Taladros

JACK UP UNITS
A TECHNICAL PRIMER FOR THE OFFSHORE INDUSTRY PROFESSIONAL

by

BENNETT & ASSOCIATES, L.L.C.
1140 St. Charles Ave. New Orleans, LA 70130, USA (1) 504-561-8912
Jvazquez@bbengr.com

and

OFFSHORE TECHNOLOGY DEVELOPMENT INC.
55, Gul Road Singapore 629353 (65) 6863-7200
matthew.quah@keppelfels.com Updates of this pamphlet may be found at www.bbengr.com andwww.keppelfels.com.sg

ACKNOWLEDGEMENT
The authors would like to thank Keppel FELS and Keppel Offshore and Marine management for support and giving permission to publish this document. The views expressed are those of the authors, Dr Jose H. Vazquez (BASS) , Mr Richard P. Michel (BASS), Mr. Jake H. Alford (BASS), Dr.Matthew Quah (OTD) and Dr. K.S. Foo (OTD) and not necessarily those of their respectiveorganizations, BASS, Offshore Technology Development, Keppel FELS and Keppel Offshore and Marine’s management. We would like to thank Mr A.K. Seah of ABS and Mr Olav Mo of DNV for giving support and technical advice on Section 5 of the document pertaining to classification societies’ role in the design of jack up rigs.

DISCLAIMER
The opinions and assertions of the authors herein are not to beconstrued as official or reflecting the views of their respective organizations. It is understood and agreed that nothing expressed here is intended or should in any way be construed to give any persons, firms or corporations any rights, remedy or claims against the authors or their employers, including their officers or members. Readers should use the information at their own risk.

Copyright 2005JACK UP PRIMER by BASS and OTD/KeppelFels, Copy Right 2005, updated July 1, 2005

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TABLE OF CONTENTS INTRODUCTION AND BACKGROUND 1.1 SYNOPSIS OF A JACK UP 1.2 PURPOSE AND DISCLAIMER 1.3 BACKGROUND 2. 2.1 2.2 2.3 2.4 2.5 3. 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 4. 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5. 5.1 5.2 6. 6.1 6.2 6.3 6.4 6.5 6.6 7. 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 COMPONENTS OFJACK UP RIGS AND THEIR FUNCTION INTRODUCTION HULL LEGS AND FOOTINGS PRELOAD AND SOIL PENETRATION EQUIPMENT BASIC JACK UP CONFIGURATIONS MAT FOOTINGS VERSUS INDEPENDENT SPUD CAN FOOTINGS CYLINDRICAL LEGS VERSUS TRUSSED LEGS 3-LEGGED VERSUS 4-LEGGED JACK UPS 3-CHORDED LEGS VERSUS 4-CHORDED LEGS ELEVATING SYSTEM UPPER AND LOWER GUIDES OPPOSED PINION CHORDS VERSUS RADIAL PINION CHORDS LEG FIXATIONSYSTEMS VERSUS NO LEG FIXATION SYSTEMS MODES OF OPERATION OF A JACK UP TRANSIT FROM ONE LOCATION TO ANOTHER ARRIVING ON LOCATION SOFT PINNING THE LEGS FINAL GOING ON LOCATION JACKING PRELOAD OPERATIONS JACKING TO FULL AIR GAP OPERATIONS ELEVATED OPERATING CONDITION ELEVATED STORM SURVIVAL CONDITION CLASS APPROVAL VS. SITE SPECIFIC ASSESSMENT CLASSIFICATION SOCIETIES SITE SPECIFIC ASSESSMENTS JACK UPDESIGN--THE ULTIMATE COMPROMISE ENVIRONMENTAL LOAD BASICS BASICS OF A STABILITY ANALYSIS BASICS OF A TOW ANALYSIS BASICS OF AN ELEVATED ANALYSIS NATURAL PERIOD AND DYNAMICS BASICS TRADING BENEFITS SELECTED TOPICS ON SENSITIVITIES OF JACK UPS TOW GOING ON LOCATION JACKING ON EXISTING FOOTPRINTS LEG PUNCH THROUGHS OTHER SOIL ISSUES (SCOUR, EARTHQUAKE) GUIDE/RACK TEETH WEAR RACK PHASE DIFFERENTIALPINION OVERLOAD PULL-OUT OF LEGS

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JACK UP PRIMER by BASS and OTD/KeppelFels, Copy Right 2005, updated July 1, 2005

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1.

INTRODUCTION AND BACKGROUND A Jack Up is an offshore structure composed of a hull, legs and a lifting system that allows itto be towed to a site, lower its legs into the seabed and elevate its hull to provide a stable work deck capable of withstanding the environmental loads. A typical modern drilling Jack Up is capable of working in harsh environments (Wave Heights up to 80 ft, Wind Speeds in excess of 100 knots) in water depths up to 500 feet. Because Jack Ups are supported by the seabed, they are preloaded when...