Butler Slug Test Solution for Confined Aquifers

Slug test configuration for a partially penetrating well in a confined aquifer

James J. Butler, Jr.A mathematical solution by Butler (1998) is useful for determining the hydraulic conductivity of confined aquifers. The solution accounts for inertial effects in the well and oscillatory slug test response in high-hydraulic conductivity (high-K) aquifers. Analysis involves matching a type curve to water-level displacement data collected during an underdamped slug test. The Butler (1998) solution also incorporates frictional well loss in small-diameter wells (Butler 2002).

AQTESOLV provides visual and automatic methods for matching the Butler solution to slug test data. This easy-to-use and intuitive software promotes rapid and accurate determination of aquifer properties.

Assumptions

The following assumptions apply to the use of the Butler slug test solution:

  • aquifer has infinite areal extent
  • aquifer is homogeneous and of uniform thickness
  • aquifer potentiometric surface is initially horizontal
  • control well is fully or partially penetrating
  • a volume of water, V, is injected or discharged instantaneously from the control well
  • aquifer is nonleaky confined
  • flow is steady

Solution
Options

provides the following options for the Butler method for underdamped slug tests:

  • partially penetrating wells
  • correction for gravel pack porosity
  • correction for frictional well loss
  • hydraulic conductivity anisotropy

Benchmark

Benchmark for a underdamped slug test
AQTESOLV benchmark for Butler (1998) solution matched to an underdamped slug test in a confined aquifer. Butler (2002) reported K=88.2 m/day for these data.

References

Butler, J.J., Jr., 1998. The Design, Performance, and Analysis of Slug Tests, Lewis Publishers, New York, 252p. [errata]