scholarly journals Mathematical description of a bounded oil reservoir with a horizontal well

2021 ◽  
Vol 2 (1) ◽  
pp. 61-66
Author(s):  
T. N. Nzomo ◽  
S. E Adewole ◽  
K. O Awuor ◽  
D. O. Oyoo
Keyword(s):  
Mathematical Model ◽  
Pressure Distribution ◽  
Mathematical Description ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Pressure Response ◽  
Oil Reservoir ◽  
Late Time ◽  
State Flow ◽  
Reservoir Geometry

When horizontal wells are compared with verticals wells, their production is always higher. If their performance can be improved, they can even be more productive. Considering a horizontal well in a completely bounded oil reservoir, when the well has been producing for some time and the effect of the boundaries is evident on the flow, the pressure distribution can be approximated by considering the effects of the boundaries on the flow. Considering when a pseudosteady state flow is attained this study presents a mathematical model for approximating pressure distribution for late time for a horizontal well in an oil reservoir with sealed boundaries. We use appropriate Source and Green’s functions to develop the model. The model developed show that when the flow reaches all the boundaries a pseudosteady state flow is attained and thus pressure distribution is influenced by the oil reservoir geometry especially its width and length. Considering that the thickness of the oil reservoir will be small compared to the length of the well, the oil reservoir width and length will determine the pressure response. This will influence the flow period occurring. By considering all aspects of the flow, the model can be applied to approximate the pressure distribution for as long as the well can continue producing.

scholarly journals Mathematical description of a bounded oil reservoir with a horizontal well

2021 ◽  
Vol 2 (1) ◽  
pp. 67-76
Author(s):  
T. N. Nzomo ◽  
S. E Adewole ◽  
K. O Awuor ◽  
D. O. Oyoo
Keyword(s):  
Pressure Distribution ◽  
Effective Permeability ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Oil Reservoir ◽  
Vertical Wells ◽  
Anisotropic Permeability ◽  
Time Approximation ◽  
Reservoir Geometry ◽  
Short Time

Horizontal wells are more productive compared to vertical wells if their performance is optimized. For a completely bounded oil reservoir, immediately the well is put into production, the boundaries of the oil reservoir have no effect on the flow. The pressure distribution thus can be approximated with this into consideration. When the flow reaches either the vertical or the horizontal boundaries of the reservoir, the effect of the boundaries can be factored into the pressure distribution approximation. In this paper we consider the above cases and present a detailed mathematical model that can be used for short time approximation of the pressure distribution for a horizontal well with sealed boundaries. The models are developed using appropriate Green’s and source functions. In all the models developed the effect of the oil reservoir boundaries as well as the oil reservoir parameters determine the flow period experienced. In particular, the effective permeability relative to horizontal anisotropic permeability, the width and length of the reservoir influence the pressure response. The models developed can be used to approximate and analyze the pressure distribution for horizontal wells during a short time of production. The models presented show that the dimensionless pressure distribution is affected by the oil reservoir geometry and the respective directional permeabilities.

scholarly journals Pressure distribution of a horizontal well in a bounded reservoir with constant pressure top and bottom

2020 ◽  
Vol 39 (1) ◽  
pp. 154-160
Author(s):  
J.J. Orene ◽  
E.S. Adewole
Keyword(s):  
Mathematical Model ◽  
Steady State ◽  
Pressure Distribution ◽  
Horizontal Well ◽  
Constant Pressure ◽  
Horizontal Wells ◽  
Minimum Time ◽  
Pressure Derivative ◽  
Dimensionless Pressure ◽  
Lateral Extent

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.

scholarly journals MODELING THE DYNAMICS OF PRESSURE AND TEMPERATURE IN THE RESERVOIR WITH HEAVY OIL WHEN HEATED

2017 ◽  
Vol 22 (1-2) ◽  
pp. 62-68
Author(s):  
V. Sh. Shagapov ◽  
Y. A. Yumagulova ◽  
A. A. Gizzatullina
Keyword(s):  
Mathematical Model ◽  
Heavy Oil ◽  
Horizontal Well ◽  
Oil Reservoir ◽  
System Of Equations ◽  
Thermal Waves ◽  
Reduced Viscosity ◽  
Symmetric Formulation ◽  
Heavy Oil Reservoir ◽  
Selection Of

In radially symmetric formulation is built and investigated mathematical model of the problem of heated heavy oil reservoir by horizontal well and the possibility of further operation of the well for the selection of oil with reduced viscosity. The resulting system of equations reveals the dynamics of the process, to evaluate the characteristics of the distance of penetration of filtration and thermal waves over the period.

The Fuzzy Evaluation Based on Entropy Method for Heavy Oil Reservoir Horizontal Well CO2 Huff and Puff Well Selection

2014 ◽  
Vol 607 ◽  
pp. 886-893
Author(s):  
Ya Hui Li ◽  
Cai Zhen Peng
Keyword(s):  
Heavy Oil ◽  
Horizontal Well ◽  
Comprehensive Evaluation ◽  
Horizontal Wells ◽  
Fuzzy Comprehensive Evaluation ◽  
Indicator System ◽  
Entropy Method ◽  
Specific Method ◽  
Oil Reservoir ◽  
Heavy Oil Reservoir

Due to its high viscosity, it is very difficult to develop heavy oil cost-effectively. Currently, CO2 huff and puff method is a better choice to develop heavy oil reservoir. The key to this method is to choose the suitable candidate target wells. However, it is now very difficult to judge the suitability of the horizontal target wells’ heavy oil reservoirs’ CO2 huff and puff. In according to such issue, this paper, based on the entropy weight method of fuzzy comprehensive evaluation, and used the established horizontal wells’ index in heavy oil reservoir CO2 huff and puff, evaluates the suitability of candidate wells comprehensively. Moreover, this paper presents a set of indicator system that suits the choice of horizontal wells with regard to its heavy oil reservoir CO2 huff and puff, and proposes a specific method and procedures to evaluate an individual candidate well. This project uses such method to calculate 19 horizontal wells in area G, and the evaluation results are consistent with the actual situations. Therefore, it proves that such proposed evaluation method and evaluation index system are feasible to a certain extent. Keyword:heavy oil reservoir;horizontal well;CO2 huff and puff;Well selection; entropy method;Fuzzy comprehensive evaluation。

A Finite-Conductivity Horizontal-Well Model for Pressure-Transient Analysis in Multiple-Fractured Horizontal Wells

SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1112-1122 ◽  
Author(s):  
Zhiming Chen ◽  
Xinwei Liao ◽  
Xiaoliang Zhao ◽  
Xiangji Dou ◽  
Langtao Zhu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Pressure Drop ◽  
Transient Analysis ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Model Verification ◽  
Finite Conductivity ◽  
Pressure Transient Analysis ◽  
Pressure Transient ◽  
Fractured Horizontal Wells

Summary In this paper, we propose a new model for pressure-transient analysis in multiple-fractured horizontal wells (MFHWs) with consideration of pressure drop along the wellbore. To make the physical model better understood, the whole formation is divided into three parts: (1) reservoir, (2) fracture, and (3) wellbore. With incorporating frictional and acceleration pressure drops, a mathematical model with a finite-conductivity horizontal well (FCHW) is developed. Newton-Raphson iterations are used to solve the mathematical model and obtain the transient-pressure solutions of the MFHW. Model verification is performed by comparing with the solutions from a numerical software. On the basis of the field cases from the Ordos Basin, performance prediction, sensitivity analysis, type-curve matching, and evaluations of uncertainty parameters are conducted. Results show that the contribution of wellbore hydraulics to the total pressure drop increases first and then decreases after reaching the peak value. Ignoring wellbore hydraulics would cause erroneous results during the well-performance forecast. In addition, the dimensionless wellbore pressure of the MFHW increases with an increase in Reynolds number (Re); it decreases as the reservoir/wellbore constant (ChD) increases. Furthermore, the impact of pressure drop on the pressure performance of the MFHW becomes more serious with the increasing Re or the decreasing ChD.

The Research for Delaying the Bottom Water Coning in Horizontal Wells Application Balance Screen Pipe

2013 ◽  
Vol 734-737 ◽  
pp. 1480-1483 ◽  
Author(s):  
Wu Yi Shan ◽  
Xue Zhang
Keyword(s):  
Pressure Distribution ◽  
Oil Recovery ◽  
Horizontal Well ◽  
Bottom Water ◽  
Horizontal Wells ◽  
Optimization Method ◽  
Well Water ◽  
Horizontal Section ◽  
Water Breakthrough ◽  
Water Coning

When horizontal wells are used to exploit reservoir with bottom water, oil wells water breakthrough prematurely due to water coning, water-free oil recovery is reduced. The reason of the formation of horizontal well water cone is analyzed. Then analysis of the mechanism using balanced screen pipe to inhibit bottom water coning in horizontal well is completed. According to the existing screen pipe size, screen configuration is optimized. Horizontal section pressure distribution is controlled by the balanced screen pipe, and then flow of horizontal well sections is adjusted. Bottom water coning speed of all well sections is controlled. An example is calculated by the software which established and the result shows that optimization method can improve water-free oil recovery.

Impact of Rheology Models on Horizontal Well Polymer Flooding in a Heavy Oil Reservoir on Alaska North Slope: A Simulation Study

2021 ◽  
Author(s):  
Jianqiao Leng ◽  
Mingzhen Wei ◽  
Baojun Bai ◽  
Randall S. Seright ◽  
Yin Zhang ◽  
...  
Keyword(s):  
Bulk Viscosity ◽  
Simulation Study ◽  
Heavy Oil ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Polymer Flooding ◽  
North Slope ◽  
Oil Reservoir ◽  
Polymer Rheology ◽  
Heavy Oil Reservoir

Abstract Polymer rheology can have either a positive or a negative effect on polymer flooding performance under varied circumstances. Many researchers have studied the effect of polymer rheology in a vertical well, but no field scale studies have been conducted to investigate whether polymer rheology is beneficial to polymer flooding in heavy oil reservoirs developed by horizontal wells. In this paper, we conducted a numerical simulation study to examine the effect of HPAM polymer rheology on a polymer flooding pilot, which is the first-ever project conducted on a heavy oil reservoir from Alaska North Slope (ANS) developed by horizontal wells. Three rheology types were considered in the study including the apparent viscosity measured during coreflooding of using a HPAM polymer, the bulk viscosity measured with a viscometer, and a Newtonian flow model. The results suggest that using the bulk viscosity in simulation underestimates the conformance control and the water-oil-ratio reduction capability of the HPAM polymer solution. When the apparent viscosity is used, the incremental oil and sweep were largely increased, and the optimal recovery period of polymer flooding was extended greatly, especially for the heterogeneous formations. Therefore, the rheology type of polymer plays a significant role in the incremental oil recovery and injection profile of the horizontal well system given the pilot testconditions. This study has provided practical guidance to field operators for the ongoing polymer flooding pilot on ANS and will also provide valuable information for other polymer projects conducted in similar conditions.

scholarly journals A Model for a Multistage Fractured Horizontal Well with Rectangular SRV in a Shale Gas Reservoir

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Jianfa Wu ◽  
Jian Zhang ◽  
Cheng Chang ◽  
Weiyang Xie ◽  
Tianpeng Wu
Keyword(s):  
Mathematical Model ◽  
Production Rate ◽  
Shale Gas ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Total Production ◽  
Gas Reservoirs ◽  
Shale Gas Reservoirs ◽  
Reservoir Permeability ◽  
Fractured Horizontal Well

Although great success has been achieved in the shale gas industry, accurate production dynamic analyses is still a challenging task. Long horizontal wells coupling with mass hydraulic fracturing has become a necessary technique to extract shale gas efficiently. In this paper, a comprehensive mathematical model of a multiple fractured horizontal well (MFHW) in a rectangular drainage area with a rectangular stimulated reservoir volume (SRV) has been established, based on the conceptual model of “tri-pores” in shale gas reservoirs. Dimensionless treatment and Laplace transformation were employed in the modeling process, while the boundary element method was used to solve the mathematical model. The Stehfest numerical inversion method and computer programing techniques were employed to obtain dimensionless type curves, production rate, and cumulative production. Results suggest that 9 flow stages can be observed from the pseudopressure derivative type curve when the reservoir and the SRV are large enough. The number of fractures, SRV permeability, and reservoir permeability have no effect on the total production when the well is abandoned. As SRV and reservoir permeability increases, the production rate is much higher in the middle production stage. Although the SRV scale and its permeability are very important for early and intermediate production rates, the key factors restricting the shale gas production rate are the properties of the shale itself, such as adsorbed gas content, natural fractures, and organic content. The proposed model is useful for analyzing production dynamics with stimulated horizontal wells in shale gas reservoirs.

The Numerical Analysis of the Velocity and Pressure Distribution of the Oil Film in Heavy Hydrostatic Thrust Bearing

2014 ◽  
Vol 541-542 ◽  
pp. 658-662
Author(s):  
Jian Li ◽  
Yuan Chen ◽  
Yang Chun Yu ◽  
Zhu Xin Tian ◽  
Yu Huang
Keyword(s):  
Mathematical Model ◽  
Numerical Analysis ◽  
Pressure Distribution ◽  
Working Conditions ◽  
Thrust Bearing ◽  
Rotation Speed ◽  
The Other ◽  
Surface Load ◽  
Oil Film ◽  
Volume Method

To study the velocity and pressure distribution of the oil film in a heavy hydrostatic thrust bearing, a mathematical model of the velocity is proposed and the finite volume method (FVM) has been used to simulate the flow field under different working conditions. Some pressure experiments were carried out and the results verified the correctness of the simulation. It is concluded that the pressure distribution varies small under different rotation speed when the surface load on the workbench is constant. But the velocity of the oil film is influenced greatly by the rotation speed. When the rotation speed of the workbench is as quick as enough, the velocity of the oil film on one radial side of the pad will be zero, that is to say the lubrication oil will be drained from the other three sides of the recess.

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