scholarly journals Calculation and evaluation of temperatures and eutectic compositions of multicomponent sections of the CaO—Al2O3—Fe2O3—Cr2O3 system

2020 ◽  
Vol 120 ◽  
pp. 120-125
Author(s):  
A. N. Korohodska ◽  
G. N. Shabanova ◽  
O. M. Tychyna ◽  
N. B. Deviatova
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Liquidus Surface ◽  
High Accuracy ◽  
Relative Volume ◽  
Oil Well ◽  
Oil Well Cement ◽  
Optimal Region ◽  
Cement Strength ◽  
Well Cement

The predicted service temperatures and eutectic compositions of the polycomponent sections of the CaO—Al2O3—Fe2O3—Cr2O3 system were calculated and evaluated. According to the results of geometrical topological studies of this system, the CaAl2O4—CaFe2O4—CaCr2O4—Ca4Al2Fe2O10 tetrahedron has the largest relative volume and the smallest degree of asymmetry. However, the composition of this tetrahedron includes two compounds that do not have hydraulic activity; this will adversely affect the cement strength. Presence of CaFe2O4 will significantly reduce the composition melting point, that why the CaAl2O4—Ca12Al7O33—CaCr2O4—Ca4Al2F2O10 tetrahedron is of more interest. The calculations result of temperatures and eutectic compositions of triple and tetra-component sections of the CaAl2O4—Ca12Al7O33—CaCr2O4—Ca4Al2F2O10 region of the CaO—Al2O3—Fe2O3—Cr2O3 system are presented. The phases that make up this tetrahedron are highly likely to exist in the CaO—Al2O3—Fe2O3—Cr2O3 system, which will allow us to develop a stable technology for the oil-well cementing materials based on calcium-ferro-alumina chromate cement without special techniques for ensuring high accuracy of the starting components dosage. The paper presents graphic images of the liquidus surface of polycomponent sections of optimal region of system. Selected areas are the most suitable for producing oil-well binding materials with an elevated temperature in application. It was found that, composite materials based on this system can be used at temperatures above 1350 °C. Based on the analysis of temperatures and eutectics compositions of polycomponent section, the use of rational area compositions for producing high-temperature resisting oil-well cement has been proved.

scholarly journals Development and Application of Novel Sodium Silicate Microcapsule-Based Self-Healing Oil Well Cement

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 456 ◽  
Author(s):  
Wenting Mao ◽  
Chrysoula Litina ◽  
Abir Al-Tabbaa
Keyword(s):  
High Temperature ◽  
Sodium Silicate ◽  
Crack Depth ◽  
Oil Well ◽  
Self Healing ◽  
Cement Pastes ◽  
Good Thermal Stability ◽  
Oil Well Cement ◽  
Cement Strength ◽  
Well Cement

A majority of well integrity problems originate from cracks of oil well cement. To address the crack issues, bespoke sodium silicate microcapsules were used in this study for introducing autonomous crack healing ability to oil well cement under high-temperature service conditions at 80 °C. Two types of sodium silicate microcapsule, which differed in their polyurea shell properties, were first evaluated on their suitability for use under the high temperature of 80 °C in the wellbore. Both types of microcapsules showed good thermal stability and survivability during mixing. The microcapsules with a more rigid shell were chosen over microcapsule with a more rubbery shell for further tests on the self-healing efficiency since the former had much less negative effect on the oil well cement strength. It was found that oil well cement itself showed very little healing capability when cured at 80 °C, but the addition of the microcapsules significantly promoted its self-healing performance. After healing for 7 days at 80 °C, the microcapsule-containing cement pastes achieved crack depth reduction up to ~58%, sorptivity coefficient reduction up to ~76%, and flexural strength regain up to ~27%. The microstructure analysis further confirmed the stability of microcapsules and their self-healing reactions upon cracking in the high temperature oil well cement system. These results provide a promising perspective for the development of self-healing microcapsule-based oil well cements.

Synthesis and Properties of Dispersive Type High Temperature Filtrate Reducer Used in Oil Well Cement

2013 ◽  
Vol 734-737 ◽  
pp. 2136-2140
Author(s):  
Di Hui Ma ◽  
Zhen Wei ◽  
Zong Gang Wang
Keyword(s):  
High Temperature ◽  
Rheological Property ◽  
Mass Fraction ◽  
Salt Resistance ◽  
Fluid Loss ◽  
Oil Well ◽  
Cement Slurry ◽  
Oil Well Cement ◽  
Cement Strength ◽  
Well Cement

The advanced dispersive type high temperature filtrate reducer used in oil well cement was synthesized with 2-acryloyl-2-methyl-propyl sulfonic (AMPS) , N, N-dimethylacrylamide (DMAA) and organic acids. When the mass fraction of synthetic filtrate reducer was 1%, the filter loss of the cement slurry was 30ml/30min at 120 °C and 49ml/30min at 150°C respectively, and the cement strength was 25MPa after 24 hours, and the rheological property of the cement slurry was well when the mass fraction of synthetic filtrate reducer was 2%, and liquidity factor was 0.85, and the consistency was 0.43. The results showed that the filtrate reducer had good dispersity and could control the fluid loss efficiently, and the ability of resistance to high temperature and salt resistance was good.

Performance Evaluation of Polycarboxylic Acid Dispersant for Oil Well Cementing

2020 ◽  
Vol 993 ◽  
pp. 1341-1350
Author(s):  
Xiu Jian Xia ◽  
Yong Jin Yu ◽  
Jian Zhou Jin ◽  
Shuo Qiong Liu ◽  
Ming Xu ◽  
...  
Keyword(s):  
High Temperature ◽  
Salt Resistance ◽  
Strength Development ◽  
Fluid Loss ◽  
Oil Well ◽  
Polycarboxylic Acid ◽  
Cement Slurry ◽  
Deep Wells ◽  
Oil Well Cement ◽  
Well Cement

The conventional oil-well cement dispersant has the characteristics of poor dispersion at high temperature, poor compatibility with other additives, and environmental pollution during the production process. In this article, with ultra-early strong polyether monomer, acrylic acid, 2-acrylamine-2-methylpropyl sulfonic acid, sodium methacrylate as copolymer monomers, an environmentally friendly polycarboxylic acid dispersant, DRPC-1L, was prepared by the aqueous solution free-radical polymerization. The chemical composition and thermal stability of the synthetic copolymer were characterized by FTIR and TGA techniques. The evaluation results show that DRPC-1L has a wide temperature range (30~210 °C), good salt-resistance and dispersing effect. It can significantly improve the rheological performance of cement slurry, and it is well matched with oil-well cement additives such as fluid loss agent, retarder and so on. Moreover, it is beneficial to the mechanical strength development of set cement, especially the early compressive strength. It can also inhibit the abnormal gelation phenomenon of cement slurry, flash set, that occurs during high temperature thickening experiments, which plays an important role in enhancing the comprehensive performance of cement slurry. Consequently, the novel polycarboxylic acid dispersant has good application prospects in deep and ultra-deep wells cementing.

Development and Change of Compressive Strength for Class G Oil Well Cement under High Temperature

2014 ◽  
Vol 941-944 ◽  
pp. 1441-1444 ◽  
Author(s):  
Jing Fu Zhang ◽  
Kai Liu ◽  
Rui Xue Hou ◽  
Bo Wang ◽  
Jin Long Yang
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Initial Period ◽  
Strength Development ◽  
Oil Well ◽  
Curing Time ◽  
Cement Slurry ◽  
Critical Temperatures ◽  
Oil Well Cement ◽  
Well Cement

The compressive strength of oil well cement would be damaged by high temperature in deep oil wells, which was caused by the obvious change of the components and microstructure of cement hydration products. The adaptability of common oil well cement for cementing under higher temperatures was confined by above reasons. Characteristics of development and change of compressive strength of Class G oil well cement were studied under different temperatures by using Static Gel Strength Analyzer and High Temperature-High Pressure curing chamber. The influence law of temperature and silica sands on compressive strength was analyzed. The results showed that the critical temperatures at which the compressive strength begun to decline were about 110°C and 150°C respectively; The compressive strength increased with curing time during the initial period and would reduced after it reached a certain value when temperature exceeded 110°C; For cement with silica sands, the compressive strength development trend was in the shape of two-stage form with increase of curing time within the range of 110~150°C, but for 160~200°C temperature range the development form was in the shape of single stage; The reasonable amounts of silica sands which would be added to cement slurry to enhance the compressive strength of hardening paste were determined to be 30%~40%.

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