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Abstract

More than 30% of total rig time is spent on drillstring tripping and casing and tubing running operations. Tripping operations always have been the cause of heavy accidents.

The easiest way to reduce the safety hazard is to reduce the number of people involved in unsafe operations. The number of people involved in manual operations on the rigfloor is directly related to the safety of the drilling rig's operation. The reduction of total personnel on board is significant for the costs. This requires the mechanization of processes now done manually.

Traditional automation concepts often required the complete re-design of rig components such as power tongs and handling equipment. Even derrick structures had to be modified to fulfill the requirements of a completely automated process. This made several of these technically interesting concepts very expensive and not many of them were actually put into operation.

A new approach to rig mechanization is based on existing technology. System components with proven designs such as hydraulic power tongs for drillpipe, tubing and casing running are modified for mechanical and remote controlled operations and are combined in a modular system.

This system includes a new technical solution to move the hydraulic power equipment towards the string and to pull it back into park position. The device is based on zipping chains guiding the equipment on a pre-defined line. It can be attached to any existing derrick structure in an elevated position not consuming any valuable rig space.

Introduction

People not working in the oil and gas industry perceive the work on the rigfloor as hard, dirty and dangerous. In many places of the world this perception still is reality. Although mechanical aids have been put into operation to ease the work, many of the steps required to trip in and out the string and to run casing and tubing is still associated with hard manual work and a high personal risk. Concepts on how to make work safer were developed early. The use of "robots" was suggested and rigs were designed to trip drillpipe and other tubular strings in and out without the need for human manual work. Most of the earlier concepts lacked either reliable technology to control the process or, even worse, a lack of understanding of the working environment on a rigfloor. Projects with the goal to "revolutionize" drilling technology did not reach their ambitious target. Instead the step-by-step evolution to adapt existing technology is currently successful. These concepts make use of existing designs such as casing or tubing tongs that are remote controlled. A flexible adaptation to existing rig installations is part of this concept. A modular design adding components allows the adjustment of the system to the various requirements.

2 The Driving Forces

A process such a the mechanization of the tubular handling and running process requires the investment of money and time. Therefore it needs driving forces, otherwise the implementation will not be accomplished. For the mechanization on the rigfloor, four different factors can be identified: - Safety

More than 30% of the rig time is spent on tripping drillpipe or running casing and tubing.

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