Server: Netscape-Commerce/1.12 Date: Friday, 21-Nov-97 01:03:08 GMT Last-modified: Friday, 01-Aug-97 19:44:30 GMT Content-length: 6409 Content-type: text/html CARBO Ceramics Tech Tidbits


Tech Tidbit Of The Week:

CARBO ECONOPROP


Performance Compared to Precured Resin Sands

CARBO'S recent report The Influence of Test Procedure and Fluid Chemistry on Proppant Performance presented a detailed comparison of light weight ceramic proppants versus curable resin coated sands. The effects of fluid chemistry and more realistic test conditions proved to be very detrimental to the performance of the curable resin sands, but not to ceramic proppants. These conclusions begged the question "what about precured resin sands?"

Further laboratory testing performed for CARBO Ceramics by Stim-Lab Inc. compares ECONOPROP® to precured and partially precured resin coated sands. All of the samples were exposed to fluids that simulate mildly caustic fracturing fluids (7 lb/1000 gal. potassium carbonate added to de-ionized water). The four proppants were tested simultaneously in a stack of four conductivity cells in a single load frame. As such, the proppants were subjected to equivalent stress and temperature conditions.

Adding 7 lb/1000 gal potassium carbonate resulted in initial pH of the fluid and proppant slurries ranging from 9.5 to 10.5. The conductivity cells were all loaded with 2 lb/ft² 20/40 mesh proppant. Temperature and stress were increased together to 200°F and 5000 psi, and then the first long term conductivity measurement was made.

Additional long term measurements were made at 6000 psi and 8000 psi using standard Stim-Lab procedures. After the 8000 psi stage, nitrogen was flowed through the cells at various rates to measure turbulent flow factors (Beta). The maximum gas flow rate translates toa bout 5 MMCFD in a well with 50 feet of net pay. Using the procedure described by Guidley, Penny and McDaniel (SPE #24008), water was then flowed through the cells at a high rate (100 ml/min., which equates to about 800 bbl/day ina well with 50 feet of net pay). After the high rate water flow interval, long term conductivity was again measured at standard liquid flow rates. The purpose of the high rate liquid flow stage was to assess the effect of fines migration on the long term conductivites of the four proppants tested.

Beta factors measured using high rate gas flows are:
ECONOPROP°0.0011
AcFrac® Ultra SB0.0026
AcFrac® Black0.0025
Santrol Tempered DC0.0031

Higher Beta factors indicate a greater turbulent effect in the proppant pack. As such, lower Beta factors are desirable.

The conductivity measured after high rate liquid flow relative to initial conductivity is used to express the percent retained conductivity. The higher the retained conductivity, the lower the damage due to fines migration. A bar graphy showing retained conductivities follows.

ECONOPROP® is chemically inert, has 2 to 3 times the conductivity of these resin coated sands, and is able to retain this conductivity advantage in high flow rate environments. ECONOPROP is the best choice!

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Other Industry sites you may find useful:

Halliburton, Inc.

Schlumberger Dowell

Society of Petroleum Engineers

Gas Research Institute

Aral Energy Links

Oil OnLine

Stim-Lab, Inc




carboinfo@carboceramics.com

CARBO Ceramics Inc.
Suite 1520
600 East Las Colinas Blvd.
Irving, Texas 75039

Telephone: 972-401-0090
Fax: 972-401-0705