Analysis of well test data---Application of probabilistic models to infer hydraulic properties of fractures. [Contains list of standardized terminology or nomenclatue used in statistical models]

Technical Report · Fri Sep 27 00:00:00 EDT 1991

DOI:https://doi.org/10.2172/5178741· OSTI ID:5178741

Osnes, J D ^[1]; Winberg, A; Andersson, J E; Larsson, N A ^[2]

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1. RE/SPEC, Inc., Rapid City, SD (United States)
2. Sveriges Geologiska AB, Goeteborg (Sweden)

Statistical and probabilistic methods for estimating the probability that a fracture is nonconductive (or equivalently, the conductive-fracture frequency) and the distribution of the transmissivities of conductive fractures from transmissivity measurements made in single-hole injection (well) tests were developed. These methods were applied to a database consisting of over 1,000 measurements made in nearly 25 km of borehole at five sites in Sweden. The depths of the measurements ranged from near the surface to over 600-m deep, and packer spacings of 20- and 25-m were used. A probabilistic model that describes the distribution of a series of transmissivity measurements was derived. When the parameters of this model were estimated using maximum likelihood estimators, the resulting estimated distributions generally fit the cumulative histograms of the transmissivity measurements very well. Further, estimates of the mean transmissivity of conductive fractures based on the maximum likelihood estimates of the model's parameters were reasonable, both in magnitude and in trend, with respect to depth. The estimates of the conductive fracture probability were generated in the range of 0.5--5.0 percent, with the higher values at shallow depths and with increasingly smaller values as depth increased. An estimation procedure based on the probabilistic model and the maximum likelihood estimators of its parameters was recommended. Some guidelines regarding the design of injection test programs were drawn from the recommended estimation procedure and the parameter estimates based on the Swedish data. 24 refs., 12 figs., 14 tabs.

• Research Organization: RE/SPEC, Inc., Rapid City, SD (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC02-89CH10378
• OSTI ID: 5178741
• Report Number(s): DOE/CH/10378-9; RSI-0338; ON: DE92000030
• Country of Publication: United States
• Language: English

Related Subjects

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
58 GEOSCIENCES
HYDRAULIC CONDUCTIVITY
PROBABILISTIC ESTIMATION
HYDRAULIC FRACTURES
STATISTICAL MODELS
INJECTION WELLS
TRANSMISSION
BOREHOLES
COMPILED DATA
DATA ANALYSIS
EVALUATED DATA
FLUID MECHANICS
FORECASTING
FRACTURE PROPERTIES
GEOLOGIC FAULTS
GNEISSES
GROUND WATER
MATHEMATICAL MODELS
RADIOACTIVE WASTE DISPOSAL
RADIONUCLIDE MIGRATION
SWEDEN
TESTING
THEORETICAL DATA
CAVITIES
DATA
DEVELOPED COUNTRIES
ENVIRONMENTAL TRANSPORT
EUROPE
FAILURES
FRACTURES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
HYDROGEN COMPOUNDS
INFORMATION
MANAGEMENT
MASS TRANSFER
MECHANICAL PROPERTIES
MECHANICS
METAMORPHIC ROCKS
NUMERICAL DATA
OXYGEN COMPOUNDS
RADIOACTIVE WASTE MANAGEMENT
ROCKS
SCANDINAVIA
WASTE DISPOSAL
WASTE MANAGEMENT
WATER
WELLS
052002* - Nuclear Fuels- Waste Disposal & Storage
053000 - Nuclear Fuels- Environmental Aspects
540230 - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- (1990-)
990200 - Mathematics & Computers
580000 - Geosciences