scholarly journals Synthesis and development of smart drilling fluids using nanoparticles to tailor their transport properties for enhanced drilling operations

2018 ◽  
Author(s):  
Ζήσης Βρύζας
Keyword(s):  
Transport Properties ◽  
Yield Stress ◽  
Drilling Fluid ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Natural Fractures ◽  
Custom Made ◽  
Drilling Operations ◽  
Induced Fractures

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.

Can Titanium and Copper Oxide Commercial Nanoparticles Be Used for HP/HT Applications? A Comparison With the Very Well Performing Fe3O4 NP

2018 ◽  
Author(s):  
Zisis Vryzas ◽  
Vassilios C. Kelessidis ◽  
Lori Nalbandian ◽  
Vassilios Zaspalis
Keyword(s):  
Iron Oxide ◽  
Copper Oxide ◽  
Rheological Properties ◽  
Yield Stress ◽  
Base Fluid ◽  
Drilling Fluid ◽  
Filter Press ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Custom Made

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.

Evaluation of Constitutive Equation for Stress in Solids in Porous Media Composed of Bridging Agents Used in Drilling Fluids

2012 ◽  
Vol 727-728 ◽  
pp. 1878-1883 ◽  
Author(s):  
Bruno Arantes Moreira ◽  
Flávia Cristina Assis Silva ◽  
Larissa dos Santos Sousa ◽  
Fábio de Oliveira Arouca ◽  
João Jorge Ribeiro Damasceno
Keyword(s):  
Porous Media ◽  
Constitutive Equation ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Oil Well ◽  
Well Drilling ◽  
Drilling Operations ◽  
The Stability

During oil well drilling processes in reservoir-rocks, the drilling fluid invades the formation, forming a layer of particles called filter cake. The formation of a thin filter cake and low permeability helps to control the drilling operation, ensuring the stability of the well and reducing the fluid loss of the liquid phase in the interior of the rocks. The empirical determination of the constitutive equation for the stress in solids is essential to evaluate the filtration and filter cake formation in drilling operations, enabling the operation simulation. In this context, this study aims to evaluate the relationship between the porosity and stress in solids of porous media composed of bridging agents used in drilling fluids. The concentration distribution in sediments was determined using a non-destructive technique based on the measure of attenuated gamma rays. The procedure employed in this study avoids the use of compression-permeability cell for the sediment characterization.

A New Low-Damage Drilling Fluid for Sandstone Reservoirs With Low-Permeability: Formulation, Evaluation, and Applications

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Chengwen Wang ◽  
Yanji Wang ◽  
Ergun Kuru ◽  
Erding Chen ◽  
Fengfeng Xiao ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Ct Scanning ◽  
Solid Particles ◽  
Formation Damage ◽  
Fluid Loss ◽  
Low Permeability ◽  
Drilling Fluids ◽  
Micro Computed Tomography ◽  
Well Drilling ◽  
Drilling Operations

Abstract Drilling-induced formation damage is the key factor dominating the failure of the development of hydrocarbon reservoirs with low-permeability (i.e., tight formation). In this paper, a new low-damage drilling fluid was formulated, evaluated, and applied to well-drilling operations in a sandstone oil reservoir with low-permeability in the Shengli Oilfield, China. To formulate this low-damage drilling fluid, filter-cake forming agents were used to prevent fluid loss, inhibitors were used to enhance the shale inhibition of the fluid, surfactants were used to minimize water block, and inorganic salts were used to enhance compatibility. A holistic experimental approach combining micro-computed tomography (CT), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) techniques was designed to identify the underlying interactions between new and conventional drilling fluids and rock samples as well as the corresponding damage mechanisms, demonstrating the significant mitigation effects of the newly formulated drilling fluid on formation damage, which mainly results from the hydration of clay minerals and the invasion of solid particles. The newly formulated low-damage drilling fluid then extended its applications to well-drilling operations with excellent performance. Not only can the new low-damage drilling fluid avoid non-fracturing stimulation, but also reduce the drilling operational costs and time, minimize the formation damage, and facilitate extending the reservoir life for a longer time.

Wood Fibre Based Lost Circulation Materials

2018 ◽  
Author(s):  
Arild Saasen ◽  
Helge Hodne ◽  
Egil Ronæs ◽  
Simen André Aarskog ◽  
Bente Hetland ◽  
...  
Keyword(s):  
Fibre Type ◽  
Drilling Fluid ◽  
Wood Fibre ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Lost Circulation ◽  
Bottom Hole Assembly ◽  
Induced Fractures ◽  
Fine Wood ◽  
Lost Circulation Materials

In this paper both a coarse and fine wood fibre type of Lost Circulation Material (LCM) is tested in the laboratory. It is shown how these fibre treatments work. The fibre type is partially oil wetting making them suitable for application in oil based drilling fluids. The fine material helps stopping small drilling induced fractures, while the coarse helps stopping lost circulation into several natural fractures or coal or conglomerate formations. In the article, the selection of wood fibres is described in more detail. Testing of the fine materials were conducted conventionally by pumping drilling fluid volumes with LCM onto slotted disks in fluid loss apparatuses. The coarse fibres are too large to be tested in these apparatuses. Therefore, gravel with grain diameter around two centimetres was filled into transparent cylinders. The pore throats created by these gravel particles were above half a centimetre. For both of these LCMs the experiments show the sensitivity of the LCM concentration in the drilling fluid to stop the lost circulation. Also, it is shown the effect of the LCM on viscous properties of the drilling fluids. Not all LCMs can be pumped through the bit. The article describes the need for circulation subs in the bottom hole assembly (BHA) to hinder the LCM blocking the entire BHA.

USING DURIAN RIND AS BRIDGING MATERIAL TO OVERCOME FLUID LOSS AND LOST CIRCULATION PROBLEMS IN DRILLING OPERATIONS

2016 ◽  
Vol 78 (8) ◽  
Author(s):  
Nor Fatihah Abdul Majid ◽  
Issham Ismail ◽  
Mohd Fauzi Hamid
Keyword(s):  
Drilling Fluid ◽  
Filter Press ◽  
Fluid Loss ◽  
Lost Circulation ◽  
Water Based ◽  
Drilling Operations ◽  
Excellent Control ◽  
Induced Fractures ◽  
Loss Control ◽  
Durian Rind

Lost circulation is one of the drilling operational problems. It refers to the total or partial loss of drilling fluid into highly permeable zones or natural or induced fractures. This problem is likely to occur when the hydrostatic head pressure of drilling fluid in the hole exceeds the formation pressure. Today, managing lost circulation remains a significant challenge to oilwell drilling operations because it may contribute to high non-productive time. It is imperative to note that the overbalance pressure situation also can cause the invasion of mud filtrate into production zones which will result in formation damage. To address these problems, an experimental investigation has been done on durian rind as an alternative fluid loss and lost circulation materials in water-based mud. Durian rind was selected as a mud loss control material because it contains close to 20% pectin which may complement the formation of high quality mat-like bridges across openings of the formation. The test involved the use of standard mud testing equipment and a lost circulation test cell. Durian rind powder was prepared by cleaning and cutting the durian rind into small pieces of 1 to 2 cm, and then dried them in an oven at 60°C for 48 hours before grinding into five different sizes from coarse to ultra-fine while Hydro-plug, the commercial lost circulation material was supplied by Scomi Energy. The fluid loss test was conducted using a standard low pressure filter press while the bridging test was carried out at 100 psi of pressure difference and ambient temperature using a lost circulation cell. Fine durian in the water-based mud gave the best fluid loss control compared to coarse durian rind, fine and coarse Hydro-plug. The experimental results also showed that at 15 lb/bbl (42.8 kg/m3) optimum concentration, coarse and intermediate durian rind have outperformed Hydro-plug by showing an excellent control of mud losses in 1 and 2 mm simulated fractures.

A Novel Self-Photodegradation Drilling Fluids Under Near-Infrared Light Irradiation with Preferable Wellbore Stability

2021 ◽  
Author(s):  
Jiafeng Jin ◽  
Kaihe Lv ◽  
Jinsheng Sun ◽  
Yingrui Bai ◽  
Jingping Liu ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Near Infrared ◽  
Drilling Fluid ◽  
Wellbore Stability ◽  
Wettability Alteration ◽  
Infrared Light ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Gas Drilling ◽  
Drilling Operations

Abstract The ever-mounting drilling operations of the petroleum industry has been accompanied by tremendous wasted drilling fluid, Polycyclic Aromatic Hydrocarbons (PAHs) in which pose a huge threat to the health of human and ecosystem. Varying approaches have been proposed to remediate the damage caused by wasted drilling fluid, among which photocatalysis has been one of the most promising approaches for organic contaminants removal. The latest investigation shows that Bi2WO6 decorated on hydrophobic CNT can remove up to 80 % organic contaminant within a short time, exhibiting a preferable photocatalytic performance. Moreover, this hydrophobic CNT can play a vital role in stabilizing the wellbore due to its excellent water repellent. The objective of the study was to find out the effect of Bi2WO6 modified hydrophobic CNT on the PAHs photodegradation and wellbore stability in the process of drilling. Bi2WO6 as a near-infrared driven photocatalyst has attracted worldwide attention due to its preferable oxygen vacancy and quantum efficiency. However, the application of Bi2WO6 was impeded by the low migration efficiency of photo-generated carriers. The combination of Bi2WO6 and composite with good conductivity has been an effective method to resolve this problem. The instability of wellbore caused by shale hydration during oil and gas drilling operations also brings a huge challenge. In this study, a photocatalyst with wellbore stabilization capacity is achieved by hydrophobic CNT modified via Bi2WO6 sheet with nano-size. The fluid loss and wettability property were measured to evaluate the wellbore stabilization capacity of this novel agent. Meanwhile, photodegradation experiments and pathway analysis were conducted to evaluate the effect of photodegradation by Bi2WO6/CNT on the organic contaminants. Data of photodegradation indicated that the PAHs can be degraded up to 80% after treated by Bi2WO6/CNT, the migration efficiency of photogenerated carriers improved significantly. A slight decrease in fluid loss and distinctive increase in viscosity can be observed after treated with 0.3% Bi2WO6/CNT solution. The results of the rheology test verified that the photocatalyst has little effect on the rheological properties of drilling fluid. The result of SEM indicated that this novel Bi2WO6/CNT composite with a bombax structure can absorb preferentially organic contaminants, which is good at in-situ photodegradation and prevention of water invasion. To sum up, PAHs in wasted drilling fluids can be photodegraded by the novel Bi2WO6 nano-sheet modified CNT, and the stability of wellbore can also be significantly enhanced due to wettability alteration.

Development of a Reproducible Method of Formulating and Testing Drilling Fluids

1969 ◽  
Vol 9 (04) ◽  
pp. 403-411 ◽  
Author(s):  
B.K. Sinha ◽  
Harvey T. Kennedy
Keyword(s):  
Large Scale ◽  
Drilling Fluid ◽  
Flow Characteristics ◽  
Field Testing ◽  
Test Methods ◽  
Water Evaporation ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Testing Procedures ◽  
Asymptotic Values

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

A Generalized Model for the Field Assessment of Drilling Fluid Viscoelasticity

2021 ◽  
Author(s):  
Chen Hongbo ◽  
Okesanya Temi ◽  
Kuru Ergun ◽  
Heath Garett ◽  
Hadley Dylan
Keyword(s):  
Drilling Fluid ◽  
Field Testing ◽  
Field Application ◽  
Testing Equipment ◽  
Drilling Fluids ◽  
Rotational Viscometer ◽  
Generalized Model ◽  
Fluid Elasticity ◽  
Field Samples ◽  
Drilling Operations

Abstract Recent studies highlight the significant role of drilling fluid elasticity in particle suspension and hole cleaning during drilling operations. Traditional methods to quantify fluid elasticity require the use of advanced rheometers not suitable for field application. The main objectives of the study were to develop a generalized model for determining viscoelasticity of a drilling fluid using standard field-testing equipment, investigate the factors influencing drilling fluid viscoelasticity in the field, and provide an understanding of the viscoelasticity concept. Over 80 fluid formulations used in this study included field samples of oil-based drilling fluids as well as laboratory samples formulated with bentonite and other polymers such as partially-hydrolyzed polyacrylamide, synthesized xanthan gum, and polyacrylic acid. Detailed rheological characterizations of these fluids used a funnel viscometer and a rotational viscometer. Elastic properties of the drilling fluids (quantified in terms of the energy required to cause an irreversible deformation in the fluid's structure) were obtained from oscillatory tests conducted using a cone-and-plate type rheometer. Using an empirical approach, a non-iterative model for quantifying elasticity correlated test results from a funnel viscometer and a rotational viscometer. The generalized model was able to predict the elasticity of drilling fluids with a mean absolute error of 5.75%. In addition, the model offers practical versatility by requiring only standard drilling fluid testing equipment to predict viscoelasticity. Experimental results showed that non-aqueous fluid (NAF) viscoelasticity is inversely proportional to the oil-water ratio and the presence of clay greatly debilitates the elasticity of the samples while enhancing their viscosity. The work efforts present a model for estimating drilling fluid elasticity using standard drilling fluid field-testing equipment. Furthermore, a revised approach helps to describe the viscoelastic property of a fluid that involves quantifying the amount of energy required to irreversibly deform a unit volume of viscoelastic fluid. The methodology, combined with the explanation of the viscoelasticity concept, provides a practical tool for optimizing drilling operations based on the viscoelasticity of drilling fluids.

Development of Digital Twins for Drilling Fluids: Local Velocities for Hole Cleaning and Rheology Monitoring

2021 ◽  
Author(s):  
Mehrdad Gharib Shirangi ◽  
Roger Aragall ◽  
Reza Ettehadi ◽  
Roland May ◽  
Edward Furlong ◽  
...  
Keyword(s):  
Machine Learning ◽  
Rheological Properties ◽  
Drilling Fluid ◽  
Training Data ◽  
Drilling Fluids ◽  
Hole Cleaning ◽  
Digital Twins ◽  
Wide Range ◽  
Drilling Operations ◽  
Cuttings Bed

Abstract In this work, we present our advances to develop and apply digital twins for drilling fluids and associated wellbore phenomena during drilling operations. A drilling fluid digital twin is a series of interconnected models that incorporate the learning from the past historical data in a wide range of operational settings to determine the fluids properties in realtime operations. From several drilling fluid functionalities and operational parameters, we describe advancements to improve hole cleaning predictions and high-pressure high-temperature (HPHT) rheological properties monitoring. In the hole cleaning application, we consider the Clark and Bickham (1994) approach which requires the prediction of the local fluid velocity above the cuttings bed as a function of operating conditions. We develop accurate computational fluid dynamics (CFD) models to capture the effects of rotation, eccentricity and bed height on local fluid velocities above cuttings bed. We then run 55,000 CFD simulations for a wide range of operational settings to generate training data for machine learning. For rheology monitoring, thousands of lab experiment records are collected as training data for machine learning. In this case, the HPHT rheological properties are determined based on rheological measurement in the American Petroleum Institute (API) condition together with the fluid type and composition data. We compare the results of application of several machine learning algorithms to represent CFD simulations (for hole cleaning application) and lab experiments (for monitoring HPHT rheological properties). Rotating cross-validation method is applied to ensure accurate and robust results. In both cases, models from the Gradient Boosting and the Artificial Neural Network algorithms provided the highest accuracy (about 0.95 in terms of R-squared) for test datasets. With developments presented in this paper, the hole cleaning calculations can be performed more accurately in real-time, and the HPHT rheological properties of drilling fluids can be estimated at the rigsite before performing the lab experiments. These contributions advance digital transformation of drilling operations.

scholarly journals Experimental Investigation of the Rheological Behavior of an Oil-Based Drilling Fluid with Rheology Modifier and Oil Wetter Additives

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4877
Author(s):  
Mobeen Murtaza ◽  
Sulaiman A. Alarifi ◽  
Muhammad Shahzad Kamal ◽  
Sagheer A. Onaizi ◽  
Mohammed Al-Ajmi ◽  
...  
Keyword(s):  
High Temperature ◽  
Zeta Potential ◽  
Hot Rolling ◽  
Emulsion Stability ◽  
Drilling Fluid ◽  
Temperature Tolerance ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Before And After ◽  
Rheology Modifier

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.

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