Eco-Friendly Drilling Fluid Deflocculant for Drilling High Temperature Well: A Review

Author(s):  
Nurul Aimi Ghazali ◽  
Shigemi Naganawa ◽  
Yoshihiro Masuda ◽  
Wan Asma Ibrahim ◽  
Noor Fitrah Abu Bakar

Conventional clay-based drilling fluids often experienced difficulties in controlling the rheological properties, gelation, and filtration due to flocculation of clay at the temperature higher than 121°C. Deflocculant or thinner, one of the drilling fluid additives, serves a significant role in preventing the association of clay particles particularly in high temperature environments such as high-pressure and high-temperature (HPHT) deep-water drilling. Lignosulfonate has been commonly used in the industry as deflocculant for clay-based drilling fluids since the late 1950s as a replacement for Quebracho tannin. Degradation at the elevated temperature limits the usage of anionic polymer and lignosulfonate. In improving the stability of deflocculant at high temperature, lignosulfonate is admixed or reacted with chromium and iron compound to obtain ferro-chrome lignosulfonate whose temperature limit is approximately 190°C. While recent ferro-chrome lignosulfonate contains less chrome than in the past, development of more environmentally friendly and higher thermally stable deflocculant is still needed. In HPHT environment which requires high-density drilling fluid, a higher thermally-stable deflocculant is also valuable for barite sagging that becomes problematic at a temperature higher than 200°C. Several findings in the past development of adhesives show that addition of tannin improves the thermal stability of lignosulfonate. Tannin is a polyphenolic compound that is natural, non-toxic and biodegradable and can be found in various part of a vascular plant other than Quebracho. Lignosulfonate, on the other hand, is a byproduct of the paper pulping process. Tannin and lignosulfonate are cross-linked to obtain tannin–lignosulfonate for use as a high-temperature drilling fluid deflocculant. Tannin and lignin are the most abundant compounds extracted from biomass. The wide availability of tannin and lignosulfonate is an advantage from a manufacturing cost viewpoint. In this paper, an overview of drilling fluids, classification of drilling fluid, high temperature reservoir environment, and mechanisms of dispersion and deflocculation are presented. Further discussion on the potential development of eco-friendly tannin–lignosulfonate based drilling fluid system for the high temperature well development also presented.

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7195
Author(s):  
Mesfin Belayneh ◽  
Bernt Aadnøy ◽  
Simen Moe Strømø

Bentonite-based drilling fluids are used for drilling, where inhibitive fluids are not required. The rheological and the density properties of the drilling fluids are highly affected by high temperature and pressure. Due to high temperature, the clay particles stick together, and the fluid system becomes more flocculated. Poorly designed drilling fluid may cause undesired operational issues such as poor hole cleaning, drill strings sticking, high torque and drag. In this study, the 80 °C thermally stable Herschel Bulkley’s and Bingham plastic yield stresses drilling fluids were formulated based on lignosulfonate-treated bentonite drilling fluid. Further, the impact of a MoS2 nanoparticle solution on the properties of the thermally stable base fluid was characterized. Results at room temperature and pressure showed that the blending of 0.26 wt.% MoS2 increased the lubricity of thermally stable base fluid by 27% and enhanced the thermal and electrical conductivities by 7.2% and 8.8%, respectively.


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 ◽  
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.


2015 ◽  
Vol 8 (1) ◽  
pp. 19-27 ◽  
Author(s):  
Hanyi Zhong ◽  
Dong Sun ◽  
Weian Huang ◽  
Yunfeng Liu ◽  
Zhengsong Qiu

In order to improve the inhibitive properties and high temperature resistance of shale inhibitor, cycloaliphatic amines were introduced as shale hydration inhibitors in water-based drilling fluids. Bulk hardness test, shale cuttings dispersion test, bentonite inhibition test and water adsorption test were carried out to characterize the inhibitive properties of the novel amines. Surface tension measurement, zeta potential measurement, XRD, contact angle test, SEM and TGA were performed to investigate the interaction between the cycloaliphatic amines and clay particles. The results indicated that cycloaliphatic amines exhibited superior inhibitive properties to the state of the art inhibitors. Moreover, the amines were high temperature resistant. The hydrophobic amine could intercalate into the clay gallery with monolayer orientation. The protonated ammonium ions neutralized the negatively charged surface. After adsorption, the hydrophobic segment covered the clay surface and provided a shell preventing the ingress of water.


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):  
Abhijeet D. Chodankar ◽  
Cheng-Xian Lin

Abstract High temperature drilling environment has a drastic effect on drilling fluids, wellbore stability, and drilling system components. It has been observed that drilling fluids displace conventional halide based fluids in High Pressure and High Temperature (HPHT) wells leading to corrosion and environmental hazards, while wellbore strengthens further as a result of an increase in fracture initiation pressure in high temperature environment. However, it seriously damages the downhole tools like sensors, elastomer dynamic seals, lithium batteries, electronic component and boards leading to increases in cost and non-productive time. The main objective of this paper is to present an analytical borehole temperature model based on classical heat transfer laws in a high temperature drilling environment. The borehole is modelled using two approaches: composite wall and concentric cylinders. The composite wall and concentric cylinder approaches consist layers of geological formations, drilling fluids outside the drill string, drill string, and drilling fluid inside the drill string. Temperature, heat transfer coefficient, and heat transfer variations along the borehole layers are determined using the derived analytical solutions and tested for different drilling fluid types, air drilling environment, and different drill string materials. The results of composite wall and concentric cylinder models are obtained by using the input field temperatures data in the geological formation and inner annulus of drill pipe to determine the borehole temperature profile in HPHT wells. Therefore, a thorough borehole heat transfer analysis will help in wellbore stability, drilling fluid selection, corrosion control, and optimal placement and material selection of drilling components in HPHT drilling environments.


SPE Journal ◽  
2021 ◽  
pp. 1-22
Author(s):  
Sidharth Gautam ◽  
Chandan Guria ◽  
Laldeep Gope

Summary Determining the rheology of drilling fluid under subsurface conditions—that is, pressure > 103.4 MPa (15,000 psi) and temperature > 450 K (350°F)—is very important for safe and trouble-free drilling operations of high-pressure/high-temperature (HP/HT) wells. As the severity of HP/HT wells increases, it is challenging to measure downhole rheology accurately. In the absence of rheology measurement tools under HP/HT conditions, it is essential to develop an accurate rheological model under extreme conditions. In this study, temperature- and pressure-dependence rheology of drilling fluids [i.e., shear viscosity, apparent viscosity (AV), and plastic viscosity (PV)] are predicted at HP/HT conditions using the fundamental momentum transport mechanism (i.e., kinetic theory) of liquids. Drilling fluid properties (e.g., density, thermal decomposition temperature, and isothermal compressibility), and Fann® 35 Viscometer (Fann Instrument Corporation, Houston, USA) readings at surface conditions, are the only input parameters for the proposed HP/HT shear viscosity model. The proposed model has been tested using 26 different types of HP/HT drilling fluids, including water, formate, oil, and synthetic oil as base fluids. The detailed error and the sensitivity analysis have been performed to demonstrate the accuracy of the proposed model and yield comparative results. The proposed model is quite simple and may be applied to accurately predict the rheology of numerous drilling fluids. In the absence of subsurface rheology under HP/HT conditions, the proposed viscosity model may be used as a reliable soft-sensor tool for the online monitoring and control of rheology under downhole conditions while drilling HP/HT wells.


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.


2009 ◽  
Vol 131 (1) ◽  
Author(s):  
M. Nasiri ◽  
S. N. Ashrafizadeh ◽  
A. Ghalambor

Ester-based drilling fluids based on aliphatic esters were introduced in 1990. Esters can be synthesized from fatty acids and alcohols. Previous studies indicated that ester hydrolysis in drilling fluids happens only under certain conditions. In order for ester hydrolysis to occur, two primary conditions must be present: high temperature and excessive hydroxyl. When the temperature exceeds 300°F, ester hydrolysis can occur under the presence of excessive hydroxyl. Hydrolysis breaks down the ester component into its parent carboxylic acid and alcohol. The current study shows that the stability of ester-based drilling fluids at high temperature conditions depends on the composition so that the selection of proper components and additives such as emulsifiers, stabilizers, copolymers, viscosifiers, and rheological modifiers can increase the temperature stability of the fluid. Hereby, the application of an ester-based drilling fluid is improved up to 350°F. The composition of the provided fluid is unique in the view point of its higher thermal stability against the previous formulations provided in literature. Furthermore, the experimental results of this study show the favorable effect of hot-rolling pressure on barite sag and electrical stability of the mud, i.e., increasing the pressure at three particular temperatures of 300°F, 325°F, and 350°F reduced the barite sag and at some instances increased the electrical stability.


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