scholarly journals Coupled effects of hydrophilic nano silica oxide and anatase nano titanium oxide on strengths of oilwell cement

2021 ◽  
Vol 47 (2) ◽  
pp. 568-582
Author(s):  
Petro E Mabeyo ◽  
Jun Gu

The life of oil wells depends on the stability of cement sheath and bond strength with the formation and casing. Extreme subsurface conditions cause substantial stresses on the cement sheath resulting in a serious impact on well integrity. The recommended API cement for oilwell fails to provide the required durability of the cemented well due to such conditions. Supplementary cementitious materials such as nanoparticles are added to improve the cement for long-lasting zonal isolation. In this study, the compressive and shear bond strengths of oilwell cement containing nano-SiO2 and nano-TiO2 were studied at 80 °C for 3, 7, 14, and 28 days of hydration. The XRD, TG, and DSC were used for the analysis of cement hydration products. The results revealed that both nano-SiO2 and nano-TiO2 increased strength evolution. A ternary system made with 2% nano-SiO2 and 2% nano-TiO2 improved compressive strength by 22.6 and 48.4%, while the shear bond strength increased by 110.6 and 55% at age of 3 days and 28 days, respectively, compared to their corresponding binary systems. Therefore, these results remark the potential of replacing an appropriate proportion of oilwell cement with coupled nano-SiO2 and nano-TiO2 to ensure cement sheath structure durability in the annular and long-lasting zonal isolation. Keywords: Nano-silica, nano-titanium, compressive strength, shear bond strength, oilwell cement

2021 ◽  
Vol 72 (1) ◽  
pp. 76-83
Author(s):  
Lam Le Hong ◽  
Lam Dao Duy ◽  
Huu Pham Duy

The demand for High Performance Concrete (HPC) is steadily increasing with massive developments. Conventionally, it is possible to use industrial products such as silica fume (SF), fly ash, as supplementary cementitious materials (SCM), to enhance the attributes of HPC. In recent years, nano-silica (NS) is used as an additive in added mainly to fill up the deviation arises with the addition of SF for HPC. This study aims to optimize the proportion of NS (produced in Vietnam) in the mixture used for fabricating 70 MPa high-performance concrete. SiO2 powder with particle size from 10 to 15 nm were used for mixing. A series of compressive strength test of HPC with nano-SiO2 varied from 0 to 2.8 percent of total of all binders (0%, 1.2%, 2%, 2.8%), and the fixed percentage of silica fume at 8% were proposed. Results show compressive strength increases with the increase of nano-SiO2, but this increase stops after reaching 2%. And at day 28 of the curing period, only concrete mixture containing of 8% silica fume and 2% nano-SiO2, had the highest compressive strength.


2012 ◽  
Vol 17 (6) ◽  
pp. 154-159 ◽  
Author(s):  
Marcel M. Farret ◽  
Eduardo Martinelli de Lima ◽  
Eduardo Gonçalves Mota ◽  
Hugo Mitsuo S. Oshima ◽  
Gabriela Maguilnik ◽  
...  

OBJECTIVE: To evaluate the mechanical properties of three glass ionomers cements (GICs) used for band cementation in Orthodontics. METHODS: Two conventional glass ionomers (Ketac Cem Easy mix/3M-ESPE and Meron/Voco) and one resin modified glass ionomer (Multi-cure Glass ionomer/3M-Unitek) were selected. For the compressive strength and diametral tensile strength tests, 12 specimens were made of each material. For the microhardness test 15 specimens were made of each material and for the shear bond strength tests 45 bovine permanent incisors were used mounted in a self-cure acrylic resin. Then, band segments with a welded bracket were cemented on the buccal surface of the crowns. For the mechanical tests of compressive and diametral tensile strength and shear bond strength a universal testing machine was used with a crosshead speed of 1,0 mm/min and for the Vickers microhardness analysis tests a Microdurometer was used with 200 g of load during 15 seconds. The results were submitted to statistical analysis through ANOVA complemented by Tukey's test at a significance level of 5%. RESULTS: The results shown that the Multi-Cure Glass Ionomer presented higher diametral tensile strength (p < 0.01) and compressive strength greater than conventional GICs (p = 0.08). Moreover, Ketac Cem showed significant less microhardness (p < 0.01). CONCLUSION: The resin-modified glass ionomer cement showed high mechanical properties, compared to the conventional glass ionomer cements, which had few differences between them.


2011 ◽  
Vol 366 ◽  
pp. 494-497
Author(s):  
Wei Jun Yang ◽  
Huan Zeng

This article analyzes about four aspects of insulation mortar of various performance indicators, including anti-cracking, flexural strength and compressive strength, shear bond strength and shrinkage rate, it is concluded that the insulation mortar meets to various performance indicators requirement of masonry mortar or plastering mortar.


2007 ◽  
Vol 330-332 ◽  
pp. 419-422 ◽  
Author(s):  
G.S. Lee ◽  
Sang Bae Lee ◽  
Doug Youn Lee ◽  
Kyeong Jun Park ◽  
S.O. Kim ◽  
...  

Histoacryl® (N-butyl-2-cyanoacrylate) has been widely utilized as a tissue adhesive. The aim of this study was to evaluate the physical and adhesive properties of newly developed cyanoacrylate-based β-TCP composite systems. The β-TCP powder was modified on the surface with citric acid to make this material mixed with cyanoacrylate easily. The setting time of acidtreated β-TCP/ Histoacryl® systems was dramatically prolonged and the polymerization heat was significantly decreased compared to that of untreated β-TCP/Histoacryl® system. The shear bond strength of cyanoacrylate-based β-TCP composites decreased with addition of acid-treated β-TCP filler. The compressive strength of β-TCP/Histoacryl® composites increased strongly with increasing the amount of acid-treated β-TCP filler. The cytotoxicity of the β-TCP/Histoacryl® composites decreased with the increasing of the amount of added β-TCP. These results indicated that our novel β-TCP/Histoacryl® composites had the great potential to serve as adhesives or filling materials in the dental field.


2021 ◽  
Author(s):  
Wajid Ali ◽  
Freddy Jose Mata ◽  
Ahmed Atef Hashmi ◽  
Abdullah Saleh Al-Yami

Abstract Assurance of well integrity is critical and important throughout the entire well's life cycle. Pressure build-up between cemented casings annuli has been a major challenge all around the world. Cement is the main element that provides isolation and protection for the well. The cause for pressure build-up in most cases is a compromise of cement sheath integrity that allows fluids to migrate through micro-channels from the formation all the way to the surface. These problems prompt cementing technologists to explore new cementing solutions, to achieve reliable long-term zonal isolation in these extreme conditions by elevating shear bond strength along-with minimal shrinkage. The resin-cement system can be regarded as a novel technology to assure long term zonal isolation. This paper presents case histories to support the efficiency and reliability of the resin-cement system to avoid casing to casing annulus (CCA) pressure build-up. This paper presents lab testing and application of the resin-cement system, where potential high-pressure influx was expected across a water-bearing formation. The resin-cement system was designed to be placed as a tail slurry to provide a better set of mechanical properties in comparison to a conventional slurry. The combined mixture of resin and cement slurry provided all the necessary properties of the desired product. The slurry was batch-mixed to ensure the homogeneity of resin-cement slurry mixture. The cement treatment was performed as designed and met all zonal isolation objectives. Resin-cement’s increased compressive strength, ductility, and enhanced shear bond strength helped to provide a dependable barrier that would help prevent future sustained casing pressure (SCP). The producing performance of a well depends in great part on a good primary cementing job. The success of achieving zonal isolation, which is the main objective of cementing, is mainly attributed to the cement design. The resin-cement system is evolving as a new solution within the industry, replacing conventional cement in many crucial primary cementing applications. This paper highlights the necessary laboratory testing, field execution procedures, and treatment evaluation methods so that this technology can be a key resource for such operations in the future. The paper describes the process used to design the resin-cement system and how its application was significant to the success of the jobs. By keeping adequate strength and flexibility, this new cement system mitigates the risk of cement sheath failure throughout the life of well. It provides a long-term well integrity solution for any well exposed to a high-pressure environment.


2014 ◽  
Vol 11 (6) ◽  
pp. 597-604 ◽  
Author(s):  
Mileva Radonjic ◽  
Arome Oyibo

Wellbore cement has been used to provide well integrity through zonal isolation in oil and gas wells as well as geothermal wells. Failures of wellbore cement result from either or both: inadequate cleaning of the wellbore and inappropriate cement slurry design for a given field/operational application. Inadequate cementing can result in creation of fractures and microannuli, through which produced fluids can migrate to the surface, leading to environmental and economic issues such as sustained casing pressure, contamination of fresh water aquifers and, in some cases, well blowout. To achieve proper cementing, the drilling fluid should be completely displaced by the cement slurry, providing clean interfaces for effective bond. This is, however, hard to achieve in practice, which results in contaminated cement mixture and poor bonds at interfaces. This paper reports findings from the experimental investigation of the impact of drilling fluid contamination on the shear bond strength at the cement-formation and the cement-casing interfaces by testing different levels of contamination as well as contaminations of different nature (physical vs. chemical). Shear bond test and material characterization techniques were used to quantify the effect of drilling fluid contamination on the shear bond strength. The results show that drilling fluid contamination is detrimental to both cement-formation and cement-casing shear bond strength.


2018 ◽  
Vol 7 (4) ◽  
pp. 2250
Author(s):  
B P. Nandurkar ◽  
Dr A. M. Pande

Performance of masonry is normally attributed to compressive strength of individual units, water absorption of individual units, strength of masonry mortar and the bond between mortar and individual units. Many researches in the past have contributed towards the bond strength and relevance of compressive strength of mortar in achieving good bonds. However, the quality of bricks available in India significantly vary from region the region. Thus, a need is felt in understanding bond strength of masonry. In this paper three types of mortars(total nine combinations), two types of bricks (red clay brick and fly ash brick) are considered, tests such as compressive strength, water absorption of the bricks, compressive strength of various mortar combinations, flexure bond strength and shear bond strength are presented. Failure patterns of the masonry units are also discussed. Results of the two tests show noticeable variation in bond strengths, however the shear bond strength has significant relationship with the compressive strength of mortar. The research outcome also points towards using bricks in saturated condition for achieving adequate performance.  


2020 ◽  
Vol 20 (02) ◽  
pp. 85-92
Author(s):  
Idham Khalid ◽  
Ali Musnal ◽  
Adi Novriansyah ◽  
Kurniawan Sitanggang

[ID] Pelaksanaaan proses penyemenan yang baik pada sumur minyak merupakan aspek penting yang berpengaruh pada suskesnya produksi minyak ke permukaan. Untuk itu, penggunaan additif dalam suspense semen direkomendasikan supaya kulitas suspense semen tetap stabil selama proses penyemenan berlangsung. Melakui penelitian ini kualitas bentonite lokal dan bentonite komersial terhadap parameter compressive strength(CS) dan shear bond strength (SBS) akan dibandingkan. Pengukuran CS dan SBS dilkukan berdasarkan rekomendasi dari American Petroleum Institute (API) pada tujuh buah sampel suspense semen dengan konsentrasi aditif yang bervariasi.  Hasil penelitian terhadap bentonite lokal menunjukkan penurunan nilai CS dengan bertambahnya konsentrasi aditif. Konsentrasi optimum bentonite lokal adalah 1.6% dengan nilai CS sebesar 1649 psi, 6%  dibawah nilai CS untuk sampel suspense semen dan bentonite komersial pada konsentrasi yang sama. Untuk nilai SBS, konsentrasi optimum untuk aditif bentonite lokal adalah 4.8% dengan nilai SBS sebesar 439 psi, 21 % diatas nilai SBS untuk sampel semen dengan 4.8% bentonite komersial. Dari penentuan nilai CS dan SBS dapat disimpulkan bahwa penggunaan bentonite lokal dapat menjadi alternatif pengganti bentonite komersial dimana hasil pengukuran CS dan SBS tidak menunjukkan perbedaan yang signifikan. [EN] The implementation of a good cementing process in oil wells is an important aspect that affects the success of oil production to the surface. For this reason, the use of additives in semen suspense is thought that the quality of the cement suspension remains stable during the cementing process. By doing this research, the quality of local bentonite and commercial bentonite against the parameters of compressive strength (CS) and shear bond strength (SBS) will be compared. CS and SBS measurements were carried out based on recommendations from the American Petroleum Institute (API) on seven cement suspension samples with varying additive concentrations. The results of research on local bentonite showed a decrease in the value of CS with an increase in additive concentration. The optimum concentration of local bentonite is 1.6% with a CS value of 1649 psi, 6% below the CS value for cement and commercial bentonite suspense samples at the same concentration. For the SBS value, the optimum concentration for local bentonite additives is 4.8% with an SBS value of 439 psi, 21% above the SBS value for cement samples with 4.8% commercial bentonite. From the determination of CS and SBS values, it can be shown that the use of local bentonite can be an alternative to commercial sites where the CS and SBS measurement results do not show a significant difference.


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