Drilling advances

	Vol. 229 No.7
LES SKINNER, PE, CONTRIBUTING EDITOR, LSKINNER@SBCGLOBAL.NET

Inherently safe designs

Over the past years, I have written several columns and articles that, hopefully, you found to be humorous, enlightening, entertaining and often just plain goofy. However, there is one subject about which I remain completely serious-safety on the rig. Everyone deserves to have a safe workplace and to go home each day with the same things he/she came to work with that day-all the fingers, toes, eyes, ears and everything else. I tell the young drillers that we don’t want any blood or oil in the water, and I’m serious about that.

Our friends in the downstream sector are under pressure everywhere to improve safety. Recently, we have heard about explosions and fires in large refineries and chemical process plants with devastating results. Their process safety programs are continually reviewed and revised.

Something the downstream guys are using now involves the concept of inherently safe equipment, procedures and processes. There are other concepts that have been used for years in both the downstream and upstream sectors. Most of these are quite familiar:

• Passive. These are safety devices that do nothing but wait until they are needed. A popoff on the discharge side of the main pump is a good example. Another one is a burst disk. They serve, but only when some condition is met that triggers them to function (like an overpressured line).
• Active. These are safety devices that function on a continuous or intermittent basis. Shutdowns are good examples of these devices or systems. They are constantly searching, monitoring, checking, verifying and working to maintain a safe work environment. A Crown-O-Matic is the best example I can muster, but there are many others on a rig.
• Procedural. These are a set of operating policies and guidelines that protect workers and maintain a safe working environment. There are many types, including emergency response plans, well control plans, evacuation and rescue plans, procedures on running casing, and LOTO (Lock Out, Tag Out). The list goes on and on. But, safety procedures can only be effective when they are followed.

Inherently safe systems are a little different. They remove a hazard from the workplace, so one is not required to deal with it at all. Our good friends in the geophysical world formerly used dynamite as an energy source for “shooting” seismic. Well, boys and girls, guess what? Dynamite is not inherently safe, nor is any other explosive. So, by taking dynamite out of the seismic crew’s hands and replacing it with Vibroseis, for example, the entire data gathering process becomes safer.

How about sodium chromate for drillpipe corrosion protection? Or asbestos to smooth out mud systems? Or diesel oil-based muds? Or mercury manometers? Many of these have been limited or eliminated altogether. Others have been replaced with less risky materials.

My favorite is the gradual replacement of the cathead on the drawworks and the catline with air hoists. More people have broken and twisted off fingers and hands while operating the catline than any other piece of equipment on the rig. Now, the industry is working on removing tongs and replacing them with iron roughnecks. How about using top drive systems instead of a spinning rotary table. Probably the safest drilling involves the use of downhole motors instead of turning the drillstring. One inherently safe drilling system involves coiled tubing drilling. The drillstring can’t rotate at all (it has other risks, of course, but not rotating pipe).

I recently saw a video with shots from a building construction project 50 yr ago. There was very little regard for safety back then, no personal protective equipment and no fall protection. Construction workers would walk across steel beams 40 or 50 stories up trusting only their balance and ability to read the wind currents. I am amazed that we didn’t lose more workers than we did back then. Now, many of the risks these workers faced have been replaced by inherently safe systems. I only hope that 50 yr from now, others will look at pictures and videos of present drilling operations and have a shiver run up their spine looking at our best efforts. That would mean that the risks that remain in the drilling industry now had been replaced by inherently safe systems.

I eagerly await the new television series “Black Gold,” brought to us by the producers of “The Deadliest Catch.” The trailers I’ve seen make me cringe. They demonstrate a callous disregard for safety on the rig with pressured fluids blowing out of a broken connection, floorhands being slapped around by tongs, spinning chains being thrown and loads being mishandled. I noticed that many of the events are not shown in real time-they are speeded-up considerably-making me wonder if the whole thing has been staged. If not, the crews need some additional training and the rigs are truly in need of some inherently safe system designs. Maybe the crews should try their hand at crab fishing. It would probably be safer.

On a lighter note, researchers at MIT have developed a new set of oil repellant materials. Oil is attracted to most materials because of its low surface tension. So, a drop of oil on steel, wood or the skin spreads and absorbs into the surface layer of the material, if it can. The new materials force the oil to form tiny droplets that stay on the material’s surface. Obviously, if the oil can’t penetrate the surface it can’t absorb into the material.

These new materials are all manmade, and the way they work is fascinating.
Fibers cushion the oil droplet trapping tiny air bubbles between the droplet and the surface. The droplet is actually floating on an air cushion and it is incapable of wetting the material’s surface.

Here’s another nifty concept, these materials can be deposited on the surface of other materials. Imagine the possibilities: O-rings that don’t absorb diesel oil or kerosene and turn to jelly, annular BOP elements that stay together and don’t end up in chunks on the shaker screens or in pump suctions, boot soles that retain their form and function for more than two weeks and anti-skid pads on rig floors that can actually be cleaned. How about slicker suits that shed oil-based mud and look decent for more than one trip.

I understand that more of these materials are being developed and perfected, based on the specific oil involved and the service demands of the base material. Maybe we can get that old derrick cleaned up yet!