Effect of Nano-Clays on the Lubricity of Drilling Fluids

2016 ◽  
Author(s):  
Jamil Abdo ◽  
Hamed Al-Sharji
Keyword(s):  
Electrical Properties ◽  
Rheological Properties ◽  
Axial Force ◽  
Drilling Fluids ◽  
Structure And Morphology ◽  
Mechanical And Electrical Properties ◽  
Force Transfer ◽  
Water Based ◽  
The Stability

In this study, nano-sepiolite (NSP) was synthesized, dispersed and used as a replacement for regular additives in water-based drilling fluids to enhance its lubricity. Due to its structure and morphology the suspended sepiolite nanoparticles is expected to enhance the stability against segmentation along with better thermal, mechanical and electrical properties. The morphology of the nano-modified drilling fluids and the dispersion of the nano-sepiolite are characterized using XRD and SEM. The influences of various sizes and compositions of the NSP on the stability of drilling fluids on HTHP conditions are investigated. Results revealed that the drilling fluids lubricity and the drillstring axial force transfer were significantly improved by using NSP in the base drilling fluids. The investigations showed that the lubricity and rheological properties of the nano-modified drilling fluids depend on the size and composition of the NSP additive. The studies were performed on normal and HTHP conditions.

scholarly journals Investigation of regulating rheological properties of water-based drilling fluids by ultrasound

2021 ◽  
Author(s):  
Wei-An Huang ◽  
Jing-Wen Wang ◽  
Ming Lei ◽  
Gong-Rang Li ◽  
Zhi-Feng Duan ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Drilling Fluids ◽  
Water Based

Annular Frictional Pressure Losses During Drilling—Predicting the Effect of Drillstring Rotation

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Arild Saasen
Keyword(s):  
Rheological Properties ◽  
Pressure Loss ◽  
Drilling Fluid ◽  
Axial Flow ◽  
Drilling Fluids ◽  
Unstable Flow ◽  
Pressure Losses ◽  
Shear Dependent Viscosity ◽  
Water Based ◽  
Dependent Viscosity

Controlling the annular frictional pressure losses is important in order to drill safely with overpressure without fracturing the formation. To predict these pressure losses, however, is not straightforward. First of all, the pressure losses depend on the annulus eccentricity. Moving the drillstring to the wall generates a wider flow channel in part of the annulus which reduces the frictional pressure losses significantly. The drillstring motion itself also affects the pressure loss significantly. The drillstring rotation, even for fairly small rotation rates, creates unstable flow and sometimes turbulence in the annulus even without axial flow. Transversal motion of the drillstring creates vortices that destabilize the flow. Consequently, the annular frictional pressure loss is increased even though the drilling fluid becomes thinner because of added shear rate. Naturally, the rheological properties of the drilling fluid play an important role. These rheological properties include more properties than the viscosity as measured by API procedures. It is impossible to use the same frictional pressure loss model for water based and oil based drilling fluids even if their viscosity profile is equal because of the different ways these fluids build viscosity. Water based drilling fluids are normally constructed as a polymer solution while the oil based are combinations of emulsions and dispersions. Furthermore, within both water based and oil based drilling fluids there are functional differences. These differences may be sufficiently large to require different models for two water based drilling fluids built with different types of polymers. In addition to these phenomena washouts and tool joints will create localised pressure losses. These localised pressure losses will again be coupled with the rheological properties of the drilling fluids. In this paper, all the above mentioned phenomena and their consequences for annular pressure losses will be discussed in detail. North Sea field data is used as an example. It is not straightforward to build general annular pressure loss models. This argument is based on flow stability analysis and the consequences of using drilling fluids with different rheological properties. These different rheological properties include shear dependent viscosity, elongational viscosity and other viscoelastic properties.

Method and Mechanism of Regulating Rheological Properties of Water-Based Drilling Fluid by High-Frequency and High-Voltage Alternating Current Electric Field

SPE Journal ◽  
2020 ◽  
Vol 25 (05) ◽  
pp. 2220-2233
Author(s):  
Weian Huang ◽  
Ming Lei ◽  
Jingwen Wang ◽  
Kaihe Lv ◽  
Lin Jiang ◽  
...  
Keyword(s):  
Electric Field ◽  
Rheological Properties ◽  
High Voltage ◽  
High Frequency ◽  
Pulse Width ◽  
Drilling Fluid ◽  
Width Ratio ◽  
Drilling Fluids ◽  
Water Based ◽  
Bentonite Suspension

Summary The rheology of drilling fluid is commonly regulated by chemical methods. In this work, a physical method of a high-frequency and high-voltage alternating current (AC) electric field to regulate the rheological properties of water-based drilling fluid is established. The effects of the electric field on the continuous phase and dispersed phase, as well as two kinds of water-based drilling fluids, were investigated, and the response relationship among rheological properties modeled by Bingham and Herschel-Bulkley (H-B) models and electric-field parameters was explored. Results showed that water conductivity increased when voltage reached 4 kV, whereas it was restored to the original state after 3 hours in the absence of an electric field, showing a memory effect. The effect was also observed on bentonite suspension, whose plastic viscosity increased with the aid of an electric field and decreased over time. Voltage showed the greatest effect on bentonite-suspension viscosity, followed by frequency and pulse-width ratio. Under the condition of voltage of 5 kV, frequency of 5 kHz, and pulse-width ratio of 80%, there was a maximum increase of 50% in viscosity. The addition of salts caused bentonite-suspension flocculation, and electric field reduced the consistency coefficient and relieved flocculation state. When polymers were incorporated in bentonite suspension, the electric field could decrease the adsorption amount between clay particles and polymeric additives such as amphoteric and acrylamide-based polymers. For two typical drilling fluids, the voltage of an introduced electric field was the main controlling factor to change the rheological properties; their plastic viscosity and consistency coefficient both started to increase when voltage reached 4 kV.

Influence of alcohol on mechanical and electrical properties of thin organic films

Open Physics ◽  
2007 ◽  
Vol 5 (3) ◽  
Author(s):  
Martin Kopáni ◽  
Martin Weis
Keyword(s):  
Electrical Properties ◽  
Conformational Changes ◽  
Structural Changes ◽  
Pure Water ◽  
Contactless Method ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Mechanical And Electrical Properties ◽  
Methanol Solutions ◽  
The Stability ◽  
Displacement Currents

AbstractStability of organic materials properties is essential for further applications and was intensely investigated in last few decades. The aim of this study is to detect the structural changes of dipalmitoyl-phosphatidylcholine (DPPC) monolayer as a model system of organic material under influence of alcohols solutions. As subphases of monolayers (Langmuir films), pure water, ethanol and methanol solutions were used. For detection of changes in charge states of the molecules as well as relation with structural and conformational changes, a contactless method employing Maxwell’s displacement currents (MDC) was used. In DPPC monolayer on the subphase of methanol-water, a gradual absorption of methanol molecules into the layer can appear. In DPPC monolayer on the subphase of ethanol-water adsorption of ethanol molecules on the layer can be observed. Influence of alcohols results in a significant change of mechanical and electrical properties as well as in the stability of thin films.

scholarly journals On the Stability of Oil-Based Drilling Fluid: Effect of Oil-Water Ratio

2020 ◽  
Author(s):  
Titus Ntow Ofei ◽  
Itung Cheng ◽  
Bjørnar Lund ◽  
Arild Saasen ◽  
Sigbjørn Sangesland
Keyword(s):  
North Sea ◽  
Storage Stability ◽  
Drilling Fluid ◽  
Stability Index ◽  
Drilling Fluids ◽  
Flow Transition ◽  
Water Based ◽  
Oil Water ◽  
The Stability ◽  
Transition Index

Abstract Drilling fluids are complex mixtures of natural and synthetic chemical compounds used to cool and lubricate the drill bit, clean the wellbore, carry drilled cuttings to the surface, control formation pressure, and improve the function of the drill string and tools in the hole. The two main types of drilling fluids are water-based and oil-based drilling fluids, where the oil-based also include synthetic-based drilling fluids. Many rheological properties of drilling fluids are key parameters that must be controlled during design and operations. The base fluid properties are constructed by the interaction of the emulsified water droplets in combination with organophilic clay particles. The rheological properties resulted from this combination, along with the particle size distribution of weight materials are vital in controlling the physical stability of the microstructure in the drilling fluid. A weak fluid microstructure induces settling and sagging of weight material particles. The presence of sag has relatively often been the cause for gas kicks and oil-based drilling fluids are known to be more vulnerable for sag than water-based drilling fluids. Hence, the shear-dependent viscosity and elasticity of drilling fluids are central properties for the engineers to control the stability of weight material particles in suspension. In this study, we examined the stability of typical oil-based drilling fluids made for North Sea oilfield drilling application with oil-water-ratios (OWR) of 80/20 and 60/40. The structural character of the fluid samples was analyzed both at rest and dynamic conditions via flow and viscosity curves, amplitude sweep, frequency sweep, and time-dependent oscillatory sweep tests using a rheometer with a measuring system applying a grooved bob at atmospheric conditions. A high precision density meter was used to measure the density of the drilling fluid samples before and after each test. The measurement criteria used to rank the fluids stability include the yield stress as measured from flow curves and oscillatory tests, flow transition index, mechanical storage stability index, and dynamic sag index. We observed that between the two drilling fluids, the sample with OWR = 60/40 showed a stable dispersion with stronger network structure as evidenced by higher yield stress and flow transition index values, while the mechanical storage stability index and dynamic sag index recorded lower values. The results of this study enable drilling fluid engineers to design realistic oil-based drilling fluids with stable microstructure to mitigate settling and sagging of weight material particles for North Sea drilling operation.

Bentonite Suspension Filtration and its Electro-Kinetics in the Presence of Additives

2021 ◽  
Vol 58 (2) ◽  
pp. 121-126
Author(s):  
R. M. Farag ◽  
A. M. Salem ◽  
A. A. El-Midany ◽  
S. E. El-Mofty
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Electrostatic Interactions ◽  
Drilling Fluid ◽  
Colloidal Suspensions ◽  
Drilling Fluids ◽  
Fluid Filtration ◽  
Filtration Loss ◽  
Suspension Filtration ◽  
The Stability

Abstract Invasion of fluids into porous media during drilling can lead to irreparable damage and reduced well productivity. Hence, minimizing the filtration loss of the drilling fluid into the formation is very important. The stability of colloidal suspensions plays a crucial role in controlling the interfacial forces and consequently on minimizing the filtration. The zeta potential is an indicator of the stability of colloids with respect to their electrostatic interactions. In this study, the rheological properties of bentonite suspensions are investigated with and without additives. The starch and CMC were used as additives to enhance the rheological properties of bentonite. The effects of these additives on the drilling fluid filtration were examined. Zeta-potential, viscosity, gel strength and yield point were measured to characterize the extent to which control of the filtration loss of the drilling fluids can be achieved. The zeta-potential and the amount of filtration loss of water-bentonite suspensions were correlated. Finally, the results showed that the addition of either starch or carboxymethyl cellulose (CMC) enhances the filtration properties of water-bentonite suspensions.

Rheological Properties of Barite Sediments in Water-Based Drilling Fluids

2018 ◽  
Author(s):  
Torbjørn Vrålstad ◽  
Ragnhild Skorpa ◽  
Arild Saasen
Keyword(s):  
Rheological Properties ◽  
Drilling Fluid ◽  
Gravity Separation ◽  
Drilling Fluids ◽  
Water Based ◽  
Different Types ◽  
Preliminary Study ◽  
Well Abandonment

When a drilling fluid column remains static over a timeframe of several years, the drilling fluid separates into different sediment phases due to gravity separation. These heavy sediments, entitled “settled barite”, are the cause of significant operational problems several years after drilling. An important problem caused by settled barite occurs when performing casing cut-and-pull operations during slot recovery and well abandonment: the casing is “stuck” due to the sediments in the annulus outside the casing. The consistency and rheological properties of the sediments determine how easily the casing is removed. In this paper, we report a preliminary study were we have artificially prepared gravity sediment phases for two different types of water-based drilling fluids; one KCl/polymer-based fluid and one bentonite-based fluid. By studying the rheological properties of the obtained sediment phases, we see that there are considerable differences between the sediments for these different drilling fluids.

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