國立虎尾科技大學 |

An extended finite element method based modeling of hydraulic fracturing.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	An extended finite element method based modeling of hydraulic fracturing./
Author:	Khodabakhshnejad, Arman.
Description:	1 online resource (189 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.
Contained By:	Dissertation Abstracts International78-04B(E).
Subject:	Petroleum engineering. -
Online resource:	click for full text (PQDT)
ISBN:	9781369150698

An extended finite element method based modeling of hydraulic fracturing.
Khodabakhshnejad, Arman.

An extended finite element method based modeling of hydraulic fracturing. - 1 online resource (189 pages)

Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.

Thesis (Ph.D.)

Includes bibliographical references

Maximizing hydrocarbon production from unconventional reservoirs requires the implementation of best practices in order to create a connected network of hydraulic and natural fractures. The desired result will be achieved if the operational hydraulic fracturing parameters are optimized. Determining the appropriate number of fracturing stages needed for peak performance demands a well calibrated model. Such a model allows for a more accurate prediction of fracture distribution. To this end, the industry currently employs several forward simulation tools. However, owing to the complexity of this problem, and the simplified assumptions made, existing methods often provide a poor representation of reality, leading to inaccurate predictions. To address these challenges, this work presents a novel, coupled approach to model hydraulically fractured subsurface cracks, providing a dynamic evolution of the subsurface fracture network.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369150698Subjects--Topical Terms:

896906
Petroleum engineering.
Index Terms--Genre/Form:

554714
Electronic books.

An extended finite element method based modeling of hydraulic fracturing.
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100 1 $a Khodabakhshnejad, Arman. $3 1180279
245 1 3 $a An extended finite element method based modeling of hydraulic fracturing.
264 0 $c 2016
300 $a 1 online resource (189 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertation Abstracts International, Volume: 78-04(E), Section: B.
500 $a Adviser: Fred Aminzadeh.
502 $a Thesis (Ph.D.) $c University of Southern California $d 2016.
504 $a Includes bibliographical references
520 $a Maximizing hydrocarbon production from unconventional reservoirs requires the implementation of best practices in order to create a connected network of hydraulic and natural fractures. The desired result will be achieved if the operational hydraulic fracturing parameters are optimized. Determining the appropriate number of fracturing stages needed for peak performance demands a well calibrated model. Such a model allows for a more accurate prediction of fracture distribution. To this end, the industry currently employs several forward simulation tools. However, owing to the complexity of this problem, and the simplified assumptions made, existing methods often provide a poor representation of reality, leading to inaccurate predictions. To address these challenges, this work presents a novel, coupled approach to model hydraulically fractured subsurface cracks, providing a dynamic evolution of the subsurface fracture network.
520 $a In this study, I introduce a new algorithm to model the initiation and propagation of hydraulic fracturing. It integrates rock deformation and fluid flow using a coupling approach. The algorithm enables us to accurately simulate fluid pressure inside the fracture and rock matrix and to calculate the in situ stress distribution within the reservoir.
520 $a An in-house fluid flow simulator is developed based on a modified diffusivity equation that takes the effect of fracture width changes into account. I calculate fluid pressure using Finite Difference Method (FDM), and export it to the geo-mechanical simulator as a load. To calculate the resulting stress distribution inside the model and to predict fracture initiation and propagation, I apply the Extended Finite Element Method (XFEM). The workflow involves integrating the fluid flow and rock deformation equations; the problem is solved by an iterative implicit scheme. I validate the performance of the algorithm, applying it to both a 2D laboratory scale and 3D field scale modeled fracturing data.
520 $a The effect of numerical parameters on the fracture behavior in 2D modeling was examined; the algorithm was used to investigate stress shadowing and the interaction between stimulated and natural fractures. To increase the computation speed of the simulation, I apply uniform pressure distribution to the entire fracture network. The algorithm later is used for performing sensitivity analyses on a set of numerical parameters. Mesh resolution, plane stress and plane strain condition, model size, and boundary condition are analyzed for a single fracture model. It became clear that the aforementioned factors significantly impact the model response to the applied stresses. I conduct sensitivity analysis for the resulting stress shadow as a function of the distance between the fractures. In addition, the interaction between a hydraulic fracture and a natural fracture was evaluated. The modeling results suggest that the hydraulic fracture can activate natural fractures both remotely or after their intersection.
520 $a I also test the algorithm to assess its capabilities in predicting the hydraulic fracturing parameters in a three dimensional model. The Griffith-Sneddon analytical solution of penny-shaped fracture was used to investigate the accuracy of the model. I show that the algorithm can accurately predict fracture width as well as fracture volume. Furthermore, the modeling results of hydraulic fracturing propagation compare to the Geertsma-de Klerk analytical solution. The results show some discrepancy between analytical and numerical solutions. Mesh size is the major factor that can control the deviation of the numerical model results from those derived from the analytical models.
520 $a In field size reservoir modeling of a fracture, the algorithm reveals the mechanisms that could not be modeled through conventional modeling of hydraulic fracturing. For example, the approach accurately models pressure disturbance in the reservoir during fracturing.
520 $a Reservoir pressure modeling suggests that pressure builds up at the central elements of the fracture, and consequently a high leak-off rate is expected. In contrast, pressure in the reservoir and near the crack tip drops due to the creation of a suction zone ahead of fluid front and behind the crack tip. Unlike conventional approaches, the results of this work demonstrate that my algorithm successfully models hydraulic fracturing propagation in a 3D reservoir. Additionally, my new approach is capable of modeling the interaction between hydraulic and natural fractures in order to generate more reliable predictions.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Petroleum engineering. $3 896906
650 4 $a Mechanical engineering. $3 557493
650 4 $a Civil engineering. $3 561339
655 7 $a Electronic books. $2 local $3 554714
690 $a 0765
690 $a 0548
690 $a 0543
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a University of Southern California. $b Petroleum Engineering. $3 1180280
773 0 $t Dissertation Abstracts International $g 78-04B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10160151 $z click for full text (PQDT)