Introduction
ClearFrac Viscoelastic Surfactant Gelling Agent is a surfactant and water-based, polymer-free systems that extends the family of viscoelastic surfactants (VES) to 275 degF [135 degC]. ClearFrac is the fracturing fluid for high-application temperatures ranging between 100 and 275 degF [38 and 135 degC]. It contains Viscoelastic Surfactant Gelling Agent, clay stabilizer and breaker. Unlike polymer-based fluid systems, crosslinkers are not needed since viscosity is developed upon mixing.
Physical Properties and Hazards
Form |
S.G. |
Water Solubility |
Health Hazard |
Physical Hazard |
pH |
Yellow Liquid |
0.95-1.05 |
Miscible |
Eyes, ingestion |
Moderate-Fire |
7.0-8.0
(1% Alcohol Solution) |
Chemical Properties and Application
(1) Visco-Elastic Surfactant (VES) fluids have been widely used as they exhibit excellent rheological properties and maintain low formation damage characteristics.
(2) VES fluids are polymer-free fluids that generate low friction, highly viscous fluids with enhanced conductivity.
(3) Viscoelastic Surfactant Gelling Agent systems are not degraded when exposed to extended periods of shearing and the viscosity is independent of time. The fluid viscosity decreases with increasing shear rate, but the original fluid viscosity is recovered when the shear rate returns to the original value. However, since the fluid viscosity is a function of shear rate, the time that a fluid needs to regain its viscosity after high-shear exposure is an important fluid characteristic. 60 gal/Mgal Viscoelastic Surfactant Gelling Agent does not need any shear recovery additives.
(4) The ClearFrac fluids are prepared by mixing Viscoelastic Surfactant Gelling Agent, Mutual Solvent when needed, breaker and clay stabilizer in freshwater. Viscoelastic Surfactant Gelling Agent are designed for use in wells with bottomhole temperatures (BHT) from 100 to 275 degF [38 to 104 degC].
(5) Mixing procedures. A typical crosslinked guar-base fracturing fluid may use up 13 different additives to provide the desired rheological properties. Complex metering and pumping equipment is needed to ensure accurate delivery of chemical concentration(Left). In the simplified VES mixing system, the surfactant is added to a brine solution, then mixed with proppant and pumped downhole(Wright). Fewer chemicals and less equipment reduce the likelihood of problems during a job.
Kindly Reminder
(1) All the performance and standard is based on Saudi Aramco standard.
(2) This products can be made by customization(Base on temperature, concentration, viscosity requirement) .