failure analysis on the drillpipe due to the twist-off

ii

FAILURE ANALYSIS ON THE DRILLPIPE DUE TO THE TWIST-OFF

MOHD IQBAL BIN MOHD ZOLKEPELI

Report submitted in partial fulfillment of the requirementsfor the award of the degree of

Bachelor of Mechanical Engineering

FACULTY OF MECHANICAL ENGINEERINGUNIVERSITI MALAYSIA PAHANG

iii

SUPERVISOR’S DECLARATION

We hereby declare that we have checked this project report and in our opinion this

project is satisfactory in terms of scope and quality for the award of the degree of

Bachelor of Mechanical Engineering with “specialization”.

Signature:

Name of Supervisor: Pn. Nurul Shahida Bt Mohd Shalahim

Position: Lecturer

Date: 11 November 2008

Signature:

Name of Panel: En. Zamri Bin Mohamed

Position: Lecturer


iv

STUDENT’S DECLARATION

I hereby declare that the work in this report is my own except for quotations and

summaries which have been duly acknowledged. The report has not been accepted for

any degree and is not concurently submitted for award of other degree.

Signature

Name: Mohd Iqbal Bin Mohd Zolkepeli

ID Number: MA05041


v

To my beloved mother, father and family, the love of my life

vi

ACKNOWLEDGEMENT

It is a great sense of pleasure that I acknowledge the help and guidance Ihave

receive from a numerous people during the course of my stay at Universiti Malaysia

Pahang. My supervisor Pn. Nurul Shahida Bt Mohd Shalahim provided me with energy,

enthusiasm and insight to work on this interesting final year project. I am very much

thankful to them for all their support in conducting and writing up my work. Moreover, I

would like to express my heartfelt and sincere for their priceless guidance and support

during my final year. In addition to being my supervisor, she also helps me a lot with

advices related to industries.

Furthermore, I also would like to thank Mr Mahendran A/L Samykano as my

co-supervisor that is very helpful, easy going and understanding person. Not forgetting

my fellow friends who gave me a lot of ideas and helps in designing and doing the

analysis. Without them, I would have been nowhere near completing my project which I

also learnt the importance of team working. Thanks to almighty God, for giving me the

life and hope to finish this project without any major problem.

Last but not least, special thanks goes to my beloved parents who supported me

from the very beginning to achieve my goals and sacrifice much in their life for my

well-being. I am indebted to their painstaking attitude, which always kept me on the

right track.

vii

ABSTRACT

This thesis reports on the design and analysis for failure at three different drill

pipes. When drilling boreholes, for example in the Oil & Gas industry, a hole is drilled

into the ground which can be several kilometers long. One of main type of problem that

can occur while drilling is the torque on the drill pipe can cause it to break (called twist-

off). This problem results in drilling delays. Twist-offs also usually results in loss of

expensive equipment. Therefore, ALGOR software has been use as the FEA tool to do

the analysis to reduce this problem. Six different values of torque range from 2000 N.m

to 3000 N.m is applied to the end of the pipe stand which is consist of three assembly of

pipes. The materials of the pipe have been chosen are AISI 1010, ASTM A36 and AISI

4150 steels that have different mechanical properties the see the differences. The test

results show that AISI 4150 is the most suitable material to use which gives 2800 N.m

torque value before it starts to fail. Meanwhile, a constant pattern of failure has

determined for these three pipes at the same location of the second engaged thread of the

pipe assembly, between the male and female thread at the joint. For improvement, to see

the differences from another point of view, the analysis for this drill pipe design is

suggested to do with different thickness and length in order to analyze how much the

maximum allowable torque value can be applied to the pipe before it starts to fail.

viii

ABSTRAK

Tesis ini melaporkan tentang rekabentuk dan analisis kegagalan pada tiga jenis

paip gerudi. Apabila proses gerudi dijalankan, sebagai contoh di industry minyak & gas,

permukaan tanak digerudi dengan menggunakan paip untuk membuat lubang sejauh

melebihi berkilo-kilo meter. Salah satu masalah yang dihadapi ketika proses menggerudi

ialah pemintalan paip gerudi yang menyebabkan paip itu patah. Masalah ini

menyebabkan penangguhan proses menggerudi. Pemintalan kebiasaannya akan

menyebabkan kerosakan peralatan – peralatan yang berkos tinggi. Oleh itu, software

ALGOR digunakan sebagai salah satu unsur FEA untuk menganalis kegagalan yang

berlaku pada paip gerudi untuk mengurangkan masalah ini. Enam nilai tenaga putaran

yang berbeza bernilai dari 2000 N.m ke 3000 N.m telah dikenakan kepada hujung paip

yang terdiri daripada tiga sambungan batang paip. Antara bahan aloi yang dipilih adalah

AISI 1010, ASTM A36 dan AISI 4150 yang mempunyai sifat mekanikal yang berlainan

antara satu sama lain. Berdasarkan analysis, AISI 4125 adalah bahan yang paling sesuai

untuk digunakan kerana nilai tenaga putaran maksima yang boleh dikenakan adalah

yang tertinggi iaitu 2800 N.m sebelum ia gagal. Sementara itu, corak kegagalan yang

sejajar dikenalpasti pada ketiga-tiga jenis paip ini yang berlaku pada sambungan kedua

paip. Untuk penambahbaikkan, analisis ini dicadangkan untuk menggunakan ketebalan

dan panjang paip yang berbeza untuk melihat perbezaan nilai tenaga putaran maksima

yang boleh dikenakan kepada paip gerudi sebelum ia gagal.

ix

TABLE OF CONTENTS

CHAPTER TITLE PAGE

DECLARATIONS ii

DEDICATION iv

ACKNOWLEDGEMENT v

ABSTRACT vi

ABSTRAK vii

TABLE OF CONTENTS viii

LIST OF TABLES xiii

LIST OF FIGURES xiv

LIST OF SYMBOLS xvii

LIST OF APPENDICES xviii

1 INTRODUCTION

1.1 Project Overview 1

1.2 Project Problem Statement 2

1.3 Project Objectives 3

1.4 Project Scopes 3

1.5 Project Organization Report 3

1.6 Project Planning 4

x

2 LITERATURE REVIEW

2.1 Introduction 5

2.2 Petroleum Drilling 5

2.2.1 Borehole Drilling 6

2.2.2 Drill String 6

2.2.3 Drill Pipe 6

2.3 Failure of Drill Pipe 7

2.3.1 Twist off 8

2.4 Failure Analysis 8

2.5 Failure Criteria 9

2.5.1 Von Misses Stress 9

2.6 Materials 10

2.6.1 The American Iron 10

and Steel Institute (AISI)

2.6.2 Factor in Material Selection 11

2.6.2.1 Mechanical Factor 11

2.6.2.2 Life of Component Factors 11

2.7 Example of Research 12

2.7.1 Research by M. Veidt and A. Berezovski, 12

Division of Mechanical Engineering,

University of Queensland, Brisbane.

xi

2.7.2 Research by K.A. Macdonald and J.V. Bjune, 13

University of Stavanger,

4036 Stavanger, Norway.

2.7.3 Research by Stanislaw Bednarz. 13

2.7.4 Research by TCR Engineering Services 14

Technical Team, 2004.

3 METHODOLOGY

3.1 The Methodology 16

3.2 Literature Review 17

3.3 Research’s Focus 17

3.4 Collecting Data 17

3.5 Design of Drill Pipe Using 17

Solidworks 2007

3.6 Finite Element Analysis 18

3.6.1 Linear Static Analysis 18

3.6.2 Build/Mesh Model 18

3.6.3 Element and Material Type 19

3.6.4 Boundary Condition and Load Application 19

3.6.5 Analyzed Model 19

3.6.6 Von Misses Stress 20

xii

3.7 Recommendation 20

3.8 Documentation 20

3.9 Flowchart of Methodology 21

4 RESULT & DISCUSSION

4.1 Failure Analysis 22

4.2 Drill Pipe Design 22

4.3 ALGOR Analysis 24

4.4 Theoretical Calculation 25

4.5 Analysis of AISI 1010 Steel 27

4.5.1 Conclusion 31

4.6 Analysis of ASTM A36 Steel 31

4.6.1 Conclusion 35

4.7 Analysis of AISI 4150 Steel 36

4.7.1 Conclusion 40

4.8 Discussion 40

5 CONCLUSION & RECOMMENDATION

5.1 Introduction 42

5.2 Conclusion 42

5.2.1 Accomplishment of Part 1 42

5.2.2 Accomplishment of Part 2 43

xiii

5.3 Recommendations 45

5.3.1 Thickness of Drill Pipe 45

5.3.2 Length of Drill Pipe 45

5.3.3 Analysis base on another Failure Criteria 46

REFERENCES 47

APPENDICES A-C 49 - 63

xiv

LIST OF TABLES

TABLE NO. TITLE PAGE

4.1 The properties of the AISI 1010 Steel 27

4.2 The conclusion of analysis AISI 1010 Steel 31

4.3 The properties of the ASTM A36 Steel 31

4.4 The conclusion of analysis ASTM A36 Steel 35

4.5 Physical and mechanical properties 36

of AISI 4150 Steel

4.6 The conclusion of analysis for AISI 4150 Steel 40

xv

LIST OF FIGURES

FIGURE NO. TITLE PAGE

1.1 Project Planning for both 4

Final Year Project 1 and 2

2.1 The example of drill pipe 7

2.2 The drilling process 8

2.3 The design of male and female pipe threaded 12

2.4 Torque-Tension Limits diagram for 5x29/16" 14

NC38 tool joint on 31/2", 13,30 lb/ft S-135 drill pipe

3.1 The Methodology’s Flowchart for the whole 21

Final Year Project

4.1 The 3D male threaded pipe 23

4.2 Shows the 2D female threaded pipe 23

4.3 The joint between 2 pipes 24

4.4 The top view of the pipe which torque is applied 24

4.5 The bottom view of the drill pipe 25

which is fix boundary condition

4.6 The maximum stress value for 2000 N.m, 28

xvi

AISI 1010


AISI 1010


AISI 1010


AISI 1010


AISI 1010


AISI 1010


ASTM A36


ASTM A36


ASTM A36


ASTM A36


xvii

ASTM A36


ASTM A36


AISI 4150


AISI 4150


AISI 4150


AISI 4150


AISI 4150


AISI 4150

5.1 The Flowchart for Final Year Project 1 43

5.2 The Flowchart for Final Year Project 2 44

xviii

LIST OF SYMBOLS

T - Motor torque

P - Pressure

C1 - Inner radius of the drill pipe

C2 - Outer radius of the pipe

J - Moment of inertia

τ - Shearing stress

t1 - Pipe thickness

d1 - Inner diameter of the drill pipe

d2 - Outer diameter of the drill pipe

xix

LIST OF APPENDICES

APPENDIX TITLE PAGE

A Drilling process & pipe design 49 – 51

B ALGOR analysis 52 – 60

C List of Tables 61 - 63

1

CHAPTER 1

INTRODUCTION

1.1 PROJECT OVERVIEW

Drilling engineering is a subset of petroleum engineering. It is primarily involved

in the design and drilling of production and injection wells. The drilling engineer has the

responsibility for the efficient penetration of the earth by a well bore, and for cementing

of the steel casing from the surface to a depth usually just about the target reservoir. The

Oil & Gas industry is involved in the global processes of exploration, extraction,

refining, transporting (often with oil tankers and pipelines), and marketing petroleum

products. The largest volume products of the industry are fuel oil and gasoline (petrol).

Petroleum is also the raw material for many chemical products, including

pharmaceuticals, solvents, fertilizers, pesticides, and plastics. Petroleum is vital to many

industries, and is of importance to the maintenance of industrialized civilization itself,

and thus is critical concern to many nations.

The usual problem in petroleum drilling is failure due to fatigue. Failure due to

fatigue is a very costly problem in oil and gas industry. Drillstring failure occurs on 14-

percent of all rigs and the resulting downtime costs roughly $106 000 per event. A

survey of all drilling problems reported worldwide over a 15-month period shows that

36-percent were due to stuck pipe. Stuck pipe cost estimates for the worldwide drilling

industry range as high as $250 million for this period. The threaded connection of the

http://en.wikipedia.org/wiki/Petroleum_engineering

http://en.wikipedia.org/wiki/Hydrocarbon_exploration

http://en.wikipedia.org/wiki/Extraction_of_petroleum

http://en.wikipedia.org/wiki/Oil_refinery

http://en.wikipedia.org/wiki/Oil_tanker

http://en.wikipedia.org/wiki/Pipeline_transport

http://en.wikipedia.org/wiki/Petroleum

http://en.wikipedia.org/wiki/Fuel_oil

http://en.wikipedia.org/wiki/Gasoline

http://en.wikipedia.org/wiki/Petrochemical

http://en.wikipedia.org/wiki/Industries

http://en.wikipedia.org/wiki/Civilization

2

type used in hydrocarbon exploration is a critical component of the drillstring that is

highly susceptible to fatigue damage. Fatigue crack growth can either lead to a

catastrophic failure of the connection, known as a twist-off, or can be a non-critical

failure, known as a wash-out.

Failure in most cases is restricted to either the drill pipe located at the upset regions

or at the threaded connections. External damage arising from poor pipe handling

practices can occasionally lead to failure at random locations along the length of the

drillpipe. The range of commonly encountered primary damage mechanisms covers

ductile fracture, brittle fracture, fatigue and stress corrosion cracking. Various simple

and complex combinations can also occur. A consistent feature where twist-off has

occurred is that post-separation damage to fracture surfaces can often be very severe,

obliterating much of the detail of the fracture morphology required to aid identification

of the failure mode. This is due to the failure remaining undetected at the surface and

consequently both weight-on-bit and rotation continues. In addition, the large pressure

differential drives flow of the mud from pipe bore to annulus should a leak path become

available, resulting in wash-out damage.

1.2 PROJECT PROBLEM STATEMENT

When drilling boreholes, for example in the Oil & Gas industry, a hole is drilled

into the ground which can be several kilometers long. One of main type of problem that

can occur whilst drilling is the torque on the drill pipe can cause it to break (called twist-

off). This problem results in drilling delays. Twist-offs also usually results in loss of

expensive equipment.

3

1.3 PROJECT OBJECTIVES

The project is conducted to achieve the following objectives:-

i) To do the failure analysis on the drillpipe for directional borehole

drilling.

ii) To find the desirable maximum allowable torque can be applied to the

drillstring to reduce its failure.

1.4 PROJECT SCOPES

The project scopes are:-

i) The borehole drilling only consider for directional borehole drilling.

ii) The focus on problem is only for and ‘twist-off’- (the torque on the drill pipe can

cause it to break).

iii) Drill pipes are manufactured to different lengths and diameters. This

investigation focuses on NQ drill pipes, which are mainly used for directional

exploration drilling.

iv) The ALGOR Software will be used as the tool of Finite Element Analysis .

1.5 PROJECT ORGANIZATION REPORT

The rest of the report is organized as follows:-

There are 4 more chapters to be discussed which are Chapter 2, 3, 4 and 5. The

literature review of this research will be explained further in chapter 2. In this chapter,

the overview and explanation for failure analysis will be discussed. The description of

step of method will be briefed detail in chapter 3. This chapter is more to the method

that use in conducting this research. In chapter 4, the process performance on the failure

analysis will be discussed. Discussion will be included in this chapter. Finally in chapter

4

5, all the results will be concluded in this chapter. Recommendation to improve the

petroleum borehole drilling process performance also will be suggested.

1.6 PROJECT PLANNING

Figure 1.1 : Project Planning for both Final Year Project 1 and 2.

Start

Conformation of title, objective and scope

Literature Review

Project Methodology

End

Submission of draft report

Submission of final report

Analysis and Discussions

5

CHAPTER 2

LITERATURE REVIEW

2.1 INTRODUCTION

The main purpose of this literature review is to get information about the project

from the reference books, magazines, journal, technical papers and web sites. In this

chapter the discussion will be made base on all the sources.

2.2 PETROLEUM DRILLING

The crew sets up the rig and starts the drilling operations. First, from the starter

hole, they drill a surface hole down to a pre-set depth, which is somewhere above where

they think the oil trap is located. There are five basic steps to drilling the surface hole:

1. Place the drill bit, collar and drill pipe in the hole.

2. Attach the kelly and turntable and begin drilling.

3. As drilling progresses, circulate mud through the pipe and out of the bit to float

the rock cuttings out of the hole.

4. Add new sections (joints) of drill pipes as the hole gets deeper.

5. Remove (trip out) the drill pipe, collar and bit when the pre-set depth (anywhere

from a few hundred to a couple-thousand feet) is reached.

Once they reach the pre-set depth, they must run and cement the casing which is

place casing-pipe sections into the hole to prevent it from collapsing in on itself. The

casing pipe has spacers around the outside to keep it centered in the hole. The casing

6

crew puts the casing pipe in the hole. The cement crew pumps cement down the casing

pipe using a bottom plug, a cement slurry, a top plug and drill mud. The pressure from

the drill mud causes the cement slurry to move through the casing and fill the space

between the outside of the casing and the hole. Finally, the cement is allowed to harden

and then tested for such properties as hardness, alignment and a proper seal.

2.2.1 Borehole Drilling

Borehole is the hole drilled by the bit(wellbore). This term also is define by a

circular hole made by boring, especially a deep hole of small diameter such as oil & gas

or water well. Borehole drilling is the extraction of minerals in liquid or gaseous state

from the Earth’s crust by mean of boreholes and suction pumps. Boreholes are used for

mining petroleum and for the extraction of liquid solution of salts, sulfur.

2.2.2 Drill String

A drill string on an oil rig is a column, or string, of drill pipe that transmits

drilling fluid (via the mud pumps) and rotational power (via the kelly drive or top drive)

to the drill bit. The term is loosely applied as the assembled collection of the drill pipe,

drill collars, tools and drill bit. The drill string is hollow so that Drilling fluid can be

pumped down through it and circulated back up the annulus (void between the drill

string and the formation).

2.2.3 Drill Pipe

Drill pipe makes up the majority of a drill string. A drill string is typically about

15,000 feet in length for an oil or gas well vertically drilled onshore in the United States

and may extend to over 30,000 feet for an offshore deviated well.

http://en.wikipedia.org/wiki/Oil_rig

http://en.wikipedia.org/wiki/Drilling_fluid

http://en.wikipedia.org/wiki/Mud_pump

http://en.wikipedia.org/wiki/Kelly_drive

http://en.wikipedia.org/w/index.php?title=Top_drive&action=edit&redlink=1

http://en.wikipedia.org/wiki/Drill_bit#well_drilling_bits

http://en.wikipedia.org/wiki/Drill_collar

http://en.wikipedia.org/wiki/Drilling_fluid

http://en.wikipedia.org/wiki/Annulus_%28oil_well%29

failure analysis on the drillpipe due to the twist-off

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