When sediments are buried by layers upon layers of succeeding sediments, the harder, the hotter, and the more compact the earlier sediments become. Eventually, pressure, heat, and time turn loose sediments into various types of sedimentary or metamorphic rocks whose properties vary according to their respective mineralogical compositions, environments of deposition, burial depths, and so on.

The high temperatures and extreme pressures that turn sediments into rocks are partly responsible for the dangers that arise when petroleum is released from deep within the earth. Partly because of the extreme pressures and temperatures encountered at depth, the extraction of buried petroleum requires the use of tough and durable materials (most commonly hardened steel alloys, carbides, nitrides, diamonds, etc.) that can chew their way through hardened, compacted, and heated rocks. And these tough materials need to be of sufficient mass in order to provide enough force and momentum to cut and punch through the toughest  and densest rocks. Therefore large and heavy equipment and machinery are necessities on drill rigs, and these huge pieces of steel have become just one of the three major sources of hazards on drill rigs that rig crews have to be always on the look out for. The other two sources of drill rig hazards include the highly pressurized, flammable, and at times toxic, gases that are released by the drilling operation, and the environmental extremes (excessive heat or cold, strong rains, strong winds, lightning, etc.) that are often encountered in remote and not-so-remote locations.

If light-weight, non-contact drilling equipment (such as large lasers for example) are available and can conveniently melt rocks out of the way, then oil drilling might become a much less physically demanding and dangerous task. But until such advanced technology comes our way, only the old-fashioned large and heavy equipment (that are for the most part made up of hardened steel) are available and capable of penetrating the almost equally hard, compressed, and deeply buried rocks that contain the oil and gas.

The problem with men being in close proximity to large pieces of machinery is that humans are too small and too fragile compared to such massive and often fast-moving machinery and equipment, which are employed not only on drilling platforms, but also at construction or mining sites, power-generation sites, grain refineries, and other industrial operations. Any time a human happens to get in the way of one of these massive, steel-filled automatons, the human always ends up getting the short end of the stick (deadly rig move, fallen top drive assembly). Personnel are also often required to work at elevated heights usually at or near the tops of these large metal structures. Thus, in and of itself, direct human interaction with large and heavy pieces of equipment is already a dangerous situation. Couple this reality with the presence of highly compressed flammable or toxic gases, and with the extremes of weather, makes oil-rig work a not-so-ordinary 9-to-5 job, with danger literally all around you.

Therefore, one of the fundamental safety problems on these rigs is concerned with preventing people from getting in the way of the massive and moving equipment and machinery while they (humans) manually or semi-manually direct or guide these equipment and machinery in order to drill the well. Some people contend that this situation is essentially an engineering problem. Engineers can or should design procedures or processes, and even other machines or systems that allow human operators indirect and power-assisted access and control of large machinery and equipment without necessarily having to be in close proximity to the large equipment. A few such advanced systems have already been made available relatively recently for this purpose (iron_roughnecks, iron_derrickman). But these recent devices have not been universally adopted and deployed on most well-drilling rigs. Remotely operated devices have been deployed in various areas of the oil-drilling industry primarily to reduce risks to human operators and to save time. But for the average floorman on a typical drill-rig floor, the work is still basically manual and up close and personal to cold, unrelenting steel.

The current universal practice is to train operators to safely and efficiently, directly or semi-directly manipulate and operate the oversized drilling equipment. And this is where safety problems arise. What is taught and the effectiveness of what is taught can be and is usually highly variable and depends to a great extent upon the capabilities and inclinations of the individual trainees and of the instructor/s, and upon the training environment and available educational/training resources. Also, there are some operations that workers cannot be trained for; they simply have to learn to perform some procedures and operations while on the job. Also, sudden equipment failure brought about by inadequate equipment monitoring and maintenance, or by extreme drilling or other operating conditions can take personnel completely by surprise (broken_chain). Training can help them know how to watch out for these situations and to take precautionary measures, but there are so many possible, unforeseen dangers and scenarios when it comes to working with huge equipment. It might be too difficult to determine all of these possible dangers, and even more so to be able to train for all of them.

The following series of articles on drill-rig safety discusses some of the more recently applied or suggested improvements and additions to the current standard safety practices, equipment, and technologies that are put to use in the oil-and-gas exploration and extraction industries. These new equipment, technologies, and standards include, among others, advanced surveillance equipment such as digital IP-networked cameras and RFID devices, operations-monitoring and data-gathering software, current and possible improvements on personal protective equipment, current and proposed state-of-the-art training systems, and recently approved/adopted or proposed work and safety regulations that have been designed by industry organizations or by government regulatory agencies.