Title: Proppant Transport Characterization of
Hydraulic Fracturing Fluids using a High Pressure
Simulator Integrated with a Fiber Optic/LED Vision
System
Author(s): S.N. Shah, The University
of Oklahoma and M. Asadi, Stim-Lab
Presentation: 1998 SPE Annual Technical Conference
and Exhibition
Location: New Orleans, Louisiana USA
Date:
September 27-30, 1998
Abstract: Slurries of selected hydraulic fracturing
fluids such as 40 lb/Mgal HPG gel and 35 lb/Mgal borate-crosslinked
guar gel were evaluated to characterize their proppant
transport properties using 6 ppg 20/40 mesh sand. In addition,
hydraulic fracturing fluids such as water, clean 40 lb/Mgal
HPG gel, clean and 35 lb/Mgal borate-crosslinked gel solution
were used to evaluate their capabilities in eroding bed height
and transporting proppant within fluidized bed located on top
of a compacted sand bed. The experimental part of this study
utilized a unique high pressure parallel plate flow cell,
simulating downhole fracture, integrated with a vision system
of fiber optic and Light Emitting Diodes (LED). The vision system
was used to quantify proppant transport characteristics and
to study various aspects of proppant transport including bank buildup.
Selected hydraulic fracturing fluid slurries were pumped into the
0.375" fracture gap width high-pressure flow cell through a
3000 ft of 1.188 in. ID coiled tubing, a 500 ft of 2 in. ID heat
exchanger, and a 2.75 in. inlet manifold that could be configured to
represent a wellbore having various perforation configurations.
The slurries were pumped at various shear rates of 60 to 120 sec-1
for a selected time. The slurries were followed by various clean
and/or slurries of water, 40 lb/Mgal HPG gel, and 35 lb/Mgal borate-
crosslinked gel to assess the degree of compaction within the deposited
bed. Data analysis indicates that slurry sedimentation in polymer
solutions follows a non-linear relationship with time at a fixed
shear rate and that perforation configuration affects proppant
transport, bed height growth, and proppant lift near the wellbore.
It is also shown that bed height growth is a non-linear function
of shear rate. In addition, the study indicates that although
fluidized bed, the upper bed height, is easily removed by the clean
crosslinked gel, erosion of the more compacted bed (below fluidized bed)
depends on factors such as type of the fluid leaving the deposit,
injection rate of clean fluid to remove bed height, pumping time,
and type of the fluid used to erode the compacted bed.