Fracture Optimization of an Unconventional Gas Resource in Southern Chile


The Magallanes Basin of Southern Chile is the southern-most hydrocarbon-producing basin in the world. The main source of the gas production in this basin is from the Glauconite Formation. The Glauconite is a clay and feldspar rich formation with extremely low permeability requiring hydraulic fracturing to recover the hydrocarbons and enhance well performance. In this project, fracture simulations with a fully three-dimensional finite element model were integrated with statistical analysis and used in an optimization study of hydraulic fracturing in the Glauconite Formation. The mechanical earth model was used to estimate the in-situ stress contrast, Young's Modulus, and leak-off profile with depth. Tri-axial compression tests of core were used to validate static Young's Modulus estimates while mini-frac data and fracture stimulation data were history matched and used to validate and/or modify in-situ stress and leak-off profiles with depth. The history matched treatments were then used to populate the database with the resulting hydraulic and propped fracture dimensions. Ultimately, a database that includes in-situ stress, stress contrast, Young's Modulus, leak-off, propped and un-propped fracture dimensions (length and conductivity) was developed. Finally, both the database and multi-variate statistical analysis were used to show the role of mechanical earth modeling in enhancing and improving the understanding of fracture optimization in the Glauconite Formation. Results from hybrid fracture fluid treatments were compared to treated water fracture treatments to determine the optimum fracture stimulation design for this unconventional extremely tight gas resource. This work provides a benefit to the petroleum industry by: 1. Using a geo-mechanical finite element model to improve the understanding of the propped fracture dimensions achieved by hybrid and treated water fracture treatments in an unconventional resource like the Glauconite Formation. 2. Establish the key drivers for successful water-frac treatments.

Meeting Name

SPE International Hydraulic Fracturing Technology Conference and Exhibition 2018, IHFT 2018 (Oct. 16-18, Muscat, Oman)


Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Compression testing; Database systems; Elastic moduli; Energy resources; Feldspar; Finite element method; Gasoline; Hydraulic fracturing; Hydrocarbons; Mica; Oil wells; Petroleum deposits; Petroleum industry; Resource valuation; Statistical methods; Stresses; Tight gas; Water treatment, Fracture simulations; Fracture stimulation; Mechanical earth models; Mechanical finite element modeling; Optimization studies; Three dimensional finite element model; Tri-axial compression tests; Unconventional resources, Fracture

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Document Type

Article - Conference proceedings

Document Version


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© 2018 Society of Petroleum Engineers (SPE), All rights reserved.

Publication Date

01 Oct 2018

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