Synthesis of Asphalt Nanoparticles and Their Effects on Drilling Fluid Properties and Shale Dispersion

Abstract

Summary Asphalt nanoparticles (ANs) were developed by synthesizing asphalt powders with chloroacetic acid (ClCH2COOH). The objective of this synthesis was to develop engineered ANs with a cationic point capable of adsorbing on the net negatively charged clay platelets, thereby improving drilling fluid functionality and pore-plugging performance, reducing shale dispersion, and ultimately enhancing shale stability. Tests carried out to study the performance of the synthesized ANs include particle size analysis, Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy, drilling fluid rheology, and filtration rate and shale dispersion tests. FT-IR spectrum results confirming the occurrence of a chemical reaction between asphalt and ClCH2COOH showed a shift in NH vibration from 3,439.95 cm−1 (before synthesis) to 3,435.05 cm−1 (after synthesis). Based on particle size analysis, an average particle size diameter of 92.9 nm was observed, suggesting the tendency of ANs to invade and seal nanopore spaces. The shape of ANs ranged from spherical to irregular, because intercalated structures were observed from the scanning electron microscopic analysis on the interaction between ANs and sodium bentonite (Na-Bent). An increase in attracting force between the Na-Bent particles caused by the adsorption of ANs cationic point on bentonite clay particles led to an increase in drilling fluid rheological properties as the ANs %w/v increased. The drilling fluid filtration rate was, however, not significantly affected by the %w/v increase in ANs because results indicated slight decrease in fluid loss when compared with the base mud (BM). According to the shale dispersion test, the shale cuttings percentage recovery of the 2%w/v ANs sample was 76.5%, owing to the decrease in fluid-rock interaction caused by ionic adsorption and encapsulation of shale surfaces by the ANs. Experimental results from this investigation indicate that the likely mechanisms of the effect of ANs on shale formations would be sealing off nanopore spaces in formations because of its ultratiny particle size; adsorption of the net negatively charged shale cuttings by the ANs cationic point, thereby reducing drilling cuttings dispersion; and improving hole-cleaning performance due to its effect on the drilling fluid rheological properties.

Analisis Penentuan Nilai Cation Exchange Capacity (CEC) Berdasarkan Hasil Methylene Blue Test (MBT) di Trayek 12¼

“…Ini juga mendinginkan dan melumasi lubang sumur, memungkinkan potongan batuan bergerak dengan lancar ke permukaan (Agwu, et al, 2021). Ada tiga jenis cairan pengeboran yaitu berbahan dasar minyak (Kesarwani, Saxena, & Sharma, 2020), berbahan dasar sintetis (Xionghu et al, 2022), dan berbahan dasar air (Ali et al, 2022). Pada penggunaan lumpur pemboran untuk setiap kondisi sumur berbeda-beda, sehingga perlukan pengamatan terhadap jenis-jenis lumpur pemboran yang digunakan agar sesuai dengan kondisi formasi.…”

Smart Fluids and Their Applications in Drilling Fluids to Meet Drilling Technical Challenges

“…Due to their relatively high surface area, these nanoparticles are able to form spatially distributed thin films on metal surfaces resulting in improved smart lubricity performance. Due to their ultratiny particle sizes, nanoparticles have been reported to enhance wellbore stability by invading and effectively plugging shale nanoporous media, helping to provide necessary stability for the wellbore [18].…”

“…In smart nanoparticle drilling fluids, nanoparticles have been known to influence drilling fluid performances due to changes in wt.% concentrations, higher specific surface area, and high quantum activity [14][15][16]. When considering the effects of nanoparticles on wellbore stability, it is suggested that, due to their tiny particle sizes, they are able to invade and plug shale nanoporous media, thereby enhancing the mechanical strength of unconsolidated shale formations and thus improving wellbore stability [17,18]. On the influence of nanoparticles on water-based drilling fluids, since bentonite clay surfaces are considered to be net negatively charged with clouds of cations due to electron deficiency owing to isomorphic substitution in their unit layer, functionalized and charged nanoparticles (cationic and anionic) can cause either an increase or decrease in drilling fluid rheological properties through electrostatic attractive and repulsive forces [13].…”

Study on the Inhibition Mechanism of Hydration Expansion of Yunnan Gas Shale using Modified Asphalt

“…To further improve the dispersibility of asphalt, asphalt shale inhibitors such as sulfonated asphalt and emulsified asphalt have been developed [27]. Xionghu et al prepared nano asphalt particles with cationic groups, improving the adsorption and blocking properties of asphalt powder [28]. However, owing to the poor matching between the existing conventional inhibitors and Yunnan shale formations, wellbore instability caused by the hydration expansion of the formation is still severe.…”