Effects of microstructure and pore water on electrical conductivity of cement slurry during early hydration

Liu, Kaiqiang; Cheng, Xiaowei; Li, Jingxue; Gao, Xianshu; Cao, Yan; Guo, Xiaolu; Zhuang, Jia; Zhang, Chunmei

doi:10.1016/j.compositesb.2019.107435

Cited by 50 publications

(18 citation statements)

References 53 publications

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“…Scholars at home and abroad have carried out research on the damage mechanism of oil and gas reservoirs in the cementing process and have achieved certain research results. Some researchers have carried out the internal relationship between the quality of the mud cake of the drilling fuid and the degree of damage to the reservoir by the cement slurry [10,[16][17][18]. Te formation of better quality internal and external mud cakes can efectively prevent the damage of drilling fuid and cement slurry to oil and gas reservoirs, so as to achieve the purpose of protecting reservoirs.…”

Section: Introductionmentioning

confidence: 99%

Damage of Green Synthetic Cement Slurry to Clastic Rock Reservoir

Tan

Yang

et al. 2023

Journal of Chemistry

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Green synthesis and metal oxide composites have attracted much attention from researchers of industry and academia. As a typical application of green synthesis and metal oxide composites, the protection of oil and gas reservoirs is related to various links such as exploration, drilling, completion, and development. It is a complex and systematic project, which directly affects whether the oil and gas fields can be discovered, evaluated, and efficiently developed in time, and it is also related to the development of oil and gas fields recovery rate. As the most critical part of oil and gas well construction, the cementing process mainly pays attention to the safe pumping of the cement slurry and the long-term effective interlayer isolation capability of the cement sheath. Less attention is paid to the reservoir protection during the cementing process. The high-pressure difference between the annulus and the formation, the high fluid loss, and the high solids content of the cementing slurry during the cementing process have also become major challenges. In order to solve this problem, this study takes a typical clastic rock block in an oilfield in western China as the research object and carries out a geological survey of fracture development, pressure deficit, and cement slurry permeability leakage in the reservoir. The reservoir physical properties, clay mineral characteristics, and formation water quality of rock reservoirs are analyzed. The influence of cement slurry filtrate and solid phase particles on reservoir clay expansion rate and permeability was tested by core porosity and permeability tester. XRD and SEM techniques were used to analyze the damage mechanism of cement slurry filtrate and solid phase particles to the reservoir. The research results show that the average porosity of the clastic rock reservoir in the study area is 15%, the permeability is high, the average pore size of the reservoir is between 37 and 56 μm, the microfractures are developed in the reservoir section, and the porosity and permeability conditions are good; high-valent cations and inorganic ions in the filtrate generate inorganic scales such as CaCO3 and Mg(OH)2 and cross-link with dissolved polymers to form flocculation substances, which cause the filtrate to damage the reservoir, and at the same time, the cement particles in the pore throats in the near wellbore zone are lost along with the leakage. Furthermore, hydration, tightly bonding the inert admixture and the clastic rock formation, forms a tight sealing layer, which reduces the permeability of the reservoir sharply; the expansive clay particles in the reservoir absorb the moisture of the cement slurry filtrate and expand. The volume of the particles increases, and the porous formation containing expansive clay minerals absorbs moisture and causes internal expansion, and the volume expansion rate can reach 9%, which eventually causes the porosity and permeability of the reservoir to decrease, resulting in reservoir damage and solid phase in the cement slurry. The damage of particles to the reservoir is mainly due to the blockage of the reservoir pore throats and the hydration and consolidation of cement particles inside the reservoir caused by the external admixtures in the cement slurry that do not participate in the hydration reaction. The solid phase particles form a filter cake on the surface of the reservoir core and cannot enter the reservoir, but under the condition of porous formation leakage, the solid phase particles with a particle size of 1–10 μm in the cement slurry will directly penetrate into the reservoir rock resulting in shallow plugging in the reservoir near the wellbore. The research results provide theoretical data support for the research on low-damage cementing slurry technology in clastic rock reservoirs. The work provides an important application guidance to green synthesis and metal oxide composites.

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Section: Introductionmentioning

confidence: 99%

Damage of Green Synthetic Cement Slurry to Clastic Rock Reservoir

Tan

Yang

et al. 2023

Journal of Chemistry

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“…Too much liquid in an AAM can, however, lead to highly porous binders which in turn can affect conductivity. While increased porosity has been reportedly linked to higher conductivity [96][97][98], it has also been linked to reduced conductivity [91,99]. Having reviewed this literature, the authors of the present review believe that increasing porosity likely leads to higher conductivities, up until a point: the dominant conduction mechanism in AAM is, after all, accepted to be via pore solution, the volume of which would be higher with more pore space.…”

Section: Electrical (Ionic) Conductivity: Reported Magnitudesmentioning

confidence: 82%

Self-Sensing Alkali-Activated Materials: A Review

2020

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Alkali-activated materials are an emerging technology that can serve as an alternative solution to ordinary Portland cement. Due to their alkaline nature, these materials are inherently more electrically conductive than ordinary Portland cement, and have therefore seen numerous applications as sensors and self-sensing materials. This review outlines the current state-of-the-art in strain, temperature and moisture sensors that have been developed using alkali activated materials. Sensor fabrication methods, electrical conductivity mechanisms, and comparisons with self-sensing ordinary Portland cements are all outlined to highlight best practice and propose future directions for research.

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“…On the other hand, as the degree of saturation increases, the electron and charge transfer speeds between the end of the test specimens and the conductive medium increase 30 , 31 , which effectively reduces the contact impedance, it can be seen from the experimental results that the degree of saturation or curing humidity of the specimens plays a major role in the contact impedance, ionic (or electrolytic) conduction is the main phenomenon of electricity transport 62 . Besides, for the specimens cured at the same humidity and using the same medium as the conductive medium, the contact impedance increase with the curing ages, this is due to the porosity and the pore solution conductivity of the cement paste both decrease with the increase of curing age as the cement hydration 63 , which cause greater contact impedance.…”

Section: Resultsmentioning

confidence: 99%

Evaluation of electrode-sample contact impedance under different curing humidity conditions during measurement of AC impedance of cement-based materials

Wang

Chen

et al. 2020

Sci Rep

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In this study, a simple method was proposed to calculate electrode-sample contact impedance in the cases of two-point and four-point measurements. The results indicated that when using the saturated calcium hydroxide solution (SCH) as conductive medium, the contact impedance in the four-point measurement is negligible for the impedance range of cement-based materials. The SCH can be used as a reference for correction of the contact impedance. A reasonable combination of curing humidity and different conductive media is recommended for the two-point measurement, which is suitable for testing the ACIS of cement-based materials. In a case of contact impedance not being precisely known, it is highly recommended that a four-point measurement with two different ratios of the length of the sample and the center spacing of the voltage electrodes (L/a) should be conducted to evaluate the effect of the contact impedance following the procedure proposed in this study.

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Effects of microstructure and pore water on electrical conductivity of cement slurry during early hydration

Cited by 50 publications

References 53 publications

Damage of Green Synthetic Cement Slurry to Clastic Rock Reservoir

Damage of Green Synthetic Cement Slurry to Clastic Rock Reservoir

Self-Sensing Alkali-Activated Materials: A Review

Evaluation of electrode-sample contact impedance under different curing humidity conditions during measurement of AC impedance of cement-based materials

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