High-energy gas-fracturing development. Quarterly report, October-December 1982

Technical Report · Tue Feb 01 04:00:00 EST 1983

DOI:https://doi.org/10.2172/6496069· OSTI ID:6496069

Cuderman, J F

The purpose of this study is to develop and optimize the High Energy Gas Fracturing (HEGF) technique to produce multiple fractures around a wellbore in order to stimulate natural-gas production in Devonian shale. The HEGF technique uses a wellbore charge of a propellant tailored to produce pressure loading in the borehole that avoids crushing yet produces multiple fractures radiating from the wellbore. The multiple-fracture regime has been characterized and releated to parameters such as borehole size, pressure risetime, and surface-wave velocity. Pressure risetimes and peak pressures, measured for different propellants in boreholes to specify a propellant for a desired peak pressure and pressure risetime. Semiempirical models, using results from previous experiments, successfully relate stress, acceleration, and fracture radii in surrounding rock to peak pressure and pressure risetime. A finite-element model also has been developed which predicts fracture type and direction of fractures as a function of pressure loading, in situ stress, and material properties. A full-scale HEGF system has been developed for application in gas-well-stimulation experiments in Devonian shale. During this quarter, a proof test of the full-scale HEGF was conducted at the Nevada Test Site (NTS). The designed pressure pulse of 0.5 ms risetime was achieved, and the tamp remained in place during the test. The borehole was successfully cleared posttest. Multiple fracturing was verified with a downhole TV camera. The test of the full-scale hardware and its operational capability was successful. As a result, the HEGF system is ready for application in gas-well-stimulation experiments in Devonian shale. Tests were conducted to determine worst-case accident scenarios to establish sensitivity to shock and fire. There appears to be no risk of initiation resulting from shock or breakage of the propellant-canister segments.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6496069
• Report Number(s): SAND-83-0082; ON: DE83009387
• Country of Publication: United States
• Language: English

Related Subjects

03 NATURAL GAS
030900* -- Natural Gas-- Artificial Stimulation
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BITUMINOUS MATERIALS
BLACK SHALES
CARBONACEOUS MATERIALS
CHATTANOOGA FORMATION
COMMINUTION
ENERGY SOURCES
EXPLOSIVE FRACTURING
FIELD TESTS
FOSSIL FUELS
FRACTURING
FUELS
GEOLOGIC FORMATIONS
MATERIALS
MATHEMATICAL MODELS
NATIONAL ORGANIZATIONS
NATURAL GAS WELLS
NEVADA TEST SITE
OIL SHALES
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US DOE
US ORGANIZATIONS
WELL STIMULATION
WELLS