Search

Drilling deviated wellbores has raised concerns about proper cutting transport. Cuttings settling downhole can create stationary cutting beds, causing drilling mishaps like stuck pipes. High fluid velocity is typically required to efficiently erode a stationary bed, but this is constrained by hydraulic and wellbore geometry. When this occurs, pipe rotation can erode the bed mechanically and enable efficient cutting transport even with lower fluid velocities. Therefore, this study formulated water-based mud (WBM) with hydroxyapatite nanoparticles (n-HAp) to examine the effect of pipe rotation on cutting transport in deviated wells. It was compared with copper II oxide nanoparticles (CuO NP) in terms of rheology, filtration, and cutting transfer efficiency (CTE). The CTE of n-HAp amounts (0.4–2.0 g) in moving cuttings with diameters of 0.80 to 3.60 mm through deviated wellbores of 40 to 65° at a 3.5 m/s fluid velocity with 60 and 120 rpm pipe rotation speeds was determined. Compared with CuO NP, n-HAp findings demonstrated enhanced rheology and CTE. However, for fluid loss control, n-HAp was slightly less effective compared to CuO NP. For all deviated angles, n-HAp increased the CTE by 9.5–50%, while CuO NP increased it by 3.4–38.7% at 120 rpm. Compared with 60 rpm, a higher CTE occurred at 120 rpm. Moreover, CTE occurs in the following manner: 40° > 65° > 45° > 60° > 50° > 55°. It suggests that stationary bed formation is more likely to occur at inclinations of 50–55°. These findings are crucial for drilling deviated wells. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering Research is the property of Sultan Qaboos University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Due to the inherent limitation of oilfield polyacrylamide in reservoir temperature and salinity, nanoparticles (NPs) have been extensively studied for their application in enhanced oil recovery (EOR) because of their unique properties and availability in large quantities. Recent trend in nanotechnology involves incorporating NPs as additive with polymer to form novel materials termed polymeric nanofluids (PNF's) for EOR. However, previous studies have investigated and focussed more on the suitability of silica (SiO 2) polymeric nanofluids. In this work, the potential application of metal oxide polymeric nanofluid for EOR was explored and evaluated. Aqueous HPAM-based Al 2 O 3 PNF's were formulated and characterised using Transmission Electron Microscopy (TEM) and Fourier-transform infrared (FTIR) spectroscopy. The performance of aluminium oxide (Al 2 O 3) NP on the rheological properties of HPAM in the presence of different electrolyte concentrations representative of field brine and typical reservoir temperatures were investigated. Wettability alteration study of Al 2 O 3 PNF was carried out using DataPhysics optical contact angle (OCA) instrument. Results obtained for Al 2 O 3 PNF were compared to the widely reported SiO 2 PNF and base polymer without nanomaterial. Experimental results show that the rheological properties improved while degradation of HPAM macromolecule was inhibited due to the addition of NPs. At 2,000 ppm HPAM solution (25 mol. % degree of hydrolysis), 0.1 wt% NP concentration was found to be the optimal choice for Al 2 O 3 NP which gives rise to the highest viscosity on the rheological characterization. Al 2 O 3 PNF exhibited better steady shear viscosity performance under the different electrolyte concentrations and temperatures studied. Al 2 O 3 PNF altered the wettability of the porous media from oil-wet to water-wetting condition. Finally, oil displacement test in sandstone cores at typical reservoir temperature and salinity showed that Al 2 O 3 PNF had 11.3% incremental oil recovery over conventional HPAM. This study is beneficial for extending the frontier of knowledge in nanotechnology application for EOR. • Al 2 O 3 PNF was formulated, characterised, and evaluated for EOR. • FTIR spectroscopy confirms the bonding of the NP's and HPAM molecules. • Al 2 O 3 PNF exhibited better rheological characteristics than SiO 2 PNF and HPAM. • The metal oxide PNF exhibited sterling wettability alteration properties. • Al 2 O 3 PNF displayed excellent oil displacement in sandstone cores. [ABSTRACT FROM AUTHOR]

Nanoparticles-stabilized foam has recently attracted increasing attention for enhanced oil recovery (EOR) applications, largely due to the potentially high stability of these foams in the oil producing formations. There are several research articles on experimental studies of nanoparticles-stabilized foam for EOR applications. However, no previous attempts has been made to comprehensively review these existing literature. To fill this identified knowledge gap, we conducted the first comprehensive review on current status of static stability experiments, macroscopic and microscopic scale experimental studies of nanoparticles-stabilized foam for EOR applications. Influence of different critical parameters on the foam performance was reviewed. The results of the previous studies were discussed, challenges and conflicting findings were identified and directions for further studies were suggested. Experiments were conducted by the authors to complement some of the results in literature. From the reviewed literature, results of experimental studies indicated that the presence of nanoparticles at an appropriate concentration and favorable hydrophobicity will improved the foam static and dynamic stability in porous media. Several critical parameters like nanoparticles types, salinity, oil presence, temperature and pressure control the efficiency of nanoparticle-stabilized foam. Review of the experimental methods showed that the pore-scale mechanisms of nanoparticles-stabilized foam generation, stability, propagation, and residual oil mobilizations in porous media are not yet explicit due to limited studies. Nanoparticles-stabilized foams for EOR have not been implemented in the field due to limited understanding of influence of controlling parameters on foam performance and insufficient mechanistic and modelling studies. The remarkable potential of nanoparticles-stabilized foam to recover the trapped oil from the low permeability layer of the heterogeneous formation, due to the occurrence of foam diversion, and the use of fly-ash nanoparticles for EOR applications remains an interesting topics for future studies. [ABSTRACT FROM AUTHOR]

A substantial volume of oil is trapped in the reservoir after the primary and secondary recovery processes because of pressure and reservoir heterogeneity. Experimental results have indicated that silica nanoparticle (SNP) flooding is highly efficient in enhanced oil recovery (EOR). The performance is a function of preparation and modification processes. The use of SNP modified by (3–Aminopropyl) triethoxysilane (APTES) is yet to be extensively examined for potential use in EOR. In this study, a modified SNP was examined to determine its influence in EOR applications. Sessile drop technique was utilized to determine the effectiveness of the modified SNP in altering the wettability of the oil-wet sandstone core. Subsequently, the interfacial tension (IFT) between oil and water was also investigated. Furthermore, the oil displacement efficiency of the modified nanofluid was compared with the unmodified. Zeta potential (ζ–potential), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscope (FESEM), and energy dispersive X–ray (EDX) spectra were used to confirm the modification of the SNP. The results show that APTES adhered to the surface of the modified SNP, and the particles are finely dispersed and stable in aqueous solution. The ζ–potential indicates that the surface charge of the particles increased from −16 mV to +26.4 mV after modification, which indicates long term stability when used in EOR processes. The silica nanofluids (SNFs) altered the wettability of sandstone core from oil–wet at a contact angle of 134.7° to water–wet at a contact angle of 54.3° (modified SNF) and 54.5° (unmodified SNF), at low concentrations. Also, the IFT of the modified SNF was low compared to unmodified SNF and APTES. The oil recovery of water flooding showed 62.9% and it improved to 75% and 69.6% when modified and unmodified SNFs were used, respectively. The pressure drop of the modified SNF was higher compared to the unmodified SNF which confirmed the stability of the modified SNF. Thus, the SNFs were very efficient in mobilizing trapped oil at ambient conditions and is, therefore, recommended for EOR processes. • SNP was modified by (3–Aminopropyl) triethoxysilane (APTES) as an EOR agent and compared with the unmodified. • Modified and unmodified silica nanofluids (SNFs) were formulated, characterized, and evaluated for EOR. • Zeta potential measurement and FTIR spectroscopy confirm the modification of the SNP. • Modified SNF exhibited sterling wettability alteration and IFT reduction properties at very low concentrations. • Modified SNF showed greater improvement in the oil displacement efficiency than the unmodified. [ABSTRACT FROM AUTHOR]