Amphoteric retarder for long-standing cementing: Preparation, properties and working mechanism

The amphoteric ion polymer cement retarder Poly‐AAMD was synthesized by aqueous solution polymerization, the chemical structure, molecular weight, and thermal stability was studied. As a result, the Mn and Mw are 1.3 × 104 and 4.7 × 104 g/mol, respectively, and the initial decomposition temperature is 260°C. Then, the effects of retarder Poly‐AAMD on the application performance of cement slurry, such as settlement stability, thickening time, compressive strength, and rheological properties, were investigated. Especially, the thickening time of cement slurry with 1.2 and 1.5 wt% retarder Poly‐AAMD is 312 and 316 min at 220°C, the compressive strength is larger than 14 MPa at 24 h. Compared to conventional retarders, the temperature resistance has been improved to 220°C. Simultaneously, the initial hydration process of cement slurry was studied by low field NMR based on the T2 value. Moreover, the hydration products of cement slurry with retarder Poly‐AAMD were analyzed depends on the qualitative and quantitative analysis methods, the type and content of hydration products were confirmed by the methods of X‐ray diffraction analysis (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TG), and differential thermal analysis (DTG). Finally, the retarding mechanism of retarder Poly‐AAMD was further studied depends on the results of adsorption amount and Zeta potential.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Preparation, characterization, and retarding mechanism of high temperature resistant amphoteric ion polymer oil well cement retarderPoly‐AAMDforHTHPapplication

Jinhua,

Xing,

Junwei

et al. 2023

“…Nevertheless, the hydroxy carboxylic acid retarder has the drawback of being dosage-sensitive, and it can often result in abnormal solidification issues such as bulging in the cement slurry. 13 The kind of retarder that has been studied and used the most recently among them is the polymer retarder. In contrast to other kinds of retarders, polymer retarders can be synthesized and designed artificially at the molecular level, and functional groups with superior performance can be introduced into the polymer under the desired formation conditions to enhance its retarding capabilities.…”

Section: Introductionmentioning

confidence: 99%

“…According to research, this retarder has a good retarding effect at 140 C, a reasonable molecular weight, and won't interfere with the growth of cement slurry strength. Wu 13 et al used AMPS, DMC, IA, and methyl allyl polyethenoxy ether (TPEG) as monomers to create an amphoteric retarder. According to experiments, this retarder may be used for cementing processes when there are significant temperature variations between 90 and 180 C. Under high-temperature conditions, the thickening time of cement slurry can be successfully extended by the majority of these synthetic polymer retarders.…”

Section: Introductionmentioning

confidence: 99%

High‐temperature resistant copolymer oil well cement retarder: Synthesis, assessment of performance, and mechanism of retardation

Bian,

Ye,

Zheng

et al. 2024

This work used aqueous solution free radical polymerization to create polymers of 2‐acrylamide‐2‐methylpropane sulfonic acid, itaconic acid, and allyl polyoxyethylene ether as a high‐temperature resistant retarder (APMS/IA/APEG, from now on referred to as AIA). Gel permeation chromatography, fourier transform infrared (FTIR), proton nuclear magnetic resonance (1HNMR), and thermo‐gravimetric analysis (TG) were used to characterize their molecular structure and characteristics. Tests were conducted on the thickening time, rheological characteristics, and compressive strength of AIA in cement slurries. The cement slurry thickened for 276 min at 180°C during the test, and the cement stone's 24‐h compressive strength was consistently more than 20 MPa. The hydration products were analyzed using x‐ray diffractometer and scanning electron microscopy methods, which were then coupled with molecular dynamics simulations to elucidate the AIA retarding mechanism. When AIA is added to a cement slurry, it forms a chelate structure with Ca2+ and a strong adsorption layer on the surfaces of the cement particles. This stops the cement from hydrating. The AIA side chain, APEG, can wrap the active group in AIA at low temperatures. AIA exposes more adsorption groups because of the APEG chains stretching at higher temperatures. AIA can, therefore, be used for deep well operations at high temperatures.

Amphoteric ionic polymer large temperature difference retarder for long sealing section cementing low‐density cement slurry: Preparation, application, and working mechanism

Jinhua,

Junwei,

et al. 2024

In this study, a novel amphoteric ionic large temperature difference retarder (marked with CLL‐1) was prepared by using functional monomer through aqueous solution polymerization method. First, the chemical structure and molecular weight of retarder CLL‐1 were obtained, and then the thermal stability of retarder CLL‐1 was investigated at the temperature range of 40–400°C, and the result shows that the retarder CLL‐1 has well thermal stability, which could be used to control the thickening time of cement slurry at higher temperatures. Second, the influences of retarder CLL‐1 on the settlement stability of cement slurry were studied by the density difference at the temperature of 150, 120, 90, and 30°C, respectively. Third, the thickening time of cement slurry samples with different retarder CLL‐1 adding amount was studied at the temperature range of 80–180°C, and the results showed that the retarder CLL‐1 can adapt well to the working conditions of large temperature difference cementing operations. Simultaneously, the compressive strength of cement slurry with different retarder CLL‐1 adding amount was obtained. Finally, the working mechanism of retarder CLL‐1 at large temperature difference was revealed depends on the methods of x‐ray diffraction, scanning electron microscope, and TG.