Petrochem - Thixotropic Cement Powder (P-TTC) is Gypsum cement used solely on its own or in combination with Portland cement can be used for multiple purposes in the oilfield industry including:
- Capping a gravel plug back
- Protecting a bridge plug
- A temporary plug on gas and oil wells
- Sealing off lost circulation zones
- Killing a gas or oil well
- Repairing holes in the pipe to set a short surface
- Repairing the conductor pipe
- Situations where you need quick setting and optimal cement placement techniques
- Aids in concrete placement offering high gel strength during the cement gelation period
- Circumstances that need pumpability during the thickening time
- Circumstances where you need to achieve compressive strength in three hours
- Circumstances where you need to withstand the weight of the cement at an early age
When using thixotropic agents for cement, it’s important to take into consideration the following things before using this product with your field workers:
- Accelerators, retarders, and temperatures significantly affect the thickening time of Gypsum cement
- Compressive strength is typically low for Gypsum cement; so Petrochem recommends resolving this issue by adding Portland cement to offset
- Gypsum cement develops rapid cement gelation strength once the motion stops
- Has the ability to seal off channels to which the slurry was previously being lost
- Do not use in wells where temperatures exceed 180°F
- Temperatures significantly reduce thickening time
Petrochem - Thixotropic Cement Liquid (P-TTCL) is a liquid additive that enables the cement slurry to be fluid when in motion or being pumped. Here are some important things to know about using this thixotropic agent:
- When sufficient force is applied to move the slurry, the gel structure is disturbed and the slurry returns to a fluid/pump-able state
- This cement gelation is strong enough to support the weight of the slurry column and it also prevents fall back.
- P-TTCL creates higher early and ultimate strength development than Gypsum cement solutions
- Can reach full strength within 24 hours while Gypsum cement normally requires seven days to attain
- P-TTCL can be used with any Portland cement while Gypsum cement cannot be used with certain portland cement that contains Tricalcium Silicate (C3A)
- A huge advantage is that P-TTCL does not depend on (C3A) content
- A great solution for local cement producers that exhibit poor quality control or low C3A content
- Laboratory tests show P-TTCL provides optimal uniform gel strength and is a superior thixotropic agent for cement slurries when used with a wide variety of brands.
- Must be thoroughly dispersed in the mixing water before being added to the neat cement.
Rheological Evaluation of slurries using Thixotropic Agents - due to the special rheological behaviors of thixotropic slurries, this procedure guide will help evaluate the gel strength that has been developed
- Prepare two identical slurries - Pour one slurry into the Fann V-G Meter for immediate rheological evaluation. Place the other slurry in a consistometer for 20 minutes for later evaluation.
- Gradually lift the slurry cup to the measurement position with the motor running at 600 RPM.
- Continue stirring at 600 RPM for one minute or until viscosity stabilizes.
- Stop the motor and allow the slurry to remain undisturbed for the indicated rest period.
- Restart the motor at 3 RPM.
- Note the minimum before the reader falls and the maximum the meter reaches before the gel breaks.
- Change the speed back to 600 RPM and allow slurry to become thoroughly dispersed.
- Note the change in viscosity value indicated by the meter. Some agitation with a stirring rod will be necessary to gauge the readings.
- Continue the 600 RPM speed for one minute and then stop for the next rest period.
- Continue the procedure until all rest periods have been covered. Recommended rest periods are 1,3,5,10,20, and 30 minutes.
- Evaluate the rheology of the slurry that had been stirred for 20 minutes. The data collected from the slurry is very important because it approximates a field application that will relate to the durability of the thixotropic nature of the cement slurry.
Contact a Thixotropic Agent Expert
At Petrochem, our oil and gas thixotropic cement additives make it easy to repair or seal various components of the well including the conductor, pipes and curated cement. These additives can also make it easier for pumping operations as it keeps the cement in a liquid form for longer periods of time. The rheological components of cement slurries can be different based on the cement brand you are using and temperature conditions. Contact a concrete additive manufacturer today to learn how thixotropic agents can increase strength for better cement gelation for most slurries on the market.