Analytical Model to Estimate the Downhole Casing Wear Using the Total Wellbore Energy

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Aniket Kumar ◽  
Joseph Nwachukwu ◽  
Robello Samuel
Keyword(s):  
Contact Zone ◽  
Integral Function ◽  
Drill String ◽  
Energy Model ◽  
Wear Volume ◽  
Average Wear ◽  
Casing Wear ◽  
Curved Section ◽  
Curvature And Torsion ◽  
Two Parameters

The increasing complexities of wellbore geometry imply an increasing potential of damage resulting from the casing-wear downhole. Much work has been done to quantify and estimate wear in casing; however, the results of such predictions have been mixed. While the locations of critical-wear areas along the casing string have been predicted fairly accurately, quantifying the actual amount of casing wear has been a magnitude off. A mathematical model that describes this casing wear in terms of the total wellbore energy has been developed and used to estimate the depth of the wear groove and the wear volume downhole. The wellbore energy provides a mathematical criterion to quantify the borehole quality and incorporates the parameters, borehole curvature, and the wellbore torsion. The casing wear observed downhole is also an integral function of these two parameters. Hence, a combined “wear-energy” model has been proposed to estimate the casing wear in curved sections of the wellbore that have the drill string lying on its low side. The fundamental assumption of this model is that the volume worn away from the casing wall is proportional to the work done by friction on its inner wall by the tool joints only. It also assumes that the primary mechanism for casing wear is the rotation of the drill string, and the wear caused during tripping is insignificant. The borehole torsion models of wellbore trajectory, namely spatial-arc, natural-curve, cylindrical-helix, and constant-tool face, have been incorporated separately to enhance the accuracy of estimating the wear volume downhole. The wear-energy model for a detailed analysis of a practical example using real-time well survey data will be presented. Wear zones along the wellbore have been identified using a mathematical criterion of the “contact zone parameter.” The wear-groove depths for each contact zone along with an equivalent average wear for the curved section of the wellbore have been estimated. The wear volumes predicted by the various curvature and torsion models of wellbore energy have been graphically studied. The wellbore torsion has been found to significantly impact the casing-wear downhole.

scholarly journals New Method for Predicting Casing Wear in Highly Deviated Wells Using Mud Logging Data

2021 ◽  
Author(s):  
Asgar Eyvazi Farab ◽  
Khalil Shahbazi ◽  
Abdolnabi Hashemi ◽  
Alireza Shahbazi
Keyword(s):  
Oil And Gas ◽  
Sliding Mode ◽  
High Accuracy ◽  
Drill String ◽  
Wear Volume ◽  
Wireline Logs ◽  
Casing Wear ◽  
Southwestern Iran ◽  
Mud Logging ◽  
Deviated Wells

Abstract Casing wear is an essential and complex phenomenon in oil and gas wells. Research is being conducted to predict this phenomenon. This study was conducted at a well in southwestern Iran. In this paper, first examine the force exerted on the drill string. Next, the contact force between the drill string and the casing is calculated. Finally, the wear volume and the depth of the wear groove are determined. These calculations were performed using MATLAB and Python software. In addition, due to the high accuracy of coding, mud log data was used to make the results more accurate. It has also been shown that increasing RPM increases the depth of wear and attempts to drill a highly deviated wells as a sliding mode. Finally, compared the results and matched them with the wireline logs recorded from the well.

Wear-Factor Prediction Based on Data-Driven Inversion Technique for Casing Wear Estimation

2020 ◽  
Author(s):  
Manish K. Mittal ◽  
Robello Samuel ◽  
Aldofo Gonzales
Keyword(s):  
Physical Model ◽  
Factor Model ◽  
Data Driven ◽  
Wear Volume ◽  
Model Parameters ◽  
Wear Factor ◽  
Side Force ◽  
Inversion Technique ◽  
Casing Wear ◽  
Volume Output

Abstract Wear factor is an important parameter for estimating casing wear, yet the industry lacks a sufficient data-driven wear-factor prediction model based on previous data. Inversion technique is a data-driven method for evaluating model parameters for a setting wherein the input and output values for the physical model/equation are known. For this case, the physical equation to calculate wear volume has wear factor, side force, RPM, tool-joint diameter, and time for a particular operation (i.e., rotating on bottom, rotating off bottom, sliding, back reaming, etc.) as inputs. Except for wear factor, these values are either available or can be calculated using another physical model (wear-volume output is available from the drilling log). Wear factor is considered the model parameter and is estimated using the inversion technique method. The preceding analysis was performed using soft-string and stiff-string models for side-force calculations and by considering linear and nonlinear wear-factor models. An iterative approach was necessary for the nonlinear wear-factor model because of its complexity. Log data provide the remaining thickness of the casing, which was converted into wear volume using standard geometric calculations. A paper [1] was presented in OMC 2019 discussing a method for bridging the gap. A study was conducted in this paper for a real well based on the new method, and successful results were discussed. The current paper extends that study to another real well casing wear prediction with this novel approach. Some methods discussed are already included in the mentioned paper.

scholarly journals Fitting Splines to Axonal Arbors Quantifies Relationship Between Branch Order and Geometry

2021 ◽  
Vol 15 ◽  
Author(s):  
Thomas L. Athey ◽  
Jacopo Teneggi ◽  
Joshua T. Vogelstein ◽  
Daniel J. Tward ◽  
Ulrich Mueller ◽  
...  
Keyword(s):  
Projection Neurons ◽  
Cortical Projection ◽  
Smooth Curves ◽  
B Splines ◽  
Terminal Axon ◽  
Axonal Arbor ◽  
Curvature And Torsion ◽  
Two Parameters ◽  
Python Package ◽  
Axonal Arbors

Neuromorphology is crucial to identifying neuronal subtypes and understanding learning. It is also implicated in neurological disease. However, standard morphological analysis focuses on macroscopic features such as branching frequency and connectivity between regions, and often neglects the internal geometry of neurons. In this work, we treat neuron trace points as a sampling of differentiable curves and fit them with a set of branching B-splines. We designed our representation with the Frenet-Serret formulas from differential geometry in mind. The Frenet-Serret formulas completely characterize smooth curves, and involve two parameters, curvature and torsion. Our representation makes it possible to compute these parameters from neuron traces in closed form. These parameters are defined continuously along the curve, in contrast to other parameters like tortuosity which depend on start and end points. We applied our method to a dataset of cortical projection neurons traced in two mouse brains, and found that the parameters are distributed differently between primary, collateral, and terminal axon branches, thus quantifying geometric differences between different components of an axonal arbor. The results agreed in both brains, further validating our representation. The code used in this work can be readily applied to neuron traces in SWC format and is available in our open-source Python package brainlit: http://brainlit.neurodata.io/.

Casing Wear Prediction Model Based on Drill String Whirling Motion in Extended-Reach Drilling

2018 ◽  
Vol 43 (11) ◽  
pp. 6325-6332 ◽  
Author(s):  
Leichuan Tan ◽  
Deli Gao ◽  
Jinhui Zhou ◽  
Yongsheng Liu ◽  
Zhengxu Wang
Keyword(s):  
Prediction Model ◽  
Drill String ◽  
Wear Prediction ◽  
Model Based ◽  
Whirling Motion ◽  
Casing Wear ◽  
Extended Reach Drilling

Nonlinear Optimal Control of a Deep Borehole Trajectory Design

2020 ◽  
Author(s):  
Valery Gulyayev ◽  
Sergii Glazunov ◽  
Olena Andrusenko
Keyword(s):  
Optimal Control ◽  
Mathematic Model ◽  
Drill String ◽  
Trajectory Design ◽  
Energy Expenditures ◽  
Total Integral ◽  
Enhance Efficiency ◽  
Step Algorithm ◽  
Curvature And Torsion ◽  
2D And 3D

Abstract In modern oil/gas producing industry, vertical, 2D and 3D directed, and multilateral (branched) boreholes are drilled. Their trajectories are designed depending on the petroleum deposit depth and structure, properties of mining rocks, their hardness, heterogeneity, fracturing anisotropy, permeability, and so on. Therefore, the borehole cost and its productivity are determined by the length, smoothness, and configuration of its trajectory. To enhance efficiency of a borehole and to reduce cost of its drivage, to enlarge rate and volume of the reservoir depletion, it is proposed to use methods of optimal control for the best tracking of its trajectory. Through application of the differential geometry correlations, the mathematic model of the borehole outline in the form of nonlinear ordinary differential equations system is elaborated. Different objective functions, representing total integral curvature of the borehole axis line, its length, and cost of its drivage, are selected; additional constraints, separating allowed and forbidden zones of passing, are chosen. The functions of the trajectory curvature and torsion are used as controlling variables. The continuous correlations of the model are discretized and, further, the techniques of nonlinear programming and optimal control are employed. On the basis of the method of objective function gradient (antigradient) projection on the linearized constraint planes, the step-by-step algorithm of approaching to the optimal trajectory is elaborated. To correct the spoilt constraints, at every step of calculations, the Newton method is used. The elaborated approach is applied to optimization of deep curvilinear borehole outlines. The results of numerical analysis are discussed. It is shown that smoothing the hole trajectory permits also to diminish the contact and frictional interaction between the drill string and bore-hole wall and, by this, to decrease the resistance forces acting on the string during tripping in/out operations performing and to diminish energy expenditures for these operations fulfillment; to decrease the rate of the drill string tube wear; and to reduce the drill string sticking occurrence probability.

Experimental Study on Mechanical Characteristics of PTFE Material

2019 ◽  
Vol 895 ◽  
pp. 224-229
Author(s):  
T. Nagaraju ◽  
K.S. Abhinanadhan ◽  
C. Anilkumar ◽  
S. Sathyanarayan
Keyword(s):  
Shape Parameter ◽  
Wear Test ◽  
Hardness Test ◽  
Wear Volume ◽  
Wear And Friction ◽  
Pin On Disc ◽  
Friction Performance ◽  
Two Parameters ◽  
Sliding Distance ◽  
Test Result

The present work is aimed to experimentally determine the mechanical properties such as Rockwell Hardness Number (RHN), tensile strength and two parameters of Weibull distribution curve (i.e. Weibull shape and characteristic life parameters) of fatigue life for the Poly Tetra Fluoro Ethylene (PTFE) material. The ultimate stress of PTFE specimen is determined using tensometer and its shape parameter and characteristic life are determined from rotary test bending machine. The PTFE specimen is also tested for wear and friction performance on pin-on-disc test rig. Based on the hardness test, RHN of PTFE was found to be 57 and its ultimate engineering stress was observed to be 20.5N/mm2. The Weibull shape parameter and characteristic life of PTFE specimen were observed to be 13.33 and 6734.5 cycles respectively. From the wear test result the sliding speed was found to have maximum influence on wear volume followed by sliding distance where as the load has least influence. .

Performance of Drill String Hardfacings

1984 ◽  
Vol 106 (2) ◽  
pp. 278-281 ◽  
Author(s):  
J. S. Williamson ◽  
J. Bolton
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Tungsten Carbide ◽  
Drill String ◽  
Abrasive Wear Resistance ◽  
Experimental Results ◽  
Casing Wear ◽  
And Tungsten

Drill string hardfacings are composites of steel and tungsten carbide applied by welding techniques. This paper discusses the important variables involved and gives experimental results for casing wear and abrasive wear resistance.

Experimental Determination of Casing Wear by Drill String Rotation

1975 ◽  
Vol 97 (2) ◽  
pp. 464-471 ◽  
Author(s):  
W. B. Bradley
Keyword(s):  
Wear Rate ◽  
Experimental Determination ◽  
Research Program ◽  
Drill Pipe ◽  
Drill String ◽  
Experimental Results ◽  
Casing Wear ◽  
Drilling Conditions ◽  
Consequent Increase

With the trend toward deeper objectives, the time spent drilling through casing has increased with a consequent increase in casing wear. As a result of the expanded importance of casing wear, a research program was undertaken to investigate means to predict the rate of casing wear and means to reduce this wear rate. This paper presents experimental results on the effectiveness of drill pipe rubbers in reducing rotational casing wear and measurements of the rate of casing wear by rotating tool joints and drill pipe rubbers under simulated drilling conditions. The results from this paper and the results from reference [1] have been used to develop techniques for predicting casing wear under field conditions. These techniques are reported in reference [2].

Photo-electric Hβ and uvby photometry

1966 ◽  
Vol 24 ◽  
pp. 170-180
Author(s):  
D. L. Crawford
Keyword(s):  
Narrow Band ◽  
Line Strength ◽  
Interference Filter ◽  
B Stars ◽  
Relative Line ◽  
The Mean ◽  
F Stars ◽  
Two Parameters ◽  
Filter Photometry ◽  
The Continuum

Early in the 1950's Strömgren (1, 2, 3, 4, 5) introduced medium to narrow-band interference filter photometry at the McDonald Observatory. He used six interference filters to obtain two parameters of astrophysical interest. These parameters he calledlandc, for line and continuum hydrogen absorption. The first measured empirically the absorption line strength of Hβby means of a filter of half width 35Å centered on Hβand compared to the mean of two filters situated in the continuum near Hβ. The second index measured empirically the Balmer discontinuity by means of a filter situated below the Balmer discontinuity and two above it. He showed that these two indices could accurately predict the spectral type and luminosity of both B stars and A and F stars. He later derived (6) an indexmfrom the same filters. This index was a measure of the relative line blanketing near 4100Å compared to two filters above 4500Å. These three indices confirmed earlier work by many people, including Lindblad and Becker. References to this earlier work and to the systems discussed today can be found in Strömgren's article inBasic Astronomical Data(7).

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