Abstract

The most important and effective industry response to date has been to replace humans working in most treacherous areas with machines. Automobile industry added robotic arms in the production line long ago. In the oil industry, oil and gas drilling and completion operations, like automobile assembly line work, also used a great deal of repetitive motion that could be automated. Rig automation has the sole purpose to enhance safety and efficiency. Modularized rigs in terms of both hardware and software changes the interaction between rig personnel and equipment. Remote monitoring of this system makes this interaction more seamless. This technology transforms the drilling procedure from reactive to proactive thus saving downtime and reducing maintenance. But case studies have shown that this system is vulnerable to potential errors and can cause accidents unless overridden manually. When the pipe buckles downhole and the hole collapses as result of impact then drilling has to be seized. Can automation handle this? Sometimes there is unwanted deviation in the well path. How can automation counteract this? This paper discusses the pros of the technology not overlooking the cons.

Introduction

Automation is being given much importance in the oil industry because of the level of hazard and precision involved in this sector. It can essentially perform cyclic tasks, isolate personnel from rig floor or other such areas, carry out multi-tasking etc. It is safer and stronger version of the human hand.

Much of the impetus for automated drilling rigs came from the North Sea, particularly the Norwegian sector where regulators interested in removing workers some distance from the well center had already seen the kinds of machines that could make that possible. It started off in the 70's when hands were withdrawn from high risk areas. Mechanized Wrenches, Power Slips came into the picture. Later that century the mechanized Iron Roughneck was born and making up of string became a much easier task. In 1991, with mechanization of the iron roughneck well advanced, Varco, working with Mærsk, produced a pipe pickup and lay down system that eliminated human intervention from the pipe deck to the rig floor. Weatherford International developed a remotely operated piece of rig floor equipment for making up drillstring, drill collars, wash pipe, drill bits, stabilizers, and other downhole and surface equipment taking this technology a step further.

Similar advances were being made in the field of computers during this time. Microprocessors which could have been an ideal solution failed to work in the vigorous and harsh environment. Consequently PLC's (Programmable Logic Controllers) were settled for.

Control of the drawworks, topdrive, iron roughneck, pipe racker, ac drive, and drilling instrumentation system is put together on a console which can be operated without any costly simulation drilling. Remote monitoring is done by compiling the data from the console onto a data logger. This is done to prevent loss of any data. It is then routed to the rig's HMI before passing onto rig's routing and satellite transmission system. Data can also be scrambled before being transmitted. 1 These developments provide a lot of information to the operator which help him in the critical decision making process.

The data is send via local intranet or internet to the experts where unencrypted information is viewed and action taken accordingly. There are certain instances during drilling when abnormal activities occur downhole viz. pipe buckling, unwanted deviation, abnormal pressure buildup etc. In such cases decisions are to be taken. It is then that human intervention is required. Such instances, though few are critical.

The mechanization has become automated as time passed and the rig floor has increasingly becoming devoid of man. Some thought is still needed to make the system capable of taking decisions.

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