Drilling advances

	Vol. 227 No. 11
LES SKINNER, PE CONTRIBUTING EDITOR

Overhaul, refurbish, refit or retrofit? In the past few years, we have all heard various terms for what rigs are undergoing to make them better, more robust, faster, more productive, enhance capabilities and generally improve the rig fleet. All this is happening when every drilling contractor and oil company is trying to drill more wells faster and cheaper to take advantage of improved product prices.

Exactly what do the various terms mean? A few definitions are in order.

• Refurbish: to renovate; clean-up; renew or restore to a like-new condition and/or appearance; to refresh, revamp or rejuvenate
• Overhaul: to restore to proper condition or function; to patch, mend, repair or make right
• Refit: to prepare and equip for additional use
• Retrofit: to provide existing equipment with parts, devices or systems not in existence or available at the time of original manufacture; to modernize with new or modified parts, devices, systems or equipment.

I think refurbish is what our old toolpusher made the crews do every six months or so when we had to clean out the top doghouse, our lockers, the toolhouse and, of course, his quarters. We had to scrape the paint off every handrail, stair tread, engine housing, pit, shaker, pump and the BOP stack. Then, we repainted everything to his satisfaction, all while drilling at breakneck speed. When the definition of refurbish came to light, I began to realize that I hated it.

Overhaul was something that motormen used to do to poorly performing engines. Fortunately, we did not try to use the engine while the mechanic was working. The engine was isolated while the mechanic pulled the heads (with the help of one or two floorhands), polished cylinders, ground valves, installed oversized rings, put in new bearings and reassembled the entire engine. That also applied to drawworks, the brake, the rotary table, the fluid end of every pump and other equipment, as needed. We were not trying to expand the rig's capability, we were just trying to make it run the way it should.

Refits were also fun, adding something to the rig to extend its life or to make it better suited for the contract the financial guys had already signed (committing the company without contacting the operations folks). So, we added a pump, an engine, a pony sub that would allow us to put another BOP under the rotary beams or some other ghastly addition to an already overtaxed structure. How we kept the rigs together during that time is beyond me.

Retrofit is the newest term, and it sounds ever so much more exotic than "overhaul." In fact, it is more exotic. The industry has decided not to just extend the life of proven rigs, both offshore and onshore, but to make them better than new. Imagine adding thrusters and full DP capability to an old semi, so it can compete with newbuilds. How about replacing an aging derrick with a new, taller, stronger and larger one with skids for a top drive that it never had before, plus better navigation, automation, communication and ballasting systems? The list is endless.

Recently, with the advent of onshore flex rigs, the focus is on making older land rigs more worker-friendly. At current day rates, one can understand the financial motivation for modernizing the larger rigs. More importantly, safety is becoming the driving force for retrofitting older rigs. One of the best retrofits is adding the iron roughneck along with kelly spinners and other devices to reduce a floorhand's risk. In fact, we have gotten so good at adding these cost-effective devices that the riskiest piece of equipment on the rig, the cathead, is all but obsolete. Good riddance  –  I almost lost a hand on one of these. Now, as Max Hall used to say, the most dangerous piece of equipment on a land rig is the forklift.

I have been expecting someone to invent a device that could easily retrofit onto a small land rig to rack pipe automatically and take the derrickman out of the basket. Well, guess what? Someone has.

Canadian co-inventors Dave Richard, Bill Stroshein and Monte Wright have perfected a robotic pipe racking system specifically for small land rigs that do not have derricks large enough for one of the big automatic pipe-handling systems. They have been working on their design for over three years. The purpose of their design was not crew reduction; these guys were interested primarily in crew safety. Everyone deserves to go home with all the parts they had when they came to work, including their lives.

Like the larger pipe-handling systems on large onshore or offshore rigs, this device has a robotic arm with a gripper that receives a stand of drillpipe from the blocks or top drive in a handshake above the rig floor. So, after the connection at the floor is backed out, the arm hoists the pipe, moves the stand to the racking boards and places it gently in the fingers while the blocks are being lowered to hoist another stand.

The arm is controlled by an operator from a belt or chest-mounted control panel with paddles that actuate hydraulic circuits. The panel is connected to the robotic arm by control lines that make it highly mobile, so the human operator can move about the floor to optimize visibility. The derrickman is on the floor racking pipe without being in harm's way in the basket.

The nicest part about this system is that it can be added to the existing rig with few, if any, modifications to the derrick. It hangs below the basket from a beam that can be easily detached and removed, if necessary.

I understand that a drilling contractor in Wyoming has been using one of these devices for over five months with good results. There have been no equipment failures or injuries during that time.

I love innovation. Nothing compares to the ingenuity of the human mind when confronted with a challenge. This simple retrofit solves a problem that has tormented the industry for years: how can we get that poor guy out of the basket on a small rig and still rack pipe.

The field of robotics for oilfield use is advancing by leaps and bounds. What new devices can we expect to retrofit our existing rigs in the near future thereby extending capabilities and improving crew safety at a reasonable cost? An interesting question. I can't wait to hear the answer.