scholarly journals Developing a Thermally Stable Ester-Based Drilling Fluid for Offshore Drilling Operations by Using Aluminum Oxide Nanorods

2021 ◽  
Vol 13 (6) ◽  
pp. 3399
Author(s):  
Alaa Ahmed ◽  
Amin Sharifi Haddad ◽  
Roozbeh Rafati ◽  
Ahmed Bashir ◽  
Ahmed M. AlSabagh ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Aluminum Oxide ◽  
Drilling Fluid ◽  
Normal Pressure ◽  
Drilling Fluids ◽  
Temperature Conditions ◽  
Oxide Nanorods ◽  
Ethyl Octanoate ◽  
Drilling Operations ◽  
Filtration Properties

Esters were found to be promising alternatives to oil, as a constituent of drilling fluids, due to their biodegradability and bioaccumulation attributes. In this study, we used ethyl octanoate ester (EO) as a low molecular weight synthetic oil for formulating an ester-based drilling fluid (EBDF). Aluminum oxide nanorods (nanoparticles) were introduced as a Pickering emulsion stabilizer. Like the commercial emulsifiers, they showed that they stabilized the invert emulsion drilling fluid in our study. The rheological and filtration properties of the EBDF were tested at normal pressure and three temperatures: low temperature deepwater (LT) conditions of 2.6 °C, normal pressure and normal temperature (NPNT) conditions of 26.8 °C, and elevated temperature conditions of 70 °C. To enhance the stability and filtration properties of the drilling fluid, aluminum oxide nanoparticles (NPs) were used. An optimum concentration of 1 wt% was found to provide superior rheological performance and higher stability than samples without NPs at NPNT, LT, and elevated temperature conditions. Steadier gel rheology was exhibited at elevated temperature conditions, and a slow rate of an increasing trend occurred at the lower temperatures, with increasing NP concentrations up to 1.5 wt%. Filtration loss tests presented a reduction of fluid loss with increasing the NP concentration. The results demonstrate that a reduction of up to 45% was achieved with the addition of 1 wt% NP. These results show that nano-enhancement of ethyl octanoate drilling fluids would suffice to provide a wider range of operational temperatures for deepwater drilling operations by providing better thermal stability at elevated temperatures and maintaining stability at lower temperatures.

scholarly journals Improvement of the Rheological and Filtration Properties of Drilling Mud Using the Syrian Clay

2020 ◽  
Vol 26 (5) ◽  
pp. 211-230
Author(s):  
Adnan Ibrahim Barodi
Keyword(s):  
Xanthan Gum ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Clay Concentration ◽  
Fluid Properties ◽  
Drilling Operations ◽  
Solid Part ◽  
Time Required ◽  
Filtration Properties

Drilling fluid properties and formulation play a fundamental role in drilling operations. The Classical water-based muds prepared from only the Syrian clay and water without any additives((Organic and industrial polymers) are generally poor in performance. Moreover, The high quantity of Syrian clay (120 gr / l) used in preparing drilling fluids. It leads to a decrease in the drilling speed and thus an increase in the time required to complete the drilling of the well. As a result, the total cost of drilling the well increased, as a result of an increase in the concentration of the solid part in the drilling fluid. In this context, our study focuses on the investigation of the improvement in drilling mud   Prepared from the Syrian clay by reducing the clay concentration to (50 gr / L). And compensate for the remaining amount (70 gr / l) of clay by adding (natural and industrial polymers) The rheological properties and filtration are measured at different concentrations of polymers .. In light of the experiments, we determine the polymers' concentrations that gave good results in improving the flow properties and controlling the Filter. It is polymers that have given good results:، HEC، HEC and Xanthan Gum  PAC and HEC، CMCHV، PolyAcryl Amid ، Xanthan Gum .

scholarly journals Effect of silica nano particles on the rheological and HTHP filtration properties of environment friendly additive in water-based drilling fluid

2021 ◽  
Author(s):  
Ved Prakash ◽  
Neetu Sharma ◽  
Munmun Bhattacharya
Keyword(s):  
Drilling Fluid ◽  
Cost Effective ◽  
Vital Role ◽  
Nano Particles ◽  
Rheological Parameters ◽  
Drilling Fluids ◽  
Filtration Loss ◽  
Water Based ◽  
Drilling Operations ◽  
Filtration Properties

AbstractRheological and filtration properties of drilling fluid contribute a vital role in successful drilling operations. Rheological parameters such as apparent viscosity (AV), plastic viscosity (PV), yield point (YP) and gel strength of drilling fluids are very essential for hydraulic calculations and lifting of drill cuttings during the drilling operation. Control of filtration loss volume is also very important for cost effective and successful drilling operations. Therefore, the main goal of this research is to improve the rheological and filtration properties of Grewia Optiva fibre powder (GOFP) by using 30–50 nm size of silica nano particles (SNP) in water-based drilling fluid. The experimental outcomes revealed that after hot rolling of mud samples at 100 °C for 16 h, the low pressure-low temperature (LPLT) and high pressure-high temperature (HPHT) filtration loss of GOFP additives was improved, after the addition of SNP on it. The mixture of 5% GOFP + 4% SNP has reduced the LPLT and HPHT filtration loss of drilling fluid by 74.03 and 78.12%, respectively, as compared to base mud. Thus, it was concluded that after the addition of 0.4% SNP, the LPLT and HPHT filtration control ability of GOFP additive in WBM were increased by 17.6 and 15%, respectively. The rheological parameters such as AV, PV, YP and gelation of drilling fluids were also improved by the addition of GOFP + SNP mixture in the base mud. Therefore, the implementation of GOFP + SNP mixture in water-based mud showed auspicious results which reaffirm the feasibility of using them in the successful drilling operations.

scholarly journals Utilization of Eco-Friendly Waste Generated Nanomaterials in Water-Based Drilling Fluids; State of the Art Review

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4171
Author(s):  
Rabia Ikram ◽  
Badrul Mohamed Jan ◽  
Akhmal Sidek ◽  
George Kenanakis
Keyword(s):  
State Of The Art ◽  
Superior Performance ◽  
Future Research ◽  
Drilling Fluids ◽  
Drill Cuttings ◽  
Environmental Friendly ◽  
Water Based ◽  
Drilling Operations ◽  
Filtration Properties

An important aspect of hydrocarbon drilling is the usage of drilling fluids, which remove drill cuttings and stabilize the wellbore to provide better filtration. To stabilize these properties, several additives are used in drilling fluids that provide satisfactory rheological and filtration properties. However, commonly used additives are environmentally hazardous; when drilling fluids are disposed after drilling operations, they are discarded with the drill cuttings and additives into water sources and causes unwanted pollution. Therefore, these additives should be substituted with additives that are environmental friendly and provide superior performance. In this regard, biodegradable additives are required for future research. This review investigates the role of various bio-wastes as potential additives to be used in water-based drilling fluids. Furthermore, utilization of these waste-derived nanomaterials is summarized for rheology and lubricity tests. Finally, sufficient rheological and filtration examinations were carried out on water-based drilling fluids to evaluate the effect of wastes as additives on the performance of drilling fluids.

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 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.

scholarly journals Numerical Modeling of Foam Drilling Hydraulics

2007 ◽  
Vol 4 (1) ◽  
pp. 103 ◽  
Author(s):  
Ozcan Baris ◽  
Luis Ayala ◽  
W. Watson Robert
Keyword(s):  
Drilling Fluid ◽  
Operating Conditions ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Lost Circulation ◽  
Pressure Profiles ◽  
Drilling Operations ◽  
Parametric Studies ◽  
Bit Life ◽  
Foam Drilling

The use of foam as a drilling fluid was developed to meet a special set of conditions under which other common drilling fluids had failed. Foam drilling is defined as the process of making boreholes by utilizing foam as the circulating fluid. When compared with conventional drilling, underbalanced or foam drilling has several advantages. These advantages include: avoidance of lost circulation problems, minimizing damage to pay zones, higher penetration rates and bit life. Foams are usually characterized by the quality, the ratio of the volume of gas, and the total foam volume. Obtaining dependable pressure profiles for aerated (gasified) fluids and foam is more difficult than for single phase fluids, since in the former ones the drilling mud contains a gas phase that is entrained within the fluid system. The primary goal of this study is to expand the knowledge-base of the hydrodynamic phenomena that occur in a foam drilling operation. In order to gain a better understanding of foam drilling operations, a hydrodynamic model is developed and run at different operating conditions. For this purpose, the flow of foam through the drilling system is modeled by invoking the basic principles of continuum mechanics and thermodynamics. The model was designed to allow gas and liquid flow at desired volumetric flow rates through the drillstring and annulus. Parametric studies are conducted in order to identify the most influential variables in the hydrodynamic modeling of foam flow. 

scholarly journals Experimental Investigation of Water Based Colloidal Gas Aphron Fluid Stability

2019 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Seyed Hosseini-Kaldozakh ◽  
Ehsan Khamehchi ◽  
Bahram Dabir ◽  
Ali Alizadeh ◽  
Zohreh Mansoori
Keyword(s):  
Xanthan Gum ◽  
Drilling Fluid ◽  
Sodium Dodecyl ◽  
Ammonium Bromide ◽  
Drilling Fluids ◽  
Size Distributions ◽  
Electrolyte System ◽  
Colloidal Gas Aphron ◽  
The Stability ◽  
Filtration Properties

Today, the drilling operators use the Colloidal Gas Aphron (CGA) fluids as a part of drilling fluids in their operations to reduce formation damages in low-pressure, mature or depleted reservoirs. In this paper, a Taguchi design of experiment (DOE) has been designed to analyse the effect of salinity, polymer and surfactant types and concentration on the stability of CGA fluids. Poly Anionic Cellulose (PacR) and Xanthan Gum (XG) polymers are employed as viscosifier; Hexadecyl Trimethyl Ammonium Bromide (HTAB) and Sodium Dodecyl Benzene Sulphonate (SDBS) have been also utilized as aphronizer. Moreover, bubble size distributions, rheological and filtration properties of aphronized fluids are investigated. According to the results, the polymer type has the highest effect, whereas the surfactant type has the lowest effect on the stability of CGA drilling fluid. It was also observed that increasing salinity in CGA fluid reduces the stability. Finally, it should be noted that the micro-bubbles generated with HTAB surfactant in an electrolyte system, are more stable than SDBS surfactant.

Well Control Simulation With Nonaqueous Drilling Fluids

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Felipe Chagas ◽  
Paulo R. Ribeiro ◽  
Otto L. A. Santos
Keyword(s):  
Drilling Fluid ◽  
Petroleum Industry ◽  
Critical Issue ◽  
Drilling Fluids ◽  
Operational Parameters ◽  
Data Set ◽  
Well Control ◽  
Operational Conditions ◽  
Control Research ◽  
Drilling Operations

Abstract The demand for energy has increased recently worldwide, requiring new oilfield discoveries to supply this need. Following this demand increase, challenges grow in all areas of the petroleum industry especially those related to drilling operations. Due to hard operational conditions found when drilling complex scenarios such as high-pressure/high-temperature (HPHT) zones, deep and ultradeep water, and other challenges, the use nonaqueous drilling fluids became a must. The reason for that is because this kind of drilling fluid is capable to tolerate these extreme drilling conditions found in those scenarios. However, it can experience changes in its properties as a result of pressure and temperature variations, requiring special attention during some drilling operations, such as the well control. The well control is a critical issue since it involves safety, social, economic, and environmental aspects. Well control simulators are a valuable tool to support well control operations and preserve the well integrity, verifying operational parameters and to assist drilling engineers in the decision-making process during well control operations and kick situations. They are also important computational tools for rig personnel training. This study presents well control research and development contributions, as well as the results of a computational well control simulator that applies the Driller's method and allows the understanding the thermodynamic behavior of synthetic drilling fluids, such as n-paraffin and ester base fluids. The simulator employed mathematical correlations for the drilling fluids pressure–volume–temperature (PVT) properties obtained from the experimental data. The simulator results were compared to a test well data set as well to the published results from other kick simulators.

Understanding the Phenomenon of Dissolved Gas Migration of Gas in Riser During Drilling Operations

2019 ◽  
Author(s):  
Syed Y. Nahri ◽  
Yuanhang Chen ◽  
Wesley Williams ◽  
Otto Santos ◽  
Louis Thibodeaux ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Mass Transfer ◽  
Drilling Fluid ◽  
Gas Absorption ◽  
Base Case ◽  
Drilling Fluids ◽  
Dissolved Carbon ◽  
Experimental Apparatus ◽  
Drilling Operations ◽  
And Diffusion

Abstract The prevention and control of gas kicks is a major concern in the petroleum industry during deepwater drilling operations. The problem is further aggravated when dealing with synthetic and oil-based muds (SOBM and OBM) that can dissolve a gas influx entering the wellbore. Due to the solubility of formation gases in drilling fluids, the gas cut mud resulting from gas absorption has a density lower than that of overlaying unsaturated drilling fluid. Lab scale experimental tests were conducted in order to understand whether buoyancy-induced convection and diffusion attribute to mass transfer of a dissolved influx. Experiments were performed on a low-pressure mass transfer apparatus using carbon-dioxide (CO2) and mineral oil to study the extent of mass transfer due to buoyancy induced convective flow and diffusion. Measurements were made on the axial distance travelled by the dissolved carbon dioxide and gas concentration over the length of a pipe by measuring the mass of gas accumulated in different test sections of the experimental apparatus. This arises due to a concentration gradient developed when contaminated fluid comes in contact with a fresh column of drilling fluid. Experimentally obtained measurements made on the mass transfer coefficient are used to tune simulations carried out using a computational fluid dynamic (CFD) software — ANSYS Fluent. This enables us to replicate field scenarios to study the extent of well control issues that could arise when a gas influx enters the wellbore, even when circulation has ceased. Results obtained here can be used as a base case to understand a similar phenomenon occurring when extended to other fluid systems such as that of a natural gas influx in synthetic oil-based drilling fluids.

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