Having written several columns about spudder rigs and the wire lines used on them, I now get to the business end of a spudder: the drill or tool string.
I think the term “string” comes from the fact that it consists of several pieces, each with its own purpose during the actual drilling. Tapered and threaded joints, similar to what one finds on rotary tools, hold the different pieces of the string together. Drilling tools come in all kinds of different shapes and sizes. You’ll find at least many, if not more, tools for driving casing and pulling it back out of the earth, and fishing tools to recover other tools stuck or lost in the hole.
With these tools, cable-tool drilling has an effective range from 3-inch hole up to 24-inch hole. You can drill larger holes with reaming bits, but these are rather unusual. In Michigan, we’d typically see holes drilled by cable tool range from 3 inches up to and including 16-inch holes. A light rig can easily handle a 3-, 4- or 5-inch drill string, but if you are going to drill 12-, 14- or 16-inch holes, you need a heavy rig.
A typical tool string from top to bottom would consist of:
- A wire-line socket
- Possibly, but not always, a set of drilling jars
- A drill stem
- And the drill bit. The drill bit is the business end of the tool string and makes the actual hole.
An old saying goes, “Well drilling is the only job where you start at the top.” So, I’ll start at the top of the drill string with the wire line socket.
The wire-line socket, a round, steel tube with heavy walls, connects the drilling or spudder line to the drill string. The top of the socket is machined smaller than the body for fishing purposes. The bottom has a female tool joint.
The wire line socket has a hole a little larger than the drill line drilled into the top of it. The drill line passes through this hole and attaches to a swivel. This is for a swivel socket and is very important, since the tools tend to turn with each stroke of the rig. The tools turn to the right using left-lay drilling line (and that’s why we always use left-lay line). The swivel is a long-beveled on the inside basket that has a hole that just fits the drill line at the top, and enlarges to almost the full diameter of the swivel at the bottom. After passing the drill line through the swivel, you start the attachment process by binding the line tightly with wire or really strong tape about half the length of the swivel from the end. The swivel varies from a length of 5 inches on 3-inch tools to 11 inches on tools for large-diameter holes. For 3-inch tools, the swivel measures 1-3/16 inches in diameter. On the large tools, it goes up to 3½ inches in diameter.
Attaching a Swivel to Wire Line
After securing the drill line with wire or tape, unwind all the wires after the secured spot. A typical drill line has 114 wires, and on a 3-inch socket swivel we would unwind about 2½ inches of them. Leave them in a semi-curly pattern. Do not straighten. Clean the 114 wires with some type of degreaser. I used to use gasoline. (Probably not the safest thing to do, but it got the wires good and clean — especially when hit with a flaming torch.) Then pull the wire line into the swivel so that the unwound individual wires sit just inside the open end of the swivel. Pack the area at the upper end of the swivel with clay or putty to help in the next step.
Now we fill the swivel with molten zinc. Do not use lead or Babbitt. Those materials seem like they would work, but really do not make a proper connection. Pure zinc can prove difficult to find, but look out for a die-cast plants — good sources if you can find one near you. Heat the zinc to a molten or liquid state. I cannot stress enough: Protect your body, especially your hands and face, while doing this. That means wearing safety glasses and a face shield and heavy welder gloves, with no short sleeves or short pants. Wear a leather welder’s apron if you have one.
I repeat: Working with molten zinc is dangerous. I know from experience. In the mid-50s, I badly injured myself the one and only time in my drilling career I set a swivel on a swivel socket. No, I did not spill the zinc. The gasoline furnace I used to heat it, in effect, backfired through the air pump that was part of the furnace. It sprayed me about the face and neck with gasoline. I spent about five days in the hospital with serious burns. The second day, I got out of bed and went to a mirror. I almost fainted when I saw myself. I was a mess. By the grace of God and the medical people, I healed up with no scars. We got rid of the gasoline furnace, and from then heated our zinc with propane. I repeat doing this is dangerous.
Once the zinc reaches the proper temperature, invert the swivel and pour, filling it fully. The zinc needs to be hot enough to adhere to the wires, but not so hot as to anneal them. It’s not a bad idea to preheat the swivel with a torch. I would test the zinc for temperature by dipping a pine stick into it. If the stick catches fire, the zinc is ready to pour. If the zinc just sticks to the wood, it is not hot enough.
Swivel, Socket Top the Drill String
After filling the swivel with the hot zinc, allow to cool naturally and then pull into the socket. People tell me that, if this procedure is done right, the swivel will withstand as much pull as the wire line itself. Done wrong, can you expect to face a fishing job pretty quickly.
There are other types of sockets, for example to use with a manila line and another primarily used for fishing that does not swivel. I have never drilled with manila rope or used a solid socket, so I will not talk about them.
I have heard, too, about another method to attach the drilling cable to the swivel. You would twist back the six large wires of the drilling cable, secure them with wire and pull them into the swivel. I believe this is impossible to do unless you run large tools, as the wires will not go into the swivel.
Another important tool to have for use with the socket is a wire line saver. This slips over the small top end of the socket and, in effect, makes a small-diameter, 90-degree rope sheave. It prevents the wire line from kinking when picking up and laying down a string of tools. Kinking the wire line severely shorten its life.
I put a lot of words into this one, very important part of rigging up a string of cable tools. As I said earlier, this the swivel connection fails, you facing real trouble — including lost tools.
We are in the dog days of August here in Michigan and have recently have had some hot, humid and unpleasant days. Usually, however, after about August 1 the nights get cooler and this year is no different. If you are going to set a socket and do some cable-tool drilling, use the right protective equipment and be careful. Have a helper around to take you to the hospital if something goes wrong. I thank God for the helper I had that day in 1956. We still see each other several times a year.
For more John Schmitt columns, visit www.thedriller.com/schmitt.