Effects of Both Wellbore and Reservoir Properties on Dimensionless Pressure and Dimensionless Pressure Derivative Distribution of a Horizontal Well in a Reservoir Subject to Bottom Water, Gas Cap and Single Edge Water Drive Mechanisms

2014 ◽  
Author(s):  
O. Edobhiye ◽  
E.S. Adewole
2011 ◽  
Vol 367 ◽  
pp. 385-392
Author(s):  
E. Steve Adewole

When a reservoir experiences water influx, the actual source of the water often cannot be ascertained with precision. Thus well work over measures to minimize the water may not be easy to fashion. Bottom water encroaches through the bottom of the reservoir and rises vertically, appearing in all the wells in the field at the same time, if the wells experience the same production histories. This further makes work over difficult, more so, if there are other external fluid influences akin to a top gas. However, if the arrival time is known, then factors affecting bottom water movement, with or without any other contiguous top gas, may be studied with a view to fashioning an effective work over to mitigate premature water arrival into the well. Horizontal wells are already known to delay encroaching water breakthrough time. For a cross flow layered reservoir completed with a horizontal well in each layer, flow dynamics will certainly be different from a single layer reservoir due to differences in individual layer, layers fluid, wellbore and interface properties and rate histories. In this paper, theoretical expressions for predicting dimensionless breakthrough times of horizontal wells in a two layered reservoir of architecture like letter ‘B’, experiencing bottom water drive mechanism of different patterns, with or without a top gas, are derived. The theoretical breakthrough times are based on dimensionless pressure and dimensionless pressure derivative distributions of each identified model. Twenty-seven (28) different models emerged as the total of the different models possible.


2021 ◽  
Author(s):  
A V Ogbamikhumi ◽  
E S Adewole

Abstract Dimensionless pressure gradients and dimensionless pressure derivatives characteristics are studied for horizontal and vertical wells completed within a pair of no-flow boundaries inclined at a general angle ‘θ’. Infinite-acting flow solution of each well is utilized. Image distances as a result of the inclinations are considered. The superposition principle is further utilized to calculate total pressure drop due to flow from both object and image wells. Characteristic dimensionless flow pressure gradients and pressure derivatives for the wells are finally determined. The number of images formed due to the inclination and dimensionless well design affect the dimensionless pressure gradients and their derivatives. For n images, shortly after very early time for each inclination, dimensionless pressure gradients of 1.151(N+1)/LD for the horizontal well and 1.151(N+1) for vertical well are observed. Dimensionless pressure derivative of (N+1)/2LD are observed for central and off-centered horizontal well locations, and (N+1)/2 for vertical well are observed. Central well locations do not affect horizontal well productivity for all the inclinations. The magnitudes of dimensionless pressure drop and dimensionless pressure derivatives are maximum at the farthest image distances, and are unaffected by well stand-off for the horizontal well.


2021 ◽  
Author(s):  
Johnson Johnson ◽  
Ezizanami Adewole

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.


2013 ◽  
Vol 824 ◽  
pp. 373-378
Author(s):  
I. Eiroboyi ◽  
E. Steve Adewole

The use of dimensionless pressure and dimensionless pressure derivative type curves has fully overcome the challenges experienced in the use of straight line methods and has brought about major successes in well tests analyses. Flow periods and reservoir boundary types are easily delineated and identified with the use of these curves. Furthermore, near wellbore characterization results are now more reliable. In this study, type curves for a reservoir subject to bottom water energy and a vertical well completion are developed to reveal specific signatures that can be used to achieve efficient pressure test analysis. Both early and late flow periods were considered for a wellbore of negligible skin and wellbore storage influences. Results obtained show that dimensionless pressures depart from infinite-acting behavior and attain steady state at dimensionless time of order proportional to the square of dimensionless reservoir thickness. Wellbore dimensionless radius affects dimensionless time of attainment of steady state inversely, which is rather accelerated by large fluid withdrawal rates (large pressure drawdown). On the other hand, dimensionless pressure derivatives show gradual collapse to zero after expiration of infinite flow. The rate of collapse is strongly affected by wellbore properties and pressure drawdown. Radial flow is generally characterized by a constant slope of 1.151 during which period the dimensionless pressure derivative gave a value of 0.5. Following assumption of negligible wellbore skin and storage, no early time hump is observed on dimensionless derivative curves.


2020 ◽  
Vol 39 (1) ◽  
pp. 154-160
Author(s):  
J.J. Orene ◽  
E.S. Adewole

The purpose of this study is to develop a mathematical model using Source and Green’s functions for a Horizontal Wells in a Bounded Reservoir with Constant Pressure at the Top and Bottom for the interpretation of pressure responses in the reservoir based on dimensionless pressure and pressure derivative. Reservoir and well parameters investigated revealed what sets of reservoir/ well parameters combination that will prolong infinite activity of the reservoir before steady state sets in. Results show that dimensionless lateral extent does not directly affect the dimensionless pressure and dimensionless pressure derivative for very short well lengths as used in this paper. Dimensionless pressure increases with reservoir pay thickness and delay the time for steady state conditions. In fact external fluid invasion is strongly affected by the size of the pay thickness, thus the minimum time for steady state period to set in is according to the relation TD ≥ LD/5. Keywords: Bounded, reservoir, steady-state conditions, horizontal well, constant pressure.


2015 ◽  
Vol 752-753 ◽  
pp. 790-795
Author(s):  
I. Eiroboyi ◽  
P.O. Obeta

Reservoir performance can be understood from system type curves. The type curve gives vivid information about maximum pressure drops, magnitude of near wellbore effects, reservoir fluid and wellbore properties needed to ascertain the strength of available drive mechanism, maximum withdrawal rates and remaining fluid in real time. This paper investigates the effects of reservoir area extent on the performance of a reservoir, subject to active bottom water, when it is completed with a vertical well. Type curves of dimensionless pressures and dimensionless pressure derivatives were produced for various dimensionless values of area extent of the reservoir. These type curves were developed from solutions to flow equations using relevant source and Green’s functions. From the results, it can be observed that the larger the reservoir area extent, the larger the dimensionless pressure drop, the longer the time it takes to attain steady state. This is validated from the pressure derivative curve, which shows that reservoirs with large area extent are characterized by longer period of radial flow and subsequently delay in the attainment of steady state, thus prolonging the arrival of bottom water.


2009 ◽  
Vol 62-64 ◽  
pp. 420-425
Author(s):  
K. Ovwigho ◽  
E. Steve Adewole

Dimensionless pressure derivatives of a laterally infinite reservoir drained with a horizontal well are studied. The effect of anisotropy on the derivative response is also studied. It is revealed that anisotropy mainly affects the start of the late radial flow regime, and for cases where LD is small (<0.5), affects the end of the first radial flow regime. Time criteria equations were also developed to delineate flow periods and have been shown to give good results for the range 0.00005 ≤ rwD ≤ 0.01 and 0.1 ≤ LD ≤ 100.


10.2118/98-19 ◽  
1998 ◽  
Author(s):  
P. Permadi ◽  
W. Wibowo ◽  
J. Erickson
Keyword(s):  

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