Title: Functional Capabilities of the High
Pressure Simulator for Fracturing Fluid
Characterization.
Author: The University of Oklahoma
Sponsor: Gas Research Institute (GRI) and US
Department of Energy (DOE)
Report Period: January -- December 1994 Topical
Report
Objective: To summarize the functional capabilities
of the High Pressure Simulator at the Fracturing Fluid
Characterization Facility at The University of Oklahoma.
Technical Perspective: The knowledge of
fracturing fluid rheology under simulated reservoir
conditions of temperature and pressure is crucial to the
hydraulic fracturing process. The simulator was created to
study the behavior and effects of fracturing fluids and
slurries during and after a hydraulic fracturing treatment.
The FFCF simulates, to the maximum degree practical, all
conditions experienced by a fracturing fluid, from its
formulation on the surface, to its degradation while flowing
down the wellbore and through the perforations, its
injection into the fracture, and its leakage into the rock
matrix.
Results: This report describes in detail the
functional capabilities of the High Pressure Simulator (HPS)
at The University of Oklahoma for the characterization of
fracturing fluids. This document also presents the
investigations that can be conducted on the HPS in the area
of fluid and slurry rheology, proppant transport,
perforation pressure losses and dynamic fluid loss, fracture
conductivity and the associated data that can be
acquired.
Technical Approach: The HPS is a parallel
plate flow cell with reconfigurable walls and inlet
perforations and designed to operate at pressure up to 1200
psig and temperature up to 250 degrees F. The walls of the
flow cell can be reconfigured to simulate either a porous
rock surface, for dynamic fluid loss studies, or a smooth
impermeable surface, for rheology studies or for
visualization of proppant transport and placement inside the
cell. The inlet perforations can be configured with
perforations of different sizes and at different spacings.
The instrumentation and data acquisition system can provide
real time information on the pressure loss across different
positions of the cell, fluid flow rate and density,
temperature and pressure, fluid leak off rate through the
permeable walls and proppant maps inside the cell. The
control system of the HPS had the capability for dynamic
control of gap width and system pressure. The auxiliary
equipment include the field-scale fluid moving equipment
including sand and fluid mixing tanks, continuous and batch
crosslinking facilities, and field-type viscometers for
fluid characterization.
Project Implications: This report is one of a series
of reports on the design of construction of a flow cell to
evaluate the performance of fluids used in the hydraulic
fracturing of tight gas sands wells. The simulator will
measure the complex chemical, physical and fluid flow
processes that occur when a fracture is created in an effort
to optimize the recovery of natural gas. This helps a
producer select the best fluids for the application,
minimize the volume of fluids pumped in a fracture
treatment, and reduce costs.
Report Contents:
|
GRI: |
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GRI 94/0438 |
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|
1. Introduction |
1 |
|
2. The High Pressure Simulator |
1 |
|
Configuration |
1 |
|
Facings |
2 |
|
Fluid Handling Equipment |
2 |
|
Data Acquisition and Flow Visualization |
3 |
|
Vision System |
3 |
|
Equipment Control |
3 |
|
3. Experimental Functional Capability |
4 |
|
4. Instrumentation |
5 |
|
Differential Pressure Measurements |
6 |
|
Flow Rate Measurements |
6 |
|
Fluid Velocities |
6 |
|
Platen Spacings |
6 |
|
Proppant Concentration |
7 |
|
Fluid Temperatures |
7 |
|
Fluid Leak-off Measurements |
7 |
|
5. Auxiliary Characterizations |
7 |
|
Fluid Viscosity |
7 |
|
Permeability |
8 |
|
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