Helical Flow of Drilling Mud With Cuttings in a Vertical Well

2021 ◽  
Author(s):  
Yaroslav Ignatenko ◽  
Andrey Gavrilov ◽  
Oleg Bocharov

Abstract The paper presents the results of an investigation into drilling mud flow with cuttings in a vertical well. The drilling mud rheology was described with the Herschel-Bulkley model. The axial Reynolds number was around 1000, the flow regime changing together with drill pipe RPM. The investigation covered the flow’s structures, integral parameters and cuttings transport in relation to drill pipe RPM and rate of penetration (ROP). In the laminar flow, most of the particles were localized in the quasi-solid region to move together with the last; the integral parameters had little dependence on drill pipe RPM increase. Increasing drill pipe RPM resulted in formation of the Görtler vortices near the channel’s external and internal walls, whose interaction led to the formation of smaller eddies converting the flow into a turbulent one. Due to the turbulence dispersion, the region taken by the particles widened. Particles suppress the vortex intensity near the channel’s external wall. Under the conditions described, increasing drill pipe RPM and ROP resulted in higher pressure drops and lower transport efficiency.

Author(s):  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Bjørnar Lund ◽  
Knud Richard Gyland ◽  
Arild Saasen

The mechanical friction of liner operations is investigated and compared to what is expected for a conventional drill pipe. In addition the cuttings transport efficiency for realistic conditions is studied. The work is also relevant for running completion strings. This article is based on results from laboratory scale flow loop for drilling applications. Sand particles were injected while circulating the drilling fluid through the test section in some of the tests. The procedures used to conduct the experiments are explained and experimental results and observations are discussed. The drilling fluids and additives in these experiments are similar to those used in in fields on the Norwegian Continental Shelf (NCS). Friction coefficient is calculated from the measured torque for different flow velocities and rotational velocities and the force perpendicular to the surface caused by the buoyed weight of the string.


2019 ◽  
Vol 10 (3) ◽  
pp. 1069-1079 ◽  
Author(s):  
K. K. Ihekoronye ◽  
N. C. Izuwa ◽  
N. U. Okereke ◽  
S. T. Ekwueme ◽  
R. C. Amaefula

Abstract In this work, experiment was carried out resulting in the utilization of local viscosifiers as substitute to conventional method (PAC-R) for hole cleaning purposes in drilling mud. The proposed viscosifiers are Irvingia gabonensis (Ogbono) and Abelmoschus esculentus (Okro) as alternative to the imported poly-anionic cellulose-regular (PAC-R) which is used in cutting carrying capacity efficiency. Laboratory tests were carried out on the proposed viscosifiers to evaluate their rheological properties. Slip velocity, annular velocity, shear stress, shear rate and cuttings transport efficiency on hole cleaning parameters were calculated to ascertain the effectiveness of the proposed viscosifiers in comparison with the conventional one (PAC-R). The results of the study showed that the proposed viscosifiers Sample B Irvingia gabonensis (Ogbono) had cutting carrying capacity of 96% for 5, 8, 10 and 15 (g), respectively. However, Sample C Abelmoschus esculentus (Okro) had 96% for 5 g and 8 g and 95% for 10 g and 15 g on the cutting transport efficiency. Based on the result of this work, the proposed viscosifiers compared favorably to that of PAC-R on hole cleaning and cutting carrying capacity.


Author(s):  
Mohammad Mojammel Huque ◽  
Syed Imtiaz ◽  
Stephen Butt ◽  
Sohrab Zendehboudi ◽  
Mohammad Azizur Rahman

Abstract Transport of cuttings is crucial in a horizontal drilling operation. Effective removal of cuttings is necessary for efficient drilling. An experimental investigation has been carried out to analyze the flow behaviour of solid cuttings in different drilling environments with visualization techniques. This study investigates the cuttings transport mechanism in a horizontal annulus section. A 6.16 m long and 4.5″ × 2.5″ annulus section was used to model the real-time drilling behaviour with different flow rates, drill pipe rotations and eccentric positions. Water as a Newtonian fluid was used as drilling mud and 2–3 mm solid glass beds were used to simulate the drill cuttings. The in-situ volume fraction of cuttings in the annulus was estimated by Electrical Resistivity Tomography (ERT) analyzer. Visualization technique used to estimate the moving bed velocity in the horizontal annulus section. A highspeed camera was used to capture the transport phenomena of the moving solid particle at 2000 frames per second. The highspeed camera can effectively track each particle in the system. Analysis of high-speed camera revealed different cuttings transport phenomena like rolling of cuttings, stationary cuttings bed and cuttings suspended into the drilling mud. Experimental investigation revealed that drill pipe rotation helps in cuttings bed movement and resist the formation of large cuttings dune in the annulus formation. Also, this study revealed that eccentric annulus shows less annular solid volume compared to a concentric annulus; however, an eccentric annulus is harder to clean compared to a concentric annulus section.


2021 ◽  
Vol 66 (05) ◽  
pp. 192-195
Author(s):  
Rövşən Azər oğlu İsmayılov ◽  

The aricle is about the pipe stick problems of deep well drilling. Pipe stick problem is one of the drilling problems. There are two types of pipe stick problems exist. One of them is differential pressure pipe sticking. Another one of them is mechanical pipe sticking. There are a lot of reasons for pipe stick problems. Indigators of differential pressure sticking are increase in torque and drug forces, inability to reciprocate drill string and uninterrupted drilling fluid circulation. Key words: pipe stick, mecanical pipe stick,difference of pressure, drill pipe, drilling mud, bottomhole pressure, formation pressure


2019 ◽  
Vol 196 ◽  
pp. 00011 ◽  
Author(s):  
Yaroslav Ignatenko ◽  
Andrey Gavrilov ◽  
Oleg Bocharov ◽  
Roland May

The current study is devoted to simulating cuttings transport by drilling fluid through a horizontal section of borehole with an annular cross section. Drill pipe rotates in fixed eccentric position. Steady-state flow is considered. Cuttings are rigid spheres with equal diameters. The carrying fluid is drilling mud with Herschel-Bulkley rheology. Suspension rheology depends on local shear rate and particles concentration. Continuous mixture model with algebraic equation for particles slipping velocity is used. Two hydrodynamic regimes are considered: axial flow without drill pipe rotation and with drill pipe rotation. In the case of axial flow was shown that increasing of power index n and consistency factor k increases pressure gradient and decreases cuttings concentration. Increasing of yield stress leads to increasing of pressure gradient and cuttings concentration. Cuttings concentration achieves constant value for high yield stress and not depends on it. Rotation of the drill pipe significantly changes the flow structure: pressure loss occurs and particles concentration decreases in the cross section. Two basic regimes of rotational flow are observed: domination of primary vortex around drill pipe and domination secondary vorticity structures. Transition between regimes leads to significant changes of flow integral parameters.


CORROSION ◽  
1999 ◽  
Vol 55 (7) ◽  
pp. 706-713 ◽  
Author(s):  
Y. Tomoe ◽  
M. Shimizu ◽  
Y. Nagae

Author(s):  
Evren M. Ozbayoglu ◽  
Flavio Rodrigues ◽  
Reza Ettehadi ◽  
Roland May ◽  
Dennis Clapper

Abstract As explorations advance and drilling techniques become more innovative, complex and challenging trajectories arise. In consequence, cuttings transport has continued to be a subject of interest because, if the drilled cuttings cannot be removed from the wellbore, drilling cannot proceed for long. Therefore, efficient cleaning of highly inclined and horizontal wellbores is still among the most important problems to solve, because these types of wells require specialized fluid formulations and/or specific hole cleaning techniques. There are numerous studies and methods that focus in cuttings transportation in highly inclined and horizontal wells. One of them is the use of viscosity and density sweeps. Sweep pills have been used in the drilling industry as a tool to improve hole cleaning. This report presents the analysis of the performance of different sweeps pills working independently and in tandem in polymeric, oil and synthetic based systems and the comparison between them. The main objective of this project is to provide experimental evidence on which types of fluids perform better under certain conditions by studying the effect of viscosity and density in the bed erosion process in highly inclined and horizontal wells. In order to achieve that, several fluid formulations were tested at different inclination angles (90, 75, 60 degrees) in the Small Indoor Flow Loop property of The University of Tulsa’s Drilling Research Projects. The results of the tests are presented in terms of volume of drilled cuttings removed from the test section and measured differential pressures. All the tests were conducted under atmospheric pressure and ambient temperature. Moreover, a 2-Layer model is used for estimating the erosion performance of sweeps for design purposes, and the model estimations are compared with experimental results. From the experiments, it was identified that polymeric, oil and synthetic based muds with similar density and rheological properties eroded and transported the drilled cuttings similarly under similar test conditions. Furthermore, pumping the sweep pills in tandem demonstrated higher cuttings transport efficiency when compared with the sweep pills applied independently.


Author(s):  
Yaroslav Ignatenko ◽  
Andrey Gavrilov ◽  
Oleg Bocharov ◽  
Roland May

Abstract An Eulerian mixture model of the two-phase flow was used for cuttings transport simulation. The model was tested using experimental data for particles transport in pipes. Three types of problem statements were analyzed: steady-state flow, non-stationary flow in a short-length channel with periodic boundary conditions, and non-stationary flow in a long channel. Simulation of cuttings transport by Herschel-Bulkley fluid through an inclined 21-inch borehole/–6.5-inch drillpipe annulus was performed. All problem statements showed very close results, even for unsteady flow. These results demonstrated the applicability of 2D steady-state problem formulation for cuttings transport simulation. The unsteady flow was observed for an inclination of less than 20 degrees. Slow downward sliding of cuttings in the lower part of inclined boreholes was observed simultaneously with upstream dunes movement. Drill pipe rotation significantly decreased the cuttings concentration and pressure gradient, and shifted the maximum cuttings transport downward sliding rate from a 20- to 40-degree inclination.


Author(s):  
Mohammad Amir Hasani ◽  
Mahmood Norouzi ◽  
Morsal Momeni Larimi ◽  
Reza Rooki

Cuttings transport from wellbore annulus to the surface via drilling fluids is one of the most important problems in gas and oil industries. In the present paper, the effects of viscoelastic property of drilling fluids on flow through wellbore annulus are studied numerically by use of computational fluid dynamics simulation in OpenFOAM software. This problem is simulated as the flow between two coaxial annulus cylinders and the inner cylinder is rotating through its axes. Here, the Giesekus model is used as the nonlinear constitutive equation. This model brings the nonlinear viscosity, normal stress differences, extensional viscosity and elastic property. The numerical solution is obtained using the second order finite volume method by considering PISO algorithm for pressure correction. The effect of elasticity, Reynolds number, Taylor number and mobility factor on the velocity and stress fields, pressure drop, and important coefficient of drilling mud flow is studied in detail. The results predicted that increasing elastic property of drilling mud lead to an initial sharp drop in the axial pressure gradient as well as Darcy-Weisbach friction coefficient. Increasing the Reynolds number at constant Taylor number, resulted an enhancing in the axial pressure drop of the fluid but Darcy-Weisbach [Formula: see text] friction coefficient mainly reduced.


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