ORCID Profile
0000-0002-4843-2107
Current Organisations
Edith Cowan University
,
University of Queensland
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Publisher: American Chemical Society (ACS)
Date: 23-10-2023
Publisher: MDPI AG
Date: 13-05-2021
DOI: 10.3390/APP11104411
Abstract: During micro-scale tracer flow in porous media, the permeability and fluid velocity significantly affect the fluid dispersion properties of the media. However, the relationships between the dispersion coefficient, permeability, and fluid velocity in core s les are still not clearly understood. Two sets of experiments were designed to study the effects of tracer fluid flow velocity and porous medium permeability on the dispersion phenomenon in a core environment, using natural and sand-filled cores, respectively. From experimental data-fitting by a mathematical model, the relationship between the dispersion coefficient, flow velocity, and permeability was identified, allowing the analysis of the underlying mechanism behind this phenomenon. The results show that a higher volumetric flow rate and lower permeability cause a delay in the tracer breakthrough time and an increase in the dispersion coefficient. The core experimental results show that the dispersion coefficient is negatively correlated with the permeability and positively correlated with the superficial velocity. The corresponding regression equations indicate linear relations between the dispersion coefficient, core permeability, and fluid velocity, resulting from the micron scale of grain diameters in cores. The combination of high velocity and low permeability yields a large dispersion coefficient. The effects of latitudinal dispersion in porous media cannot be ignored in low-permeability cores or formations. These findings can help to improve the understanding of tracer flow in porous media, the design of injection parameters, and the interpretation of tracer concentration distribution in inter-well tracer tests.
Publisher: World Scientific Pub Co Pte Lt
Date: 20-11-2008
DOI: 10.1142/S0217984908017333
Abstract: The viscosity properties of the semi-concentrated suspensions of fibers with small aspect ratio were investigated in transient shear flow using a concentric cylinder geometry. Experimental results were compared with predictions by utilizing the constructive model developed by Batchelor in conjunction with the hybrid closure proposed by Advani and Tucker. To rectify the discrepancy between the theoretical prediction available at the present time and the measured data, a new expression for the specific viscosity in the semi-concentrated shear flows of fiber suspension is proposed allowing for the effects of the fiber–fiber interactions and the finite-aspect-ratio fiber. The results show that the model predictions for the fiber suspensions of different aspect ratio and concentration are fairly good.
Publisher: SPE
Date: 09-11-2015
DOI: 10.2118/176995-MS
Abstract: Estimating flow rate distribution along the depth in the wellbore is very important for reservoir and production management purposes, because it provides information for distinction of the production rates from different layers. This is critical for optimizing well performance and maximizing recovery of reserves. The temperature and pressure sensors in the well are small and inexpensive, while flowmeters are cumbersome and expensive, and affect the flow in the well. In this study, a mathematical model for pressure and temperature profiles along a gas well has been developed, which is readily used for prediction of flow rates in different layers. Temperature and pressure measurements from gas well in field C (Australia) have been matched with the mathematical model to determine the flow rates from different layers in the well. The proposed model considers the variables as functions of thermal properties at different depth, which is more accurate than previous methods. A simple and effective method is developed for fast estimation of rate distribution along the depth. The proposed approach has been applied to field case for determining gas flow rate in the wellbore and thermal conductivity of the formation from the acquired pressure and temperature data. It allows for recommending well stimulation of layers with low production rate.
Publisher: SPE
Date: 24-02-2016
DOI: 10.2118/179026-MS
Abstract: Compressibility needs to be accounted for when estimating injectivity decline for water disposal in gas reservoirs and in closed aquifers, and for waterflooding of gas-condensate fields. The problem with given wellbore pressure at the injector aims avoiding the reservoir fracturing. An analytical model is developed that provides well injectivity index decline with time. Under this model, the solution of damage-free compressible flow in a closed reservoir is asymptotically matched with the impedance growth formulae for incompressible flow in the well vicinity. For the well regime of a given wellbore pressure, the injection rate decline is described by a nonlinear integro-differential equation that is solved iteratively. The solution under the field conditions investigated shows that well impedance grows faster during deep bed filtration than during external cake formation. This unusual pattern is explained by low permeability of the reservoir. Well impedance is more sensitive to the effect of formation damage than to the compressibility effect of rock and water. Lower formation damage, higher compressibility, or lower injected particle concentration results in larger total injection volume into a closed reservoir.
Publisher: Elsevier BV
Date: 2016
Publisher: Emerald
Date: 02-03-2015
Abstract: – The present work is devoted to the numerical study of the stability of shallow jet. The effects of important parameters on the stability behavior for large scale shallow jets are considered and investigated. Connections between the stability theory and observed features reported in the literature are emphasized. The paper aims to discuss these issues. – A linear stability analysis of shallow jet incorporating the effects of bottom topography, bed friction and viscosity has been carried out by using the shallow water stability equation derived from the depth averaged shallow water equations in conjunction with both Chézy and Manning resistance formulae. Effects of the following main factors on the stability of shallow water jets are examined: Rossby number, bottom friction number, Reynolds number, topographic parameters, base velocity profile and resistance model. Special attention has been paid to the Coriolis effects on the jet stability by limiting the rotation number in the range of Ro ∈[0, 1.0]. – It is found that the Rossby number may either lify or attenuate the growth of the flow instability depending on the values of the topographic parameters. There is a regime where the near cancellation of Coriolis effects due to other relevant parameters influences is responsible for enhancement of stability. The instability can be suppressed by the bottom friction when the bottom friction number is large enough. The lification rate may become sensitive to the relatively small Reynolds number. The stability region using the Manning formula is larger than that using the Chézy formula. The combination of these effects may stabilize or destabilize the shallow jet flow. These results of the stability analysis are compared with those from the literature. – Results of linear stability analysis on shallow jets along roughness bottom bed are presented. Different from the previous studies, this paper includes the effects of bottom topography, Rossby number, Reynolds number, resistance formula and bed friction. It is found that the influence of Reynolds number on the stability of the jet is notable for relative small value. Therefore, it is important to experimental investigators that the viscosity should be considered with comparison to the results from inviscid assumption. In contrast with the classical analysis, the use of multi-parameters of the base velocity and topographic profile gives an extension to the jet stability analysis. To characterize the large scale motion, besides the bottom friction as proposed in the related literature, the Reynolds number Re , Rossby number Ro , the topographic parameters and parameters controlling base velocity profile may also be important to the stability analysis of shallow jet flows.
Publisher: Elsevier BV
Date: 08-2017
Publisher: Elsevier BV
Date: 04-2017
Publisher: Elsevier BV
Date: 06-2020
Publisher: American Chemical Society (ACS)
Date: 28-01-2021
Publisher: Elsevier BV
Date: 07-2003
Publisher: Elsevier BV
Date: 07-2006
Publisher: Elsevier BV
Date: 06-2018
Publisher: SPE
Date: 25-10-2016
DOI: 10.2118/182320-MS
Abstract: Fines migration involving particle detachment in reservoirs often leads to severe permeability damage. It is the consequence of straining of the detached fines in relatively narrower pore throats. Many laboratory coreflood tests indicate that the time of permeability stabilisation can reach hundreds or thousands of pore volumes injected. However, the classical filtration theory assumes that the mobilised fines are transported by the bulk of the carrier fluid, thus the permeability stabilises after one pore volume injected. The current paper attributes the stabilisation delay to the slow drift of the released fines close to the rock surface. We propose the system of flow equations for fines migration in porous media taking into account the velocity of particles lower than that of the fluid. An analytical model for one-dimensional flow with particle mobilisation and straining during piecewise increasing flow rate is obtained. The laboratory data are in good agreement with the results of mathematical modelling. The effective particle speed is 500-1000 times lower than the water velocity.
Publisher: AIP
Date: 2008
DOI: 10.1063/1.2964656
Publisher: SPE
Date: 25-10-2016
DOI: 10.2118/182295-MS
Abstract: Twelve clastic core s les from the Walloon Coal Measures, Surat Basin were tested for disintegration in artificially produced fluids varying in ionic strength. XRD data confirm the presence of smectite (water sensitive clay) in the s les. Flow-through rock disintegration experiments demonstrate that the higher the concentration of smectite and soluble plagioclase is, the quicker rock disintegrates in artificial low ionic strength fluid. Pre-soaking of rocks with high ionic strength fluid reduces rock disintegration rate in low ionic strength fluids. This is explained by very strong clay-clay and clay-sand attraction forces, evidenced through zeta-potential measurements, which inhibit rock degradation. For the studied s les it is clear that rock disintegration rate is proportional to fluid velocity. Experimental rock disintegration data are fitted by a power erosion model with two adjusted parameters: fluid ionic strength and Reynolds number. The experimental results satisfactorily agree with theoretical data. Rock disintegration rates are calculated as released particle volume per thickness of interburden layer per day at a fixed Reynolds number and low ionic strength. The laboratory work suggests that keeping wells under strong ionic fluid during shut-in times and a reduction of water production rate will preserve rock integrity for a longer period of time.
Publisher: Elsevier BV
Date: 2022
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2023
Publisher: American Chemical Society (ACS)
Date: 07-07-2021
Publisher: Zhejiang University Press
Date: 08-2007
Publisher: Elsevier BV
Date: 08-2016
Publisher: MDPI AG
Date: 16-04-2021
DOI: 10.3390/APP11083616
Abstract: Foam-assisted steam flooding is a promising technique to alleviate gas channeling and enhance sweep efficiency in heterogeneous heavy-oil reservoirs. However, long-term foam stabilization remains problematic at high temperatures. Three-phase foam (TPF), containing dispersed solid particles, has been proposed to improve foam stability under harsh reservoir conditions. We fabricated a novel TPF system by adding ultrafine fly ash particles, as well as high-temperature resistant microspheres with an adhesive coating layer. This work aims at assessing the ability of the generated TPF in controlling steam channeling and enhancing oil recovery. Static and core flood tests were performed to evaluate foam strength and stability. Our results suggested a stronger foamability at a lower consolidation agent concentration, while a longer half-life period of foam and settling time of solid particles at a larger consolidation agent concentration were observed. Bubbles suspended independently in the liquid phase, with sizes varying from 10 to 100 μm, smaller than that of the conventional foam, suggesting a significant enhancement of foam dispersity and stability. The plugging rate was close to 90% when the temperature was as high as 300 °C, demonstrating a well-accepted plugging effect under high temperatures. A larger pore volume injection of TPF yielded a higher EOR in parallel cores, which substantiated the effectiveness of the three-phase foam system in sealing high-permeability channels.
Publisher: Science China Press., Co. Ltd.
Date: 2003
DOI: 10.1360/03JZ9017
Publisher: American Chemical Society (ACS)
Date: 28-02-2020
Publisher: Elsevier BV
Date: 11-2020
Publisher: Elsevier BV
Date: 05-2019
Publisher: National Library of Serbia
Date: 2012
DOI: 10.2298/TSCI1205344A
Abstract: An analytical model for deep bed filtration of suspension in porous media and straining under size exclusion capture mechanism is developed and validated by laboratory tests on suspension flow in engineered media. The fraction of swept particles is introduced in the inlet boundary condition. The model is successfully matched with the results from column experiments, predicting the suspended particle concentrations at the outlet.
Publisher: SPE
Date: 05-05-2017
DOI: 10.2118/186070-MS
Abstract: The aim of this work is the development of mathematical models for oil–water flow with varying injected water compositions in oil reservoirs. The model accounts for two main mechanisms of low salinity waterflooding (LSW): wettability alteration and salinity-variation-induced fines migration. Analytical and numerical models are developed and applied to low salinity fines-assisted core flood tests. In large reservoir scale, the general system of equations permits for an analytical solution. The solution is obtained by recently developed splitting technique, where the stream function is used as a variable instead of time. Large-scale approximation assumes that six dimensionless groups for dissipative and non-equilibrium effects are negligibly small. Numerical results are obtained for the general system, which accounts for dissipative and non-equilibrium effects. The effects of fines migration and wettability variation on oil recovery are discovered as two separate mechanisms in LSW. The significant EOR-effects of both mechanisms are observed under the typical oil reservoir conditions.
Publisher: Elsevier BV
Date: 10-2014
Publisher: Zhejiang University Press
Date: 08-2005
Publisher: Elsevier BV
Date: 05-2009
Publisher: Elsevier BV
Date: 11-2012
Publisher: Elsevier BV
Date: 11-2019
Publisher: MDPI AG
Date: 10-08-2022
DOI: 10.3390/EN15165811
Abstract: After hydraulic fracturing, some treatments intended for production enhancement fail to yield predetermined effects. The main reason is the insufficient research about the fracture propagation mechanism. There is compelling evidence that I-shaped fracture, two horizontal fractures at the junction of coalbed and cover/bottom layer, and one vertical fracture in the coalbed have formed in part of the coalbed after hydraulic fracturing. Therefore, this paper aims at I-shaped fracture propagation simulation. A novel propagation model is derived on the basis of a three-dimensional (3D) model, and the coupling conditions of vertical fracture and horizontal fractures are established based on the flow rate distribution and the bottom-hole pressure equality, respectively. Moreover, an associated PDA (pressure decline analysis of post-fracturing) model is established. Both models complement with each other and work together to guide fracturing treatment. Finally, a field case is studied to show that the proposed models can effectively investigate and simulate fracture initiation ropagation and pressure decline.
Publisher: Computers, Materials and Continua (Tech Science Press)
Date: 2020
Publisher: Elsevier BV
Date: 03-2018
Publisher: National Library of Serbia
Date: 2012
DOI: 10.2298/TSCI1205339B
Abstract: A simple and effective method of the gas rate prediction from temperature and pressure data is discussed in this paper. Solving the inverse problem allows determination of the flow rate by matching the gas pressure and temperature distributions with measured profiles. Results of field data treatment show good agreement with the model prediction.
Publisher: Elsevier BV
Date: 02-2018
Publisher: IOP Publishing
Date: 04-2004
Publisher: American Chemical Society (ACS)
Date: 23-11-2022
Publisher: World Scientific Pub Co Pte Lt
Date: 20-10-2007
DOI: 10.1142/S0217984907014000
Abstract: An analysis for the linear stability of fiber suspensions in the Taylor–Couette flow is conducted. The orientation state of fibers is determined using the linear, quadratic and composite HL-I closure model and the model of the fiber contribution to the total stress is established based on the slender-body theory. The linear stability equation is derived and solved with the Chebyshev spectral method. The results show that the suppression effect is most predominant for the composite HL-I model, while least predominant for the linear closure model. The longer fibers and suspensions with high volume fraction have a more predominant influence on suppressing the instability. The contribution of the suspending fluid to the change rate of the disturbance energy dominates the energy dissipation. While the contribution of the fiber shear stress increases monotonously with increasing fiber aspect ratio for the three closure models, the contribution based on the composite HL-I closure model is the largest, and that based on the linear closure model is the smallest. The effect of fiber aspect ratio on the change rate of the disturbance energy caused by the fiber shear stress is more predominant than that of the fiber volume fraction. The positive energy caused by the fiber shear stress consumes the gross energy of the fluid system and leads to a suppression of the flow instability.
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 11-2016
Publisher: Elsevier BV
Date: 07-2005
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 09-2016
Publisher: ASME International
Date: 18-01-2019
DOI: 10.1115/1.4042230
Abstract: Produced water re-injection (PWRI) is an important economic and environmental-friendly option to convert waste to value with waterflooding operations. However, it often causes rapid injectivity decline. In the present study, a coreflood test on a low permeable core s le is carried out to investigate the injectivity decline behavior. An analytical model for well impedance (normalized reciprocal of injectivity) growth, along with probabilistic histograms of injectivity damage parameters, is applied to well injectivity decline prediction during produced water disposal in a thick low permeable formation (Völkersen field). An impedance curve with an unusual convex form is observed in both coreflood test and well behavior modeling the impedance growth rate is lower during external filter cake build-up if compared with the deep bed filtration stage. Low reservoir rock permeability and, consequently, high values of filtration and formation damage coefficients lead to fast impedance growth during deep bed filtration while external filter cake formation results in relatively slow impedance growth. A risk analysis employing probabilistic histograms of injectivity damage parameters is used to well behavior prediction under high uncertainty conditions.
Publisher: American Chemical Society (ACS)
Date: 20-04-2020
Publisher: Elsevier BV
Date: 12-2017
Publisher: National Library of Serbia
Date: 2015
DOI: 10.2298/TSCI1504189C
Abstract: A method for prediction of fine particle transport in a turbulent flow is proposed, the interaction between particles and fluid is studied numerically, and fractal agglomerate of fine particles is analyzed using Taylor-expansion moment method. The paper provides a better understanding of fine particle dynamics in the evolved flows.
Publisher: Elsevier BV
Date: 11-2021
Publisher: IOP Publishing
Date: 24-05-2019
Publisher: Springer Science and Business Media LLC
Date: 06-2021
Publisher: Elsevier BV
Date: 09-2015
Publisher: Elsevier BV
Date: 2012
Publisher: Elsevier BV
Date: 08-2023
Publisher: American Chemical Society (ACS)
Date: 28-07-2020
Publisher: American Chemical Society (ACS)
Date: 27-06-2017
Publisher: Hindawi Limited
Date: 2013
DOI: 10.1155/2013/680693
Abstract: Long-term deep bed filtration in porous media with size exclusion particle capture mechanism is studied. For monodispersed suspension and transport in porous media with distributed pore sizes, the microstochastic model allows for upscaling and the exact solution is derived for the obtained macroscale equation system. Results show that transient pore size distribution and nonlinear relation between the filtration coefficient and captured particle concentration during suspension filtration and retention are the main features of long-term deep bed filtration, which generalises the classical deep bed filtration model and its latter modifications. Furthermore, the exact solution demonstrates earlier breakthrough and lower breakthrough concentration for larger particles. Among all the pores with different sizes, the ones with intermediate sizes (between the minimum pore size and the particle size) vanish first. Total concentration of all the pores smaller than the particles turns to zero asymptotically when time tends to infinity, which corresponds to complete plugging of smaller pores.
Publisher: SPE
Date: 07-02-2018
DOI: 10.2118/189532-MS
Abstract: Compressibility needs to be accounted for when estimating productivity decline in closed gas and oil reservoirs, and in closed aquifers. Previous works derived an analytical model and well index for inflow performance accompanied by fines migration and consequent permeability damage for incompressible flow towards well. In the present work, we account for fluid and rock compressibility. The problem with given and constant well production rate is investigated. Mathematical model is developed, which provides well productivity index decline with time. Under this model, the solution of damage-free compressible flow in a closed reservoir is matched with the impedance growth formulae for incompressible flow in the well vicinity. The well production data have been successfully matched by the model the tuning parameters have the common values. It allows indicating the fines mobilization, migration and straining as possible well impairment mechanism in wells under investigation.
Publisher: Elsevier BV
Date: 08-2023
Publisher: SPE
Date: 24-02-2016
DOI: 10.2118/179027-MS
Abstract: Fines migration causes significant permeability damage, due to mobilisation of particles at increased velocities, their migration in pores followed by straining at pore throats and attachment to pore walls. Numerous coreflooding tests with piecewise increasing rates are conducted. There are two main features of these tests: the first is long-term injection, which allows calculating permeability stabilisation time the second is pressure measurement at intermediate points, allowing for evaluating the permeability profile along the core. The impedance data obtained from experiments are matched with the results from analytical model. It shows that the mobilised particles move with velocity much smaller than the carrier fluid, yielding long time for permeability stabilisation. It contradicts the classical filtration theory, which indicates the fines are transported with the carrier fluid velocity.
Publisher: National Library of Serbia
Date: 2013
DOI: 10.2298/TSCI1305403W
Abstract: It is an undoubted fact that particle aggregates from marine, aerosol, and engineering systems have fractal structures. In this study, fractal geometry is used to describe the morphology of irregular aggregates. The mean-field theory is employed to solve coagulation kinetic equation of aggregates. The Taylor-expansion method of moments in conjunction with the self-similar fractal characteristics is used to represent the particulate field. The effect of the target fractal dimensions on zeroth-order moment, second-order moment, and geometric standard deviation of the aggregates is explored. Results show that the developed moment method is an efficient and powerful approach to solving such evolution equations.
Publisher: AIP Publishing
Date: 2014
DOI: 10.1063/1.4861096
Abstract: A detailed uncertainty analysis associated with carboxyl-modified latex particle capture in glass bead-formed porous media enabled verification of the two theoretical stochastic models for prediction of particle retention due to size exclusion. At the beginning of this analysis it is established that size exclusion is a dominant particle capture mechanism in the present study: calculated significant repulsive Derjaguin-Landau-Verwey-Overbeek potential between latex particles and glass beads is an indication of their mutual repulsion, thus, fulfilling the necessary condition for size exclusion. Applying linear uncertainty propagation method in the form of truncated Taylor's series expansion, combined standard uncertainties (CSUs) in normalised suspended particle concentrations are calculated using CSUs in experimentally determined parameters such as: an inlet volumetric flowrate of suspension, particle number in suspensions, particle concentrations in inlet and outlet streams, particle and pore throat size distributions. Weathering of glass beads in high alkaline solutions does not appreciably change particle size distribution, and, therefore, is not considered as an additional contributor to the weighted mean particle radius and corresponded weighted mean standard deviation. Weighted mean particle radius and LogNormal mean pore throat radius are characterised by the highest CSUs among all experimental parameters translating to high CSU in the jamming ratio factor (dimensionless particle size). Normalised suspended particle concentrations calculated via two theoretical models are characterised by higher CSUs than those for experimental data. The model accounting the fraction of inaccessible flow as a function of latex particle radius excellently predicts normalised suspended particle concentrations for the whole range of jamming ratios. The presented uncertainty analysis can be also used for comparison of intra- and inter-laboratory particle size exclusion data.
Publisher: Hindawi Limited
Date: 2018
DOI: 10.1155/2018/7602982
Abstract: Traditional polymeric microsphere has several technical advantages in enhancing oil recovery. Nevertheless, its performance in some field application is unsatisfactory due to limited blockage strength. Since the last decade, novel core-shell microsphere has been developed as the next-generation profile control agent. To understand the expansion characteristic differences between these two types of microspheres, we conduct size measurement experiments on the polymeric and core-shell microspheres, respectively. The experimental results show two main differences between them. First, the core-shell microsphere exhibits a unimodal distribution, compared to multimodal distribution of the polymeric microsphere. Second, the average diameter of the core-shell microsphere increases faster than that of the polymeric microsphere in the early stage of swelling, that is, 0–3 days. These two main differences both result from the electrostatic attraction between core-shell microspheres with different hydration degrees. Based on the experimental results, the core-shell microsphere is suitable for injection in the early stage to block the near-wellbore zone, and the polymeric microsphere is suitable for subsequent injection to block the formation away from the well. A simple mathematical model is proposed for size evolution of the polymeric and core-shell microspheres.
Publisher: World Scientific Pub Co Pte Lt
Date: 30-06-2008
DOI: 10.1142/S0217979208039666
Abstract: Sediment transport in fully developed turbulent open channel flow has been investigated using large eddy simulation (LES) of the incompressible Navier–Stokes equations. The scalar transport equation of the sediments concentration, which is based on the continuous-phase approach, is adopted. The settling process is taken into account with a modified settling velocity appearing in the sediment concentration equation. A Smagorinsky model allowing for the interaction between the fluid flow and the suspended sediment is used to simulate the unresolved, subgrid scale terms. The LES results are compared with the experimental data, and good general agreement is achieved.
Publisher: Elsevier BV
Date: 08-2008
Publisher: American Chemical Society (ACS)
Date: 08-2023
Publisher: Springer Science and Business Media LLC
Date: 03-01-2020
Publisher: Elsevier BV
Date: 2017
Publisher: Elsevier BV
Date: 2023
Publisher: Yandy Scientific Press
Date: 17-07-2020
Publisher: Elsevier BV
Date: 2021
Publisher: Walter de Gruyter GmbH
Date: 14-12-2012
Abstract: Fine particles aggregating into larger units or flocculation body is a random combination process. Increasing the size and density of flocculation body is the main approach to rapid particle removal or sedimentation in water. Aiming at the Brownian coagulation of fine particles, a new method of Taylor expansion moment construction of fractal flocs has been developed in this paper, incorporating the Taylor expansion approach based on the moment method and the fractal dimension of the floc structure originated from fractal theories. This method successfully overcomes the limit of previous moment methods that require pre-assumed particle size distribution. Results of the zero and second order moments of Brownian flocs from the proposed method are compared with those from the Laguerre method, integral moment method and finite element method. It is found that the higher accuracy and efficiency of computation have been achieved by the new method, compared to the previous ones. Effects of the fractal dimension on the zero and second order moments, geometric average volume and standard deviation are also analyzed using this method. The self-conservation characteristics of particle distribution is observed without presumption of initial distributions.
Publisher: Elsevier BV
Date: 11-2018
Publisher: Elsevier BV
Date: 06-2018
Publisher: Elsevier BV
Date: 06-2013
Publisher: Society of Petroleum Engineers (SPE)
Date: 08-06-2017
DOI: 10.2118/182266-PA
Abstract: Drill-in fluid loss is the most important cause of formation damage during the drill-in process in fractured tight reservoirs. The addition of lost-circulation material (LCM) into drill-in fluid is the most popular technique for loss control. However, traditional LCM selection is mainly performed by use of the trial-and-error method because of the lack of mathematical models. The present work aims at filling this gap by developing a new mathematical model to characterize the performance of drill-in fluid-loss control by use of LCM during the drill-in process of fractured tight reservoirs. Plugging-zone strength and fracture-propagation pressure are the two main factors affecting drill-in fluid-loss control. The developed mathematical model consists of two submodels: the plugging-zone-strength model and the fracture-propagation-pressure model. Explicit formulae are obtained for LCM selection dependent on the proposed model to control drill-in fluid loss and prevent formation damage. Effects of LCM mechanical and geometrical properties on loss-control performance are analyzed for optimal fracture plugging and propagation control. Laboratory tests on loss-control effect by use of different types and concentrations of LCMs are performed. Different combinations of acid-soluble rigid particles, fibers, and elastic particles are tested to generate a synergy effect for drill-in fluid-loss control. The derived model is validated by laboratory data and successfully applied to the field case study in Sichuan Basin, China.
Publisher: Elsevier
Date: 2018
Publisher: Elsevier BV
Date: 02-2024
Publisher: SPE
Date: 09-11-2015
DOI: 10.2118/177021-MS
Abstract: In unconventional water-wet gas reservoirs with very low permeability, water entrapment or blockage can occur near the wellbore due to the capillary end effect, resulting in low gas production. A reduction in capillary forces through wettability alteration of reservoir rock surface is proposed as an effective approach to reduce water blockage and enhance gas production. The method can be applied to accelerating dewatering and preventing drilling and fracturing fluid leak-off as well. Analytical models for steady-state water-gas linear and radial flows are developed in the current paper. The effects of contact angle on capillary pressure and relative permeabilities have been included. The new model is validated using experimental data. Applications to fully and partially treated regimes show the competition between viscous and capillary effects on productivity of gas and water, which leads to an optimal contact angle for the maximum productivity index for each phase. This study shows the potential for optimising unconventional gas productivity through wettability control. Application of nanotechnology to rock wettability alteration is proposed.
Publisher: Unconventional Resources Technology Conference
Date: 2019
Publisher: Elsevier BV
Date: 11-2015
Publisher: American Geophysical Union (AGU)
Date: 28-04-2015
DOI: 10.1002/2015GL063986
Publisher: Elsevier BV
Date: 12-2023
Publisher: Hindawi Limited
Date: 30-12-2019
DOI: 10.1155/2019/5723694
Abstract: Coal fines migration exerts negative impacts on early water drainage of undersaturated coal seam gas (CSG) reservoirs. The complicated migration process results in ineffective and inaccurate forecast of coal fines production. Hence, a robust modelling tool is required to include the mechanisms of fines migration and to predict their impacts on rock and production. In this paper, fines migration in coal is categorized into three stages: generation, migration, and deposition processes. The corresponding models for different stages are established, including (1) a fines generation model, (2) the maximum fines-carrying concentration model and deviation factor of the modified Darcy model, (3) a fines deposition model, and (4) a dynamic permeability and porosity model. The above models are coupled with a water flow model, solved numerically using the finite difference method. Then, two dewatering strategies, including fast and moderate depressurization, are compared using the proposed models to study their effects on coal properties and following production. Finally, the production history of a CSG well in the Qinshui Basin, China, is utilized for history matching in a field case study. The simulation results indicate that new fines will be generated in a fast depressurization process and the water rate decline reduces the cleat permeability significantly. The newly generated fines can enhance the permeability temporarily, but they will block the flow channels and bring serious damage to the permeability when the water rate declines. The moderate depressurization strategy can produce the coal fines in a continuous mode, and the formation damage induced by fines deposition can be reduced to the acceptable level, which is the more reliable way to maintain well productivity. In addition, multiple well shut-in can trigger the irreversible fines deposition, reduce the permeability, and decrease the production rate.
Publisher: American Chemical Society (ACS)
Date: 11-03-2015
DOI: 10.1021/IE504936Q
Publisher: Society of Petroleum Engineers
Date: 2015
DOI: 10.2118/176595-MS
Publisher: Elsevier BV
Date: 03-2022
Publisher: Springer Science and Business Media LLC
Date: 16-11-2020
Publisher: AIP Publishing
Date: 09-2012
DOI: 10.1063/1.4749844
Abstract: Using the law of propagation of uncertainties we show how equipment- and measurement-related uncertainties contribute to the overall combined standard uncertainties (CSU) in filter permeability and in modelling the results for polystyrene latex microspheres filtration through a borosilicate glass filter at various injection velocities. Standard uncertainties in dynamic viscosity and volumetric flowrate of microspheres suspension have the greatest influence on the overall CSU in filter permeability which excellently agrees with results obtained from Monte Carlo simulations. Two model parameters “maximum critical retention concentration” and “minimum injection velocity” and their uncertainties were calculated by fitting two quadratic mathematical models to the experimental data using a weighted least squares approximation. Uncertainty in the internal cake porosity has the highest impact on modelling uncertainties in critical retention concentration. The model with the internal cake porosity reproduces experimental “critical retention concentration vs velocity”-data better than the second model which contains the total electrostatic force whose value and uncertainty have not been reliably calculated due to the lack of experimental dielectric data.
Publisher: Elsevier BV
Date: 2019
Publisher: Elsevier
Date: 2018
Publisher: Unconventional Resources Technology Conference
Date: 2019
Publisher: Elsevier BV
Date: 09-2019
Publisher: Elsevier BV
Date: 08-2018
Publisher: Elsevier BV
Date: 12-2014
Publisher: SPE
Date: 24-02-2016
DOI: 10.2118/179025-MS
Abstract: Evaluation of flow rate profile along the wellbore is very important for reservoir characterization, because it indicates the contribution of each inflow point at different depth to the overall production rate. The temperature and pressure sensors in the wellbore are small and cheap, whereas flow meters are cumbersome and expensive, and affect the flow in the well. The method presented in the current paper shows its significance in predicting the gas rate from temperature and pressure data. A mathematical model for pressure and temperature distributions along gas well has been developed. Temperature and pressure profiles from nine well intervals in field C (Australia) have been matched with the mathematical model to determine the flow rates from different layers in the well. The present model considers the variables as functions of thermal properties at each depth, which is more accurate if compared to previous models. Results of tuning the mathematical model to field data show good agreement with the model prediction. Simple and explicit formulae are derived for effective evaluation of flow rate and thermal conductivity in gas wells. The proposed approach has been applied to the estimation of gas rates and formation thermal conductivities from the measured well pressure and temperature data in field C. It provides useful information for identifying the source and magnitude of formation damage and recommending well stimulation of the layers with low rates.
Publisher: MDPI AG
Date: 27-06-2023
DOI: 10.3390/MA16134618
Abstract: U-Mo alloys were considered to be the most promising candidates for high-density nuclear fuel. The uniaxial tensile behavior of nanocrystalline U-10Mo alloys with average grain sizes of 8–23 nm was systematically studied by molecular dynamics (MD) simulation, mainly focusing on the influence of average grain size on the mechanical properties and deformation mechanisms. The results show that Young’s modulus, yield strength and ultimate tensile strength follow as average grain size increases. During the deformation process, localized phase transitions were observed in s les. Grain boundary sliding and grain rotation, as well as twinning, dominated the deformation in the smaller and larger grain sizes s les, respectively. Increased grain size led to greater localized shear deformation, resulting in greater stress drop. Additionally, we elucidated the effects of temperature and strain rate on tensile behavior and found that lower temperatures and higher strain rates not only facilitated the twinning tendency but also favored the occurrence of phase transitions in s les. Results from this research could provide guidance for the design and optimization of U-10Mo alloys materials.
Publisher: SPE
Date: 25-10-2016
DOI: 10.2118/182283-MS
Abstract: Water blocking is a widespread formation damage mechanism in oil and gas reservoirs. The end effect on the well sand-face or fracture results in the creation of a water film which significantly reduces gas permeability. The removal of the water film by changing wettability near to the wellbore or hydraulic fracture is the traditional method of well stimulation. We describe inflow performance by two-phase steady-state flow towards well. The wettability affects the relative permeability and the capillary pressure. Treatment of the well neighbourhood by nanoparticles or surfactants results in a reservoir with non-uniform wettability. We present a steady-state solution for inflow performance and show how the alteration of the contact angle and the treatment depth affects the well productivity index. The model is verified by comparison with coreflood data. The developed analytical model can be used for the prediction of gas well productivity, and for the planning and design of wettability-alteration well-stimulation. The main result of the paper is the existence of the optimal contact angle.
Publisher: Hindawi Limited
Date: 2018
DOI: 10.1155/2018/2968629
Abstract: It has been observed in many laboratory tests that the carbon number of the maximum concentration components (CNMCC) of produced oil varies monotonically with CO 2 injection volume at the core scale. However, in CO 2 flooding pilot test at the field scale, we find that the CNMCC is usually nonmonotonic function of CO 2 injection volume, which is called “pulse characteristic” of CNMCC. To investigate the mechanism of this phenomenon, we analyze the physical process of CO 2 flooding in heterogeneous reservoir and explain the reason of the pulse characteristic of CNMCC. Moreover, two 3D reservoir models with 35 nonaqueous components are proposed for numerical simulation to validate the conjecture. The simulation results show that pulse characteristic of CNMCC only occurs in the heterogeneous model, confirming that the pulse characteristic results from the channeling path between wells, which yields nonmonotonic variation of oil-CO 2 mixing degree. Based on it, a new method can be developed to identify and quantify the reservoir heterogeneity.
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 11-2020
Publisher: National Library of Serbia
Date: 2012
DOI: 10.2298/TSCI1205551W
Abstract: Temporal stability analysis of fiber suspended shear flow is performed. After introducing the second order structure tensor to determine the Folgar-Tucker inter-fiber interactions based on the Langevin?s equation, a system governing the flow stability is derived in conjunction with the fiber orientation closure. Effect of the inter-fiber interactions on the dynamic stability is studied by solving the general eigenvalue problem. Results show that fiber interaction has significant stabilizing effects on the flow. The most unstable wave number changes with the interaction coefficient. For given interaction coefficient, wave number and other relevant parameters, there is a Re number which corresponds to the critical flow. This Re number is related to the wave number.
Publisher: SPE
Date: 25-10-2016
DOI: 10.2118/182266-MS
Abstract: Drill-in fluid loss is the most important cause of formation damage during drill-in process in fractured tight reservoirs. Lost circulation material (LCM) addition into drill-in fluid is the most popular technique for loss control. However, traditional LCM selection is mainly performed by trial-and-error method, due to lack of mathematical models. The present work aims at filling this gap, by developing a new mathematical model to characterize the performance of drill-in fluid loss control using LCM during drill-in process of fractured tight reservoirs. Plugging zone strength and fracture propagation pressure are the two main factors affecting drill-in fluid loss control. The developed mathematical model consists of two sub-models, i.e., the plugging zone strength model and the fracture propagation pressure model. Explicit formulae are obtained for LCM selection based on the proposed model, in order to control drill-in fluid loss and prevent formation damage. Laboratory tests on loss control effect by different types and concentrations of LCMs are performed. Plugging pressure and total loss volume are measured and compared with modeling results. Effects of LCM mechanical and geometric properties on loss control performance are analyzed, for optimal fracture plugging and propagation control. Different combinations of acid-soluble rigid particles, fibers and elastic particles are tested in order to generate a synergy effect for drill-in fluid loss control. The derived model is validated by laboratory data.
Publisher: Elsevier BV
Date: 11-2017
Publisher: American Chemical Society (ACS)
Date: 25-03-2019
Publisher: National Library of Serbia
Date: 2014
DOI: 10.2298/TSCI1405517W
Abstract: The linear stability analysis is carried out for the suspension flow of spherical particles between a rotating inner cylinder and a stationary concentric outer cylinder. The mass conservation equation and Navier-Stokes equation are applied to the continuous fluid phase and the particle phase. Results of stability analysis show that the increase of wave number in the circumferential direction attenuates the effect of the axial wave number on the lification factor. The ratio of particle density to fluid density increasing above 0.1 lifies the flow instability, while it can be weakened with higher circumferential direction wave number. Effect of the critical Taylor number on the lification factor is reduced by increasing the circumferential direction wave number. The flow stability is affected by the geometry of flow field (the radius ratio) at non-zero circumferential direction wave numbers.
Publisher: Springer Science and Business Media LLC
Date: 22-02-2021
Publisher: Springer Science and Business Media LLC
Date: 07-2010
Start Date: 2015
End Date: 2017
Funder: Australian Research Council
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