A Computer-Controlled System for Automated Racking of Pipe on Drilling Vessels

Abstract

A system is under development that provides computer control of the pipe-racking operation on offshore drilling vessels. In this latest pipe-racking operation on offshore drilling vessels. In this latest advance in automated offshore pipe-handling equipment, the need for a man in the derrick is eliminated and the racker is put under push-button control of the driller. Tests indicate the system is push-button control of the driller. Tests indicate the system is smooth and accurate and provides reduced driller. Tests indicate the system is smooth and accurate and provides reduced operating times compared with manually controlled systems. Introduction The application of computer control to the BJ-Hughes vertical pipe-racking system is the latest advance in the development of automated pipe-handling equipment for offshore drilling vessels. The manually operated, hydraulically powered system has allowed more efficient drilling operations by increasing the ability of the rig to operate in bad weather, increasing crew safety, and reducing the trip time. The computer-controlled system, is being developed to improve further the operating safety by taking the man out of the derrick. In addition, faster operating times can be achieved with substantial reduction in operator fatigue. The system will provide the driller with a continuous record of the pipe in the hole, the hole depth, and the bit depth, as well as the number of stands in the rack. The computer-controlled, power racking system has been designed as an integrated system providing all the sensors and control devices necessary for safe and efficient automatic operation, and yet retaining the full capability of manual control. Thus, should it be necessary to perform maintenance on the automatic controls, the racker system still may be operated manually. Discussion In determining the best approach for designing an automated pipe-racking system, several possibilities were considered. Either a vertical or a horizontal system could be automated, or an entirely new arrangement might be developed. It was decided that it would be advantageous to automate the fully developed BJ-Hughes vertical system. This system has been proven on actual drilling vessels and, since the various power-operated components already have been developed, the task of designing an automated system was simplified. A further advantage of automating the existing vertical system is that if computer maintenance should become necessary while tripping, the system can be easily switched back to a power-operated, manually controlled racking mode and can be reverted to a conventional hand-racking operation if necessary. Power-Racking System Power-Racking System A photograph of the computer-controlled test rig is shown in Fig. 1. The small building on the rig floor houses the computer and auxiliary control equipment. The power-racking system is shown in simplified form in Fig. 2. With the exception of the small building housing the computer, all the elements shown in this figure are part of the standard vertical power-racking system. This system has been described power-racking system. This system has been described in detail previously. JPT P. 253