Drill String Strength Evaluation for Deep Earthquake Zone Drilling

2012 ◽  
Author(s):  
Tomoya Inoue ◽  
Masanori Kyo ◽  
Koji Sakura ◽  
Toshihiko Fukui
Keyword(s):  
Nankai Trough ◽  
Drill Pipe ◽  
High Strength ◽  
Seismogenic Zone ◽  
Deep Drilling ◽  
Deep Earthquake ◽  
Strength Evaluation ◽  
Scientific Drilling ◽  
Drill Pipes ◽  
Earthquake Zone

The scientific drilling vessel Chikyu was designed to have the deep drilling capability to reach the deep earthquake zone. To realize such deep drilling, a drill pipe with higher than ever strength and reliability is of necessity. A strength evaluation of such high strength drill pipe is also necessary. Around Japan, the earthquake zones are widely located under the seabed in deep water. For example, the Nankai Trough located beneath the ocean off the southwest coast of Japan is one of the most active earthquake zones where large-scale earthquakes have occurred repeatedly throughout history. Thus, the Chikyu has started the first scientific drilling at the Nankai Trough as the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE). NanTroSEIZE targets the megasplay fault zone at 3500 m below the seafloor and finally 6000m deep drilling into the seismogenic zone and across the plate interface into the subducting crust at water depths of around 2500m. In addition, a huge earthquake zone is expected to be located about 1000m below the seafloor at water depths of around 7000m. For this drilling task, the riserless drilling technique should be applied. To realize such deep drilling with both riser and riserless techniques, a S150 drill pipe was developed during the construction phase and has been used in the past scientific drillings of the Chikyu. For deeper drillings in the future and drilling operations in harsh environments, we are developing superior high strength drill pipes, S155 and S160, possessing high reliability including corrosion resistance to achieve high toughness and reduction of stress concentration. An evaluation of the maximum possible stress was conducted. In the maximum strength evaluation, we considered dynamic stress and bending stress due to the current and the vessel inclination. This paper describes the development of superior high strength drill pipes and the strength evaluation of such drill pipes for deep earthquake zone drilling.

Fatigue Evaluation of Drill Pipes for Scientific Drilling Program by Applying Non-Stop Driller Concept

2019 ◽  
Author(s):  
Tomoya Inoue ◽  
Masahiko Fujikubo ◽  
Kenji Nakano ◽  
Noriaki Sakurai
Keyword(s):  
Time Series ◽  
Fatigue Strength ◽  
Nankai Trough ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Ship Motions ◽  
Bending Stress ◽  
Deep Drilling ◽  
Scientific Drilling ◽  
Drilling Equipment

Abstract The scientific drilling vessel Chikyu is performing Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE), a challenging deep drilling activity, for scientific purpose. We faced difficulty to drill deep during past NanTroSEIZE operations due to unstable sediments and insufficient cutting removal. Non-Stop Driller concept is, therefore, applied for the operation of NanTroSEIZE scheduled to start Oct. 2018 to enable continuous circulation of drilling fluid circulation. The Non-Stop Driller concept requires an additional, specially-designed sub called an “NSD sub” with a ball valve for drilling fluid inlet. Generally, the fatigue strength of a drill pipe is a critical factor governing the performance of challenging deep drilling. This study, therefore, focused on the fatigue failure of the NSD sub due to the bending stress caused by interference with risers including flex joints, ship structure, or drilling equipment resulting from ship motions. The bending stress leads to cyclic stress caused by rotation of the drill pipe. This is especially the case at the Nankai Trough where ocean currents are very strong reaching or sometimes exceeding 4 knots, a high bending stress is assumed to be exerted on the NSD sub. Full-scale fatigue tests of the NSD sub were first conducted to acquire the actual fatigue curve. Further, the bending stress distribution of a drill pipe, which refers to the locus of the bending stress during the drilling operation, was analyzed by considering interference of the drill string with the structure, drilling equipment, and risers that are deformed by the ocean current. Time-series ship motions is prepared using the response amplitude operators of the Chikyu for the sea states at Nankai Trough area, and then time-series stress response is obtained by considering the operational conditions such as rate of penetration and rotational velocity of drill pipe. The numbers of occurrence of each stress amplitude can be counted from the time-series stress response. Consequently, the cumulative damage ratio is calculated for evaluating the fatigue of the NSD sub. The results confirmed that the cumulative fatigue is within a safe range. This study focused on the evaluation of the fatigue strength of the specially designed NSD sub for the challenging scientific drilling operation at Nankai Trough, a harsh environment because of the presence of strong ocean currents. This paper presents the overview of NanTroSEIZE including the Non-Stop Driller concept, and the results of fatigue evaluations.

scholarly journals Research on the Method of Strength Evaluation of Drill Pipe for Deep Drilling

2008 ◽  
Vol 7 (0) ◽  
pp. 65-72 ◽  
Author(s):  
Tomoya Inoue ◽  
Makoto Nishigaki ◽  
Koji Setta ◽  
Shin Terada
Keyword(s):  
Drill Pipe ◽  
Deep Drilling ◽  
Strength Evaluation

Effect of Drill-Ship Motions on Core Sample Conditions During the Nankai Trough Seismogenic Zone Experiment

2009 ◽  
Author(s):  
Yuichi Shinmoto ◽  
Kazuyasu Wada
Keyword(s):  
Deep Sea ◽  
Nankai Trough ◽  
Drill String ◽  
Seismogenic Zone ◽  
Ship Motions ◽  
Scientific Drilling ◽  
Core Samples ◽  
Core Recovery ◽  
Drilling Parameters ◽  
Core Conditions

The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Stage 1A, which is a part of the Integrated Ocean Drilling Program (IODP), is a series of expeditions in scientific drilling and coring operations aboard the first riser-equipped deep sea drilling vessel, Chikyu. The objectives are to recover good quality core samples and collect data on undersea properties and drilling conditions, which will also provide valuable information for future expeditions. The coring operations were carried out under harsh drilling and ocean conditions so that core recovery was inconsistent and fluctuated from high to low. Moreover, differences in independent lithology, depth, and the type of coring tools from previous expeditions made it necessary to analyze and optimize drilling parameters with new data. A serious concern in retrieving core samples was the vertical heave motions caused by the drill-ship since the active heave compensator system could not be activated before operations due to the extreme deep sea conditions and only the passive heave compensator was used. The drill string and coring tools are particularly vulnerable to the high heaving movements of the vessel so that the core recovery rate and quality are also adversely affected. The present work presents an analysis of geotechnical information, drilling parameters and the drill-ship motions the NanTroSEIZE expedition in order to optimize core conditions and maintain high core recovery.

Scientific Drilling Program of Drilling Vessel Chikyu and Drilling Data Acquisition for Future Technical Development

2011 ◽  
Author(s):  
Tomoya Inoue ◽  
Kazuyasu Wada ◽  
Eigo Miyazaki ◽  
Tsuyoshi Miyazaki
Keyword(s):  
Data Acquisition ◽  
Subduction Zones ◽  
Large Scale ◽  
Nankai Trough ◽  
Technical Development ◽  
Seismogenic Zone ◽  
Validity Data ◽  
Scientific Drilling ◽  
Drilling Data ◽  
Drilling Operations

The scientific drilling vessel Chikyu has started drilling at Nankai trough under the international organization, IODP. The Nankai trough located beneath the ocean off the southwest coast of Japan is one of the most active earthquake zones on the planet and one of the best-studied subduction zones as well. The Nankai Trough Seismogenic Zone Experiment attempts for the first time to drill, sample, and instrument the earthquake-causing or the seismogenic portion of Earth’s crust, where violent, large-scale earthquakes have occurred repeatedly throughout history. Before starting the international drilling operations, an integration drilling test off Shimokita Peninsula was conducted and we acquired actual drilling data such as vessel heave, hook load, and compensator position. Confirming its validity, data acquisition systems have worked continuously in international drilling operations. It is very important to consider the actual drilling data for the drilling operation and for further technical development. This paper describes the scientific drilling programs of the drilling vessel Chikyu and the drilling data acquisition for future technical development in relation with the sample data acquired in the internal drilling operations.

Development and Application of New Design Method by High-Strength Composite Material - Fusing of Optimum Strength Evaluation and Product Design

2013 ◽  
Vol 372 ◽  
pp. 17-20 ◽  
Author(s):  
Haruhiko Iida ◽  
Hidetoshi Sakamoto ◽  
Yoshifumi Ohbuchi
Keyword(s):  
Composite Material ◽  
Carbon Fiber ◽  
Product Design ◽  
Design Method ◽  
Target Material ◽  
High Strength ◽  
Fiber Glass ◽  
Strength Evaluation ◽  
Fiber Reinforced Materials ◽  
Manufacturing Methods

The purpose of this research is the development of new design method for integrating the optimum strength evaluation and the product design which can make the best use of material's characteristics obtained by the experiment and the analysis. Further we do design using high-strength composite material with this developed concept which is different from conventional design. First, to establish this design method of high-strength materials, we examined these materials characteristics and manufacturing methods and the commercialized products. As this research target material, we focus the fiber reinforced materials such as composite with carbon fiber, glass fiber and aramid fiber. Above all, we marked the carbon fiber which has the high specific tensile strength, wear resistance, heat conductivity and conductance. Here, we introduce the fundamental design concept which makes the best use of the design with enough strength.

scholarly journals Workshop explores seismogenic zone drilling in the Nankai trough

Eos ◽  
2001 ◽  
Vol 82 (45) ◽  
pp. 532-532
Author(s):  
A. Taira ◽  
G. Moore ◽  
H. Tobin ◽  
G. Kimura ◽  
S. Kodaira
Keyword(s):  
Nankai Trough ◽  
Seismogenic Zone

A Comparison of Fracture Mechanics and S–N Curve Approaches in Designing Drill Pipe

1992 ◽  
Vol 114 (3) ◽  
pp. 205-211 ◽  
Author(s):  
A. Ertas ◽  
G. Mustafa ◽  
O. Cuvalci
Keyword(s):  
Fracture Mechanics ◽  
Fatigue Damage ◽  
Drill Pipe ◽  
Ball Joint ◽  
Marine Riser ◽  
Deep Drilling ◽  
Miner’S Rule ◽  
Miner's Rule ◽  
Total Damage ◽  
Dynamic Fatigue

It is well known that the upper ball joint in a marine riser, in deep drilling, can cause fatigue damage in the drill pipe passing through it. A study of fracture mechanics and S–N curve approaches has been undertaken to determine the dynamic fatigue damage in the drill pipe. Miner’s rule is utilized in both methods to determine the total damage. The results of both methods are compared.

Effect of In Situ TiB2 Particles on the Grain Size and Mechanical Properties of 7075 Aluminum Alloy

2021 ◽  
Vol 1035 ◽  
pp. 102-107
Author(s):  
Shao Ming Ma ◽  
Chuan Liu Wang ◽  
Yun Lin Fan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Aluminum Alloy ◽  
High Strength ◽  
Light Weight ◽  
7075 Aluminum Alloy ◽  
Directional Drilling ◽  
High Strength Aluminum Alloy ◽  
Drill Pipes

Light-weight and high-strength aluminum alloy drill pipes are potential and promising to replace traditional steel drill pipes. In this study, the grain size and mechanical properties of aluminum alloy drilling pipe materials reinforced by in-situ TiB2 particles were studied. The results showed when reinforced by in-situ TiB2 particles the grain size of aluminum alloy materials was refined from 155 m to 57 m and ultimate tensile strength was increased from 590 MPa to 720 MPa. Besides, the results also indicated that the friction coefficient was reduced from 0.99 to 0.50 and thus the abrasion resistance of 7075 aluminum alloy was enhanced by 34 %. This study provided theoretical basis for the application of light-weight and high-strength aluminum alloy drill pipes in directional drilling and ultra-deep wells.

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