scholarly journals The application of MWCNT to enhance the rheological behavior of drilling fluids at high temperature

Author(s):  
Abdul Razak Ismail ◽  
W. R. W Sulaiman ◽  
M. Z. Jaafar ◽  
A. Aftab ◽  
A. A. Razi ◽  
...  

Drilling fluid is the key component to drill oil and gas wells. The rheological behavior of drilling fluid will be affected when drilling deep wells especially at high temperature and high pressure reservoir. This research was conducted to study the effect of the nanoparticles over the rheological properties of the drilling fluid when aging at high temperature condition. Several drilling fluids were prepared using synthetic based fluids (Sarapar and Saraline) to study the effect of multi-walled carbon nanotube (MWCNT) at different concentrations. The rheological properties of drilling fluid were analyzed after aging at 250 °F and 350 °F for 16 hours. The results revealed that the addition of MWCNT improved the 10-sec gel strength by 33% and filtrate loss volume was reduced to 10% after aging at 250°F in Saraline drilling fluid. Moreover, the plastic viscosity of Saraline and Sarapar drilling fluid after addition of MWCNT was enhanced by 6% and 27% at 350 °F. Filtrate loss volume of Sarapar drilling fluid was reduced by 19 % after aging at 250 °F for 16 hours. The overall results showed that the addition of MWCNT into the drilling fluid have slightly improved the rheological properties of drilling fluids under high temperature conditions.

2021 ◽  
Author(s):  
Wenxi Zhu ◽  
Xiuhua Zheng

Colloidal gas aphron (CGA) drilling fluids are a kind of environmentally-friendly underbalanced drilling technique, which has attracted more attention in depleted reservoirs and other low-pressure areas. With the shortage of global oil/gas resources, drilling has gradually shifted to high-temperature and deep wells. Hence, a study on the ultra-high temperature rheology properties of CGA fluids is lacking and urgently needed. In this study, a novel CGA drilling fluid system was prepared by modified starch and amino acid surfactant, and rheological properties after 120-300°C aged was investigate. Results show that: (1) Herschel-Bulkley model is the preferred model to predict CGA drilling fluid at ultra-high temperatures; (2) It was proved that CGA drilling fluid is a high-quality drilling fluid with extremely high value of LSRV and shear thinning property within 280°C. Compared to the traditional XG-based CGA drilling fluid, the improvement of LSRV at ultra-high temperatures is a significant advantage of EST-based CGA drilling fluid which is conducive to carrying cuttings and sealing formation pores.


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 %.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinliang Liu ◽  
Fengshan Zhou ◽  
Fengyi Deng ◽  
Hongxing Zhao ◽  
Zhongjin Wei ◽  
...  

Abstract Most of bentonite used in modern drilling engineering is physically and chemically modified calcium bentonite. However, with the increase of drilling depth, the bottom hole temperature may reach 180 °C, thus a large amount of calcium bentonite used in the drilling fluid will be unstable. This paper covers three kinds of calcium bentonite with poor rheological properties at high temperature, such as apparent viscosity is greater than 45 mPa·s or less than 10 mPa·s, API filtration loss is greater than 25 mL/30 min, which are diluted type, shear thickening type and low-shear type, these defects will make the rheological properties of drilling fluid worse. The difference is attributed to bentonite mineral composition, such as montmorillonite with good hydration expansion performance. By adding three kinds of heat-resistant water-soluble copolymers Na-HPAN (hydrolyzed polyacrylonitrile sodium), PAS (polycarboxylate salt) and SMP (sulfomethyl phenolic resin), the rheological properties of calcium bentonite drilling fluids can be significantly improved. For example, the addition of 0.1 wt% Na-HPAN and 0.1 wt% PAS increased the apparent viscosity of the XZJ calcium bentonite suspension from 4.5 to 19.5 mPa·s at 180 °C, and the filtration loss also decreased from 20.2 to 17.8 mL.


2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mohamed Mahmoud

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.


2011 ◽  
Vol 134 (1) ◽  
Author(s):  
J. Abdo ◽  
M. Danish Haneef

The idea of pushing the limits of drilling oil and gas wells by improving drilling fluids for undemanding and cost efficient drilling operations by extracting advantage from the wonders of nanotechnology forms the basis of the work presented here. Foremost, in order to highlight the significance of reducing the size distribution of particles, new clay ATR which has a chain like structure and offers enormous surface area and increased reactivity was tested in different sizes that were chemically and mechanically milled. Bentonite which is a commonly used drilling fluid additive was also tested in different particle size distribution (PSD) and rheological properties were tested. Significant reduction in viscosity with small sized particles was recorded. The tested material called ATR throughout this paper is shown to offer better functionality than bentonite without the requirement of other expensive additives. Experiments were performed with different size distributions and compositions and drastic changes in rheological properties are observed. A detailed investigation of the shear thinning behavior was also carried out with ATR samples in order to confirm its functionality for eliminating the problem of mechanical and differential pipe sticking, while retaining suitable viscosity and density for avoidance of problems like lost circulation, poor hole cleaning and inappropriate operating hydrostatic pressures.


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.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxi Zhu ◽  
Xiuhua Zheng

Abstract Colloidal gas aphrons (CGA) are finding increasing application in depleted oil and gas reservoirs because of their distinctive characteristics. To overcome the limitations of its application in high-temperature drilling, a modified starch foams stabilizer WST with a temperature resistance of 160 °C was synthesized via radical polymerization. The chemical structure of WST was characterized by Fourier infrared spectroscopy and results showed that all three monomers acrylamide, 2-acrylamido-2-methyl-1-propane sulfonic acid, and N-vinylpyrrolidone have been grafted onto starch efficiently. Based on the microscopic observations, highly stable aphrons have been successfully generated in the WST-based CGA drilling fluids within 160 °C, and most aphrons lie in the range of 10–150 μm. WST can provide higher viscosity at high temperatures compared to xanthan gum, which helps to extend foam life and stability by enhancing the film strength and slowing down the gravity drainage. Results show that WST-CGA aged at elevated temperatures (120–160 °C) is a high-performance drilling fluid with excellent shear-thinning behavior, cutting carrying capacity, and filtration control ability. The significant improvement of filtration control and well-building capability at high temperatures is an important advantage of WST-CGA, which can be attributed to the enhancement of mud cake quality by WST.


2012 ◽  
Vol 9 (3) ◽  
pp. 354-362 ◽  
Author(s):  
Fuhua Wang ◽  
Xuechao Tan ◽  
Ruihe Wang ◽  
Mingbo Sun ◽  
Li Wang ◽  
...  

2017 ◽  
Vol 11 (1) ◽  
pp. 274-284
Author(s):  
Kaffayatullah Khan ◽  
Shaukat Ali Khan ◽  
Muhammad Umair Saleem ◽  
Muhammad Ashraf

Background: Bentonite clays are widely used in a drilling operation and play a vital role as a drilling fluid. Bentonite clay mud performs several functions during the drilling operation and facilitates the drilling process. Objective: In this study, the locally available raw bentonite clays were investigated to evaluate its potential use as a mud for borehole drilling operation after its improvement with the additives. Method: Rheological properties such as plastic viscosity, yield point and gel strength were evaluated by using a viscometer and filtrate loss test was performed by using filter press on both locally available raw bentonite clays and the commercial bentonite named as Mill gel. Results: From the test results obtained for the up gradation of clays with the different beneficiating materials, the drastic increase in the plastic viscosity, yield point and gel strength has been observed. It shows that Xanthum gum produced better results for the improvement of rheological properties of such clays. Carboxymethyl cellulose and starch were used as additives and it has been observed that carboxymethyl cellulose has improved both viscosity and filtrate loss control, whereas starch muds have the best filtration control properties. Conclusion: Improved bentonite clays have rheological and filtration characteristics that have satisfied American Petroleum Institute specification at optimum conditions of clay. It was concluded that improved clays are the suitable material for the drilling operations and suitable to substitute commercial bentonite.


2021 ◽  
Author(s):  
Moamen Gasser ◽  
Omar Mahmoud ◽  
Fatma Ibrahim ◽  
Magdi Abadir

Abstract Drilling process is one of the main operations in the extraction of hydrocarbons from petroleum reservoirs. It comes right after the exploration processes. Drilling fluids are necessary for controlling the wells and performing different functions during the drilling operation. They perform many roles in lifting the cuttings from the bottom of the well to the surface and cooling/lubricating the drill pipes and bit. Furthermore, they provide the desired hydrostatic pressure to overbalance pore pressure in addition to produce a thin/impermeable filter cake that can prevent or reduce the possible damage to the formations. It is mandatory to keep monitoring, enhancing, and optimizing the properties of the drilling fluids. Recently, different additives, among which nanoparticles (NPs), have been investigated to improve, and maximize the benefits of the drilling fluids accordingly to meet the new challenges. The rheological behavior of such complex fluids has shown different enhancements up on the utilization of those additives. The rheological properties of the drilling fluids are accurately measured on the surface; however, the behavior of those properties may change with time and under harsh drilling conditions, such as high pressure/high temperature environments. For that, different models are introduced and used to predict and optimize the rheological characteristics of such fluids. Bingham, Herschel-Bulkley, Power Law, Casson and others are commonly used as rheological models to predict the drilling fluid behavior. In the last decade, a new trend of developing new models and correlations using the artificial neural networks (ANN) have been introduced to the petroleum field. Mathematical formulas can be developed using ANN, which then can be used to predict the behavior of certain parameter(s) by knowing other ones. Using ANN have shown to be more reliable and accurate in predicting the rheological properties of the drilling fluids, such as apparent viscosity (AV), plastic viscosity (PV), yield point (YP), maximum shear stress, and change in the mud density at various conditions. This work aims at using ANN technique to develop suitable models that can predict the rheological behavior of nano-based drilling fluids. The effect of NPs-type, -size, -concentration, and drilling fluid formulations will be considered, which may pave the road for new applications and efficient utilizations.


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