In response to industry requirements for a reduction in rig crew numbers and an increase in safety, significant advances have been made in the mechanization of the pipe running and handling process in the last two years.
This paper will outline the advances made in the industry to bring up to date process in pipe running and handling without making them too complex.
Highlighted are the new systems for adapting hydraulic roughnecks to carry casing and tubing tongs, and for this equipment to operate remotely. Initially, this development was in response to Norwegian Petroleum Directorate requirements, but is now finding wider use in many countries because of the opportunities to reduce the number of personnel on the rig floor.
There have also been significant advances in the moving of pipe from the racks to the catwalk, up to the Vee Door and in presenting pipe to the pipe makeup machine for running, these developments will also be described.
Surveys have shown that the handling of pipe, especially on offshore rigs, is one of the most hazardous operations for rig personnel and service crews. Handling and running of pipe has always been hard and repetitive manual work with many attendant safety hazards. This paper will show how these new systems reduce the need for direct personnel intervention and result in an improvement in safety.
Attempts have been made in the past to completely automate all mechanical functions on a rig, but these have proved too costly and complex. Recently there has been a focus on the improvement of specific parts of the rig systems which have shown great economic and safety benefits, such as Top Drives, Racking Systems, pipe handling without cranes, etc. The key ingredient in many of these advances has been the use and adaptation of Programmable Logic Controllers (P.L.C.'s). These topics will also be discussed.
At a time when the upgrading of many offshore rigs is in sharp focus, these developments are showing major benefits for operators and drilling contractors alike.
In 1994 Weatherford together with Maritime Hydraulics A/S introduced the Casing Modems where casing tongs and free floating backups were mounted to a special frame attached to the hydraulic roughneck (Fig. 1).
These hydraulic tongs are remotely operated by a technician standing at a safe distance away from the well center using a portable control panel incorporating a joystick for maneuvering. The tong and it's accompanying free floating hydraulic backup are suspended from a compensation device attached to the casing modem frame. The casing modem and tongs can be mounted to the hydraulic roughneck in approximately 30 minutes. In operation the hydraulic roughneck provides the motion to move the whole assembly out to the well center so that the makeup of the pipe connection can be carried out.
Automatic doors close around the pipe, first on the hydraulic backup then on the tong. The jaws are then engaged and makeup commences. All forces from the tong react directly to the free floating backup. No snub lines are required and no excess force is transferred to the casing modem frame. The free floating backup is specially designed so that shearing and bending forces are not imparted to the pipe or the connection. This is a critically important feature.