HR: 15:25h
AN: H13G-08    [Abstracts]
TI: Relationship between horizontal flow measurements in wells and flow in the surrounding formation
AU: Beauheim, R L
EM: rlbeauh@sandia.gov
AF: Sandia National Laboratories, Carlsbad Programs 4100 National Parks Highway, Carlsbad, NM 88220 United States
AU: * James, S C
EM: scjames@sandia.gov
AF: Sandia National Laboratories, Geohydrology Department P.O. Box 5800, Albuquerque, NM 87185-0735 United States
AU: Pedler, W H
EM: PedlerRAS@aol.com
AF: RAS Inc., 311 Rock Ave., Golden, CO 80401 United States
AB: Two computational models are developed to estimate and visualize the flow field through a wellbore to evaluate the utility and accuracy of a scanning colloidal borescope flowmeter (SCBFM). The SCBFM images colloidal particles traveling through a well, and measures the direction and velocity of movement. The first model calculates the flow that would arise in a fractured medium where the majority of flow is through a single fracture into an unscreened well. For comparison to this model, an SCBFM was deployed in a sand tank flow simulator to measure the flow field within a PVC well screen having a single slot (representing a fracture) aligned with the flow direction. In this case, the SCBFM and model agree with respect to the flow direction and to within a factor of three for the velocity near the center of the well. For a well drilled in a fractured rock medium with no casing and with proper calibration, the SCBFM could be used to identify and quantify flowing features. The second model numerically estimates the flow field within a multi-slot well screen in an attempt to evaluate the potential usefulness of employing the SCBFM in a screened well to estimate flow speed and direction in the surrounding porous medium. Results indicate that when the slots are aligned with the principal flow direction, the SCBFM can be used to infer the local ground-water flow speed and direction. However, if the slots are not aligned with the flow (a situation difficult to evaluate a priori), the SCBFM can only provide order of magnitude velocity measurements and direction measurements with an uncertainty of approximately ñ25ø. Controlled laboratory experiments and detailed modeling are strongly recommended to calibrate any device intended to measure flow within a well. {\st Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.}
DE: 1829 Groundwater hydrology
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting