A Deep Water Mat-Supported Jack-Up Drilling Unit With Tubular Telescoping Columns and Intermediate Column Frame

1976 ◽  
Author(s):  
Ralph E. Scales
Keyword(s):  
Deep Water ◽  
Intermediate Column ◽  
Drilling Unit ◽  
Jack Up

The Wind Tunnel Experiment Study of Wind Load on Jack-Up Drilling Unit

2012 ◽  
Author(s):  
Lin Yi ◽  
An-kang Hu ◽  
Jiang Wei ◽  
Xiong Fei
Keyword(s):  
Wind Tunnel ◽  
Wind Load ◽  
Wind Tunnel Experiment ◽  
Shape Coefficient ◽  
Reynolds Number Effects ◽  
Calculation Results ◽  
Drilling Unit ◽  
Aerodynamic Interference ◽  
Storm Condition ◽  
Jack Up

Owing to the characteristics of the Jack-up drilling unit, the environment loads are important factors to the structure safety of jack-up. The wind load takes up a much larger proportion in structure analysis, and it has been now paid more and more attention in the field of offshore engineering. According to the MODU rule, the projected area method is used to calculate wind load. The height coefficient Ch and shape coefficient Cs are chosen by experience listed in MODU rule. However, the aerodynamic interference between platform components, such as wind shielding effects and acceleration flow effects are ignored. So the calculation results in accordance with MODU rule are conservative, and not good for structure optimization designing to some degree. Therefore, the wind tunnel experiment is very important and necessary. In this paper, a 400ft jack-up, which is developed by CIMC, is studied as an example. Considering the Reynolds number effects, the wind loads of jack-up both in normal drilling condition and severe storm condition are obtained in the experiment. Compared with the results, which are calculated according to MODU rule, it indicates that the experiment results are less, and the effect of aerodynamic interference and updraft can’t be ignored.

The Wind Tunnel Experiment Study of Wind Load on Jack-Up Drilling Unit

2013 ◽  
Author(s):  
An-kang Hu ◽  
Yi Lin ◽  
Wei Jiang
Keyword(s):  
Wind Tunnel ◽  
Wind Load ◽  
Wind Tunnel Experiment ◽  
Shape Coefficient ◽  
Reynolds Number Effects ◽  
Calculation Results ◽  
Drilling Unit ◽  
Aerodynamic Interference ◽  
Storm Condition ◽  
Jack Up

Owing to the characteristics of the Jack-up drilling unit, the environment loads are important factors to the structure safety of jack-up. The wind load takes up a much larger proportion in structure analysis, and it has been now paid more and more attention in the field of offshore engineering. According to the MODU rule, the projected area method is used to calculate wind load. The height coefficient Ch and shape coefficient Cs are chosen by experience listed in MODU rule. However, the aerodynamic interference between platform components, such as wind shielding effects and acceleration flow effects are ignored. So the calculation results in accordance with MODU rule are conservative, and not good for structure optimization designing to some degree. Therefore, the wind tunnel experiment is very important and necessary. In this paper, a 400ft jack-up, which is developed by CIMC, is studied as an example. Considering the Reynolds number effects, the wind loads of jack-up both in normal drilling condition and severe storm condition are obtained in the experiment. Compared with the results, which are calculated according to MODU rule, it indicates that the experiment results are less, and the effect of aerodynamic interference and updraft can’t be ignored.

The General Arrangement Study of Jack-Up Drilling Unit

2010 ◽  
Author(s):  
Xiangang Ren ◽  
Yong Bai
Keyword(s):  
Variable Load ◽  
Drilling Tool ◽  
General Arrangement ◽  
Drilling Unit ◽  
Drilling System ◽  
Jack Up ◽  
Optimum Capacity

In this paper, the general arrangement principal of offshore jack-up drilling unit and some latest generations are introduced. The key technical points including variable load, drilling system, drilling tool storage and engine rooms are analyzed. Then the general arrangement is illuminated synthetically. Finally, the general arrangement corresponding to China’s offshore characteristic and its most optimum capacity are presented.

The Research on the Fatigue Analysis of the Jack-Up’s Leg Based on SESAM Software

2015 ◽  
Author(s):  
Zeng Ji ◽  
Yuan Hongtao ◽  
Wang Chao ◽  
Wang Yuhan ◽  
Mo Jian
Keyword(s):  
Wave Direction ◽  
Dynamic Amplification Factor ◽  
Design Life ◽  
Force Transfer ◽  
Drilling Unit ◽  
Concentration Factors ◽  
Cumulative Fatigue Damage ◽  
Dynamic Amplification ◽  
Stress Concentration Factors ◽  
Jack Up

In this paper, a fatigue assessment based on spectrum analysis for Jack-up’s legs is performed by adopting stochastic method for three water depths using DNV/SESAM. Firstly, force transfer function is determined by the DNV/WAJAC for each wave direction considered. Secondly, members end stresses are computed by the DNV/SESTRA. Then SCF (stress concentration factors), DAF (dynamic amplification factor) and P-delat effects are applied in the stress range calculations. Finally, the cumulative fatigue damage of unidirectional waves to the critical connections is determined by the DNV/FRAMEWORK. The critical connections at the chords and the braces are selected and reviewed for fatigue life calculation. The results show that the legs have fatigue lives exceeding the expected design life of Jack-Up Drilling Unit of twenty-five (25) years and meet ABS requirement.

An Investigation About the Trajectory Control During the Subsea Equipment Installation Using Cable

2012 ◽  
Author(s):  
Eugenio Fortaleza ◽  
Daniel Albuquerque ◽  
Marcio Yamamoto
Keyword(s):  
Natural Gas ◽  
Deep Water ◽  
Time Domain ◽  
Christmas Tree ◽  
Offshore Drilling ◽  
Cable System ◽  
Deep Waters ◽  
Drilling Unit ◽  
And Control ◽  
Installation Cost

Nowadays, several seafloor equipments have been developed and deployed in order to enhance the production of petroleum and natural gas from reservoirs in deep and ultra-deep waters. Thus the installation and maintenance of such seafloor equipments shall be an issue. The most important seafloor equipment during the production phase is the “Wet Christmas-Tree” (X-tree), which is a set of valves that controls the pressure at well bottom. This equipment is installed by a Mobile Offshore Drilling Unit (MODU) after the drilling and completion are finished. Recently, beside the X-mas, a variety of subsea pumps, usually called as Subsea Booster System, have been deployed in the development of new reservoirs in deep-water. At the beginning, such subsea pumps and even other seafloor equipments had been installed by a MODU. But the high-cost of the MODUs is one of the main concerns about the installation and maintenance of the subsea equipments. One alternative to reduce the installation cost is to use cable system installed on a service boat instead the completion riser of a MODU. This paper presents an initial investigation for the installation of a seafloor equipment using cable. The dynamic model will be featured; the dynamic analysis will be carried out using an in house developed simulation program in time-domain. Discussion about the trajectory and control of the equipment to be installed is also included.

Analyzing the Corrosion of "Hai Yang Shi You 931" Jack-Up Drilling Unit

2014 ◽  
Vol 936 ◽  
pp. 1112-1115
Author(s):  
Hong Wang ◽  
Xu Zhi
Keyword(s):  
Service Life ◽  
Surface Area ◽  
Cathodic Protection ◽  
Electrochemical Reaction ◽  
Corrective Action ◽  
Environmental Condition ◽  
Chemical Test ◽  
Drilling Unit ◽  
Cathodic Protection System ◽  
Jack Up

Severe corrosion was found on structures and spud leg of "Hai Yang Shi You 931" jack-up drilling unit according to the data of inspection. Some analysis and corrective action was required for Cathodic Protection system. The reason was concluded according to the environmental condition, service life, coating surface area, coating breakdown area, protection surface area and chemical test of anode etc. The electrochemical reaction was rapid suppressed and lost its due utility with the anode was covered by "Sacrifice" product and marine growth. Near the waterline, the oxygen strong bad battery effect was easy to form, and the chance and degree of corrosion occurrence was increased on spud leg.

scholarly journals OPTIMALISASI PEMBORAN LEPAS PANTAI MENGGUNAKAN DRILLING TEMPLATE SEBAGAI TEMPAT DUDUKNYA SUBSEA WELLHEADS DAN X-MASS TREE DENGAN MEMANFAATKAN LONG LEG JACK UP RIG

PETRO ◽  
2018 ◽  
Vol 4 (4) ◽  
Author(s):  
P Simorangkir
Keyword(s):  
Christmas Tree ◽  
Offshore Drilling ◽  
Drilling Rig ◽  
Drilling Unit ◽  
Jack Up

LONG LEG JACKUP RIG DAN PEMANFAATAN<br />Pemboran dilepas pantai pada umumnya dilakukan dengan perangkat pemboran lepas pantai yang dikenal dengan istilah Mobile Offshore Drilling Unit (MODU). Ada beberapa macam MODU yang lazim dikenal yaitu Jack Up Drilling Rig, Drillship, Semi Submersible Rig dan Tender Assist Platform Rig.<br />Untuk pemboran dilepas pantai dengan kedalaman laut 100 meter seperti di lapangan lepas pantai “Natuna”, dapat dipergunakan jenis Semi submersible Rig, DrillShip ataupun Long Leg Jack Up Drilling Rig. Dilihat dari aspek biaya dari ketiga jenis rig ini, maka yang paling murah dan cocok untuk daerah lepas pantai dilaut Natuna ini adalah jenis Long Leg Jack Up Drilling Rig, yang memiliki kaki yang panjangnya dapat mencapai kedalaman laut tersebut. Jenis mobile rig ini adalah yang termurah dari dua jenis mobile rig lainnya.<br />Dengan menggunakan Long Leg Jack Up Drilling Rig ini akan dapat dilakukan pemboran beberapa sumur pengembangan dilapangan minyak didaerah lepas pantai Natuna itu dengan menggunakan Drilling Template sebagai tempat duduknya Subsea Well Head dan Christmas Tree. Dengan demikian maka tidak perlu digunakan Subsea Blow Out Preventer (BOP), yang membutuhkan waktu yang lama dan rumit pemasangannya. Sebagai gantinya dapat digunakan BOP yang lazim dipergunkan pada operasi pemboran didarat (Onshore),.yang posisinya berada diatas permukaan laut .<br />Untuk menghemat biaya mobilisasi rig dari pemboran satu sumur ke sumur lainnya, maka pemboran sumur pengembangan dilepas pantai ini dapat dilakukan dengan cara menggeser (skid) rig pada landasan yang tersedia di Jack Up tersebut, sehingga beberapa sumur dapat dibor dari lokasi dimana<br />Long Leg Jack Up Drilling Rig tersebut berdiri, sesuai dengan slot yang terdapat pada Drilling Template yang digunakan. Dapat terdiri dari 3slot, 4slot, atau bahkan lebih, tergantung dari luas penyebaran dari resevoir hidrokarbon yang akan diproduksikan. Biasanya salah satu dari beberapa sumur yang akan dibor melalui slot di Drilling Template ini adalah sumur vertkal dan selebihnya adalah sumur berarah atau directional well.

The Study on Hull Structure Strength Analysis and Opening Calculation of CJ46 Jack-Up Drilling Unit

2015 ◽  
Author(s):  
Zeng Ji ◽  
Chen Gang ◽  
Mo Jian ◽  
Wang Yuhan ◽  
Zhang Wei
Keyword(s):  
Yield Strength ◽  
Element Model ◽  
Strength Analysis ◽  
Ocean Engineering ◽  
Engineering Structures ◽  
Hull Structure ◽  
Key Issues ◽  
Drilling Unit ◽  
Main Support ◽  
Jack Up

The structural strength of jack-up units is the key issues in the design of ship and ocean engineering structures. Based on ABS MODU, the yield strength of CJ46 self-elevating drilling platform main hull structure is checked. Firstly, the environmental loads (wind, wave and flow) in three loading conditions which are required by specification are calculated by using GeniE (DNV). Then the 3D finite element model of main hull structure is established. The yield strength is checked and the results shown the large stress areas are leg well, jackcase which is connected with the leg and bulkhead which is main support structure under the cantilever sliding device, while the results meet the requirements of ABS MODU. Finally, the influence of the openings located in main longitudinal bulkheads are evaluated, meanwhile the main longitudinal bulkheads under skidding box need particular concern.

The Deep-Water-Horizon Spill: Flow-Rate Estimation Based on Satellite Images

2012 ◽  
Author(s):  
Diego Garcia Giraldo ◽  
Ronald W. Yeung
Keyword(s):  
Gulf Of Mexico ◽  
Flow Rate ◽  
Deep Water ◽  
Infrared Imaging ◽  
Oil Spills ◽  
Imaging Spectrometer ◽  
Riser Pipe ◽  
Oil Flow ◽  
Plume Modeling ◽  
Drilling Unit

The “Deep Water Horizon” Mobil Offshore Drilling Unit (MODU) is one of several classes of floatable drilling machines. As a consequence of the accident on April 20, 2010, the worst ecological disaster with regard to oil spills in the US history was generated in the Gulf of Mexico, causing extensive damage to marine and wildlife habitats, as well as the Gulf’s fishing and tourism industries. Since that moment, experts are trying to estimate the total amount of oil being lost into the sea. The objective of this presentation is to report a procedure developed in the first author’s thesis1 an independent and logical estimate of the oil flow rate into the Gulf of Mexico produced by the rupture in this rig. There are a number of possible approaches to estimate the flow rate of oil spilling into the Gulf of Mexico. The Plume Modeling Team has developed an approach by observing video image of the oil/gas mixture escaping from the kinks in the riser and the end of the riser pipe. The Mass Balance Team has developed a range of values using USGS (US Geological Survey) and NOAA (National Oceanic and Atmospheric Administration) data analysis collected from NASA’s (National Aeronautics and Space Administration) Airborne Visible InfraRed Imaging Spectrometer (AVIRIS). Finally, a reality-check estimate was based on the amount of oil collected by the Riser Insertion Tube Tool (RITT) plus the estimate of how much oil is escaping from the RITT, and from the kink in the riser. However, there are several limitations in each of these techniques.

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