Algorithm for selecting systems horizontal wells and mathematical models for unconventional reservoirs

2020 ◽  
Vol 20 (6) ◽  
pp. 1-8
Author(s):  
D. G. Yarakhanova ◽  
M. E. Hossain
Keyword(s):  
Mathematical Models ◽  
Horizontal Wells ◽  
Unconventional Reservoirs

History Matching and Rate Forecasting in Unconventional Oil Reservoirs With an Approximate Analytical Solution to the Double-Porosity Model

2015 ◽  
Vol 19 (01) ◽  
pp. 070-082 ◽  
Author(s):  
B. A. Ogunyomi ◽  
T. W. Patzek ◽  
L. W. Lake ◽  
C. S. Kabir
Keyword(s):  
Analytical Solution ◽  
History Matching ◽  
Horizontal Wells ◽  
Double Porosity ◽  
Unconventional Reservoirs ◽  
Production Data ◽  
Time Space ◽  
Double Porosity Model ◽  
Fractured Horizontal Wells ◽  
Porosity Model

Summary Production data from most fractured horizontal wells in gas and liquid-rich unconventional reservoirs plot as straight lines with a one-half slope on a log-log plot of rate vs. time. This production signature (half-slope) is identical to that expected from a 1D linear flow from reservoir matrix to the fracture face, when production occurs at constant bottomhole pressure. In addition, microseismic data obtained around these fractured wells suggest that an area of enhanced permeability is developed around the horizontal well, and outside this region is an undisturbed part of the reservoir with low permeability. On the basis of these observations, geoscientists have, in general, adopted the conceptual double-porosity model in modeling production from fractured horizontal wells in unconventional reservoirs. The analytical solution to this mathematical model exists in Laplace space, but it cannot be inverted back to real-time space without use of a numerical inversion algorithm. We present a new approximate analytical solution to the double-porosity model in real-time space and its use in modeling and forecasting production from unconventional oil reservoirs. The first step in developing the approximate solution was to convert the systems of partial-differential equations (PDEs) for the double-porosity model into a system of ordinary-differential equations (ODEs). After which, we developed a function that gives the relationship between the average pressures in the high- and the low-permeability regions. With this relationship, the system of ODEs was solved and used to obtain a rate/time function that one can use to predict oil production from unconventional reservoirs. The approximate solution was validated with numerical reservoir simulation. We then performed a sensitivity analysis on the model parameters to understand how the model behaves. After the model was validated and tested, we applied it to field-production data by partially history matching and forecasting the expected ultimate recovery (EUR). The rate/time function fits production data and also yields realistic estimates of ultimate oil recovery. We also investigated the existence of any correlation between the model-derived parameters and available reservoir and well-completion parameters.

An Integrated Approach to Design Completions for Horizontal Wells for Unconventional Reservoirs

2011 ◽  
Author(s):  
Rachna Jain ◽  
Shivani Syal ◽  
Ted Alan Long ◽  
Chick Chick Wattenbarger ◽  
Ivan Kosik
Keyword(s):  
Horizontal Wells ◽  
Integrated Approach ◽  
Unconventional Reservoirs

Use of FDI Data for Comprehensive Evaluation of Horizontal Well Frac Treatments

2021 ◽  
Author(s):  
Ali Daneshy
Keyword(s):  
Comprehensive Evaluation ◽  
Continuous Process ◽  
Horizontal Wells ◽  
Cost Effective ◽  
Unconventional Reservoirs ◽  
Continuous Process Improvement ◽  
Effective Evaluation ◽  
Measurement And Analysis ◽  
Total Process

Abstract Effective fracturing of horizontal wells is the key to successfully producing unconventional reservoirs. Correct evaluation of existing created fractures is essential for identification of key treatment variables in the target reservoir and continuous process improvement of the total process. Measurement and analysis of Frac-driven Interactions (FDI) has become a popular technique for rapid and cost-effective evaluation of existing and new fractures created in horizontal wells for production of unconventional reservoirs. Specific parameters used for their evaluation include detection of the start and end time of FDI during each frac stage, its magnitude, and duration. Another important parameter is observing smoothness of FDI variations with time. The paper offers specific recommendations for additional measurement and computational steps that can be used for determination of the volume and rate of fluid migration causing the observed FDI.

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