Title: The Use of Laser Doppler Velocimetry (LDV)
for the Measurement of Fracturing Fluid Flow in the FFCF
Simulator
Author(s): R.B. Mears, J.J. Sluss, Jr., J.E. Fagan,
The University of Oklahoma and R.K. Menon, TSI Inc.
Presentation: SPE Annual Technical Conference and
Exhibition
Location: Houston, Texas USA
Date: October 3-6, 1993
Abstract: Laser Doppler Velocimetry (LDV) is an
optical pint velocity measuring technique that has
revolutionized velocity measurements in hostile flow
environments. The high pressures and high temperatures
encountered in hydraulic fracturing simulations at the
Fracturing Fluid Characterization Facility (FFCF), coupled
with the abrasive character of the proppant laden fracturing
gels proposed for study, makes LDV the preferred technique
for this application. This paper describes a unique nine
probe LDV system that is applied to fluid flows in FFCF
simulator. The LDV system consists of nine specially
designed laser probes, three power supplies, a unique signal
processor/muliplexer, and a personal computer for system
control and data display. In addition, three automated
precision traversing stages are coupled to three of the
laser probes for velocity profile studies. This system has
been applied to both Newtonian and non-Newtonian fluids in
the simulator at several crack widths and flow rates. Some
point velocity data, along with extensive velocity profile
data, is presented and discussed for several fluids. The
fracturing fluid studies presented are for flows without
proppant. The velocity profiles are compared to theoretical
models that are applied with volumetric flow rates measured
by an independent flowmeter. The results show that LDV is a
valuable tool for gathering point velocity information from
fracturing fluid flows in the FFCF simulator.