Date of Graduation

2014

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Civil and Environmental Engineering

Committee Chair

Hema J Siriwardane

Committee Co-Chair

Raj K Gondle

Committee Member

John D Quaranta

Abstract

In this report, the vertical extent of hydraulic fractures in a layered geological formation was investigated. In reality, the geology of the earth is heterogeneous, and therefore fracture growth will be significantly different. Fracture growth was simulated by using numerical models with relevant geomechanical, fluid flow and proppant transport properties. Results show the horizontal stress gradient plays an important role in fracture propagation. Lower horizontal stress contrasts between layers allow for greater fracture propagation in the vertical direction. Higher fluid viscosities tend to increase the fracture height and width, while decreasing the fracture length. Several other geomechanical properties such as the elastic modulus, fracture toughness, and leakoff coefficient have some influence on the vertical fracture growth. To account for the variability of properties, 300 realizations were considered by using a statistical sampling method. Most of the simulated fractures (about 50%) extended into the immediate overburden layers. Results from these cases show that the clearance depth was in the range from about 4300 feet to 7500 feet.

Download

Share

COinS