Incorporation of Hydroxyethylcellulose-Functionalized Halloysite as a Means of Decreasing the Thermal Conductivity of Oilwell Cement

Abstract

The significant heat loss and severe thermal fluctuations inherent in steam-assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS) impose considerable constraints on well cementing. In order to obtain better energy efficiency and mechanical robustness, there is considerable interest in the development of low-thermal-conductivity cement that can provide a combination of enhanced thermal insulation and mechanical resilience upon thermal cycling. However, the current palette of thermal cements is exceedingly sparse. In this article, we illustrate a method for decreasing the thermal conductivity of cement by inclusion of hydroxyethylcellulose-functionalized halloysite nanotubes. Halloysite/hydroxyethylcellulose inclusions offer an abundance of disparate interfaces and void space that can effectively scatter phonons, thereby bringing about a pronounced reduction of thermal conductivity. The microstructure of the nanocomposite cementitious matrix is strongly modified even as the compositional profile remains essentially unaltered. Modified cement nanocomposites incorporating halloysite nanotubes along with hydroxyethylcellulose in a 8:1 ratio with an overall loading of 2 wt.% exhibit the lowest measured thermal conductivity of 0.212 ± 0.003 W/m.K, which is substantially reduced from the thermal conductivity of unmodified cement (1.252 W/m.K). The ability to substantially decrease thermal conductivity without deleterious modification of mechanical properties through alteration of microstructure, inclusion of encapsulated void spaces, and introduction of multiple phonon-scattering interfaces suggests an entirely new approach to oilwell cementing based on the design of tailored nanocomposites.

Mesoporous halloysite nanotubes modified by CuFe2O4 spinel ferrite nanoparticles and study of its application as a novel and efficient heterogeneous catalyst in the synthesis of pyrazolopyridine derivatives

“…The structure and morphology of HNTs are dependent on the pore properties of nanotubes, also, it’s size could be easily changed under thermal, acidic and alkaline treatments 13 . The nano-sized tubular structure, mesoporosity and macroporosity of HNTs have been applied in several areas such as environmental uses 14 , tissue engineering 15 , cosmetic 16 , medicine 17 and catalysis 18 . HNTs with two kinds of hydroxyl groups in the inside and outside walls can be modified by different functional groups.…”

In situ Resource Utilization and Reconfiguration of Soils Into Construction Materials for the Additive Manufacturing of Buildings

“…The amount of clay added in the cement in the study is along the lines of soil added to concrete in previous reports (Lei and Plank, 2012;Li et al, 2017). The reduction of thermal conductivity derives from the inclusion of nanoscopic voids and the phonon scattering at interfaces within the composite (Cho et al, 2018;Udayakantha et al, 2019).…”

“…Such an approach provides a sharp reduction of thermal conductivity, thereby mitigating heat losses through oilwell cement during thermal extraction processes. Specifically, we have examined the incorporation of hydroxyethylcellulose-functionalized halloysite in class G Portland cement (Cho et al, 2018;Udayakantha et al, 2019). Approximately 2-5 wt.% of halloysite nano-clays with nanotubular voids are added to the cement achieving 7 days compressive strengths as high as 15.71 MPa (with even a slight enhancement of compressive strength with respect to control specimens without halloysite) whilst engendering upto ca.…”

Analisis Molekular dan Transpor Ion Amonium Clorida

“…karena kecepatan hanyut mengatur laju transportasi ion (119)(120)(121)(122)(123)(124)(125)(126)(127) ,maka dapat mengharapkan konduktivitas akan berkurang dengan bertambahnya viskositas pelarut akan ukuran ion (233,234) . Contohnya, konduktivitas molar ion logam alkali bertambah dari Li + ke Cs + ,walaupun radius ionnya bertambah, paradoks ini terpecahkan jika kita menyadari bahwa radius a dalam rumus stokes adalah radius hidrodinamik (128,129) ion, yaitu radius efektifnya dalam larutan dengan memperhitungkan molekul H2O yang dibawa dalam bola hidrasinya.ion kecil (180) menimbulkan medan listrik lebih kuat dari pada ion besar sehingga ion kecil lebih terlarut secara ekstensif dari ion besar.jadi,ion dengan radius kecil dapat mempunyai radius hidrodinamik besar (200) ,karena ion itu menyeret banyak molekul pelarut melalui larutan itu,saat bermigrasi (207) .…”

“…Kondutivitas atau hantaran (119)(120)(121)(122)(123)(124)(125)(126)(127)(141)(142)(143)(144)(145)(146)(147)(148) merupakan pengukuran dasar untuk mempelajari gerakan ion (149)(150)(151)(152) , konduktivitas atau daya hantar listrik adalah kekuatan seberapa kuat larutan dapat menghantarkan listrik (188) . Hantaran merupakan kebalikan dari hambatan listrik (195) .…”