Heat flow inhibitor suitable for oil well cement at low temperature
A cement paste with low hydration heat flow is in high demand in hydrate layers cementing at low temperature to inhibit the hydrate decomposition. This paper prepared a heat flow inhibitor (HFI), which was compounded of disodium hydrogen phosphate dodecahydrate (DHPD), sodium silicate (SS) and nano calcium carbonate (NCC). DHPD was employed to reduce the heat flow of cement pastes. Porous ceramic particles were applied to carry DHPD to achieve slow-release. SS and NCC were employed to encapsulate and disperse the particles. The components were released in multi-stage into the cement paste to avoid their being blended into the cement paste at the same time. Setting time, thickening time , compressive strength , isothermal calorimetry , X-ray diffraction, mercury intrusion porosimetry and scanning electron microscopy were used to investigate the effects of HFI on cement hydration . The results showed that HFI reduced the hydration heat flow of cement pastes effectively, while displaying no negative impact on the compressive strength, setting time and thickening time. The maximum temperature of the cement paste dropped by 14.0 °C, and the maximum hydration heat flow was reduced by 28.75% at 8% HFI dosage . HFI is promising to be used in hydrate layers cementing.
危险品化学品经营许可证（带存储）