This paper is focused primarily on the current capabilities of the CRD100 subsea robotic drilling platform. An overview is given of the available hardware and interface approach. Time analysis of our wireline system over conventional drilling is included. Reasoning for several design decisions are provided. Aspects of the interface and its semi-automated hierarchical control system of Ethernet distributed pressure tolerant electronics (PTE) I/O modules are presented.
The discussion includes explanation of several ‘lessons learned’ that have been encountered over several years of off-shore drilling experience. From these we have determined that the method of human control of the remote subsea robotic drill should be performed by two operators simultaneously. A pilot chooses what they want to control, be it the drill, its arms, the thrusters or the legs and their co-pilot chooses a complementary set of controls. Data from factory acceptance tests are used to demonstrate how well two operators expedite the procedure.
Although we strive to automate as many aspects of the drilling operation as practical, we show that at present two competent operators (assisted by automated processes) drive the system more efficiently than one. The wireline system has greatly reduced the time to acquire core samples compared to conventional drilling techniques. Further, we have developed this system so that core barrels may be exchanged for scientific probes, such as the cone penetration test (CPT), without the need for conventional trip out.
Our system was implemented with the first subsea PTE that operates over Ethernet. Using distributed PTE has reduced the costs of controlling subsea robotic equipment, both in cost of the electronics housings and cabling, while improving data collection. The paper discusses the use of several of these PTE in a hierarchical control system. The applications of our drill to the petroleum industry is primarily in the exploration and ground analysis for off-shore construction. The approach of using robotic sea floor drills is a means to avoid the expense of employing drill ships for geotechnical exploration.