A New Computer Package for Simulating Cuttings Transport and Predicting Hole Cleaning in Deviated and Horizontal Wells

2000 ◽  
Author(s):  
Longqing Zou ◽  
M.H. Patel ◽  
Guoyou Han
Keyword(s):  
Horizontal Wells ◽  
Cuttings Transport ◽  
Hole Cleaning ◽  
Computer Package

Viscosity and Density Sweeps in Directional Wells

2020 ◽  
Author(s):  
Evren M. Ozbayoglu ◽  
Flavio Rodrigues ◽  
Reza Ettehadi ◽  
Roland May ◽  
Dennis Clapper
Keyword(s):  
Horizontal Wells ◽  
Flow Loop ◽  
Cuttings Transport ◽  
Transport Efficiency ◽  
Hole Cleaning ◽  
Bed Erosion ◽  
Inclination Angles ◽  
Similar Density ◽  
Horizontal Wellbores ◽  
The University

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.

scholarly journals Numerical Simulation of Effective Hole Cleaning by Using an Innovative Elliptical Drillpipe in Horizontal Wellbore

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 399
Author(s):  
Guoshuai Ju ◽  
Tie Yan ◽  
Xiaofeng Sun
Keyword(s):  
Pressure Drop ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Horizontal Wells ◽  
Swirl Flow ◽  
Cuttings Transport ◽  
Cleaning Efficiency ◽  
Two Phase ◽  
Drill Cuttings ◽  
Hole Cleaning

In the drilling of horizontal wells, the drill cuttings tend to settle down on the low side of the annulus due to gravity and form a stationary bed, which results in hole cleaning problems. In this paper, a novel type of drillpipe with an elliptical shape was proposed to alleviate inadequate hole cleaning during the drilling of horizontal wells. A three-dimensional computational fluid dynamic (CFD) Eulerian-Eulerian approach with the Realizable k-ɛ turbulence model was developed to predict the solid–liquid two-phase flow in the annular space. Numerical examples were given to investigate the influence of different parameters on cuttings’ transport behavior, and the elliptical drillpipe was compared with the circular drillpipe. The annular cuttings concentration, annular pressure drop, and hole cleaning efficiency were evaluated. The numerical results clarify the potential of the elliptical drillpipe to enhance the hole cleaning efficiency without significantly increasing the annular pressure drop. Due to the swirl flow and secondary flow caused by the rotation of the curvature wall, the swaying phenomenon of drill cuttings’ distribution along the rotation direction of drillpipe was observed and enhanced the cuttings transport ability. Using the elliptical drillpipe as a joint-type tool can improve hole cleaning performance. Under the optimum conditions applied in this study, the hole cleaning efficiency increased by nearly 18%.

A Probabilistic Belief System to Track the Cleanliness of a Hole in Real-Time

2021 ◽  
Author(s):  
Pradeepkumar Ashok ◽  
John D' Angelo ◽  
Dawson Ramos ◽  
Michael Yi ◽  
Taylor Thetford ◽  
...  
Keyword(s):  
Bayesian Network ◽  
Real Time ◽  
North American ◽  
Transport Model ◽  
Belief System ◽  
Cuttings Transport ◽  
Construction Operations ◽  
Hole Cleaning ◽  
Computational Overhead ◽  
Over Time

Abstract Hole cleaning is important in preventing stuck pipe events during well construction operations. A cuttings transport model is traditionally used to determine the cleanliness of a hole, but its real-time rig site implementation is often made difficult by a lack of necessary inputs. There is a need for a simpler yet reliable approach to quantifying hole cleanliness using data readily available at the rig site. The paper proposes a method that relies on the detection of events over a long time horizon and the use of key parameters relating to such events to quantify hole cleanliness. These events are then related through duration and frequency to probabilistic features in a Bayesian network, to infer the probability that the hole cleaning process has been efficient or poor. These events are also weighted by their age to ensure that current beliefs are not strongly influenced by those that are far in the past. The method was deployed on a drilling advisory system and is currently used on rigs in North American land operations. The events and features found to be most relevant to quantifying hole cleanliness were the circulation rates during drilling, tight spots when moving the drillstring, bit hydraulics, and prolonged periods of inactivity. Proactive hole cleaning actions such as working of the pipe, off bottom circulation and pipe rotation were also considered. The Bayesian network model used by the proposed method was able to be run with low computational overhead (micro-seconds on a standard edge device) compared to a traditional cuttings transport model. This was enabled by an event logging procedure that keeps track of hole-cleaning events over time and consolidates several hours (days) of drilling information into relevant hole-cleaning features that can be processed quickly. The proposed method was validated with statistical methods using surface datasets from six wells involved in North American land operations. Through this validation it was determined that the method was highly effective in correctly characterizing hole conditions throughout the well operation. On the rig, the system was helpful in not only in alerting the drillers whenever hole cleanliness deteriorated but also providing the most likely causes of the deterioration. This provided the rig crew real-time guidance to make actionable decisions to avoid a stuck pipe situation. The proposed method differentiates itself from the published methods of hole cleaning analysis in two main aspects. First, it does not presume to estimate the cuttings bed height or accumulation over time. Instead, it attempts to infer the probability that the hole cleaning operations are effective over time using features in data that suggest efficient or poor hole cleaning. Second, this method provides a clear indication of when hole cleaning actions are needed and why.

scholarly journals Numerical and experimental investigation on the depressurization capacity of a new type of depressure-dominated jet mill bit

2020 ◽  
Vol 17 (6) ◽  
pp. 1602-1615
Author(s):  
Xu-Yue Chen ◽  
Tong Cao ◽  
Kai-An Yu ◽  
De-Li Gao ◽  
Jin Yang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Rate Ratio ◽  
Area Ratio ◽  
Low Flow ◽  
Flow Rate Ratio ◽  
Cuttings Transport ◽  
Horizontal Drilling ◽  
Hole Cleaning ◽  
Bottom Hole ◽  
New Type

AbstractEfficient cuttings transport and improving rate of penetration (ROP) are two major challenges in horizontal drilling and extended reach drilling. A type of jet mill bit (JMB) may provide an opportunity to catch the two birds with one stone: not only enhancing cuttings transport efficiency but also improving ROP by depressuring at the bottom hole. In this paper, the JMB is further improved and a new type of depressure-dominated JMB is presented; meanwhile, the depressurization capacity of the depressure-dominated JMB is investigated by numerical simulation and experiment. The numerical study shows that low flow-rate ratio helps to enhance the depressurization capacity of the depressure-dominated JMB; for both depressurization and bottom hole cleaning concern, the flow-rate ratio is suggested to be set at approximately 1:1. With all other parameter values being constant, lower dimensionless nozzle-to-throat-area ratio may result in higher depressurization capacity and better bottom hole cleaning, and the optimal dimensionless nozzle-to-throat-area ratio is at approximately 0.15. Experiments also indicate that reducing the dimensionless flow-rate ratio may help to increase the depressurization capacity of the depressure-dominated JMB. This work provides drilling engineers with a promising tool to improve ROP.

Real-Time Evaluation of Hole Cleaning Conditions Using a Transient Cuttings Transport Model

2013 ◽  
Author(s):  
E. Cayeux ◽  
T. Mesagan ◽  
S. Tanripada ◽  
M. Zidan ◽  
K. K. Fjelde
Keyword(s):  
Real Time ◽  
Transport Model ◽  
Cuttings Transport ◽  
Hole Cleaning ◽  
Time Evaluation

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.

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