Seepage Patterns Research Articles

Research on the basic theory and application of enhanced recovery in tight sandstone gas reservoirs.

Tight sandstone gas reservoirs are characterized by high water saturation, significant seepage resistance, low single-well productivity, rapid decline, and low gas recovery. Enhancing the recovery rate of tight sandstone gas reservoirs is a complex engineering challenge that necessitates thorough, refined, and systematic research into its fundamental theories. This study employs a comprehensive approach integrating mercury injection, nuclear magnetic resonance, micro-model visualization, and simulation experiments of displacement and inter-layer seepage flow, alongside foundational seepage theories, to systematically explore the characteristics of tight sandstone gas reservoirs, seepage patterns, and methods for improving gas recovery. Our findings reveal: (1) Detailed characterization of the microscopic pore characteristics in tight sandstone reservoirs helps disclose the status and mechanisms of gas-water occurrence and the principal mechanisms of water production under gas-water co-sealing conditions, such as gas expansion, energy of water-sealed gas, movable water volume, and displacement pressure gradient; (2) Testing single-phase and gas-water two-phase seepage characteristics under bound water saturation identifies permeability and water saturation as critical parameters influencing gas seepage characteristics; (3) Inter-layer gas-water interaction flow experiments demonstrate the interference in multi-layer commingled production and introduce the concept of an interference index, a predictive model for well productivity and dynamic performance in the Sulige tight sandstone gas reservoir; (4) A model correlating reservoir recovery rates with drive indices has been developed, highlighting that increasing production pressure differential and reducing seepage resistance are the primary strategies for enhancing recovery rates in tight sandstone gas reservoirs, supplemented by six technological countermeasures including water-blocking, water control, and densifying well networks. The research outcomes provide effective guidance for practical measures to enhance recovery in tight sandstone gas reservoirs.

Deformation, Seepage, and Energy Characteristics of Gas-Containing Coal Rocks under Complex Stress Paths

The exploitation and utilization of coal resources are closely related to sustainable social and economic development. To uncover the deformation and seepage patterns of coal on the mining process, this study devised a new stress program with simultaneous changes in axial and confining pressures, then performed coal seepage experiments at various gas pressures. The results show that the residual deformation exhibited a stepwise change, the relative residual deformation at the same level decreased gradually, and the increase in gas pressure led to a reduction in residual deformation. In each stress grade, the absolute permeability damage rate increased gradually, while the relative permeability damage rate decreased with the number of cycles, and the growth of gas pressure could decrease the permeability damage rate. The higher gas pressure led to a lower average energy dissipation ratio at each stress level and increased the rate of growth of elastic energy before destruction of the specimens. A higher gas pressure led to a quicker rate of change in damage variables at high stress levels. The findings have implications for the effective mining and sustainable development of coal resources.

Perbandingan Metode Kalibrasi Sistem Celup Dan Chamber Untuk Vibrating Wire Piezometer In Situ

Piezometers are geotechnical monitoring instruments commonly used to obtain pore water pressure or groundwater level values. The most popular piezometer is the electric type (vibrating wire). The way this type of piezometer works is that the pore water pressure acting on the diaphragm causes a change in voltage and resonance on the vibrating wire. From the resonance of the vibrating wire will issue a frequency that will be recorded by the reading unit. This change in water force will affect the magnitude of the frequency read in the reading unit. In addition, seepage patterns, possible piping zones, and the effectiveness of seepage control used can be evaluated with the help of this tool. Currently piezometers are widely used for Monitoring embankment stability and safety, Measuring water load behind retaining walls, Assessing soil consolidation, Measurement of uplift pressure acting on structural foundations, Verification of seepage patterns and models, Monitoring slope stability, Monitoring water levels for environmental control, Assessment of tidal influence, Pump testing. Due to the importance of these instruments and their high sensitivity, it is necessary to calibrate them before installation to ensure that the equipment functions properly and accurately. Some methods of conducting in-situ calibration that are often used are the dip method and the pressurized chamber or cell method. This study will compare the two methods to determine the accuracy of the calibration implementation that can be used as a consideration for the acceptance of instruments from certain manufacturers. Based on the research that has been done, calibration with the chamber method is more accurate and acceptable after analysis. Because in its implementation it can be more thorough and there is not much external disturbance as in the dip method calibration method carried out in lakes or reservoirs where there is a lot of external disturbance.

The impact of lenses on the seepage failure of tailings dam.

The presence of lenses such as tailings slurry, frozen soil, and saturated zones disrupts the continuity of tailings dams and their normal seepage patterns, elevating the seepage line of the dam body and significantly impacting local stability. This study, to investigate how lenses affect the stability and failure mechanisms of tailings dams, employs numerical simulation and physical models and constructs a model of the tailings dam, incorporating tailings clay lens and void lens, to investigate variations in hydraulic gradients, seepage velocities, seepage flow, pore water pressure, and the patterns of seepage failure. This research reveals that the tailings clay lens within the dam body increases the hydraulic gradient in its vicinity due to its low permeability and raises the phreatic line. As the tailings clay lens approaches the dam body, the phreatic line tends to escape along the upper part of the lens towards the dam surface. In addition, the void lens could lead to a more pronounced seepage gradient along its path on the dam surface, with a liquefaction beneath it. As the void lens nears the toe of the slope, the dam failure mode transitions from a step-like progressive failure to an arch-shaped settlement failure along the void lens.

Experimental Study on Gas Production Capacity of Composite Reservoir Depletion in Deep Carbonate Gas Reservoirs

Deep carbonate gas reservoirs exhibit diverse reservoir types and complex seepage patterns. To study the gas production capabilities of different composite reservoir types, we classified the reservoirs of the fourth member of the Dengying Formation in the Anyue Gas Field into high-quality reservoirs (HRs) and poor-quality reservoirs (PRs) based on high-pressure mercury injection (HPMI) experiment results. By varying the differential pressure of the depletion experiment and the connection method, as well as the permeability and water saturation of the composite core, the effects of well location deployment, permeability ratio of the high-quality reservoir and poor-quality reservoir (PRHPR), gas well production pressure difference (GWPPD), and water saturation on the depletion gas production characteristics of the composite reservoir were studied. The research results show that (1) deploying wells on HR enables high gas production rates and ultimate recovery rates; (2) only when the PRHPR falls within a reasonable range (21.88–43.19) can the “dynamic recharge” capability of PR and the high permeability of HR be coordinated to achieve high gas recovery rates; (3) a GWPPD of 3 MPa is optimal, resulting in fast gas production rates and high ultimate recovery rates for PR; (4) high water saturation (≥50%) leads to premature water breakthrough at the well bottom, decreased gas production rate, and sealing of HR and PR reserves by formation water. Combining experimental results with field production data is our next research focus. Our future research focus will be on integrating experimental results with field production data to provide solid theoretical support for the efficient development of this type of gas reservoir.

Characterization of Pore Structure and Two-Phase Seepage Pattern in Sandstone Conglomerate Based on CT Scanning

Characterization of Pore Structure and Two-Phase Seepage Pattern in Sandstone Conglomerate Based on CT Scanning

Non-invasive geophysical methods for monitoring the shallow aquifer based on time-lapse electrical resistivity tomography, magnetic resonance sounding, and spontaneous potential methods

The Ningdong coalfield has played a pivotal role in advancing local economic development and meeting national energy. Nevertheless, mining operations have engendered ecological challenges encompassing subterranean water depletion, land desertification, and ground subsidence, primarily stemming from the disruption of coal seam roof strata. Consequently, the local ecosystem has incurred substantial harm. Water-preserved coal mining presently constitutes the pivotal technology in mitigating this problem. The primary challenge of this technique lies in identifying critical aquifer layers and understanding the heights of water-conducting fracture zones. To obtain a precise comprehension of the seepage patterns within the upper coal seam aquifer during mining, delineate the extent of water-conducting fracture zones, non-invasive geophysical techniques such as time-lapse electrical resistivity tomography (TL-ERT), magnetic resonance sounding (MRS), and spontaneous potential (SP) have been employed to monitor alterations within the shallow coalfield’s aquifer throughout the mining process in the Ningdong coalfield. By conducting meticulous examinations of fluctuations in resistivity, moisture content, and self-potential within the superjacent strata during coal seam extraction, the predominant underground water infiltration strata were ascertained, concurrently enabling the estimation of the development elevation of water-conducting fracture zones. This outcome furnishes a geophysical underpinning for endeavors concerning local water-preserved coal mining and ecological rehabilitation.

Microscopic seepage simulation of gas and water in shale pores and slits based on VOF

Abstract The microscopic pore-fracture structure and wettability have a significant influence on the two-phase seepage of shale gas and water. Due to the limitation of experimental conditions, the seepage patterns of gas and water in shale pores and slits under different wetting conditions have not been clarified yet. In this study, the three-dimensional digital rock models of shale inorganic pores, organic pores, and microfractures are established by focused ion beam-scanning electron microscopy scanning, and gas-driven water seepage simulation in shale microscopic pore-fracture structure under different wetting conditions is carried out based on volume of fluid method. The simulation results show that the gas–water relative permeability curves of microfractures are up-concave, and the gas–water relative permeability curves of inorganic and organic pores are up-convex; the gas–water two-phase percolation in microfractures is least affected by the change of wettability, the gas–water two-phase percolation in inorganic pores is most affected by the change of wettability, and the organic pores are in between; the gas–water two-phase percolation zone of microfractures is the largest, and the isotonic saturation is the highest; under the water-wet conditions, the critical gas saturation of microfractures, inorganic pores, and organic pores are 0.13, 0.315, and 0.34, respectively, and the critical gas saturation of organic pores under non-water-wet conditions is 0.525, indicating that under water-bearing conditions, the shale gas flow capacity in water-wet microfractures is the strongest, followed by water-wet inorganic pores, water-wet organic pores, and hydrophobic organic pores, respectively.

Kajian Penyebab Rembesan pada Bendungan Situ Lembang di Kabupaten Bandung Barat

A dam is a construction structure built to hold back the flow of water from upstream to downstream. Geographically, the Situ Lembang Dam is located in Kertawangi Village, Cisarua District, West Bandung Regency, the Situ Lembang Dam has a length of 350 m. One of the problems with dams is seepage. Seepage is defined as the property of a porous material that allows fluid in the form of water to flow through the pore cavity. The aim of this research is to determine the effect of variations in hydrostatic height on seepage that occurs in the dam body. The material forming the dam body is a type of organic clay. Almost all of the instrumentation equipment at 'Situ Lembang' no longer functions. This research uses laboratory simulations to review seepage patterns and seepage discharge against variations in hydrostatic height. Seepage discharge (Qf) is calculated using 3 methods, namely the Dupuit method, Schaffernak method, and Cassagrande method. The hydrostatic height variations reviewed are H10, H15, and H20.

Monitoring underwater volcano degassing using fiber-optic sensing

Continuous monitoring of volcanic gas emissions is crucial for understanding volcanic activity and potential eruptions. However, emissions of volcanic gases underwater are infrequently studied or quantified. This study explores the potential of Distributed Acoustic Sensing (DAS) technology to monitor underwater volcanic degassing. DAS converts fiber-optic cables into high-resolution vibration recording arrays, providing measurements at unprecedented spatio-temporal resolution. We conducted an experiment at Laacher See volcano in Germany, immersing a fiber-optic cable in the lake and interrogating it with a DAS system. We detected and analyzed numerous acoustic signals that we associated with bubble emissions in different lake areas. Three types of text-book bubbles exhibiting characteristic waveforms are all found from our detections, indicating different nucleation processes and bubble sizes. Using clustering algorithms, we classified bubble events into four distinct clusters based on their temporal and spectral characteristics. The temporal distribution of the events provided insights into the evolution of gas seepage patterns. This technology has the potential to revolutionize underwater degassing monitoring and provide valuable information for studying volcanic processes and estimating gas emissions. Furthermore, DAS can be applied to other applications, such as monitoring underwater carbon capture and storage operations or methane leaks associated with climate change.

Study on Flow Line Characteristics and Well Test Interpretation Methods of Multi Branch Fractured Wells in Dual Porous Media

Fractured reservoirs have developed fractures, strong heterogeneity, and complex seepage patterns. The analysis of core and imaging logging data in Bohai BZ Oilfield shows that there are a large number of fractures developed in the formation, with some wells having up to 6-8 fractures per meter. To study the impact of fractures on seepage, a multi fracture system seepage field simulation method was established, and the characteristic curves of flow lines under different fracture shapes were drawn. The fracture flow line morphology shows that there is a significant difference in the distribution of flow lines between the presence and absence of fractures, and the location of the fractures The size and shape of the reservoir have varying degrees of influence on the distribution of the streamline. The streamline around the well is distributed radially around it. When the fluid encounters an area with developed fractures, it first flows into the fractures and then flows from the fractures towards the wellbore. At the same time, based on the characteristics of fracture development in BZ oilfield and the theory of vertical fracture well testing, a dual medium multi fracture system oil well testing model was established. The model was numerically solved using Laplace transform, and a dual logarithmic curve chart for dual pore medium multi branch fracture well testing was obtained. The effects of fracture branching number, fracture length, conductivity coefficient ratio, and fracture conductivity on the shape of the testing curve were analyzed. The established well testing interpretation model can analyze oilfield stratigraphic information, reservoir fracture development, and boundary conditions. The research results have important guiding significance for evaluating the dynamic performance of oil wells in a dual pore medium multi fracture system and designing oilfield development plans.

Study of seepage patterns and calculation of infiltration coefficients of loose stacked layers on slopes under rainfall action

Rainfall is one of the most important factors inducing landslide occurrence, and previous researchers have carefully studied the stages of rainfall infiltration as well as the factors that affect infiltration (e.g., rainfall intensity, rainfall duration, initial water content and dry density). However, previous studies using homogeneous soils were overly idealised and ignored the effects of water content and dry density on infiltration, which vary with depth. In this paper, based on indoor rainfall infiltration tests under the above initial conditions and influencing factors, the following patterns were found: (1) dry density and water content of natural soils tend to increase along the direction of gravity under long-term gravity and repeated rainfall evapotranspiration; (2) stepped dry density increases infiltration resistance, which increases the total response time; stepped initial water content decreases infiltration water volume, which decreases the total response time; stepped dry density and water content have the shortest total response time;(3) The increase in dry density delayed the sudden change point in the permeability coefficient, and the initial moisture content had little effect on the sudden change point.

SEEPAGE ANALYSIS ON THE EMBANKMENT BODY ZONAL TYPE DAM IN BAGONG EAST JAVA INDONESIA

Dam construction is one form of water resource utilization in Indonesia. In addition to its potential functions and benefits, dams in Indonesia also pose significant risks. Therefore, detailed planning for dam construction is essential. The Bagong Dam has a zonal embankment type with a vertical core. This type of dam has larger pores or voids compared to concrete/asphalt dams. Consequently, a detailed seepage calculation is necessary to avoid adverse events. Water seepage can be addressed by analyzing it using the Geo-Studio software, which can identify the depression line, as well as the velocity and discharge of seepage through the dam body. The analysis includes conditions such as Normal Water Surface (NWS), Flood Water Surface (FWS), Rapid Drawdown, and Dead Storage. The analysis will produce seepage patterns (depression lines), seepage discharge, and seepage velocity. The calculated seepage discharge in Geo-Studio is 5.82 x 10-3 m3/s, compared to the manually calculated seepage discharge of 5.98 x 10-3 m3/s, resulting in a negligible difference of 2.672%, with a discharge difference of 0.00016 m3/s. The highest critical velocity occurs in rip-rap material and embankments at a height of 4.04 x 10-1 in the NWS modelling. The critical diameter limit for the most critical (smallest) material to be carried away is found in clay material with a critical diameter of 5.61.10-14 cm. The safety factor for suffusion symptoms indicates the most critical value in NWS modelling, with a value of 4.51. The seepage discharge is still within safe limits since the calculated discharge through the dam body is 0.062 m3/s less than the permitted discharge.

Investigation on effect evaluation of seepage control system of large underground powerhouse of the Baihetan hydropower station

The Baihetan Hydropower Station, situated in the lower reaches of Jinsha River in China, ranks as the second largest hydropower project. Effective seepage control in the underground powerhouse area is paramount due to the complex geological conditions on the left bank compared to the right bank. To assess the efficiency of the seepage control system, a combination of field measurements and numerical simulations was employed. In the session of field measurements, the characteristics of seepage field such as the groundwater level, hydraulic head, and leakage quantity in the impoundment process were analyzed. It became evident that the seepage patterns within the underground powerhouse were heavily influenced by geological structures, particularly the staggered zones C3 and C2, along with the columnar joint basalt. Notably, the leakage quantity of these areas rate considerably increased during impoundment, peaking at 1049.7 L/ min at the water level of 816 m in 2021. A finite element model with the seepage control system was developed based on the stable seepage theory, simulating the seepage field under two different water levels (816 m and 825 m).The numerical simulation results indicated that the grouting curtain and drainage hole arrays had a substantial lowering the groundwater levels. Comparing with the measurements, the inaccuracy of calculated total leakage quantity was 0.7 %, which was within the pumping capacity. The study provided a method of combining field measurement and numerical simulation to evaluate the effect of a complicated seepage control system for a large hydropower project. This method comprehensively revealed the seepage field of the underground powerhouse during the impoundment. It proved to have guiding significance for the operational stability of the hydropower station.

Simulation Study on Seepage Patterns of Geothermal Reinjection in Carbonate Thermal Reservoir and Geothermal Doublet Well Patterns in Xiong’an New Area

The karst fissures of the carbonate thermal reservoir in Xiong’an New Area have developed, and they have the advantages of a concentrated distribution, shallow burial, large water volume, and easy recharge, which are conducive to the development and utilization of geothermal resources. This paper took the carbonate thermal reservoir in Xiong’an New Area as the research object and studied the characteristics of the seepage patterns and temperature distribution in thermal storage with different well arrangements and recharge methods by laser etching the micromodel of the carbonate thermal reservoir and simulating the recharge methods. The paper established a numerical model of the resettlement area of Xiong’an New Area based on the production data and the current recharge well pattern, and it proposed a plan for a geothermal doublet well arrangement. The results showed that the injection speed and angle significantly influenced the seepage of injected water in the fractured reservoir. The injection speed correlated with the breakthrough time and swept area. The breakthrough time plummeted as the injection speed increased, and the swept area crept up as the injection-fracture dip increased. The well arrangements also impacted the seepage patterns. The well pattern of two injectors and three producers was relatively suitable for geothermal reinjection, and it was more appropriate to choose the maximum injection-fracture dip because of the largest swept area. Factors that affected the sustainable development and utilization of geothermal fields included the well pattern arrangement, well spacing, injection and production volumes, and the temperature of the injected water. Based on the modeling, it is recommended that the well spacing be greater than 500 m, and the injection and production volumes less than 110 m3/h in the resettlement area of Xiong’an New Area. Moreover, a vertical fracture well is recommended to reduce thermal breakthroughs.

Finite Element Analysis and Prediction of Rock Mass Permeability Based on a Two-Dimensional Plane Discrete Fracture Model

The safety of underground engineering projects is significantly influenced by groundwater. One of the key complexities is identifying the primary seepage paths within underground rock formations, understanding the patterns of seepage, and determining the effects of fracture parameters on the fluid movement inside the rock mass. To address these issues, a probabilistic model is constructed for random fractures using the finite element method, reflecting the random nature of fracture distributions in the real world. This model allows for an in-depth examination of the distribution of pore water pressure and Darcy velocity field, revealing the permeability trends in fractured rock masses. A variety of fracture models were devised to understand the relationship between factors such as fracture density, length, length power law, angle, dispersion coefficient, aperture, and power law, and how they affect the overall permeability of rock masses. The study suggests that, in the context of discrete fractured rock masses, there is a linear increase in permeability with an increase in fracture density and aperture. Moreover, fractures of greater length lead to increased permeability, with fractures aligned with the direction of water pressure having the most impact on seepage velocity. A thorough investigation of the factors that affect each fracture parameter was performed, and the permeability of each model was computed. From these findings, a series of predictive equations were suggested for estimating rock permeability based on fracture geometry parameters.

Size Effects of Rough Fracture Seepage in Rocks of Different Scales

Percolation experiments were conducted on coal samples with various fracture lengths and inclination angles under different stress conditions using a gravity-loaded rock percolation test device. The goals of these experiments are (1) to improve the technology for protecting water resources while mining coal and (2) to enhance the research on how the size effects of fracture affect seepage. A three-dimensional seepage model was constructed using COMSOL numerical simulation software for larger fracture lengths ranging from 1 to 30 m to investigate the seepage pattern under the coupling of fracture roughness, fracture width, and other factors. Multiple regression analysis was used to investigate the effects of different factors on seepage from large and small fractures independently. The results show that, under laboratory conditions, for fracture lengths 10–70 mm (small length), permeability increases non-linearly with an increase in fracture length, and the overall increase is approximately 1.8 times. Whereas, for fracture lengths of 1–30 m (large length) in the simulation, permeability decreases and then increases with an increase in fracture length, and the overall change is approximately 0.03 times. The permeability varies in three stages (1–8 m obvious change, 8–23 m stabilization, 23–30 m stability) under different fracture lengths, widths, and roughness conditions. Acritical size was found to exist. The effect of fracture length on large length fracture seepage and small length fracture seepage was further verified by parameter sensitivity. The results of this study further reveal the mechanism of fracture seepage under coupling of fracture geometry size stress.

Prediction of the pore structure by machine learning techniques in the carbonate reservoirs in Iraq H oilfield

Pore structure impacts the capability of seepage pattern of subsurface fluid mineral and mineral exploitation efficiency. Because of the strong heterogeneity in carbonate reservoirs, the pore structure is nonlinearly varying and complex in reservoirs. It is necessary to establish a method for pore structure type (PST) prediction. Machine learning provides an efficient prediction method by finding the relationship between core test data and well‐logging data. In this paper, a reservoir identification method based on Gradient Boost Decision Trees (GBDT) is proposed for the pore structure characteristics of carbonate reservoirs integrating core test and logging data. Core testing data are utilized to form the training set for PST prediction. Then, we adopt the mutual information method to optimize the logging data as the input of the machine learning model. GBDT hyperparameters are optimized using the learning curve to make it have optimal performance. Finally, we compare the predicted result of GBDT with K‐Nearest Neighbor and support vector machines, demonstrating the superior performance of GBDT. The results indicate that the four PS are different in some properties, such as permeability, pore radius and shape of pore and throat. 20%, 10 and 0.15 are recommended as the optimal parameter values for Maximum feature, iteration number and Sub‐sample number to improve GBDT accuracy in carbonate reservoir PST prediction. Evaluation indicators of machine learning, including the Kappa coefficient, Heming distance, Jaccard similarity coefficient and Confusion matrices, indicate that GBDT has better performance. This research proves the high accuracy and applicability of machine learning technology in the carbonate reservoir and also provides a meaningful reference for the identification of the carbonate reservoirs in the central area of Iraq.

Experimental study on the interaction mechanism between fracturing fluid and continental shale oil reservoir

ABSTRACT Onshore shale oil is difficult to develop due to its special pore structure and low permeability characteristics. Artificial fracturing causes a large amount of fracturing fluid to intrude into the reservoir, resulting in a complex reservoir seepage pattern. Therefore, this paper aims to explore the changes in the reservoir at the macro and micro levels due to the interaction between fracturing fluids and shale oil reservoirs. For this, four rock samples from shale oil reservoirs and two fracturing fluids commonly used in the mine were used. Then, core repulsion, scanning electron microscopy, X-ray diffraction and CT scanning experiments were carried out successively. The following results were derived from our analyses. (1) Permeability of the rock samples was reduced by an average of 24.47% after replacement by fracturing fluid, while the experimental groups with larger fluid-grain sizes and well-developed fracture networks suffered more significant solid-phase damage and fluid-phase trapping. (2) Fracturing fluids have different effects on fractures at different scales; large fractures (>7.71 μm) were widened, while small fractures (<3.47 μm) were shrunk or even plugged. (3) Based on the water-sensitive effect, fracturing fluids can disperse and transport clay minerals, resulting in fluid-phase damage and an average decrease of 14.33% in clay content in the reservoir. (4) Analysis of the digital core model shows that fracturing fluid intrusion and retention can cause solid-phase damage to the reservoir matrix, with 38.14% and 60% damage to the pore and throat channels, respectively. This paper uses a combination of physical experiments and numerical analysis to investigate the interaction mechanism between fracturing fluids and shale oil reservoirs from both microscopic and macroscopic perspectives. Overall, the results of this study provide experimental support for future studies on the seepage characteristics of this type of reservoir and the design of fracturing construction schemes.

Study of non-linear flow in coarse granular material through converging boundaries

Over the past century, there has been a continuously growing research interest in fluid seepage through coarse porous material. Experimental data on nonlinear flow behaviour in several coarse granular materials are provided in the current work. The aim of the present work is to investigate, theoretically and experimentally, the seepage patterns arising from non– Darcy fluid flows through coarse granular materials, with a particular reference to the effect of convergence. Along with the above, the effect of variation in size and shape of the media on the seepage patterns is also analyzed. Experiments have been conducted on flow through porous material with converging permeameter and equations relating the different parameters affecting the seepage flow are established. A thorough review of different regimes of seepage flow has been carried out. In order to meet the prime objective, i.e., to propose governing equations for different regimes of radial seepage flow, experiments are conducted in a converging permeameter with crushed rock and small glass balls as solid material and water as fluid media. The analysis of the experimental data is carried out in two phases. In first phase, coefficient of resistance and Reynolds number is computed using ‘volume diameter’ as ‘characteristic length’. Then expressions relating these two parameters are proposed for different regimes of flow. In second phase, hydraulic radius is used as characteristic length while defining the coefficient of resistance and Reynolds number. Then analysis is repeated as done in first phase and the corresponding equations have been proposed relating the coefficient of resistance and Reynolds number.