scholarly journals Study of the cuttings transport in stable foam drilling

2018 ◽  
Vol 73 ◽  
pp. 30 ◽  
Author(s):  
Jie Zhang ◽  
Wen Luo ◽  
Cuinan Li ◽  
Tingyu Wan ◽  
Zhen Zhang ◽  
...  
Keyword(s):  
Drilling Fluid ◽  
Key Factors ◽  
Cuttings Transport ◽  
Factors Affecting ◽  
Stable Foam ◽  
Flow Parameters ◽  
Bed Thickness ◽  
Transitional Section ◽  
Foam Drilling ◽  
Cuttings Bed

Based on the special rheological model of foam fluid, the mathematical models of cuttings transport for stable foam drilling in vertical/near vertical sections, the transitional section, and inclined/horizontal sections are established in this paper. The effects of various flow parameters on the cuttings bed thickness in the annulus are analyzed. The results show that inclination, annulus velocity, foam flow rate, and eccentricity are key factors affecting cuttings transport. The thickness of a cuttings bed gradually decreases with the inclination decrease of the highly deviated/horizontal sections. When the inclination is reduced to approximately 60°, the dynamic and static cuttings bed disappears and is substituted by the glide lamella, which consists of cuttings grains. Cuttings grains have various forms of movement on the lower borehole wall. When the inclination is reduced to below 30°, the cuttings are brought out of the well by the stable foam if the returning velocity of the annulus foam is larger than the depositing velocity of the cuttings. The thickness of the cuttings bed gradually decreases with the increase of annulus velocity. The increased foam quality reduces the concentration of annulus cuttings when the annulus velocity is constant and when it reaches a stable status earlier than the foam drilling fluid of lower foam quality. However, the concentration of the annulus cuttings at the final stage is constant. The thickness of the cuttings bed increases with increased eccentricity of the drill stem. When the eccentricity is large, the change of eccentricity has a high effect on the cuttings bed thickness.

scholarly journals Wet Drilled Cuttings Bed Rheology

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1644
Author(s):  
Camilo Pedrosa ◽  
Arild Saasen ◽  
Bjørnar Lund ◽  
Jan David Ytrehus
Keyword(s):  
Drilling Fluid ◽  
Drilling Fluids ◽  
Parallel Plates ◽  
Single Particles ◽  
Cuttings Transport ◽  
Transport Studies ◽  
Water Based ◽  
Fluid Properties ◽  
External Forces ◽  
Cuttings Bed

The cuttings transport efficiency of various drilling fluids has been studied in several approaches. This is an important aspect, since hole cleaning is often a bottleneck in well construction. The studies so far have targeted the drilling fluid cuttings’ transport capability through experiments, simulations or field data. Observed differences in the efficiency due to changes in the drilling fluid properties and compositions have been reported but not always fully understood. In this study, the cuttings bed, wetted with a single drilling fluid, was evaluated. The experiments were performed with parallel plates in an Anton Paar Physica 301 rheometer. The results showed systematic differences in the internal friction behaviors between tests of beds with oil-based and beds with water-based fluids. The observations indicated that cutting beds wetted with a polymeric water-based fluid released clusters of particles when external forces overcame the bonding forces and the beds started to break up. Similarly, it was observed that an oil-based fluid wetted bed allowed particles to break free as single particles. These findings may explain the observed differences in previous cutting transport studies.

Simple Correlations and Analysis of Cuttings Transport With Newtonian and Non-Newtonian Fluids in Horizontal and Deviated Wells

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Mehmet Sorgun
Keyword(s):  
Pure Water ◽  
Newtonian Fluids ◽  
The Other ◽  
Cuttings Transport ◽  
Pressure Losses ◽  
Test Conditions ◽  
Bed Thickness ◽  
Solid Liquid ◽  
Cuttings Bed ◽  
Pipe Rotation

In this study, simple empirical frictional pressure losses and cuttings bed thickness correlations including pipe rotation are developed for solid-liquid flow in horizontal and deviated wellbores. Pipe rotation effects on cuttings transport in horizontal and highly inclined wells are investigated experimentally. Correlations are validated experimental data with pure water as well as four different non-Newtonian fluids for hole inclinations from horizontal to 60 degrees, flow velocities from 0.64 m/s to 3.56 m/s, rate of penetrations from 0.00127 to 0.0038 m/s, and pipe rotations from 0 to 250 rpm. Pressure drop within the test section, and stationary and/or moving bed thickness are recorded besides the other test conditions. The new correlations generated in this study are believed to be very practical and handy when they are used in the field.

Prediction of Cuttings Transport Behavior under Drill String Rotation Conditions in High-Inclination Section

2020 ◽  
Vol 34 (10) ◽  
pp. 2059035
Author(s):  
Shihui Sun ◽  
Jinyu Feng ◽  
Zhaokai Hou ◽  
Guoqing Yu
Keyword(s):  
Fluid Flow ◽  
Flow Rate ◽  
Drilling Fluid ◽  
Drill String ◽  
Additional Contribution ◽  
Fluid Viscosity ◽  
Fluid Flow Rate ◽  
Cuttings Transport ◽  
Hole Cleaning ◽  
Cuttings Bed

Cuttings are likely to accumulate and eventually form a cuttings bed in the highly-deviated section, which usually lead to high friction and torque, slower rate of penetration, pipe stuck and other problems. It is therefore necessary to study cuttings transport mechanism and improve hole cleaning efficiency. In this study, the cuttings-transport behaviors with pipe rotation under turbulent flow conditions in the highly deviated eccentric section were numerically simulated based on Euler solid–fluid model and Realizable [Formula: see text]–[Formula: see text] model. The resulted numerical results were compared with available experimental data in reported literature to validate the algorithm, and good agreement was found. Under the conditions of drill string rotation, cuttings bed surface tilts in the direction of rotation and distributes asymmetrically in annulus. Drill string rotation, drilling fluid flow rate, cuttings diameter, cuttings injection concentration and drilling fluid viscosity affect the axial velocity of drilling fluid; whereas drilling fluid tangential velocity is mainly controlled by the rotational speed of drill string. Increase in value of drill string rotation, drilling fluid flow rate or hole inclination will increase cuttings migration velocity. Notably, drill string rotation reduces cuttings concentration and solid–fluid pressure loss, and their variations are dependent on inclination, cuttings injection concentration, cuttings diameter, drilling fluid velocity and viscosity. However, when a critical rotation speed is reached, no additional contribution is observed. The results can provide theoretical support for optimizing hole cleaning and realizing safety drilling of horizontal wells and extended reach wells.

scholarly journals Investigation: Cutting Transport Mechanism in Inclined Well Section under Pulsed Drilling Fluid Action

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2141
Author(s):  
Xiaohua Zhu ◽  
Keyu Shen ◽  
Bo Li
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Friction Torque ◽  
Drilling Fluids ◽  
Cuttings Transport ◽  
Turbulent Dissipation ◽  
Duty Cycles ◽  
Transport Velocity ◽  
Cuttings Bed ◽  
Conventional Drilling

Due to gravity, drilling cuttings are easily accumulated in an inclined well section, ultimately forming a cuttings bed, which places the drill pipe under strong friction torque. In severe cases, this can cause dragging, stuck drills, and broken drill tools. Because conventional drilling fluids are difficult to prevent the formation of cuttings in inclined well sections, a method of carrying cuttings with the pulsed drilling fluid to improve wellbore cleanness is proposed. Experiments and numerical simulations are conducted to investigate the effects of cuttings bed transport velocity, cuttings size, cuttings height, drill pipe rotation speed, cuttings bed mass, and roughness height. The optimal pulse parameters are determined per their respective impact on cuttings transport concerning varied periods, amplitudes, and duty cycles of the pulsed drilling fluid. Compared to cuttings transport under the conventional drilling fluid flow rate, the pulsed drilling fluid produces the turbulent dissipation rate, increases cuttings transport velocity, and thus improves the wellbore clearance rate.

Steady-State Cuttings Transport Simulation in Horizontal Borehole Annulus

2018 ◽  
Author(s):  
Yaroslav Ignatenko ◽  
Oleg Bocharov ◽  
Andrey Gavrilov ◽  
Roland May
Keyword(s):  
Steady State ◽  
Pressure Drop ◽  
Flow Structure ◽  
Structural Changes ◽  
Drilling Fluid ◽  
Drill String ◽  
Cuttings Transport ◽  
Horizontal Drilling ◽  
Fluid Properties ◽  
Cuttings Bed

The paper presents the results of modeling the steady-state flow of drilling fluid with cuttings in an annulus for the flow regimes typical for horizontal drilling. The studied parameters include effects like fluid rheology, drillstring rotation and eccentricity on flow regime, pressure drop and cuttings bed. It has been demonstrated that increasing the drilling fluid’s effective viscosity increases the pressure drop, but it decreases the cuttings bed area, while drillstring rotation significantly changes the flow structure, improving cuttings transport and reducing the pressure drop. The considered flow structure can change abruptly due to changed drill string positioning and rheological fluid properties. Such structural changes are followed by abrupt changes in the pressure drop and cuttings bed area.

Improving Gas Bubbles’ Half Life in Foam Drilling Fluid

2013 ◽  
Vol 62 (1) ◽  
Author(s):  
Issham Ismail ◽  
Nur Suriani Mamat ◽  
Baihaqi Mamat ◽  
Ahmad Shamsulizwan Ismail ◽  
Azmi Kamis ◽  
...  
Keyword(s):  
Rheological Properties ◽  
Xanthan Gum ◽  
Drilling Fluid ◽  
Water Soluble ◽  
Polymer Foam ◽  
Water Soluble Polymers ◽  
Stable Foam ◽  
Soluble Polymers ◽  
The Stability ◽  
Foam Drilling

An underbalanced drilling using foam drilling fluid is one of the most effective solutions which are capable of preventing formation damage, differential sticking, or circulation lost. Nevertheless, the limitation of using foam drilling fluid is the stability of its rheological properties which would affect its lubricity characteristics. Therefore, a research study was carried out to determine the stability and effectiveness of water soluble polymers as an additive in foam drilling fluid. To produce the required and most stable foam, four types of surfactants had been tested, namely sodium dodecyl sulfate (anionic), cetyltrimethylammonium bromide (cationic), T×100 (non ionic), and n-alkyl betaines (amphoteric). Then, the water soluble polymers, namely xanthan gum, hydroxyethyl cellulose, guar gum, and carboxymethyl cellulose, were evaluated as a stabilizer in the said foam drilling fluid. The laboratory works involved lubricity and rheological properties tests, which were conducted at ambient condition. The experimental results showed that the use of xanthan gum with anionic surfactant produced the most stable foam drilling fluid compared to other polymers. Rheological properties of the polymer foam drilling fluid were compared with water-based mud, and it was revealed that polymer foam drilling fluid could perform as effective as the latter. The significant advantage of using polymer foam drilling fluid was its coefficient of friction which was found to be lower than the water-based mud. 

scholarly journals Cuttings Transport Using Pulsed Drilling Fluid in the Horizontal Section of the Slim-Hole: An Experimental and Numerical Simulation Study

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3939 ◽  
Author(s):  
Xiaohua Zhu ◽  
Keyu Shen ◽  
Bo Li ◽  
Yanxin Lv
Keyword(s):  
Numerical Simulation ◽  
Drilling Fluid ◽  
Fluid Velocity ◽  
Cuttings Transport ◽  
Safe Operation ◽  
Horizontal Section ◽  
Transport Distance ◽  
Cutting Velocity ◽  
Cuttings Bed ◽  
Transport Method

Poor transport of cuttings in horizontal sections of small-bore well holes leads to high torque and increases the risk of the drill becoming stuck, reducing its service life and posing a threat to safe operation. Because the conventional cuttings transport method cannot effectively remove the cuttings bed, a transport method using pulsed drilling fluid based on a shunt relay mechanism is proposed. A three-layer numerical simulation model of cuttings transport in horizontal small-bore wells is established. Using both experiments and numerical simulations, the cuttings transport is studied in terms of the moving cuttings velocity, cuttings concentration, and distance of movement of the cuttings bed. By varying the pulsed drilling fluid velocity cycle, amplitude, and duty cycle at the annulus inlet, their effects on cuttings transport are analyzed, and the optimal pulse parameters are determined. The results show that the use of pulsed drilling fluid can effectively enhance the moving cutting velocity and transport distance of the cuttings bed, reduce the cuttings concentration, and improve wellbore cleaning.

EVALUATION OF FINANCIAL SECURITY OF THE REPUBLIC OF CRIMEA

2020 ◽  
pp. 56-67
Author(s):  
Elena Evgenevna Mashyanova ◽  
Elena Aleksandrovna Smirnova
Keyword(s):  
Financial Markets ◽  
Negative Impact ◽  
Gradual Increase ◽  
Financial System ◽  
Financial Security ◽  
Key Factors ◽  
Factors Affecting ◽  
External Threats ◽  
The Republic ◽  
Global Financial System

In modern conditions of development, financial security is an integral part of the overall security of the region and is formed on the basis of the functioning of the financial system. The complication of relationships between key segments of international financial markets, as well as the limited ability to accurately predict future trends in the development of the global financial system, lead to a gradual increase in the risks that accompany the activities of economic entities, and an increase in the number and scale of internal and external threats that have a negative impact on the financial security of the state. This formulation of the issue requires generalization of approaches to determining the financial security of the region in order to further formalize this issue and determine the key factors affecting it. The article considers the types of financial security, as well as certain areas of ensuring the financial security of the region and their priority. In work the assessment of the level of socio-economic development of the region with a view to ensuring financial security on the basis of which offers the main activities and priority areas of implementation of the investment policy that will ensure financial security of the Republic of Crimea.

scholarly journals Comparison of the sensitivity of Western blotting between PVDF and NC membranes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  
Keyword(s):  
Western Blotting ◽  
Polyvinylidene Fluoride ◽  
Staining Intensity ◽  
Detection Sensitivity ◽  
Key Factors ◽  
Post Translational Modifications ◽  
Factors Affecting ◽  
Molecular Weights ◽  
Direct Blue ◽  
The Relationship

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.

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