Drill Pipe Fatigue Analysis: Full Size Apparatus and Coupon Tests

2002 ◽  
Author(s):  
Joa˜o Carlos Ribeiro Pla´cido ◽  
Guilherme F. Miscow ◽  
Paulo E. V. de Miranda ◽  
Theodoro A. Netto
Keyword(s):  
Fatigue Life ◽  
Structural Integrity ◽  
Crack Nucleation ◽  
Drill Pipe ◽  
Small Scale ◽  
Second Phase ◽  
Transition Zones ◽  
Second Phase Particles ◽  
Geometric Discontinuities ◽  
Drill Pipes

Drill pipe fatigue damage occurs under cyclic loading conditions due to, for instance, rotation in curved sections of the well. Failures caused by crack nucleation and propagation are one of the highest risks to the structural integrity of these pipes. Usually, failure mechanisms develop in the transition region of the tool joint. Several mechanical and metallurgical factors affect the fatigue life of drill pipes. The former are mainly geometric discontinuities such as transition zones, pits and slip marks. The latter are related to the size and distribution of crystalline grains, phases and second phase particles (inclusions). In this study, the roles played by both factors in the fatigue life of drill pipes are studied through an extensive experimental test program. To this end, a fatigue simulator was designed and built to test full-scale drill pipes under rotating cyclic bending and constant tension loading. Additionally, the fundamental fatigue mechanisms are investigated via laboratory tests in small-scale coupons. These tests were performed in an opto-mechanical fatigue apparatus that was specially designed to perform in-situ real time monitoring surface analysis during the experiments.

Aluminum Drill Pipe Fatigue Analysis

2004 ◽  
Author(s):  
Guilherme Farias Miscow ◽  
Joa˜o Carlos Ribeiro Pla´cido ◽  
Paulo Emi´lio Valada˜o de Miranda ◽  
Theodoro Antoun Netto
Keyword(s):  
Fatigue Life ◽  
Structural Integrity ◽  
Crack Nucleation ◽  
Drill Pipe ◽  
Drill String ◽  
Small Scale ◽  
Second Phase ◽  
Horizontal Section ◽  
Steel Drill ◽  
Drill Pipes

While drilling extended reach wells, the weight per foot of the drill string is a critical design parameter that can limit the depth to be reached. One practical solution is the use of drill pipes made of alternative materials to the conventional steel drill pipes. The most direct options are titanium and aluminum. Titanium is in general impaired due to its high cost, although the titanium alloy Ti-6Al4V has already been used in the airplane industry. More recently, Russia has been manufacturing drill pipes using aluminum alloys of the system Al-Cu-Mg, similar to alloys 2024, also used in airplanes. These pipes present a reasonable commercial cost. Drill pipe fatigue damage occurs under cyclic loading conditions due to, for instance, rotation in curved sections of the well. Failures caused by crack nucleation and propagation are one of the highest risks to the structural integrity of these pipes. Usually, failure mechanisms develop in the transition region of the tool joint. Several mechanical and metallurgical factors affect the fatigue life of drill pipes. The former are mainly geometric discontinuities such as transition zones, pits and slip marks. The latter are related to the size and distribution of crystalline grains, phases and second phase particles (inclusions). In this study, the roles played by both factors in the fatigue life of drill pipes are studied through an experimental test program. The fundamental fatigue mechanisms are investigated via laboratory tests in small-scale coupons performed in an opto-mechanical fatigue apparatus. Additionally, full-scale fatigue testes on three aluminum drill pipes were performed. The pipes tested are being used in the horizontal section of some extended reach wells in the Northeast of Brazil.

Atomic Force And Scanning Electron Microscopy Of Corrosion And Fatigue Of An Aluminum-Copper Alloy

1995 ◽  
Vol 409 ◽  
Author(s):  
K. Kowal ◽  
J. DeLuccia ◽  
J.Y. Josefowicz ◽  
C. Laird ◽  
G.C. Farrington
Keyword(s):  
Fatigue Life ◽  
Crack Nucleation ◽  
Mechanical Deformation ◽  
Simultaneous Action ◽  
Second Phase ◽  
Corrosive Environment ◽  
Intergranular Cracking ◽  
Early Stages ◽  
Atomic Force ◽  
Persistent Slip Bands

AbstractThe morphological features of 2024-T3 aluminum alloy were delineated using atomic force microscopy (AFM) during separate and combined actions of corrosion and fatigue.In-situ AFM corrosion studies in hydrochloric acid environments without mechanical deformation showed accelerated dissolution in the vicinity of second phase precipitates leading to intergranular corrosion. During fatigue in air, AFM images revealed steps along grain boundaries, as well as parallel extrusions and intrusions during the early stages of fatigue life. At later stages of mechanical deformation persistent slip bands (PSBs) were observed on the sample's surface. Cracks were observed to nucleate and propagate along PSBs. For experiments where samples were subjected to the simultaneous action of a corrosive environment and mechanical deformation, intergranular cracking was observed during the early stages of fatigue life. The corrosive environment was observed to accelerate the crack nucleation process.

Application, Calculation and Experimental Evaluation of SCF for Aluminum Drill Pipe With Steel Connector

2010 ◽  
Author(s):  
Vadim Tikhonov ◽  
Alexander Kultsep ◽  
Rudolf Alikin ◽  
Mikhail Gelfgat ◽  
Vladimir Basovich ◽  
...  
Keyword(s):  
Fatigue Testing ◽  
Drill Pipe ◽  
Bending Moment ◽  
Full Scale ◽  
Fatigue Properties ◽  
Small Scale ◽  
Steel Tool ◽  
Friction Factors ◽  
Bending Load ◽  
Drill Pipes

Aluminum alloys are among the most promising materials for manufacture of drill pipes for deepwater and ultra-deepwater drilling in corrosive environment. Aluminum drill pipes are made with steel tool-joints to increase the number of connection makings-and-breakings. One of the major concerns of aluminum drill pipe operation in deepwater complex profile wells is the fatigue of their connection. This paper presents the results of study of fatigue properties of aluminum alloy 1953T1 Light Alloy Drill Pipes of Improved Dependability (LAIDP) 147×13 mm that are most extensively used in Russia. During assembly, the pin and box of steel tool-joint are heated and screwed on the tubular ends. After cooling, this assembly provides a reliable permanent connection. The study includes experimental determination of the S-N curve of small-scale specimens of aluminum tubular, FEA of the connection with the SCF determined and fatigue testing of the full-scale LAIDP connection. FEA is based on 3D model. The material properties of tubular are modeled as elastic-plastic. The distribution of hot-assembly stresses is considered in detail. Alternating bending load is applied by several semi-cycles. The results of analysis of Stress Concentration Factor (SCF) at various axial loads, bending moment ranges, friction factors of contact surfaces and interference of connection are given. Full-scale fatigue testing of connection specimen is carried out to verify the results of analysis.

Experimental and Numerical Evaluations of Aluminum Drill Pipes Under Cyclic Loads

2006 ◽  
Author(s):  
Marcelo Igor Lourenc¸o ◽  
Theodoro A. Netto ◽  
Neilon S. Silva ◽  
Paulo Emi´lio Valada˜o de Miranda ◽  
Joa˜o Carloes Ribeiro Pla´cido
Keyword(s):  
Drill Pipe ◽  
Fatigue Tests ◽  
Full Scale ◽  
Experimental Program ◽  
Small Scale ◽  
Strain Stress ◽  
Drill Pipes ◽  
Aluminum Pipe ◽  
Tool Joint ◽  
Joint Assembly

Experimental program and numerical analyses were carried out to investigate the fatigue mechanisms of aluminum drill pipes designed and manufactured in compliance with ISO 15546. Material mechanical properties, including S-N curve, were determined through small-scale tests on specimens cut from actual drill pipes. Full-scale experiments were also performed in laboratory. Initially, the tool-joint assembly procedure was actually performed to monitor the resulting strain/stress level in selected points of the aluminum pipe. Three full-scale aluminum drill pipe specimens were then fatigue tested under combined cyclic bending and constant axial tension. In parallel, a finite element model of the tool-joint region, where two drill pipe specimens failed in the fatigue tests, was developed. The model was first used to reproduce the tool-joint assembly. Then, the physical experiments were simulated numerically in order to obtain the actual stress distribution in this region. Good correlation between full-scale and small-scale fatigue tests was obtained by adjusting the strain/stress levels monitored in the full-scale tests in light of the numerical simulations.

Brittle cleavage of L12 trialuminides

1990 ◽  
Vol 5 (8) ◽  
pp. 1639-1648 ◽  
Author(s):  
E. P. George ◽  
J. A. Horton ◽  
W. D. Porter ◽  
J. H. Schneibel
Keyword(s):  
Room Temperature ◽  
Crack Nucleation ◽  
Cleavage Plane ◽  
Second Phase ◽  
Cleavage Crack ◽  
Transgranular Cleavage ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Second Phase Particles ◽  
Cleavage Strength

Three trialuminide alloys, binary Al–25Sc, ternary Al–25Zr–6Fe, and quaternary Al–23Ti–6Fe–5V, all having the cubic L12 structure, were investigated. All three alloys fracture in a brittle manner (fracture toughness, 2–3 MPa m½), predominantly by transgranular cleavage. Of nineteen cleavage facets examined in binary Al3Sc, seventeen were of the {110} type and only two were of the {100} type, consistent with our earlier work which showed that the cleavage plane occurring most frequently in quaternary Al–23Ti–6Fe–5V is also {110}. The room-temperature hardnesses and yield strengths (100–200 DPH and 100–270 MPa, respectively) of all three alloys are quite low (comparable to ductile L12 alloys like Ni3Al), indicating that there is significant dislocation activity in these materials. Consistent with this, transmission electron microscopy identified several APB-coupled dislocations with b - a/2〈110〉 gliding on the {111} planes in both binary Al–25Sc and quaternary Al–23Ti–6Fe–5V. The separations between the superpartials in Al–25Sc and Al–23Ti–6Fe–5V were measured to be 3.7 and 4 nm, respectively, giving APB energies of 313 and 274 mJ/m2, respectively. Auger analyses failed to detect any impurities on the cleavage facets themselves, or on second phase particles (or other potential cleavage crack nucleation sites). It is therefore concluded that brittle fracture in these alloys is not impurity-induced. Based on all the results obtained to date we conclude that the unusual brittleness of L12 trialuminides is related to their intrinsically low cleavage strength. Possible reasons for their low cleavage strength are discussed.

Aluminum Drill Pipes: Material and Design Developments

2008 ◽  
Author(s):  
Marcelo Igor Lourenc¸o ◽  
Theodoro A. Netto ◽  
Joa˜o Carlos Ribeiro Pla´cido
Keyword(s):  
Mechanical Design ◽  
Fatigue Behavior ◽  
Axial Stress ◽  
Drill Pipe ◽  
Element Model ◽  
Fatigue Tests ◽  
Small Scale ◽  
Physical Experiments ◽  
Drill Pipes ◽  
Tool Joint

An extensive research program on the structural strength of aluminum drill-pipes is being conducted at COPPE/UFRJ. The main objective is to improve the fatigue performance of these components by selecting the appropriate aluminum alloy and by enhancing the mechanical design of the threaded steel connector. This paper presents the experimental test program and numerical analyses conducted on a drill-pipe of different materials (Al-Zn-Mg alloy) and geometries from those previously presented [1,2]. Small-scale specimens were tested to determine its uni-axial stress-strain and fatigue behavior. Full-scale fatigue test results are also presented. A finite element model of the drill pipe, including the tool-joint region, was developed. The model simulates, through different load steps, the tool-joint hot assembly, and then reproduces the physical experiments numerically in order to obtain the actual stress distribution. The correlation between full and small-scale fatigue tests is performed via multi-axial fatigue models. The weak points of the current practice design are highlighted for further development.

Evaluation of Burnished Subsurface Mechanical Behavior Using Nanoindentation

2011 ◽  
Vol 686 ◽  
pp. 546-552
Author(s):  
Hong Yun Luo ◽  
Zhi Yuan Han ◽  
Qun Peng Zhong
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Surface Integrity ◽  
Main Part ◽  
Small Scale ◽  
Second Phase ◽  
Research Results ◽  
Second Phase Particles ◽  
Burnishing Process

The performance and life of machined components in service are mainly effect by their surface integrity. Burnishing process is a kind of chipless processing which improve the surface integrity obviously. A subsurface “hardness film” is formed during the processing. Subsurface mechanical behavior is the main part of surface integrity. Since the very small scale of the subsurface in burnished surface nanoindentation is used to identify how the local changes of microstructure influence the hardness distributions of subsurface mechanical properties. This study focuses on the relationships between burnishing parameters (burnishing feed and burnishing depth) and nanohardness. A series of burnishing processing experiments and nanoindentation tests were conducted on the surface of the burnished samples. The microstructure and nanoindentation research results indicate that there is no visible phase transformed region in the subsurface of burnished specimens, the hardening film is larger than 4 micro meters, the nanohardness is about 2.2~3.5Gpa which depends on the burnishing parameters and distribution and position of the second phase particles, while the nanohardness in turned material is about 1.8Gpa.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

Analytical Electron Microscopy Study of Second-Phase Particles in 7075 and 7475 Aluminum Alloys

1985 ◽  
Vol 43 ◽  
pp. 348-349
Author(s):  
M. Raghavan ◽  
J. Y. Koo ◽  
J. W. Steeds ◽  
B. K. Park
Keyword(s):  
Aluminum Alloys ◽  
Silicon Oxide ◽  
Analytical Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Partial Substitution ◽  
Second Phase ◽  
X Ray ◽  
Second Phase Particles ◽  
Almost All

X-ray microanalysis and Convergent Beam Electron Diffraction (CBD) studies were conducted to characterize the second phase particles in two commercial aluminum alloys -- 7075 and 7475. The second phase particles studied were large (approximately 2-5μm) constituent phases and relatively fine ( ∼ 0.05-1μn) dispersoid particles, Figures 1A and B. Based on the crystal structure and chemical composition analyses, the constituent phases found in these alloys were identified to be Al7Cu2Fe, (Al,Cu)6(Fe,Cu), α-Al12Fe3Si, Mg2Si, amorphous silicon oxide and the modified 6Fe compounds, in decreasing order of abundance. The results of quantitative X-ray microanalysis of all the constituent phases are listed in Table I. The data show that, in almost all the phases, partial substitution of alloying elements occurred resulting in small deviations from the published stoichiometric compositions of the binary and ternary compounds.

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