Modeling the hydration, viscosity and ultrasonic property evolution of class G cement up to 90 °C and 200 MPa by a scale factor method

Sun, Lijun; Pang, Xueyu; Ghabezloo, Siavash; Yan, Haibing

doi:10.1016/j.petsci.2023.01.014

Cited by 7 publications

(1 citation statement)

References 35 publications

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“…However, it has been found both in laboratory research and field application that the addition of polycarboxylic additives could lead to abnormal thickening behaviors of oil well cementing slurry systems at high temperature, such as rapid thickening, abnormal gelation phenomenon (AGP), thickening time inversion, and so on. − In laboratorial research, the thickening experiment is commonly utilized to monitor the flow state changes of cement slurry during its dynamic hydration reaction and draws a thickening curve to record the real-time consistency value of the slurry (unit: Bc). Under normal circumstances, the thickening curve of the cement slurry should be smooth.…”

Section: Introductionmentioning

confidence: 99%

Occurrence Mechanism of the Abnormal Gelation Phenomenon of High Temperature Cementing Slurry Induced by a Polycarboxylic Retarder

Xia,

Zhang,

et al. 2024

ACS Omega

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The class G oil well cement is a type of special cement that can be subjected to a high temperature formation environment. It was found that the class G cement tail slurry with a low polycarboxylic retarder dosage (usually ≤1% by weight of cement) was more prone to cause the abnormal gelation phenomenon (AGP) than the lead slurry with a high retarder dosage at a high temperature (usually when T ≥ 120 °C). This study aimed at the occurrence mechanism of this unfavorable phenomenon that seriously endangers the cementing security. Results showed that the abnormal gelatinous region underwent premature hydration; namely, the calcium hydroxide and calcium silicate hydrate (C−S−H) content were all higher than the nongelatinous region, while the copolymer content was the opposite. Correspondingly, the theory of "premature hydration and crystal nucleation" was proposed to explain the abnormal gelation mechanism of a cementing tail slurry with an insufficient retarder dosage. Furthermore, a novel functionalized copolymer retarder "PAIANS" was synthesized to alleviate the AGP.

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Section: Introductionmentioning

confidence: 99%