Markov and Matrix-Based Methods

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3097
Author(s):  
Roberto Benato ◽  
Antonio Chiarelli ◽  
Sebastian Dambone Sessa
Keyword(s):  
Current System ◽  
Estimation Method ◽  
Reliability Estimation ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Hvdc System ◽  
Critical Elements ◽  
The Matrix ◽  
The Impact

The purpose of this paper is to highlight that, in order to assess the availability of different HVDC cable transmission systems, a more detailed characterization of the cable management significantly affects the availability estimation since the cable represents one of the most critical elements of such systems. The analyzed case study consists of a multi-terminal direct current system based on both line commutated converter and voltage source converter technologies in different configurations, whose availability is computed for different transmitted power capacities. For these analyses, the matrix-based reliability estimation method is exploited together with the Monte Carlo approach and the Markov state space one. This paper shows how reliability analysis requires a deep knowledge of the real installation conditions. The impact of these conditions on the reliability evaluation and the involved benefits are also presented.

67 Current Status and Future Prospective of the Use of Plant Bioactive Compounds in Dairy and Beef Cattle

2021 ◽  
Vol 99 (Supplement_1) ◽  
pp. 132-132
Author(s):  
Sergio Calsamiglia ◽  
Maria Rodriguez-Prado ◽  
Gonzalo Fernandez-Turren ◽  
Lorena Castillejos
Keyword(s):  
Beef Cattle ◽  
Essential Oils ◽  
Average Daily Gain ◽  
Rumen Fermentation ◽  
Production Performance ◽  
In Vivo Studies ◽  
Current Status ◽  
The Impact

Abstract In the last 20 years there has been extensive in vitro research on the effects of plant extracts and essential oils on rumen microbial fermentation. The main objectives have been to improve energy metabolism through a reduction in methane emissions and an increase in propionate production; and to improve protein metabolism by reducing proteolysis and deamination. While the positive results from in vitro studies has stimulated the release of commercial products based on blends of essential oils, there is limited in vivo evidence on the rumen fermentation and production performance effects. A literature search was conducted to select in vivo studies where information on rumen fermentation and animal performance was reported. For dairy cattle, we identified 37 studies of which 21 were adequate to test production performance. Ten studies reported increases and 3 decreases in milk yield. For beef cattle, we identified 20 studies with rumen fermentation profile and 22 with performance data. Average daily gain improved in 7 and decreased in 1 study. Only 1 out of 16 studies reported an improvement in feed efficiency. Data indicate that out of more than 500 products tested in vitro, only around 20 have been tested in vivo in different mixtures and doses. The use of statistical approaches will allow to describe the conditions, doses and responses in dairy and beef cattle performance. The search for postruminal effects offers another alternative use. Evidence for effects on the intestinal and systemic effects on the immune system and antioxidant status (i.e., capsicum, garlic, eugenol, cinnamaldehyde curcuma, catechins, anethol or pinene), and in the modulation of metabolic regulation (capsicum, cinnamaldehyde, curcuma or garlic) may open the opportunity for future applications. However, stability of the product in the GI tract, description of the mechanisms of action and the impact of these changes on performance needs to be further demonstrated.

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