scholarly journals Stream depletion rate with horizontal or slanted wells in confined aquifers near a stream

2010 ◽  
Vol 14 (8) ◽  
pp. 1477-1485 ◽  
Author(s):  
P.-R. Tsou ◽  
Z.-Y. Feng ◽  
H.-D. Yeh ◽  
C.-S. Huang
Keyword(s):  
Point Source ◽  
Horizontal Well ◽  
Late Time ◽  
Principle Of Superposition ◽  
Stream Depletion ◽  
Well Location ◽  
Depletion Rate ◽  
Drawdown Constraint ◽  
Steady Solutions ◽  
Time Required

Abstract. Pumping in a vertical well may produce a large drawdown cone near the well. In this paper, the solution is first developed for describing the groundwater flow associated with a point source in a confined aquifer near a stream. Based on the principle of superposition, analytical solutions for horizontal and slanted wells are then developed by integrating the point source solution along the well axis. The solutions can be simplified to quasi-steady solutions by neglecting the exponential terms to describe the late-time drawdown, which can provide useful information in designing horizontal well location and length. The direction of the well axis can be determined from the best SDR subject to the drawdown constraint. It is found that hydraulic conductivity in the direction perpendicular to the stream plays a crucial role in influencing the time required for reaching quasi-steady SDR. In addition, the effects of the well length as well as the distance between the well and stream on the SDR are also examined.

scholarly journals Stream depletion rate with horizontal or slanted wells in confined aquifers near a stream

2010 ◽  
Vol 7 (2) ◽  
pp. 2347-2371 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Point Source ◽  
Late Time ◽  
Vertical Wells ◽  
Principle Of Superposition ◽  
Stream Depletion ◽  
Well Location ◽  
Depletion Rate ◽  
Drawdown Constraint ◽  
Steady Solutions ◽  
Time Required

Abstract. The stream depletion rate (SDR) associated with pumping from vertical wells located in an aquifer is commonly estimated, where a large drawdown near the well may, however, be produced. In this paper, the solution is first developed for describing the groundwater flow associated with a point source in a confined aquifer near a stream. Based on the principle of superposition, analytical solutions for horizontal and slanted wells are then developed by integrating the point source solution along the well axis. The solutions can be simplified to quasi-steady solutions by neglecting the exponential terms to describe the late-time drawdown, which can provide useful information in designing horizontal well location and length. The direction of the well axis can be determined from the best SDR subject to the drawdown constraint. It is found that hydraulic conductivity in the direction perpendicular to the stream plays a crucial role in influencing the time required for reaching quasi-steady SDR. In addition, the effects of the well length as well as the distance between the well and stream on the SDR are also examined.

Optimized Model of Slotted Liners Completion Parameters in Horizontal Well

2012 ◽  
Vol 616-618 ◽  
pp. 804-811
Author(s):  
Quan Tang Fang ◽  
Wei Chen ◽  
Rong Wang
Keyword(s):  
Point Source ◽  
Line Source ◽  
Flow Resistance ◽  
Horizontal Well ◽  
Source Function ◽  
Geometric Model ◽  
Superposition Principle ◽  
Evaluation Index ◽  
Flow Convergence ◽  
Optimized Model

The transient flowing model of slotted liner completion was established by superposition principle based on the geometric model of slotted liners, with the point source function and the single slotting equal to line source, and then the optimized model of slotted liner completion parameter was established with the skin factor of slotted liners completion as evaluation index. After analyzing the parameter sensitivity with cases, the slot density is confirmed as the main reason leading to flow convergence and additional flow resistance. Furthermore, the optimization principles of slotted liners completion of horizontal well are determined. These results are significant in optimizing the slot distribution pattern and parameter allocation.

Review of the Role of Analytical Modelling Methods in Riverbank Filtration System

2014 ◽  
Vol 71 (1) ◽  
Author(s):  
Shaymaa Mustafa ◽  
Arifah Bahar ◽  
Zainal Abdul Aziz ◽  
Saim Suratman
Keyword(s):  
Point Of View ◽  
Analytical Modelling ◽  
Analytical Models ◽  
Riverbank Filtration ◽  
Stream Depletion ◽  
Filtration System ◽  
Depletion Rate ◽  
Contaminants Transport ◽  
Modelling Methods

Riverbank filtration (RBF) technology is applied in several countries around the world as one of the main sources of drinking water supply both from quantitative and qualitative point of view. Consequently, several analytical modelling methods, mostly based on the transformation techniques, are developed in literature to describe different processes which occur in RBF system. An extensive overview of these analytical methods, their uses and limitations are discussed. The review disclosed that most analytical models usually are concerned in evaluating stream depletion rate rather than contaminants transport especially the transportation of pesticides and pathogens. Laplace and Fourier methods are more popular methods used by researchers to solve the system of partial differential equation that developed to simulate the RBF problem.

Pressures and Pressure Derivatives of a Vertical Well Located Within Two Inclined Faults: Case Study of Basic Angles and Unequal Well Distances from Faults

2021 ◽  
Author(s):  
Michael Ojah ◽  
Steve Adewole
Keyword(s):  
Transient Behavior ◽  
Accurate Estimation ◽  
Maximum Point ◽  
Well Performance ◽  
Principle Of Superposition ◽  
Pressure Transient ◽  
Vertical Well ◽  
Well Location ◽  
Well Design ◽  
Diffusivity Equation

Abstract Pressure transient analysis has been used to evaluate performance of a vertical well located within two intersecting sealing faults. The nature and types of boundary affect productivity in bounded reservoirs. Well performance is strongly affected by well location with respect to the boundary, be it single, paired and parallel or paired and inclined. The goal of this research was to study pressure behavior as well as performance of a vertical well located within two intersecting sealing faults inclined at various angles θ and at unequal distances to faults. Unlike similar works previously carried out, this work can be used to study or predict pressure distribution of a well in a wedge system located at unequal distances to faults. Using the concept of images, the study proposed new models for estimating distances between image well(s) and active well. These models were applied in the solution to the dimensionless diffusivity equation to characterize pressure transient behavior of a well located at unequal distances to the inclined faults. These pressures and pressure derivatives were computed from the total pressure drop expression summing all the image wells by the principle of superposition. The MATLAB, Python and Excel software were deployed to compute all the dimensionless pressures for the different well designs. The results obtained show that 1) the proposed models give accurate estimation of active well distances to image wells; 2) the models show that the distance between the active and image wells d0,i increases for the range of values of angles 0°< θ0,i ≤ 180° and decreases for the range 180° < θ0,i < 360°; 3) the relationship between unequal well distances and productivity has a maximum point; 4) beyond this point, the well ceases to be productive and; 5) this maximum point is at equal distances of the well from both faults, in this case, 15 ft. Larger magnitudes of dimensionless pressure derivatives would indicate higher oil production for any well design and inclination of the boundaries. Worthy of future works are similar studies on 1) horizontal wells and 2) mixed boundaries, that is, one sealing fault and one constant pressure boundary.

Flow Behavior of Horinzontal Well Cmpleted within Two Sealing Fauts Inclined at Right Angle

2021 ◽  
Author(s):  
Johnson Johnson ◽  
Ezizanami Adewole
Keyword(s):  
Horizontal Well ◽  
Flow Behavior ◽  
Superposition Principle ◽  
External Boundary ◽  
Pressure Derivative ◽  
Effective Work ◽  
Drainage Radius ◽  
Dimensionless Pressure ◽  
Well Location ◽  
Wellbore Pressure

Abstract At inception of a production rate regime, a horizontal well is expected to sweep oil within its drainage radius until the flow transients are interrupted by an external boundary or an impermeable heterogeneity. If the interruption is an impermeable heterogeneity or sealing fault, then the architecture of the heterogeneity must be deciphered in order to be able to design and implement an effective work-over or well re-entry to boost oil production from the reservoir. In this paper, therefore, the behavior of a horizontal well located within a pair of sealing faults inclined at 90 degrees is investigated using flow pressures and their derivatives. It is assumed that the well flow pressure is undergoing infinite activity, and each fault acts as a plane mirror. The total pressure drop in the object well is calculated by superposition principle. Damage and mechanical skin and wellbore storage are not considered. The main objective of our investigation is to establish identifiable signatures on pressure-time plots that represent infinite flow in the presence of adjacent no flow faults inclined at 90degrees. Results obtained show that the flowing wellbore pressure is influenced strongly by object well design, object well distance from each fault, and distance of each image from the object well. Irrespective of object well distance from the fault, there are three (3) images formed. Central object well location yields a square polygon, with two image wells nearer to the object well at equidistance from the object well, and the farthest image well to be 2d2. From the object well For off-centered object well location within the faults, a rectangular polygon is formed, with each image at a different distance from one well to another. Dimensionless pressure and dimensionless pressure derivative gradients during infinite-acting flow are (4.6052/LD) and 2/LD, respectively for all well locations within the faults.

scholarly journals Analysis of groundwater flow and stream depletion in L-shaped fluvial aquifers

2018 ◽  
Vol 22 (4) ◽  
pp. 2359-2375 ◽  
Author(s):  
Chao-Chih Lin ◽  
Ya-Chi Chang ◽  
Hund-Der Yeh
Keyword(s):  
Steady State ◽  
Groundwater Resources ◽  
Separation Of Variables ◽  
Measurement Data ◽  
Steady State Solution ◽  
State Solution ◽  
Stream Depletion ◽  
Numerical Studies ◽  
Present Solution ◽  
Depletion Rate

Abstract. Understanding the head distribution in aquifers is crucial for the evaluation of groundwater resources. This article develops a model for describing flow induced by pumping in an L-shaped fluvial aquifer bounded by impermeable bedrocks and two nearly fully penetrating streams. A similar scenario for numerical studies was reported in Kihm et al. (2007). The water level of the streams is assumed to be linearly varying with distance. The aquifer is divided into two subregions and the continuity conditions of the hydraulic head and flux are imposed at the interface of the subregions. The steady-state solution describing the head distribution for the model without pumping is first developed by the method of separation of variables. The transient solution for the head distribution induced by pumping is then derived based on the steady-state solution as initial condition and the methods of finite Fourier transform and Laplace transform. Moreover, the solution for stream depletion rate (SDR) from each of the two streams is also developed based on the head solution and Darcy's law. Both head and SDR solutions in the real time domain are obtained by a numerical inversion scheme called the Stehfest algorithm. The software MODFLOW is chosen to compare with the proposed head solution for the L-shaped aquifer. The steady-state and transient head distributions within the L-shaped aquifer predicted by the present solution are compared with the numerical simulations and measurement data presented in Kihm et al. (2007).

scholarly journals Characterization of Fractured Reservoirs Using a Combination of Downhole Pressure and Self-Potential Transient Data

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Yuji Nishi ◽  
Tsuneo Ishido
Keyword(s):  
Fractured Rock ◽  
Fractured Reservoirs ◽  
Pressure Change ◽  
Double Porosity ◽  
Late Time ◽  
The Matrix ◽  
Matrix Region ◽  
Transient Data ◽  
Time Required ◽  
Self Potential

In order to appraise the utility of self-potential (SP) measurements to characterize fractured reservoirs, we carried out continuous SP monitoring using multi Ag-AgCl electrodes installed within two open holes at the Kamaishi Mine, Japan. The observed ratio of SP change to pressure change associated with fluid flow showed different behaviors between intact host rock and fractured rock regions. Characteristic behavior peculiar to fractured reservoirs, which is predicted from numerical simulations of electrokinetic phenomena in MINC (multiple interacting continua) double-porosity media, was observed near the fractures. Semilog plots of the ratio of SP change to pressure change observed in one of the two wells show obvious transition from intermediate time increasing to late time stable trends, which indicate that the time required for pressure equilibration between the fracture and matrix regions is about 800 seconds. Fracture spacing was estimated to be a few meters assuming several micro-darcies (10-18 m2) of the matrix region permeability, which is consistent with geological and hydrological observations.

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