Richard L. Beauheim

Well testing in fractured media: flow dimensions and diagnostic plots

Hydraulic tests in heterogeneous media, particularly fractured media, are difficult to analyze because of the absence of radial flow. The theory of flow dimensions introduced by Barker in 1988 (Water Resour. Res. 24(10). 1988. 1796) provided a method of analyzing pumping (constant-rate) tests in non-radial systems, and this approach was later extended to constant-pressure tests. However, little use seems to be made of the flow-dimension approach to well-test analysis, perhaps because no easily applied method has been presented for determining, at the initial stage of an analysis, if such an approach would be productive. Depending on the distribution of heterogeneities within an aquifer, flow to a well may have almost any dimension (not limited to linear, radial, or spherical), or no constant dimension at all. Any well-test analytical solution requires that hydraulic properties be stable on some scale before those properties can be uniquely quantified. For each type of hydraulic test (constant-rate, constant-pressure, or slug/pulse), we suggest that a diagnostic plot of the scaled first or second derivative of the pressure or flow-rate response be created to determine, first, if a stable flow dimension was reached during the test and. second, what the value of that flow dimension is. If a stable flow dimension was reached, the scaled derivative will exhibit a constant value (scaled to be equal to the flow dimension). If the scaled derivative does not stabilize at a constant value, then no flow dimension can be specilied and no unique hydraulic properties can be inferred analytically from the test. In all cases, the scale of testing must be appropriate to the scale of underlying interest.

Hydraulic testing of Salado Formation evaporites at the Waste Isolation Pilot Plant site: Second interpretive report

Pressure-pulse, constant-pressure flow, and pressure-buildup tests have been performed in bedded evaporites of the Salado Formation at the Waste Isolation Pilot Plant (WIPP) site to evaluate the hydraulic properties controlling brine flow through the Salado. Transmissivities have been interpreted from six sequences of tests conducted on five stratigraphic intervals within 15 m of the WIPP underground excavations.

Predicting fractured zones in the culebra dolomite.

Fracturing in the Culebra Dolomite Member of the Permian Rustler Formation exhibits a high degree of spatial variability in the vicinity of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP is the U.S. Department of Energys deep geological repository for transuranic and mixed wastes resulting from the nations defense programs. The WIPP repository is located 655 m below ground surface in bedded halite of the Permian Salado Formation, which underlies the Rustler and Culebra. Culebra transmissivities (Ts) in the vicinity of the WIPP vary over six orders of magnitude, with higher Ts (log 10 T (m 2 /s) > -5,4) reflecting zones of well-interconnected fractures. We develop, test, and refine a conceptual model for predicting fracture zones within the Culebra. We define three regional-scale controls on Culebra fracturing, including the dissolution of salt from below the Culebra, the presence of halite above and below the Culebra, and overburden thickness. We also identify two local-scale controls on Culebra fracture zones including fracture-filling cements and localized deformation due to ductile flow of the mudstone that underlies the Culebra. The spatial distribution of the regional-scale controls is easily predicted. However, the influence of local controls can only be uniquely identified in hydraulic test data. A drilling program initiated in 2003 tests aspects of this conceptual model and leads to minor revisions of our conceptual understanding of the geologic controls on fracturing in the Culebra.

Hydraulic Testing of Salado Formation Evaporites at the Waste Isolation Pilot Plant Site: Final Report

This report presents interpretations of hydraulic tests conducted in bedded evaporates of the Salado Formation from May 1992 through May 1995 at the Waste Isolation Pilot Plant (WIPP) site in southeastern New Mexico. The WIPP is a US Department of Energy research and development facility designed to demonstrate safe disposal of transuranic wastes from the nations defense programs. The WIPP disposal horizon is located in the lower portion of the Permian Salado Formation. The hydraulic tests discussed in this report were performed in the WIPP underground facility by INTERA inc. (now Duke Engineering and Services, Inc.), Austin, Texas, following the Field Operations Plan and Addendum prepared by Saulnier (1988, 1991 ) under the technical direction of Sandia National Laboratories, Albuquerque, New Mexico.