This article is not about drilling an oil well on the planet Mars. It is the description of a process by which an MWD system that enables remote directional drilling and helps achieve drilling automation starting with the elimination of the MWD operators was successfully designed and commercialized. Engineers felt that if they could design a system for interplanetary exploration, it would translate well to implementing the remote directional drilling and drilling automation efforts on Earth.

Using the example of a Martian drilling project, an MWD system that eliminates the need for an MWD operator was successfully designed. The system enables remote directional drilling and interfaces to control systems required for full drilling automation. These engineers felt that MWD operators add zero value to the drilling process, especially when the drilling process is being controlled remotely or automatically.

diagram of the NES unmanned MWD system

The NES unmanned MWD system is shown in an automated drilling environment. (Image courtesy of Navigate Energy)

This idea required a few assumptions. First, it had to be assumed that the equipment could be transported to Mars and that the engineers had the technology and know-how to drill the well. The next question was how would this drilling operation be staffed? Would there be a day and night company man, tool pusher, directional drillers, mud loggers, MWD operators, drillers, and roughnecks? The answer to this question is obviously "no." It would be likely and entirely possible that everything would be done remotely and automatically using control systems and robotics. It also was assumed that most of the drilling industry would agree that this is a feasible concept.

Therefore, it was hard to understand why there was so much consternation and gnashing of teeth when it was suggested that a well be drilled three hours outside of Houston without an MWD operator, directional driller, or drilling crew on location. By examining this challenge it became obvious that there truly were no technical barriers, only emotional and cultural barriers to overcome to achieve the goal of remote directional drilling and eventual complete drilling automation.

The impossible can become a requirement

What was required of an MWD system in 1982 is quite different than what is required in 2012. In 1982, the industry was drilling vertical wells and simple directional wells with long tangent sections targeting clastic or carbonate reservoirs using rotary assemblies. In 1982, replacing wireline logs with LWD logs was consid-

ered ridiculous and was met with the same skepticism unmanned operations are met with today. However, triple-combo LWD systems went from being impossible in 1982 to being an absolute requirement by 1989. Fast-forward to 2012, and the industry now is drilling mostly horizontal wells with build rates greater than 12°/100 ft that target shales and other poor excuses for reservoir rock with steerable motors or rotary steerable systems (RSS). The data and subsequently the MWD systems required to drill wells in 2012 are much different than what was required in 1989, and arguably the primary requirement of an MWD system has shifted away from formation evaluation toward improved drilling efficiency, accurate wellbore placement, and drilling automation. This has been a rapid change, and subsequently most of today's MWD systems have not kept up. It is time to step back and have a look at the new reality and what it means to MWD system requirements.

NES unmanned MWD system

There are two main components to any MWD system: the downhole tool and the surface system. The NES system comprises a pre-assembled battery-powered MWD tool. The MWD tool has approximately six weeks of battery life. The tool is currently capable of providing gamma and directional measurements and is being expanded to provide additional measurements.

The surface system consists of one certified computer that also doubles as the driller's display if required. To support remote operations and automation, the MWD system must provide the data in the appropriate format.

MWD tool. What happens when there are problems? The answer is that there is nothing anyone can do with a failed MWD tool that is still in the ground. The challenge is determining if the tool has really failed or if there are rig conditions that are causing the issue. The troubleshooting process can be handled remotely by experts who have access to the same data that they would normally have at the well site.

Surface systems. An MWD surface system has two basic requirements; data decoding and data display/transmission. Most MWD surface systems to date have been designed assuming there will be at least one MWD operator on location at all times. The prime directive for the NES surface system was that there were no people and there is only one computer.

Data decoding. Accurate and reliable decoding of the data transmitted from the MWD tool is an absolute requirement. Although different conditions can require different filters/settings, this is solved with an automated, intelligent decoding system programmed to handle different situations. As long as all data required for troubleshooting are available, there is no need to have anyone at the rig, especially if remote control of the top drive and pumps is available.

Data display and transmission. The MWD data must be made available to the other systems and people that need it in a format that is usable. The NES surface system receives drilling data from the electronic drilling recorder and, serving as an aggregator, makes the data available wirelessly via local area network and also via the Internet using Cloud storage. The aggregated data can then be used for controlling the top drive, managed-pressure drilling, and RSS automatically or via human-machine interface at the remote operations center. For simple remote viewing, users have access to the data anywhere with Internet access.

Surface system hardware requirements. Most existing MWD systems have been designed assuming there will be an MWD operator to rig up and test the system; this makes it easy for designers to add hardware and complexity. The assumption that there are no personnel available forces a simplified hardware design.

By using the concept of drilling on Mars, an MWD system was successfully designed that adds to the vision of complete automation. There have been many recent advances in drilling automation, particularly with regard to top drive and RSS, and an MWD system must be designed with these advances in mind.