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

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%.

2020 ◽  
Vol 993 ◽  
pp. 1341-1350
Author(s):  
Xiu Jian Xia ◽  
Yong Jin Yu ◽  
Jian Zhou Jin ◽  
Shuo Qiong Liu ◽  
Ming Xu ◽  
...  

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.


2015 ◽  
Vol 814 ◽  
pp. 191-198 ◽  
Author(s):  
Xiu Jian Xia ◽  
Jin Tang Guo ◽  
Shuo Qiong Liu ◽  
Jian Zhou Jin ◽  
Yong Jin Yu ◽  
...  

In this study, a novel polymer retarder DRH-200LG was synthesized to solve the problems of retarding failure, strong dispersivity under high temperature and adverse impact on the strength development of cement stone. The composition of the polymer was confirmed by IR, and its thermal stability was proved by DSC, TG analysis and thermal treatment at 200 °C. Furthermore, the stability and strength development of cement slurry was evaluated by the comparative consistency method and ultrasonic method, respectively. The results show that DRH-200LG has good high temperature-resistance and retarding performance, presenting favourable influence on the stability and strength development of cement slurry. DRH-200LG shows a good application prospect in the cementation of deep & ultra-deep wells. And it has some guiding significance in the research and innovation of a novel polymer used as oil well cement retarder.


2014 ◽  
Vol 692 ◽  
pp. 433-438 ◽  
Author(s):  
Jing Fu Zhang ◽  
Jin Long Yang ◽  
Kai Liu ◽  
Bo Wang ◽  
Rui Xue Hou

Carbon dioxide CO2could corrode the oil well cement paste matrix under agreeable moisture and pressure condition in deep oil wells, which could decrease the compressive strength and damage the annular seal reliability of cement paste matrix. The problem of oil well cement paste matrix corrosion by CO2was researched in the paper for obtain the feasible corrosion prevention technical measures. The microstructure and compressive strength of corroded cement paste matrix were examined by scanning electron microscopeSEMand strength test instrument etc. under different corrosion conditions. The mechanism and effect law of corrosion on oil well cement paste matrix by CO2were analyzed. And the suitable method to protect CO2corrosion in deep oil wells was explored. The results show that the corrosion mechanism of cement paste matrix by CO2was that the wetting phase CO2could generate chemical reaction with original hydration products produced from cement hydration, which CaCO3were developed and the original composition and microstructure of cement paste matrix were destroyed. The compressive strength of corrosion cement paste matrix always was lower than that of un-corrosion cement paste matrix. The compressive strength of corrosion cement paste matrix decreased with increase of curing temperature and differential pressure. The corroded degree of cement paste matrix was intimately related with the compositions of cement slurry. Developing and design anti-corrosive cement slurry should base on effectively improving the compact degree and original strength of cement paste matrix. The compounding additive R designed in the paper could effectively improve the anti-corrosive ability of cement slurry.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jianglin Zhu ◽  
Jiangxiong Wei ◽  
Qijun Yu ◽  
Mingbiao Xu ◽  
Yuwei Luo

Oil well cement is a type of natural brittle material that cannot be used directly in cementing operations. Fiber is a type of material that can effectively improve the strength and toughness of cement stone, and hybrid fiber materials can more effectively improve the performance of a cement sample. To overcome the natural defects of oil well cement, the new mineral fiber, i.e., wollastonite fiber, and common carbon fiber were used in oil well cement, and the micromorphology, mechanical properties, and stress-strain behavior of the cement were evaluated. The experimental results show that carbon fiber and wollastonite fiber are randomly distributed in the cement paste. The mechanical properties of the cement paste are improved by bridging and pulling out. The compressive strength, flexural strength, and impact strength of cement stone containing only carbon fiber or wollastonite fiber are higher than those of the pure cement, but too many fibers are not conducive to the development of mechanical properties. A mixture of 0.3% carbon fiber with 6% wollastonite fiber in oil well cement slurry results in a greater increase in compressive strength, flexural strength, and impact strength. In addition, compared with blank cement stone, the strain of the mixed cement stone increases substantially, and the elastic modulus decreases by 37.8%. The experimental results supply technical support for the design of a high-performance cement slurry system.


2013 ◽  
Vol 734-737 ◽  
pp. 2136-2140
Author(s):  
Di Hui Ma ◽  
Zhen Wei ◽  
Zong Gang Wang

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.


2012 ◽  
Vol 204-208 ◽  
pp. 3771-3775
Author(s):  
Xiao Wei Cheng ◽  
Sheng Huang ◽  
Yuan Yi Yang ◽  
Zao Yuan Li ◽  
Xiao Yang Guo

The influences of KCl on the performance of G-Grade oil-well cement are discussed in this article. The macro performances including the rheological property, filter loss of slurry and the thickening time, strength and shrinkage of cement are tested. And the reasons why those influence could happen are explained by analyzing the microscopic structure of the cement. The results show that: KCl takes participation in hydration reaction of cement, KAlSiO3 and Ca4Al2H0.34O6.34Cl1.67 are generated in the reaction that could improve the compressive strength of the cement and reduce the shrinkage of the cement, but there is a limited added amount, less than 12% (BWOW) is the best.


2017 ◽  
Vol 13 (4) ◽  
pp. 255
Author(s):  
Arnoldus Meidio Adi Prasetyo ◽  
Ade Lisantono

One of the critical factors of cementing process in oil drilling of off-shore-project is designing the cement slurry. For this reason, the slurry properties which have been classified by American Petroleum Institute (API) should be changed so it will match with the requirement of reservoir condition. Changing the slurry properties can be done by adding the additive material into the cement slurry such as Calcium Carbonate and Silica Fume. The research objective is to study the effect of calcium carbonate and silica fume to the compressive and shear bond strength of oil well cement. Fourty five cylinder specimens with the size of (75 x 150) mm were made for compressive strength testing and fourty five cylinder specimens with the size of (25.4 x 50.8) mm were made for shear bond strength testing. Five variants of the specimen were made in this study. The variant were cement slurry with (0% Calcium Carbonate + 0 % Silica Fume) as a reference specimen; (5% Calcium Carbonate + 5 % Silica Fume); (10% Calcium Carbonate + 10 % Silica Fume); (15% Calcium Carbonate + 15 % Silica Fume); (20% Calcium Carbonate + 20 % Silica Fume). The oil well cement specimens were tested in 7, 14, and 28 days. The experimental results show that the compressive strength of oil well cement will decrease when it is added with calcium carbonate and silica fume. The shear bond strength of the oil well cement increases for the specimen with 5 % Calcium Carbonate + 5 % Silica Fume. However, the shear bond strength will decrease when content of the Calcium Carbonate + Silica Fume more than 5 %. Based on the result of this research, the optimum amount of calcium carbonate and silica fume that can be use is 5%, because with 5% of calcium carbonate and 5% of silica fume, the reducing of compressive strength is the smallest and the shear bond strength is increased compare to the others specimen with 10%, 15%, and 20% calcium carbonate and silica fume.


2017 ◽  
Vol 748 ◽  
pp. 323-327 ◽  
Author(s):  
Ming Gin Lee ◽  
Wei Chien Wang ◽  
Yi Shuo Huang ◽  
Yu Min Su ◽  
Quan Zhou Jiang

This study was conducted to assess the acceleration of strength development by CO2 curing and to evaluate the strength and microstructure of two cement mortars. Three curing pressures (1, 5, 8 bars), three curing time (20, 120, 180 minutes) and four CO2 concentration (0%, 25%, 50% and 100%) were used in this investigation. Two mortar specimens are made with Type Ι Portland cement and oil-well cement. After the CO2 curing duration and demolding, the mortar samples were assessed through the mass gain, the compressive strength, the pressure drop, the temperature rise in the curing chamber, and the microstructure characteristics. The performance of the CO2 cured mortars was found through the measurement of pressure drop, temperature rise, strength development, mass gain and carbonation. In general, higher CO2 concentration, longer carbonation time, higher CO2 pressure could increase the compressive strength of the mortar and promote more CO2 absorption. The better results obtained from this study are the Type 1 cement mortars curing three hours under 5-bar pressure with 100% CO2 concentration using one-time supply method. The three-hour mortar samples had a high percent strength development. The increasing of CO2 concentration results in higher carbonation degree of mortar, more mass gain, and a stiffer and denser material.


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