After a cement slurry has been pumped downhole, it begins to develop static gel strength (SGS). The beginning of SGS development signals the point at which the slurry starts to change from a hydraulic fluid to a solid material with measurable compressive strength.
The gel strength during this transition phase is important because it determines the shut down safety factor on the job and it affects the pressure reduction and the fluid flow of gas into the cement-filled annulus.
The OFITE Static Gel Strength Measurement (SGSM) device is an accessory component to the Twin-Cell Ultrasonic Cement Analyzer (UCA). This system measures the static gel strength development of a cement sample over time. You can also run a standard UCA test to measure compressive strength with the same slurry batch.
Method of Operation:
The SGSM attaches directly to a UCA cell during testing. The veined rotor inside the cell conditions the cement in-place. Throughout the test, the rotor periodically rotates, the resistance is measured, and the software calculates the gel strength.
Each cell can also perform a standard UCA test, using acoustic signals to monitor compressive strength over time. The results from both cells are plotted in the OFITE software, giving the operator a complete view of the curing characteristics of the cement slurry.
Features & Specifications:
- Automatically conditions the slurry in-place
- Directly measures static gel strength
- Data acquisition system with automatic control included
- Accessory to all OFITE UCA instruments
- Simultaneously measures static gel strength and compressive strength
- Non-destructive test procedure
- Continuous measurement under high-temperature, high-pressure conditions
- – Maximum Pressure: 5,000 PSI
- – Maximum Temperature: 400°F
- Programmable temperature control
- OFITE software plots static gel strength and compressive strength on the same graph