Title: Tests Confirm Operational Status of a
Large-Slot Flow Apparatus for Characterization Fracturing
Fluids
Author(s): S.N. Shah, The University of Oklahoma and
D.L. Lord, Halliburton Energy Services
Presentation: SPE Production Operations Symposium
Location: Oklahoma City, Oklahoma USA
Date: April 2-4, 1995
Abstract: A large-slot flow apparatus for
investigating hydraulic fracturing fluid flow and proppant
transport phenomena has been jointly developed by the Gas
Research Institute (GRI), the Department of Energy (DOE),
and the University of Oklahoma. A series of tests were
performed to confirm the operational readiness of this
apparatus to perform that many functions for which it was
designed. This paper describes results obtained form the
verification tests, particularly in terms of the proper
functioning of instrumentation and control systems under a
wide range of operating conditions. Tests performed were:
flow of crosslinked gels, high-temperature (200 and 225)
flow tests, high-pressure (1,000 psi) flow tests to confirm
proper operation of unique throttling valve, effect of
pressure on perforation pressure loss, and dynamic
fluid-loss tests with permeable facing at 1,000 psi.
Verification tests listed above were performed and the
large-scale, high-pressure, fracture-flow simulator was
found to be fully functional in nearly every respect.
Functionality was established by comparing flow data form
the simulator to conventional viscometric results whenever
possible. Some surprises, in terms of both flow cell
response and fluid behavior, were found during the course of
verification testing. For example, there was the discovery
that crosslinked gels exhibit a slip-like flow phenomenon in
the simulator. This latter phenomenon was discovered while
using the variable width capability of the apparatus. A
methodology was developed which allow collection of
meaningful flow data in the presence of this slip-like
phenomenon. An additional surprise was the discoveries that
there was no effect of elevated pressure on the perforation
pressure loss, as some industry critics have suggested.