scholarly journals Effect of Iron Oxide Nanoparticles on the Properties of Water-Based Drilling Fluids

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6718
Author(s):  
Muhammad Awais Ashfaq Alvi ◽  
Mesfin Belayneh ◽  
Sulalit Bandyopadhyay ◽  
Mona Wetrhus Minde

In recent years, several studies have indicated the impact of nanoparticles (NPs) on various properties (such as viscosity and fluid loss) of conventional drilling fluids. Our previous study with commercial iron oxide NPs indicated the potential of using NPs to improve the properties of a laboratory bentonite-based drilling fluid without barite. In the present work, iron oxide NPs have been synthesized using the co-precipitation method. The effect of these hydrophilic NPs has been evaluated in bentonite and KCl-based drilling fluids. Rheological properties at different temperatures, viscoelastic properties, lubricity, and filtrate loss were measured to study the effect of NPs on the base fluid. Also, elemental analysis of the filtrate and microscale analysis of the filter cake was performed. Results for bentonite-based fluid showed that 0.019 wt% (0.1 g) of NPs reduced the coefficient of friction by 47%, and 0.0095 wt% (0.05 g) of NPs reduced the fluid loss by 20%. Moreover, for KCl-based fluids, 0.019 wt% (0.1 g) of additive reduced the coefficient of friction by 45%, while higher concentration of 0.038 wt% (0.2 g) of NPs shows 14% reduction in the filtrate loss. Microscale analysis shows that presence of NPs in the cake structure produces a more compact and less porous structure. This study indicates that very small concentration of NPs can provide better performance for the drilling fluids. Additionally, results from this work indicate the ability of NPs to fine-tune the properties of drilling fluids.

2020 ◽  
Vol 143 (4) ◽  
Author(s):  
Muhammad Awais Ashfaq Alvi ◽  
Mesfin Belayneh ◽  
Kjell Kåre Fjelde ◽  
Arild Saasen ◽  
Sulalit Bandyopadhyay

Abstract Lately, nanoparticles (NPs) have shown the potential to improve the performance of oil well fluids significantly. Several studies have reported the ability of NPs to produce improved properties of both water and oil-based drilling fluids. In this study, hydrophobic iron oxide NPs were synthesized by thermal decomposition of iron pentacarbonyl in an inert atmosphere, and its performance was tested in the oil-based drilling fluid with 90/10 oil-to-water ratio (base fluid). Oil-based drilling fluids treated with nanofluids were formulated by adding 0.5 wt% and 1.0 wt% iron oxide NPs in hexane solution to the base drilling fluid. The base fluid and the nanofluid-treated drilling fluids were evaluated by characterizing their rheological properties at different temperatures, viscoelastic properties, lubricity, filtrate loss, static and dynamic settling, and separation properties. Results showed that 0.5 wt% iron oxide dispersed in hexane reduced the high pressure high temperature (HPHT) filtrate loss by 70%, filter cake thickness by 55%, and the coefficient of friction by 39%. Moreover, the nanofluid based drilling fluid reduced the free oil layer caused by syneresis during aging at high temperature by 16.3% compared to the base fluid. This study has shown that hydrophobic iron oxide NPs have the potential to improve the properties of oil-based drilling fluid.


Author(s):  
Muhammad Awais Ashfaq Alvi ◽  
Mesfin Belayneh ◽  
Kjell Kåre Fjelde ◽  
Arild Saasen ◽  
Sulalit Bandyopadhyay

Abstract In recent years, nanoparticles (NPs) have shown the potential to improve the performance of oil well fluids significantly. Several studies have reported the ability of NPs to produce improved properties of both water and oil-based drilling fluids. In this paper, hydrophobic iron oxide NPs were synthesized by thermal decomposition of iron pentacarbonyl in an inert atmosphere, and its performance was tested in the oil-based drilling fluid with 90/10 oil to water ratio (base fluid). Oil-based drilling fluids treated with nanofluids were formulated by adding 0.5 wt. % and 1.0 wt. % iron oxide NPs in hexane solution to the base drilling fluid. The base fluid and the nanofluid treated drilling fluids were evaluated by characterizing their rheological properties at different temperatures, viscoelastic properties, lubricity, filtrate loss, static & dynamic settling, and separation properties. Results showed that 0.5 wt. % iron oxide dispersed in hexane reduced the HPHT filtrate loss by 70%, filter cake thickness by 55%, and the coefficient of friction by 39%. Moreover, the nanofluid based drilling fluid reduced the free oil layer caused by syneresis during aging at high temperature by 16.3% compared to the base fluid. This study has shown that hydrophobic iron oxide NPs have the potential to improve the properties of oil-based drilling fluid.


Author(s):  
Zisis Vryzas ◽  
Vassilios C. Kelessidis ◽  
Lori Nalbandian ◽  
Vassilios Zaspalis

Smart drilling fluids, which can change their properties according to the flow environment, must be carefully designed so that they can handle the difficult challenges of HP/HT drilling successfully. Due to their unique physico-chemical properties, nanoparticles (NP) are considered as very good candidates for the formulation of these smart drilling fluids. This study presents filtration and rheological results of newly developed high-performance water-based drilling fluid systems containing different nanoparticles, commercial (C) titanium oxide (TiO2) and commercial (C) copper oxide (CuO) NP and compares them with results from using custom-made (CM) iron oxide (Fe3O4) NP and commercial (C) iron oxide (Fe3O4) NP, previously reported. Novel nano-based drilling fluids were made of de-ionized water, 7 wt% commercial Na-bentonite (base fluid), and NP were added at 0.5 wt%. The rheological properties of the produced suspensions were measured at temperatures up to 60°C and at atmospheric pressure with a Couette-type viscometer. Filtration characteristics were determined at elevated pressures and temperatures in a HP/HT filter press (500 psi/176°C) using ceramic discs as filter media, of permeability, k = 775 mD. The results of this study showed that the samples containing 0.5 wt% C TiO2 caused a reduction in the fluid loss by 23%, while C CuO NP resulted in 16% reduction, when compared to that of the base fluid, at these HPHT conditions. This should be compared to the 47% and 34% reduction in fluid loss of 0.5% CM Fe3O4 NP and of 0.5% of C Fe3O4 NP, reported previously. Analysis of rheological data revealed shear-thinning behavior for all the tested novel drilling fluids. The samples containing TiO2 and CuO NP exhibited a yield stress less than that of the base fluid, compared to the increased yield stress observed for the C and CM Fe3O4 NP. This behavior can be attributed to the fact that TiO2 and CuO NP may also act as deflocculants and prevent the gelation of bentonite suspensions. This study shows that commercial nanoparticles of TiO2 and CuO do not perform as well as the Fe3O4 NP on filtration but provide drilling fluids with lower yield stresses, thus they could be considered as alternatives to Fe3O4 in situations where the rheological properties are critical.


Author(s):  
Muhammad Awais Ashfaq Alvi ◽  
Mesfin Belayneh ◽  
Arild Saasen ◽  
Kjell Kåre Fjelde ◽  
Bernt S. Aadnøy

In recent years, the application of nanomaterial has been attracting the oil and gas industry. Nanomaterials research results show an improving performance of cement, drilling fluid and enhanced oil recovery. In this paper, the effect of multi-walled carbon nanotube (MWCNT) and MWCNT functionalized with ligands–OH and - COOH nanoparticles on laboratory drilling fluids formulated from bentonite, KCL, Carboxymethyl cellulose (CMC) and xanthan gum (XG) was studied. The formulations and tests were performed at room temperature. The results show that addition of 0.0095wt.% of MWCNT, MWCNT-OH and MWCNT-COOH nanoparticles in CMC/bentonite system decreases the filtrate-loss by 8.6 %, 7.1 % and 17.9 % respectively. These particles also decreased the coefficient of friction by 34 %, 37 % and 33 % respectively. In xanthan gum drilling fluid, 0.019wt%. MWCNT reduced the friction coefficient by 38 %.


2015 ◽  
Vol 1125 ◽  
pp. 210-214 ◽  
Author(s):  
Abdul Razak Ismail ◽  
Muhammad Syafiq Ab Rashid ◽  
Nurul Jannah Ismail ◽  
Wan Rosli Wan Sulaiman ◽  
Mohd Zaidi Jaafar

The key performance of any drilling operation depends heavily on the choice of drilling fluid used as well as how good it can overcome the drill pipe friction. It is essential that the drilling fluid be able to reduce bit wear, torque and drag. Drilling with oil-based drilling fluid offer less torque and drag. However, water based drilling fluid are cheaper and environmental friendly compared to oil-based and synthetic-based drilling fluids. Lubricants are added to drilling fluid to produce a thin film of liquid that separates the solid surfaces in contact to reduce the friction to an acceptable range. This study focused on the performance evaluation of two different commercial lubricants, which are EBL and EME salt to improve the lubricity of water based drilling fluid. The performances of lubricants were evaluated by ranging the concentrations from 1%, 2% and 3%. Fann Lubricity Tester is used to test the lubricity of these lubricants. The results reveal that the coefficients of friction for all lubricants were reduced after reaching the optimum concentration at the range of 1 - 2%. Some improvements were observed on the rheological properties such as plastic viscosity, yield point and gel strength when the lubricants were added to the drilling fluid. The values satisfy the requirement accepted by the industry. This study also showed that the applicants of EBL lubricant is better than EME salt in term of reducing the coefficient of friction in drilling fluid.


1969 ◽  
Vol 9 (04) ◽  
pp. 403-411 ◽  
Author(s):  
B.K. Sinha ◽  
Harvey T. Kennedy

Abstract Recommendations are made for obtaining consistent and reproducible test data on drilling fluids having identical composition. Previously, such a procedure has been difficult to accomplish even when the fluids were mixed in similar equipment. A survey of work in this area indicates that previous methods have been unsatisfactory because previous methods have been unsatisfactory because (1) the muds are extremely sensitive to the duration and violence of agitation during a normal mixing routine, and (2) gelling of the muds occurs before the properties can reach constant values. This gelling is caused by water evaporation resulting from the increase in temperature associated with the agitation. The work shows that these problems largely can be overcome by (1) agitating the constituents of the drilling fluid more vigorously, (2) maintaining a fairly constant temperature, and(3) Protecting the fluid from evaporation. When these steps are followed, the fluid properties approach asymptotic values that do not change by prolonged or accelerated agitation or by aging for a month. The time required to reach asymptotic values or a stabilized state is from 2 to 6 hours and is a function of the mud composition. Introduction Preparation of drilling fluids in the laboratory to determine their suitability to meet specific drilling requirements or to serve as a base fluid to evaluate the effectiveness of thinners, dispersants or other additives normally begins with combining measured quantities of the constituents and stirring them for a short time in a low-speed mixer. This is done to obtain a uniform mixture and to hydrate clays. Then the fluid is further agitated in a higher-speed device (Hamilton Beach mixer or Waring blender) to disperse more thoroughly and clay particles The biggest obstacle in the laboratory investigation of drilling fluids has been the lack of a method of producing a mixture by which reproducible results of the measured properties could be obtained. Numerous investigators have encountered this difficulty. Prior to 1929, density was the only property of mud that customarily was measured. The use of Wyoming bentonite on a large scale after 1929 was mainly responsible for the development of more elaborate testing procedures and for the application of the principles of colloid chemistry to the drilling fluids. Ambrose and Loomis in 1931 were among the first to recognize the plastic flow characteristics of drilling fluids, although Bingham in 1916 had observed The same phenomenon with dilute clay suspensions. Marsh introduced the Marsh funnel for field testing in 1931. By this time, non-Newtonian characteristics of drilling fluids were established. The Stormer and MacMichael viscometers were used to study the rheological properties of the fluids. In the 1930's and early 1940's, the work conducted by several investigators contributed toward a better understanding of drilling fluids. In the mid 1930's, fluid-loss and the associated mud-cake-forming properties of drilling fluids were recognized as important to the behavior of these fluids. The other properties of drilling fluids, including gel strength, pH, and sand content soon were recognized. In 1937, API published its first recommended procedure for test methods. Since that time, these procedures have been revised periodically. The latest edition, RP-13B, was published in 1961 However, in spite of the recognized need for a method of mixing that provides drilling fluids with stabilized properties, no such method previously has been described. SPEJ P. 403


2021 ◽  
Author(s):  
Zhao Xionghu ◽  
Saviour Bassey Egwu ◽  
Deng Jingen ◽  
Miao Liujie

Abstract The effect of corrosion inhibitor Benzotriazole on synthetic-based mud system was studied. Rheological performance of the benzotriazole enhanced synthetic-based fluid system was studied and compared against the base mud. To study its effect on dynamic wellbore conditions, different drilling fluid compositions were placed in a hot rolling oven for 16 hours at temperatures 150 °C and 170°C and the effect of temperature on mud properties were studied. Tests carried out include rheological test (before and after hot rolling), filtrate pH, lubricity test, and fluid loss test. The corrosion penetration rate was studied using the weight loss method. Based on experiment results, the synthetic-based mud system which comprised of benzotriazole displayed a reduction in coefficient of friction up to 95.93%. At ambient condition, optimal ratio of mineral oil:benzotriazole (M:B) which gives best lubricity performance on synthetic-based mud system is 80:20. This leads to improved corrosion inhibition and lubricity of the synthetic-based fluid by reducing the coefficient of friction up to 90.13%. Increased temperature led to further decrease in coefficient of friction with a % torque reduction of 95.93 displayed by the 80:20 ratio M:B mud composition at 170 °C. Significant alterations of the mud composition rheological and fluid loss parameters before and after exposure to high temperature in hot rolling oven were not observed. pH values were maintained ≥7 at the dynamic conditions highlighting solubility of the formulated fluid composition and absence of contaminants which can pose significant threats to the rates of corrosion in drill pipes. Increasing the concentration of Benzotriazole led to a reduction in corrosion rate. However, as the temperature effect increased, the corrosion rate elevated. Based on results from this investigation, it was concluded that Benzotriazole can be applied as a corrosion inhibitor in a synthetic-based drilling fluid system as an alternative corrosion inhibitor without significant alteration of the base mud properties. Benefits of this will be the optimization of extended reach well drilling operations due to excellent lubricity performance, corrosion rate reduction, compatibility with HPHT wellbore condition and fluid loss control.


2018 ◽  
Author(s):  
Ζήσης Βρύζας

Η γεώτρηση αποτελεί την πλέον δαπανηρή εργασία σε μια καμπάνια εξεύρεσης και παραγωγής υδρογονανθράκων. Πέραν αυτού συνιστά και την μοναδική διεργασία που δίνει τη δυνατότητα ακριβούς προσδιορισμού των αποθεμάτων στο υπέδαφος. Ο πολφός (γεωτρητικά ρευστά) είναι το ‘αίμα’ της γεώτρησης: παρέχει πίεση, μεταφορά τριμμάτων/θραυσμάτων από τον πυθμένα του φρέατος, ψύξη και λίπανση κοπτικού και στήλης, καθώς επίσης διατηρεί τα θραύσματα εν αιωρήσει όταν υπάρχει διακοπή της κυκλοφορίας. Ως ρευστό γεώτρησης (drilling fluid) χρησιμοποιείται συνήθως ένα αιώρημα πηλού και άλλων υλικών σε νερό. Τα ρευστά διάτρησης με βάση το νερό αποτελούνται από α) νερό, το οποίο αποτελεί την συνεχή φάση και παρέχει το αρχικό ιξώδες (φρέσκο ή θαλασσινό), β) ενεργά στερεά για την ενίσχυση του ιξώδους και του σημείου διαρροής (μπεντονίτης, που συνιστάται στην περίπτωση του φρέσκου νερού και ατταπουλγίτης, αμίαντος ή σιπιόλιθος, που συνιστώνται στην περίπτωση του θαλασσινού νερού), και γ) αδρανή στερεά για την επίτευξη της απαιτούμενης πυκνότητας (βαρύτης, θειούχος μόλυβδος, σιδηρομεταλλεύματα ή χαλαζιακά υλικά).Τα γεωτρητικά ρευστά αποτελούν το 10-20% του συνολικού κόστους κατά την διάρκεια μιας γεώτρησης. Ποσοστό πολύ υψηλό όταν μιλάμε για επενδύσεις εκκατομυρίων δολλαρίων. Λόγω των ολοένα πιο βαθιών αλλά και περίπλοκων γεωλογικών σχηματισμών υπάρχει τεράστια ανάγκη από την πετρελαική βιομηχανία για καινούργια και περισσότερο αποδοτικά γεωτρητικά ρευστά τα οποία θα μπορούν να ανταπεξέλθουν στα ολοένα και πιο απαιτητικά περβάλλοντα θερμοκρασίας και πίεσης. Τα σημαντικότερα ζητήματα τα οποία καλούνται να ανταποκριθούν τα ρευστά είναι οι ολοένα αυξανόμενες συνθήκες πίεσης και θερμοκρασίας στο υπέδαφος που είναι απόροια της αναζήτησης υδρογονανθράκων σε πλέον δύσβατες περιοχές με μεγαλύτερα βάθη που αυξάνουν τους κινδύνους και το κόστος για μια γεώτρηση. Η απώλεια ρευστού κυκλοφορίας (fluid loss) είναι ένα από τα σημαντικότερα και πλέον δαπανηρά προβλήματα κατά την διαδικασία μιας γεώτρησης. Ως απώλεια ρευστού κυκλοφορίας ορίζεται η συνολική ή μερική απώλεια των ρευστών της γεώτρησης σε εξαιρετικά διαπερατές ζώνες (porous sands), σε σπηλαιώδεις σχηματισμούς (cavernous zones), σε φυσικές ρηγματώσεις (natural fractures) και σε ρηγματώσεις προκαλούμενες κατά τη διάτρηση (induced fractures). Τα τελευταία χρόνια έχουν γίνει αρκετές προσπάθειες για την βελτίωση των γεωτρητικών ρευστών με την χρήση νανοσωματιδίων, τα οποία έχουν τη δυνατότητα να βελτιώσουν τις ιδιότητες των γεωτρητικών ρευστών όταν προστίθενται ακόμα και σε χαμηλές συγκεντρώσεις (<1 wt%). Οι μοναδικές τους ιδιότητες σχετίζονται με το μικρό τους μέγεθος και επομένως τον εξαιρετικά μεγάλο λόγο επιφάνειας προς όγκο.Σε αυτή την εργασία, εξετάστηκαν διάφορα εμπορικά νανοσωματίδια (Fe2O3, Fe3O4, SiO2) καθώς επίσης συντέθηκαν, με την μέθοδο της συγκαταβύθισης, νανοσωματιδία μαγνητίτη (custom-made Fe3O4), με και χωρίς επικάλυψη κιτρικού οξέος, τα οποία ερευνήθηκαν ως προς την ικανότητα τους να βελτιώσουν τις ρεολογικές ιδιότητες και την απώλεια ρευστών σε αιωρήματα μπετονίτη. Προκειμένου να χαρακτηρισθούν φυσικοχημικά τα αιωρήματα υπέστησαν ξήρανση με κοκκοποίηση σε θερμοκρασία υγρού Ν2 και κρυοξήρανση. Η μορφολογία, η κρυσταλλική δομή και οι επιφανειακές ομάδες των ξηρών κόνεων εξετάσθηκαν με ηλεκτρονική μικροσκοπία HR-TΕM, περίθλαση ακτίνων Χ (XRD), φυσική ρόφηση Ν2 και φασματοσκοπία FTIR. Οι αλληλεπιδράσεις των σωματιδίων μπετονίτη με τα νανοσωματίδια και οι διάφορες δομές που δημιουργούνται και πως τελικά αυτές επηρεάζουν τις ρεολογικές ιδιότητες των αιωρημάτων εξετάστηκαν με το HR-TEM στους 25°C και 60°C. Με βάση τις εικόνες από το HR-TEM, ένα μοντέλο αλληλεπιδράσεων μεταξύ των διαφορετικών τύπων νανοσωματιδίων και σωματιδίων μπετονίτη δημιουργήθηκε για πρώτη φορά για τέτοια αιωρήματα. Οι ρεολογικές ιδιότητες των παραγόμενων δειγμάτων εξετάστηκαν και σε συνθήκες ατμοσφαιρικής πίεσης (μέχρι 70°C) με την χρήση περιστροφικού ιξωδόμετρου (Grace M3600-Couette type geometry) αλλά και σε συνθήκες υψηλής πίεσης και θερμοκρασίας (69 bar-121°C) (Chandler 7600 HPHT viscometer). Το μοντέλο Herschel-Bulkley χρησιμοποιήθηκε για να περιγράψει τη μεταβολή του ιξώδους με τη μεταβολή των ρεολογικών παραμέτρων δείχνοντας εξαιρετική εφαρμογή για τις διαφορετικές πειραματικές μετρήσεις με συντελεστές συσχέτισης (R2) >0.99 σε όλες τις περιπτώσεις. Οι ρεολογικές μετρήσεις έδειξαν ότι η προσθήκη των νανοσωματιδίων βελτιώνει σημαντικά τις ρεολογικές ιδιότητες των αιωρημάτων μπετονίτη στις διάφορες συνθήκες πίεσης και θερμοκρασίας. Οι απώλειες ρευστών (fluid loss) εξετάστηκαν με φιλτροπρέσες υψηλής πίεσης και θερμοκρασίας (20.7 bar και 121°C) οι οποίες υπολογίζουν τον ρυθμό διήθησης του πολφού μέσω του χρησιμοποιούμενου φίλτρου (κεραμικός δίσκος). Η μεγαλύτερη μείωση στην απώλεια ρευστών επιτεύχθηκε για το δείγμα που περιείχε 0.5 wt% custom-made Fe3O4 με μείωση -40% σε σχέση με το αρχικό δείγμα μπετονίτη που δείχνει την τεράστια ικανότητα των νανοσωματιδίων να βελτιώσουν σημαντικά τις απώλειες ρευστών ακόμα και σε τόσο μικρές συγκεντρώσεις. Τέλος, εξετάστηκε η ικανότητα των παραγόμενων ρευστών να αλλάζουν τις ρεολογικές τους ιδιότητες υπό την επίδραση διάφορων μαγνητικών πεδίων (μέχρι 0.7 Tesla). Τα αποτελέσματα έδειξαν ότι τα καινούργια γεωτρητικά ρευστά έχουν την ικανότητα να αυξάνουν την τάση διολίσθησης (yield stress) έως και 300% σε σχέση με αυτή που μετρήθηκε χωρίς την εφαρμογή μαγνητικού πεδίου. Αυτό είναι κάτι πολύ σημαντικό που επιτρέπει την χρήση έξυπνων ρευστών (smart drilling fluids) τα οποία μπορούν να εξοικονομήσουν και χρόνο αλλά και κόστη κατά την διάρκεια μιας γεώτρησης.Τα νανοσωματίδια δείχνουν πολλές ελπιδοφόρες δυνατότητες σε εφαρμογές γεωτρήσεων αφού έχουν τη δυνατότητα να βελτιώσουν ή και να λύσουν το πρόβλημα της απώλειας ρευστών, όταν προστίθενται ακόμα και σε χαμηλές συγκεντρώσεις (>0.5 wt%), ενώ ταυτόχρονα βελτιστοποιούν τις ρεολογικές ιδιότητες των γεωτρητικών ρευστών. Η χρήση τους για την ανάπτυξη βελτιωμένων γεωτρητικών ρευστών υπόσχεται να αλλάξει την βιομηχανία των γεωτρήσεων και να την βοηθήσει να εξορυχθούν πολύπλοκοι γεωλογικοί σχηματισμοί πιο αποδοτικά αλλά και οικονομικά.


Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4877
Author(s):  
Mobeen Murtaza ◽  
Sulaiman A. Alarifi ◽  
Muhammad Shahzad Kamal ◽  
Sagheer A. Onaizi ◽  
Mohammed Al-Ajmi ◽  
...  

Drilling issues such as shale hydration, high-temperature tolerance, torque and drag are often resolved by applying an appropriate drilling fluid formulation. Oil-based drilling fluid (OBDF) formulations are usually composed of emulsifiers, lime, brine, viscosifier, fluid loss controller and weighting agent. These additives sometimes outperform in extended exposure to high pressure high temperature (HPHT) conditions encountered in deep wells, resulting in weighting material segregation, high fluid loss, poor rheology and poor emulsion stability. In this study, two additives, oil wetter and rheology modifier were incorporated into the OBDF and their performance was investigated by conducting rheology, fluid loss, zeta potential and emulsion stability tests before and after hot rolling at 16 h and 32 h. Extending the hot rolling period beyond what is commonly used in this type of experiment is necessary to ensure the fluid’s stability. It was found that HPHT hot rolling affected the properties of drilling fluids by decreasing the rheology parameters and emulsion stability with the increase in the hot rolling time to 32 h. Also, the fluid loss additive’s performance degraded as rolling temperature and time increased. Adding oil wetter and rheology modifier additives resulted in a slight loss of rheological profile after 32 h and maintained flat rheology profile. The emulsion stability was slightly decreased and stayed close to the recommended value (400 V). The fluid loss was controlled by optimizing the concentration of fluid loss additive and oil wetter. The presence of oil wetter improved the carrying capacity of drilling fluids and prevented the barite sag problem. The zeta potential test confirmed that the oil wetter converted the surface of barite from water to oil and improved its dispersion in the oil.


2021 ◽  
pp. 2150411
Author(s):  
Rania Hasan Huseen ◽  
Ali A. Taha ◽  
Ihab Q. Ali ◽  
Oday Mahmmod Abdulhusein ◽  
Selma M. H. Al-Jawad

In this study, iron oxide nanoparticles (NPs) had been prepared by co-precipitation method. In order to reduce their toxicity and increase stability, prepared iron oxide was coated with gum Arabic. Gum Arabic is preferred over synthetic materials due to their non-toxicity, low cost and availability. Characterization of coated and non-coated iron oxide NPs had been performed by spectrophotometer, Fourier transfer infra-red spectrophotometer (FTIR), Zeta potential, X-ray diffraction (XRD) and field emission scanning electron microscopic (FE-SEM). The fabricated nanoparticles appeared purity and crystalline nature by XRD, with diameter average of 27.01 nm and 55.12 nm for iron oxide NPs and iron oxide NPs coated with gum Arabic, respectively. On the other hand, four biological activities of coated and non-coated iron oxide had been investigated. High removal of methylene blue pollutant dye (46%) was observed with iron oxide NPs, while removal percentage was 22.6 performed by iron oxide NPs coated with gum Arabic within 72 h. Iron oxide NPs revealed high inhibition zones of 27.5 nm and 30 mm, at 1000 [Formula: see text]g/ml, against S. aureus and E. coli, respectively, while coated iron oxide NPs with gum Arabic revealed low antibacterial activity against both examined bacteria even when used at 1000 [Formula: see text]g/ml. The hemolytic activity of prepared NPs had been determined. The hemolytic percentage was increased whenever concentrations of nanoparticles increased. Lower hemolytic percentages were 69.76 and 50.98 for iron oxide NPs and iron oxide NPs coated with gum Arabic were observed at a concentration of 250 [Formula: see text]g/ml. Finally, cytotoxic activity was estimated against MCF-7 cell line and normal cell line WRL68 by MTT assay. A decrease in MCF-7 viability to 65.1% was observed when 400 [Formula: see text]g/ml of iron oxide NPs was used, while WRL68 viability was 75.03%. Iron oxide NPs coated with gum Arabic revealed significant reduction in MCF-7 and WRL68 viability to 69.90% and 80.05%, respectively, when 400 [Formula: see text]g/ml of nanoparticles was applied.


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