Expansive admixtures (mainly ettringite)

Nagataki, Shigeyoshi; Gomi, Hideaki

doi:10.1016/s0958-9465(97)00064-4

Cited by 239 publications

(96 citation statements)

References 7 publications

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“…Anhydrite (CaSO4) and calcium oxide (CaO) are the main expansive additives available in SCDA and have been combined with cement [48,49]. ASTM C 845-96 [50] classifies three categories of expansive cement based on its additives as follows.…”

Section: Chemical Composition Of Scdamentioning

confidence: 99%

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

2016

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Global energy and material consumption are expected to rise in exponential proportions during the next few decades, generating huge demands for deep earth energy (oil/gas) recovery and mineral processing. Under such circumstances, the continuation of existing methods in rock fragmentation in such applications is questionable due to the proven adverse environmental impacts associated with them. In this regard; the possibility of using more environmentally friendly options as Soundless Chemical Demolition Agents (SCDAs) play a vital role in replacing harmful conventional rock fragmentation techniques for gas; oil and mineral recovery. This study reviews up to date research on soundless cracking demolition agent (SCDA) application on rock fracturing including its limitations and strengths, possible applications in the petroleum industry and the possibility of using existing rock fragmentation models for SCDA-based rock fragmentation; also known as fracking. Though the expansive properties of SCDAs are currently used in some demolition works, the poor usage guidelines available reflect the insufficient research carried out on its material's behavior. SCDA is a cementitious powdery substance with quicklime (CaO) as its primary ingredient that expands upon contact with water; which results in a huge expansive pressure if this CaO hydration reaction occurs in a confined condition. So, the mechanism can be used for rock fragmentation by injecting the SCDA into boreholes of a rock mass; where the resulting expansive pressure is sufficient to create an effective fracture network in the confined rock mass around the borehole. This expansive pressure development, however, dependent on many factors, where formation water content creates a negative influence on this due to required greater degree of hydration under greater water contents and temperature creates a positive influence by accelerating the reaction. Having a precise understanding of the fracture propagation mechanisms when using SCDA is important due to the formation of complex fracture networks in rocks. Several models can be found in the literature based on the tangential and radial stresses acting on a rock mass surrounding an SCDA charged borehole. Those fracture models with quasi-static fracturing mechanism that occurs in Mode I type tensile failure show compatibility with SCDA fracturing mechanisms. The effect of borehole diameter, spacing and the arrangement on expansive pressure generation and corresponding fracture network generation is important in the SCDA fracturing process and effective handling of them would pave the way to creating an optimum fracture network in a targeted rock formation. SCDA has many potential applications in unconventional gas and oil recovery and in-situ mining in mineral processing. However, effective utilization of SCDA in such application needs much extensive research on the performance of SCDA with respect to its potential applications, particularly when considering unique issues arising in using SCDA in different ...

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Section: Chemical Composition Of Scdamentioning

confidence: 99%

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

2016

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“…The expansive mechanism of the increasing volume of gel state during the early age of the EX may occur from several factors such as the expansion from water adsorption, the crystal growth from the crystalline structure development of calcium hydroxide, and forming of coexisting pores from the disintegration of the ingredients within the EX during the hydration process [27]. There is a rate of change in volume of the chemical compounds of calcium hydroxide which increases from the reaction of CaO + H 2 O = 1.9 times [27]. The expansion considerably concerns the solubility.…”

Section: Discussionmentioning

confidence: 99%

Effects of Shrinkage Reducing Agent and Expansive Additive on Mortar Properties

Treesuwan

Maleesee

2017

Advances in Materials Science and Engineering

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This research is to study the effect of mortar mixed with shrinkage reducing agent (polyoxyalkylene alkyl ether type), expansive additive (CaO type), and fly ash (hereinafter "SRA," "EX," and "FA," resp.). Moreover, steam curing was studied to improve the properties of mortar. The plastic shrinkage test was conducted by using the strain gauge embedded at 0.5 cm from the surface according to the ASTM C1579-06 standard within early age followed by the total shrinkage test and compressive strength test. The test results showed that mixing both the EX and SRA increases the plastic enlargement of the mortar during the early age more than using either the EX or SRA solely. The steam curing helps to reduce the plastic shrinkage when the mortar is added with the FA and SRA while adding the EX increases the enlargement compared to the normal curing. When the EX, SRA, and FA are all added to the mortar mixing, great attention should be paid due to the increase of greater enlargement. For the compressive strength view, the steam curing increases the compressive strength in all types of mixture. The steam curing significantly helps increasing the compressive strength of mortar with combination of EX, SRA, and FA. Nevertheless, the XRD and SEM tests explain such enlargement accordingly.

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“…Calcium sulfoaluminate requires large quantities of water for its hydration product ettringite to form (Nagataki and Gomi, 1998), otherwise it's reaction is hindered. The major limitation for use in cement sheaths of expansive systems, which rely upon the formation of ettringite, is its instability at temperatures above 76 ℃ (Nelson and Guillot, 2006).…”

Section: Expansive Additivesmentioning

confidence: 99%

Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review

Jafariesfad

Geiker

Gong

et al. 2017

Journal of Petroleum Science and Engineering

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Well cementing is an important operation during drilling and completion of oil wells. The cement sheath must maintain well integrity behind the casing and provide long-term zonal isolation to ensure safety and prevent environmental problems. Despite recent technological advancement in smart polymeric materials, fibers and self-healing materials, it is still a big challenge to provide adequate long-term zonal isolation in severe oil well conditions. This review provides an overview of challenges faced in oil wells compromising the long-term ability of the cement sheath to provide zonal isolation. Factors controlling the long-term performance of cement sheath are discussed, in terms of shrinkage, tensile strength and flexibility. The use of nanomaterials as cement additive to fabricate flexible, high-tensile strength, and low-shrinkage cement system are reviewed.Introduction of nanomaterials into the cement system is a promising approach to design a sealant for the entire life of the well, thereby avoiding potential remedial costs and environmental impacts.

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Expansive admixtures (mainly ettringite)

Cited by 239 publications

References 7 publications

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

An Alternative to Conventional Rock Fragmentation Methods Using SCDA: A Review

Effects of Shrinkage Reducing Agent and Expansive Additive on Mortar Properties

Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review

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