scholarly journals Influence of Nanoclay Content on Cement Matrix for Oil Wells Subjected to Cyclic Steam Injection

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1452 ◽  
Author(s):  
Ahmed Abdulhamid Mahmoud ◽  
Salaheldin Elkatatny ◽  
Abdulmalek Ahmed ◽  
Rahul Gajbhiye

High-temperature conditions drastically compromise the physical properties of cement, especially, its strengths. In this work, the influence of adding nanoclay (NC) particles to Saudi class G oil well cement (OWC) strength retrogression resistance under high-temperature condition (300 °C) is evaluated. Six cement slurries with different concentrations of silica flour (SF) and NC were prepared and tested under conditions of 38 °C and 300 °C for different time periods (7 and 28 days) of curing. The changes in the cement matrix compressive and tensile strengths, permeability, loss in the absorbed water, and the cement slurry rheology were evaluated as a function of NC content and temperature, the changes in the structure of the cement surfaces were investigated through the optical microscope. The results revealed that the use of NC (up to 3% by weight of cement (BWOC)) can prevent the OWC deterioration under extremely high-temperature conditions. Incorporating more than 3% of NC severely damaged the cement matrix microstructure due to the agglomeration of the nanoparticles. Incorporation of NC particles increased all the cement slurry rheological properties.

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.


2011 ◽  
Vol 287-290 ◽  
pp. 3127-3130 ◽  
Author(s):  
Zao Yuan Li ◽  
Chao Zhou ◽  
Jia Ying Li ◽  
Qi Bing Wu ◽  
Xiao Yang Guo

In the construction of the conductor casing and surface casing cementing, due to the low bottom hole circulating temperature(BHCT), the compressing strength of oil well cement development slowly, waiting on cement(WOC)need a long time, an increase of drilling costs, could easily lead to annular gas channeling, and have a bad effect on cement job quality and safety of operations. For the type of current domestic oil well cement early strength agent are few, The effective of some early strength agent are not satisfied. Some are Corrosive to the casing, and have a great influence on slurry rheology and other issues. Laboratory selected a new compound early strength agent with on chlorine and containing crystal seed.The thickening time, compressive strength, settlement stability properties, anti-gas channeling ability and other parameters of the slurry are tested. The results show that: There are some advantages of the cement slurry like right-angle-set, low temperature rapid strength, excellent settlement stability properties, and strong ability of anti-gas channeling and form a low density cement slurry which density range from 1.30 to 1.90g/cm3, it provide a reliable guarantee to cementing operation in shallow well with low-temperature under the different reservoir pressure.


2019 ◽  
Vol 11 (23) ◽  
pp. 6776 ◽  
Author(s):  
Abdulmalek Ahmed ◽  
Ahmed Abdulhamid Mahmoud ◽  
Salaheldin Elkatatny ◽  
Weiqing Chen

In deep hydrocarbon development wells, cement slurry with high density is required to effectively balance the high-pressure formations. The increase in the slurry density could be achieved by adding different heavy materials. In this study, the effect of the weighting materials (barite, hematite, and ilmenite) on the properties of Saudi Class G cement matrix of vertical homogeneity, compressive strength, porosity, and permeability was evaluated. Three cement slurries were weighted with barite, hematite, and ilmenite, and cured at 294 °F and 3000 psi for 24 h. All slurries have the same concentration of the different additives except the weighting material. The amount of weighting material used in every slurry was determined based on the targeted density of 18 lbm/gal. The results of this study revealed that the most vertically homogenous cement matrix was the ilmenite-weighted sample with a vertical variation of 17.6% compared to 20.2 and 24.8% for hematite- and barite-weighted cement, respectively. This is attributed to the small particle size of the ilmenite. The medical computerized tomography (CT) scan confirmed that the ilmenite-weighted sample is the most homogeneous, with a narrow range of density variation vertically along the sample. Hematite-weighted cement showed the highest compressive strength of 55.3 MPa, and the barite- and ilmenite-weighted cement compressive strengths are each 18.4 and 36.7% less than the compressive strength of the hematite-weighted cement, respectively. Barite-weighted cement has the lowest porosity and permeability of 6.1% and 18.9 mD, respectively. The maximum particle size of ilmenite used in this study is less than 42 μm to ensure no abrasion effect on the drilling system, and it minimized the solids segregation while maintaining a compressive strength that is higher than the minimum acceptable strength, which is the recommended weighting material for Saudi Class G cement.


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%.


2008 ◽  
Vol 591-593 ◽  
pp. 423-429 ◽  
Author(s):  
José Heriberto O. Nascimento ◽  
Antonio Eduardo Martinelli ◽  
D.M.A. Melo ◽  
A.C.V. Nóbrega ◽  
D.M.H. Martinelli ◽  
...  

The presence of fissures in the cement material of an oil well due to thermo-mechanic conditions caused by steam injection and acidizing operations, tends to commit the mechanical integrity of the annular space, resulting in the environmental contamination of the phreatic sheets and oil producing zones. However, the development of new materials for oil wells cementing has lead to several researches to achieve the optimization of this process. This work proposes the formulation of portland/polyurethane nonionic composites as a new material for oil wells cementing. The results prove the ability of the formulated composite to improve the mechanical properties when compared with portland/water cement slurry. Also, were obtained significant improvements in mass losses when acids were present.


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.


2011 ◽  
Vol 413 ◽  
pp. 24-28
Author(s):  
Ping Wang ◽  
Zhan Qu ◽  
Jian Bing Zhang

The effect of CO2 on seal capacity of cement mantle causes casing corrosion and reduces the life of oil well. The corrosion proof of cement system is studied to improve the integrity and seal properties of the cement stone under acidic medium. The CO2 corrosion test of 5 blocks cement under high temperature and high pressure was conducted. Compressive strength, permeability and corrosion depth were measured and morphology after corrosion was observed by scanning electron microscope. A density cement slurry formulations was selected by analyzing the experimental data. It not only has excellent corrosion resistance, but also has properties of anti-gas breakthrough, reduction of free water and stability. It can meet cementing requirement of different well depth conditions.


2021 ◽  
Author(s):  
Rahul Jadhav ◽  
Thomas Pisklak

Abstract To mitigate strength retrogression at temperatures, higher than 230°F, well cement designs typically include strength retrogression control additives (SRCAs). Solid siliceous materials (e.g., silica flour, fume, and sized-sands) are commonly used SRCAs that are incorporated into cements using dry-blending techniques. This study highlights liquid silica compositions as alternative SRCAs to dry-blended silica for high-temperature cementing. Liquid additives can be managed easily, delivered accurately, and offer a reduced on-site footprint, thus making them particularly advantageous for operations offshore and in remote locations. This paper presents a study on the use of liquid silica compositions as SRCAs and their effect on cement slurry properties, such as thickening time, mixability, fluid loss, rheology, and free water. The cement slurry used during the current study was prepared and tested according to API RP 10B-2 (2005). The performance of the liquid silica composition was tested at temperatures up to 400°F. Set cement samples were prepared using the liquid silica composition and silica flour, cured for up to 14 days at different temperatures. In addition, permeability testing was also performed on the samples. This paper presents the findings of this research, including strength and permeability test results on cement blends cured at temperatures of 300, 330, 350, and 400°F. The liquid silica composition, which provided silica to the cement formulation equivalent to 35% BWOC dry silica (48% BWOC liquid SRCA), functioned effectively as an SRCA at temperatures up to 330°F. Signs of strength retrogression were observed at 350°F and were more pronounced at 400°F. A greater concentration of the liquid silica composition may be necessary to prevent strength retrogression at temperatures higher than 330°F. The liquid silica composition also demonstrated mild retardation and a dispersing effect on the slurry. However, it helped enable improved slurry stability and suspension, thus providing improved control over free water without adverse effects on fluid loss and sedimentation. The study results demonstrate that a liquid SRCA can help improve the performance of annular cement designs to provide dependable barriers and effective zonal isolation during high-temperature cementing applications. The improved performance enabled by this liquid silica composition verifies its potential use as an alternative SRCA for high-temperature oil well cementing operations.


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