0
Research Papers: Alternative Energy Sources

Analysis of Hydraulic Fracturing and Reservoir Performance in Enhanced Geothermal Systems

[+] Author and Article Information
Mengying Li

Department of Mechanical Engineering
and Applied Mechanics,
University of Pennsylvania,
Philadelphia, PA 19104-6315

Noam Lior

Department of Mechanical Engineering
and Applied Mechanics,
University of Pennsylvania,
Philadelphia, PA 19104-6315
e-mail: lior@seas.upenn.edu

1Corresponding author.

Contributed by the Advanced Energy Systems Division of ASME for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received February 9, 2015; final manuscript received February 25, 2015; published online April 22, 2015. Editor: Hameed Metghalchi.

J. Energy Resour. Technol 137(4), 041203 (Jul 01, 2015) (14 pages) Paper No: JERT-15-1055; doi: 10.1115/1.4030111 History: Received February 09, 2015; Revised February 25, 2015; Online April 22, 2015

Analyses of fracturing and thermal performance of fractured reservoirs in engineered geothermal system (EGS) are extended from a depth of 5 km to 10 km, and models for flow and heat transfer in EGS are improved. Effects of the geofluid flow direction choice, distance between fractures, fracture width, permeability, radius, and number of fractures, on reservoir heat drawdown time are computed. The number of fractures and fracture radius for desired reservoir thermal drawdown rates are recommended. A simplified model for reservoir hydraulic fracturing energy consumption is developed, indicating it to be 51.8–99.6 MJ per m3 fracture for depths of 5–10 km.

FIGURES IN THIS ARTICLE
<>
Copyright © 2015 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Fig. 1

Ellipse of stress for underground rock, SL is the vertical compressive stress, SH is the horizontal compressive stress, and Z¯r is the depth of point A

Grahic Jump Location
Fig. 2

Vertical propagation of fractures: (a) linearly propagating rectangular shape fracture and (b) radially propagating cylindrical shape fracture (modified from Ref. [9])

Grahic Jump Location
Fig. 3

Schematic representation of radially propagating fracture with laminar fluid flow (modified from Ref. [15]). R is the radius of fracture, w is the fracture width, riw is the radius of injection wellbore, and Vr is the fracturing fluid velocity.

Grahic Jump Location
Fig. 4

Fracture radius R (a) and average width w¯ (b) with respect to treatment time thf, and (c) fracturing energy consumption Whf with respect to fracture volume Vhf at flow rates q·hf = 0.05 m3/s, 0.1 m3/s, and 0.15 m3/s, for reservoirs with depths Z¯r = 5 km, 7.5 km, and 10 km

Grahic Jump Location
Fig. 5

Scheme of flow in the modeled EGS reservoir with parallel radial fractures. The cross-sectional sketch on the right shows computed typical velocity vectors inside a fracture (modified from Ref. [22]).

Grahic Jump Location
Fig. 6

The mesh scheme of model domain and coordinates used in the numerical simulation

Grahic Jump Location
Fig. 7

(a), (c), and (e): The rock dimensionless temperature T˜r field; Dimensionally, T˜r = 0 corresponds to Tr = 70 °C and T˜r = 1 to 465 °C. (b), (d), (f): The rock relative dynamic pressure field P∧d (GPa), The arrows in (d) and (f) show the fluid dimensionless velocity vectors. V˜ = 1 (at the geofluid inlet) corresponds to a dimensional velocity value of V = 5.37 cm/s, and V˜ = 0 to V = 0 cm/s. (a) and (b): At start of operation, (c) and (d): after 40 years of operation, Case SC0. (e) and (f): after 40 years of operation, Case SC1.

Grahic Jump Location
Fig. 8

Geofluid dimensionless outlet temperature T˜out as a function of operation time: case SC0 and SC1 (a), case SC2 (b), case SC3 (c), case SC4 (d), case SC5 (e), and case SC6 (f)

Grahic Jump Location
Fig. 9

Geofluid dynamic pressure drop in reservoir ΔPd (GPa) as a function of operation time: case SC0 and SC1 (a), case SC2 (b), case SC3 (c), case SC4 (d), case SC5 (e), and case SC6 (f)

Grahic Jump Location
Fig. 10

Minimal number of fractures (for 10% drawdown in 40 yr) as a function of fracture radius R; Fs = 60 m, w¯ = 2 mm, kf = 10 −13 m2, flow upward

Grahic Jump Location
Fig. 11

The relation of fracturing energy cost Wrsv with respect to fracture radius R; F = 60 m, Nf = Nf,minw¯ = 2 mm, kf = 10−13 m2, flow upward

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In