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

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.

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

SPE Journal ◽

10.2118/201192-pa ◽

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.

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Experimental Investigation of Water Based Drilling Fluids Rheological Properties Using Iron Oxide Nanoparticles

10.3997/2214-4609.202011311 ◽

2020 ◽

Author(s):

H. Ghorbani ◽

R. Lashkari ◽

S. Akbari Arbabi

Keyword(s):

Experimental Investigation ◽

Iron Oxide ◽

Rheological Properties ◽

Iron Oxide Nanoparticles ◽

Oxide Nanoparticles ◽

Drilling Fluids ◽

Water Based

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Rheological properties of bentonite-free water-based drilling fluids with novel polymer viscosifier

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2018.01.074 ◽

2018 ◽

Vol 164 ◽

pp. 302-310 ◽

Cited By ~ 19

Author(s):

Binqiang Xie ◽

Li Ting ◽

Yan Zhang ◽

Chen Liu

Keyword(s):

Rheological Properties ◽

Free Water ◽

Drilling Fluids ◽

Water Based

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Rheological Properties of Barite Sediments in Water-Based Drilling Fluids

Volume 8: Polar and Arctic Sciences and Technology; Petroleum Technology ◽

10.1115/omae2018-78695 ◽

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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Are the rheological properties of water-based and synthetic drilling fluids obtained by the Fann 35A viscometer reliable?

Journal of Petroleum Science and Engineering ◽

10.1016/j.petrol.2019.02.063 ◽

2019 ◽

Vol 177 ◽

pp. 872-879 ◽

Cited By ~ 3

Author(s):

Rubens Rosario Fernandes ◽

Guilherme Turezo ◽

Diogo E.V. Andrade ◽

Admilson T. Franco ◽

Cezar Otaviano Ribeiro Negrão

Keyword(s):

Rheological Properties ◽

Drilling Fluids ◽

Water Based

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Laponite Nanoparticle as a High Performance Rheological Modifier in Water-Based Drilling Fluids

Materials Science Forum ◽

10.4028/www.scientific.net/msf.917.134 ◽

2018 ◽

Vol 917 ◽

pp. 134-139

Author(s):

Fan Liu ◽

Guang Cheng Jiang ◽

Kai Wang ◽

Jin Xi Wang

Keyword(s):

Shear Rate ◽

Rheological Properties ◽

Yield Point ◽

High Performance ◽

Shear Thinning ◽

Drilling Fluids ◽

Star Network ◽

Water Based ◽

Rate Test ◽

Rheological Modifier

In this paper, we demonstrated an artificial nanoparticles, Laponite, as a high performance rheological modifier in water-based drilling fluids. We made a comparison between Laponite nanoparticle and bentonite as rheological modifier in polyanionic cellulose (PAC) solution and weitghted water-based drilling fluids. In viscosity-shear rate test, both Laponite and bentonite could translate 0.5 wt.% PAC solution from Newton fluids to yield-pseudoplastic fluid. However, 1 wt.% Laponite was better in improving the shear-thinning behavior compared with 4 wt.% bentonite. In the stress-shear rate test, the results were fit with Bingham model with a high R2, and 1 wt.% Laponite/0.5 wt.% PAC suspension had a yield point of 5.19 Pa, which was higher than that of 4 wt.% bentonite/0.5 wt.% PAC suspension (3.13 Pa). Similarly, 1 wt.% Laponite/0.5 wt.% PAC suspension maintained a G’ of 12 Pa in the oscillation frequency sweep test, whereas G’ of 4%bentonite/0.5%PAC suspension was nearly 5 Pa. Particularly, 0.5 wt.% PAC /Laponite suspensions could maintain higher gel structure, yield point and better shear-thinning behaviors after 120°C hot rolling. The TEM image revealed that nanoscaled Laponite could form a “star network” with PAC in water, which explained the good rheological properties of PAC/LAP mixed suspensions. Besides, in the weighted drilling fluids, 1 wt.% Laponite could maintained a much higher gel strength compared with 4 wt.% bentonite.As the unique rheological properties, Laponite nanoparticles can greatly enhance abilities of water-based drilling fluids in circulating cuttings and making the borehole clean.

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