Crown Mounted Compensator

Drilling String Compensator

Wireline Motion Compensation-Logging A motion arrestor for nullifying vessel heave in wireline operations, especially in well logging operations, is available. This compensation device hangs below the hook and uses a working wireline reeved from the top of the riser pipe around the motion arrester working sheave, and to the drill floor. The logging sheave and working sheave are connected to the same yoke, which is suspended from the motion arrester by a pneumatic spring special tensioner . As...

Blowout Preventer Operating Procedures

Subsea Drilling Stack

The following covers the use of the blowout preventer BOP stacks and equipment used when drilling from a floating vessel. Figure 3-14 shows typical BOP stack with the major components normally used in a typical BOP stack. Though the size and pressure ratings may vary, all major BOP stacks in use for subsea drilling today contain the major components shown. These major components are 1 hydraulic wellhead connectors 2 ram type BOP's 3 annular type BOP's 4 hydraulic or elec-trohydraulic control...

Blowout Preventer Control Systems

Drilling Rig Panel

Foreman C. Jim Stewart amp Stevenson, Inc. Next to the blowout preventers, the most important component for well control in floating drilling is the system that monitors and controls the behavior of the subsea BOP s from the drilling rig. From 1955 to 1963, the control system design used in subsea drilling was basically a land rig or closed-type system. A hydraulic power unit provided fluid to a shipboard mounted control valve manifold. Hydraulic power lines were...

Chronology Of Submersible Rigs

Mat Supported Jackups

CHRONOLOGY OF JACKUP RIGS, 1953-1969 In 1955, the first 3-legged jack-up appeared on the scene Figure 1-6 . The rig was the R. G. LeTourneau jack-up, the Scorpion, for Zapata Offshore Company. The Scorpion, an independent leg jack-up, used a rack and pinion elevating system on a truss framed leg. The rig worked very successfully for several years but was lost during a move in the Gulf of Mexico. The Scorpion was closely followed by The Offshore Company Rig No. 54. For Rig No. 54, however, a...

Techniques To Control Catastrophic Blowouts

Gas Well Blowout Offshore Libya

Control over a catastrophic blowout can be gained by any technique that blocks the escaping reservoir fluid either in the wellbore or in the formation. The method most frequently used is wellbore blockage, i.e., the recapping of a wild well. Relief well techniques, although more expensive to implement, have popular support because water pollution can be minimized by allowing the flowing wells to burn. Relief wells are sometimes drilled to establish direct connection with the wild-well bore...

Wind Wave and Current Forces on Offshore Structures

Force The Wind

The forces produced by wind, wave, and current are the primary design loads on mobile drilling units and other offshore structures. These forces are dynamic and ever-changing rarely can they be expressed as a mathematical function of time. They are statistical in nature and should, if possible, be handled by means of statistical tools. The most commonly used method so far for evaluating wave loads on an offshore structure has been to base the calculations on one or more design waves of...