Scaling Formulae for the Wellbore Hydraulics Similitude with Drill Pipe Rotation and Eccentricity

2021 ◽  
Author(s):  
Thad Nosar ◽  
Pooya Khodaparast ◽  
Wei Zhang ◽  
Amin Mehrabian
Keyword(s):  
Power Law ◽  
Flow Rate ◽  
Annular Flow ◽  
Rotation Speed ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Flow Loop ◽  
Annular Flows ◽  
Fluid Rheology ◽  
Pipe Rotation

Abstract Equivalent circulation density of the fluid circulation system in drilling rigs is determined by the frictional pressure losses in the wellbore annulus. Flow loop experiments are commonly used to simulate the annular wellbore hydraulics in the laboratory. However, proper scaling of the experiment design parameters including the drill pipe rotation and eccentricity has been a weak link in the literature. Our study uses the similarity laws and dimensional analysis to obtain a complete set of scaling formulae that would relate the pressure loss gradients of annular flows at the laboratory and wellbore scales while considering the effects of inner pipe rotation and eccentricity. Dimensional analysis is conducted for commonly encountered types of drilling fluid rheology, namely, Newtonian, power-law, and yield power-law. Appropriate dimensionless groups of the involved variables are developed to characterize fluid flow in an eccentric annulus with a rotating inner pipe. Characteristic shear strain rate at the pipe walls is obtained from the characteristic velocity and length scale of the considered annular flow. The relation between lab-scale and wellbore scale variables are obtained by imposing the geometric, kinematic, and dynamic similarities between the laboratory flow loop and wellbore annular flows. The outcomes of the considered scaling scheme is expressed in terms of closed-form formulae that would determine the flow rate and inner pipe rotation speed of the laboratory experiments in terms of the wellbore flow rate and drill pipe rotation speed, as well as other parameters of the problem, in such a way that the resulting Fanning friction factors of the laboratory and wellbore-scale annular flows become identical. Findings suggest that the appropriate value for lab flow rate and pipe rotation speed are linearly related to those of the field condition for all fluid types. The length ratio, density ratio, consistency index ratio, and power index determine the proportionality constant. Attaining complete similarity between the similitude and wellbore-scale annular flow may require the fluid rheology of the lab experiments to be different from the drilling fluid. The expressions of lab flow rate and rotational speed for the yield power-law fluid are identical to those of the power-law fluid case, provided that the yield stress of the lab fluid is constrained to a proper value.

Comprehensive experimental investigation of hole cleaning performance in horizontal wells including the effects of drillstring eccentricity, pipe rotation and cuttings size

2021 ◽  
pp. 1-11
Author(s):  
Ahmed K. Abbas ◽  
Mortadha T. Alsaba ◽  
Mohammed F. Al Dushaishi
Keyword(s):  
Flow Rate ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Real Field ◽  
Operational Parameters ◽  
Cleaning Efficiency ◽  
Hole Cleaning ◽  
Cleaning Performance ◽  
Pipe Rotation

Abstract Extended reach (ERD) wells with a horizontal and highly deviated section are widely applied in the oil and gas industry because they provide higher drainage area than vertical wells; and hence, increase the productivity or injectivity of the well. Among many issues encountered in a complex well trajectory, poor hole cleaning is the most common problem, which occurs mainly in the deviated and horizontal section of oil and gas wells. There are significant parameters that have a serious impact on hole cleaning performance in high-angle and horizontal sections. These include flow rate, rheology and density of the drilling fluid, drillstring eccentricity, pipe rotation, and cuttings size. It has been recognized that the action of most of these parameters to transport drilled cuttings is constantly a point of controversy among oilfield engineers. In the present study, extensive experiments were conducted in an advanced purpose-built flow rig to identify the main parameters affecting on circulate the cuttings out of the test section in a horizontal position. The flow-loop simulator has been designed to allow easy variation of operational parameters in terms of flow rate, mud density, drillstring eccentricity, pipe rotation, and cuttings size. In addition, the study covers the impacts of laminar, transition, and turbulent flow regimes. The goal of such variation in the operational conditions is to simulate real field situations. The results have shown that drill string rotation and flow rate were the operational parameters with the highest positive influence on the cuttings transports process. In contrast, drill pipe eccentricity has a negative influence on cuttings removal efficiency. The cuttings transportation performance is further improved by pipe rotation at different levels of eccentricity, especially at fully eccentric annuli. It was also shown that larger cuttings appeared to be easier to remove in a horizontal annulus than smaller ones. The experimental results would provide a more in-depth understanding of the relationship between drilling operation parameters and hole cleaning efficiency in ERD operations. This will help the drilling teams to realize what action is better to take for efficient cutting transportation.

scholarly journals Optimization of Hole Cleaning and Cuttings Removal in High Inclined Till Horizontal Well

2020 ◽  
Vol 21 (1) ◽  
pp. 61-66
Author(s):  
Karrar Ahmed Mohammed ◽  
Ayad A. Al-Haleem
Keyword(s):  
Flow Rate ◽  
Horizontal Well ◽  
Rolling Force ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Negative Influence ◽  
Flow Loop ◽  
Cleaning Efficiency ◽  
Hole Cleaning ◽  
Inclination Angles

The goal of this experimental study is to determine the effects of different parameters (Flow rate, cuttings density, cuttings size, and hole inclination degree) on hole cleaning efficiency. Freshwater was used as a drilling fluid in this experiment. The experiments were conducted by using flow loop consist of approximately 14 m (46 ft) long with transparent glass test section of 3m (9.84 ft.) long with 4 inches (101.6 mm) ID, the inner metal drill pipe with 2 inches (50.8 mm) OD settled with eccentric position positive 0.5. The results obtained from this study show that the hole cleanings efficiency become better with high flow rate (21 m3/hr) and it increase as the hole inclination angles increased from 60 to 90 degree due to dominated of the rolling force. The cuttings size has negative influence on cuttings recovered as size increased and that is true for all cuttings specific gravity due to direct effect of the cuttings size and density on the gravity force which work against lifting force. The increasing of hole inclination angle above 60 degree will affect positively on cuttings removal efficiency.

scholarly journals Experimental investigation on barite sag under flowing condition and drill pipe rotation

2020 ◽  
Vol 10 (8) ◽  
pp. 3497-3503
Author(s):  
Saeed Zaker ◽  
Pegah Sarafzadeh ◽  
Amin Ahmadi ◽  
Seyyed Hamid Esmaeili-Faraj ◽  
Roohollah Parvizi
Keyword(s):  
Flow Rate ◽  
Solid Phase ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Density Fluctuations ◽  
Drilling Fluids ◽  
Drilling Process ◽  
Flow Loop ◽  
Well Control ◽  
Mud Loss

Abstract Using drilling fluids with optimum density is one of the most important approaches to stabilize the pressure of the bottom formation and prevent blowout through the drilling process. One of the common methods for this purpose is adding some additives with high specific gravity to the drilling fluid to tune its density. Among the possible chemicals, barite and hematite with the density of 4.2 and 5.2 g/cc are the most common additives. Unfortunately, although the application of these additives is advantageous, they have some drawbacks which the most important one is separation and settlement of solid phase called barite sag. The barite sag comes from barite, or other dense materials particles deposition resulted in undesired density fluctuations in drilling fluid can lead to mud loss, well control problems, poorly cementing and even pipe sticking which occurs in severe cases. With respect to these concerns, the current investigation is concentrated to obtain the relation between the dynamic conditions such as flow rate (0.308 and 0.19 l/s) and deviation angles of 30°,45°,60° and 90° and barite sag phenomenon through a flow loop equipment. Besides, the effect of drilling string rotational speed (70 rpm) on the barite deposition is investigated. The results not only indicate that increasing the flow rate from 0.19 l/s to 0.308 l/s can reduce the deposition rate, but also increasing the deviation angle from 45 to 60 o enhance the barite deposition to its maximum value. Graphic abstract

scholarly journals Simulation of steady-state cuttings transport through a horizontal annulus channel

2019 ◽  
Vol 196 ◽  
pp. 00011 ◽  
Author(s):  
Yaroslav Ignatenko ◽  
Andrey Gavrilov ◽  
Oleg Bocharov ◽  
Roland May
Keyword(s):  
Steady State ◽  
Pressure Gradient ◽  
Yield Stress ◽  
Cross Section ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Axial Flow ◽  
Cuttings Transport ◽  
Rigid Spheres ◽  
Pipe Rotation

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.

Influence of Pipe Rotation and Reciprocation in Flow of Non-Newtonian Fluids in Eccentric Annular Spaces

2006 ◽  
Author(s):  
David J. Lugo ◽  
Armando J. Blanco
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Power Law ◽  
Rotation Speed ◽  
Oil Industry ◽  
Annular Space ◽  
Bingham Plastic ◽  
Static Fluid ◽  
Pipe Rotation

Some industrials processes are associated with flow of non-Newtonian fluids in annular spaces created between parallel pipes. Examples are found in oil industry and food industrial processing. Depending on relative position of both axes, a concentric or eccentric annular space is created. In some typical applications the fluid rheology non-Newtonian and models such as Bingham Plastic or Power Law are required for adequate representation of internal deformations of fluid elements when shear stresses are applied. Depending on annulus eccentricity high resistance can be opposed to flow on narrowest section, including the possibility of having static or quasi-static fluid close to the internal annulus walls. In order to remove this static fluid, two different operations are usually proposed: pipe rotation and pipe reciprocation. In this way, less mobile fluid can be put in motion increasing shear stress. These operations are justified by experimental evidence exists. Scale experiments have been done and predictions for flow behavior in large facilities are extrapolated. However, in large facilities, as oil wells are highly pressurized and they are very deep, it is almost impossible to verify if the whole fluid is mobile and no by-pass fluid remains in the narrowest section of annular space. So, Computational Fluid Dynamics constitutes an ideal technique for analyzing this kind of problem. In this paper, though a Computational Fluid Dynamics study we aim to evaluate the efficiency of pipe rotation and pipe reciprocation in static or quasi-static fluids for Bingham Plastic or Power Law fluid. In order to consider realistic scenarios, oil industry typical conditions are considered for fluid density, rheological parameters, flow rates, casing and hole sizes, and annulus eccentricity. The influence of the variables eccentricity and rotation speed, and the use of reciprocation in shear stress at walls, were used as a measure to evaluate efficiency in static fluid removal. The flow regime was considered laminar. Numerical model capability to reproduce accurately flow patterns in these conditions was assured by comparing it with others analytical-numerical solutions for concentric systems. Results show that both operations are effective for helping in static fluid remotion. However, notable increment for efficiency is observed for eccentricities below 60%. In particular, pipe rotation is effective when rotation speed is greater than 20 RPM for eccentricity greater than 40%. Below this limit, pipe reciprocation is more effective than pipe rotation, independently of the rheological model used to represent the fluid.

Non-Newtonian Flow in Eccentric Annuli

1990 ◽  
Vol 112 (3) ◽  
pp. 163-169 ◽  
Author(s):  
M. Haciislamoglu ◽  
J. Langlinais
Keyword(s):  
Velocity Profile ◽  
Power Law ◽  
Flow Rate ◽  
Pressure Loss ◽  
Annular Flow ◽  
Flow Behavior ◽  
Drilling Fluids ◽  
Viscosity Term ◽  
Power Law Fluids ◽  
Eccentric Annuli

A common assumption for annular flow used in the petroleum industry is that the inner pipe is concentrically located inside the flow geometry; however, this is rarely the case, even in slightly deviated wells. Considering the increasing number of directional and horizontal wells, the flow behavior of drilling fluids and cement slurries in eccentric annuli is becoming particularly important. In this paper, the governing equation of laminar flow is numerically solved using a finite differences technique to obtain velocity and viscosity profiles of yield-power law fluids (including Bingham plastic and power law fluids). Later, the velocity profile is integrated to obtain flow rate. Results show that the velocity profile is substantially altered in the annulus when the inner pipe is no longer concentric. Stagnant regions of flow were calculated in the low side of the hole. Viscosity profiles predicted for an eccentric annulus show how misleading the widely used single-value apparent viscosity term can be for non-Newtonian fluids. Profiles of velocity and viscosity in concentric and varying eccentric annuli are presented in 3-D and 2-D contour plots for a better visualization of annular flow. Frictional pressure loss gradient versus flow rate relationship data for power law fluids is generated using the computer program. Later, this data is fitted to obtain a simple equation utilizing regressional analysis, allowing for a quick calculation of friction pressure losses in eccentric annuli. For a given flow rate, frictional pressure loss is reduced as the inner pipe becomes eccentric. In most cases, about a 50-percent reduction in frictional pressure loss is predicted when the inner pipe lies on the low side.

Experimental Investigation of Mechanical Friction and Hydraulics for Liner Drilling and Liner Running

2016 ◽  
Author(s):  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Bjørnar Lund ◽  
Knud Richard Gyland ◽  
Arild Saasen
Keyword(s):  
Experimental Investigation ◽  
Friction Coefficient ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Drilling Fluids ◽  
Flow Loop ◽  
Cuttings Transport ◽  
Transport Efficiency ◽  
Sand Particles ◽  
Norwegian Continental Shelf

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.

Experimental Research on the Particles Reflux in the Particle Impact Drilling System

2011 ◽  
Vol 361-363 ◽  
pp. 381-385
Author(s):  
Zhen Zhong Ma ◽  
Yang Zhang ◽  
Bin Bin Wang
Keyword(s):  
Flow Rate ◽  
Volume Fraction ◽  
Drilling Fluid ◽  
Particle Volume Fraction ◽  
Drill Pipe ◽  
Dimension Theory ◽  
Particle Impact ◽  
Fluid Viscosity ◽  
Annular Gap ◽  
Drilling Technology

Particle Impact Drilling technology (PID) is a new drilling technology, which is designed especially to solve the oil and gas exploration under hard terrane. In PID system, the steel particles were added in the drilling fluid to impact rock. The particles would be recycled and put to use again, thus it is of great significance to adjust proper drilling fluid flow rate for steel particle’s reflux. The flow rate of drilling fluids carrying particles is influenced by the fluid viscosity, the annular gap between drill pipe and wellbore, the particle volume fraction and particle size, etc. This paper mainly studied the influence of the annular gap and the flow rate, while the other factors keep constant. Both experimental method and dimension theory were employed in the research. Furthermore, empirical formula was proposed to describe the mechanism.

Cuttings Bed Removal in Deviated Wells

2018 ◽  
Author(s):  
Jan David Ytrehus ◽  
Bjørnar Lund ◽  
Ali Taghipour ◽  
Birgitte Ruud Kosberg ◽  
Luca Carazza ◽  
...  
Keyword(s):  
Test Section ◽  
Critical Angle ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Drill String ◽  
Flow Loop ◽  
Cleaning Efficiency ◽  
Hole Cleaning ◽  
Low Viscosity ◽  
Deviated Wells

A drilling fluid for drilling deviated wellbores must provide adequate hole cleaning efficiency for all well angles relevant to the operation. For angles near vertical, experience show that hole cleaning is straight forward. In wellbore angles larger than, say, 45 degrees hole cleaning is more difficult. Cuttings beds are formed and at some well angles these beds may avalanche during circulation stops etc. This paper presents results from laboratory tests with injected cuttings using a low viscosity oil based drilling fluid with micronized grained barite as weight material. The fluid is designed for highly deviated wells with low ECD requirements and the cuttings transport performance through relevant wellbore inclinations was investigated. The experiments have been performed under realistic conditions. The flow loop includes a 10 meters long test section with 2” OD freely rotating steel drill string inside a 4” ID wellbore made of steel, representing a cased wellbore. Sand particles were injected while circulating the drilling fluid through the test section. Experiments were performed in three wellbore inclinations: 48, 60 and 90 degrees from vertical. Results show that hole cleaning in absence of drill pipe rotation is significantly improved if the well angle is less than a critical angle. This critical angle appears to be less than 60 degrees from vertical. Further result show that this critical inclination angle is dependent to the drill string rotation rate and the annular flow velocity.

New Hybrid Hole Cleaning Model for Vertical and Deviated Wells

2019 ◽  
Vol 142 (3) ◽  
Author(s):  
Ahmed Abdulhamid Mahmoud ◽  
Mahmoud Elzenary ◽  
Salaheldin Elkatatny
Keyword(s):  
Drilling Fluid ◽  
Drill Pipe ◽  
Real Field ◽  
Oil Well ◽  
Hole Size ◽  
Drilling Mud ◽  
Rate Of Penetration ◽  
Hole Cleaning ◽  
Fluid Rheology ◽  
Pipe Size

Abstract Drilled cuttings transportation from the bottom hole to the surface to maintain efficient hole cleaning is a challenging issue while drilling vertical, deviated, high angle, and extended reach wells. This is attributed to the huge number of the parameters affecting the ability of the drilling fluid to leave the drilled solids. Drilling fluid rheology, density, and flowrate, hole size, drill pipe size, hole inclination, and rate of penetration are all confirmed experimentally to affect the effectiveness of the drilling mud to lift the fluid and keep a clean hole. Several parameters were developed earlier to account for the hole cleaning conditions, most of these parameters lake to including many of the parameters influencing the hole cleaning conditions. In this study, a new hole cleaning parameter was developed, which is called hole cleaning factor (HCF). The HCF parameter was developed based on the cutting carrying index (CCI) parameter, and it considered the effect of the drilling fluid rheology, density, and flowrate, the hole size, drill pipe size, hole inclination, and rate of penetration to identify the hole cleaning condition. The HCF model was applied in an oil well from North Africa to predict the hole cleaning condition at different 135 points where the depth ranges from 33 to 12,854 ft. The outcomes of the HCF were well correlated with the real-field scenarios, where the crew members faced by erratic torque with differentiation in drilling parameters resulting in worst stuck pipe conditions at the same depths as predicted by the HCF parameter. The developed HCF model will help the drilling engineers to avoid many issues while drilling such as cutting accumulation and drill pipe sticking. The predictability of the HCF model was compared with commercially available software, and the results indicated a good match between the predictability of the HCF model and the commercial software.

Sign in / Sign up

Export Citation Format

Share Document