Last month, I wrote about fishing for tools that were loosely lodged in the drill hole or perhaps for a bit wedged into the casing shoe by a stone, pebble or what have you. This month, we are going after a string of tools that is really stuck for whatever reason, and either contains no drilling jars or the drilling jars have become stuck. Our fishing tool of choice will be a combination socket. If the drilling line has been jerked out of the socket of the drill string, we can begin with this tool. If the drill line is still attached to the drill string, we’re going to have to cut it with a tool called a rope knife.
The rope knife, sometimes called a wire-line cutting outfit or tool, is relatively easy to rig up and operate, but like many things in drilling this operation is somewhat tricky. The rope knife, as I will call it, is run on our sand line. A word of caution here: Our knife assembly will weigh about 350 pounds. Please be sure the sand line with the accumulated line on the reel will handle that weight with something to spare. I would recommend an additional 200 to 250 pounds of lift. We will need to remove our bailer and any bailer hitch before attaching our bailing or sand line to our rope knife.
Our knife outfit will consist of a wire line socket generally smaller than most drilling sockets, sinker bar, an 18-inch stroke fishing jars, and the rope knife itself. We will have to fasten our sand line to the socket just like we would do on our drilling string. Once we are all assembled, we will attach the knife assembly to the drilling line-this is very important-without the cutters installed. At this point, we should take slight tension on our drill line. We don’t want to get to much or too little tension on the drill line. We then will run our rope knife assembly into the hole and if we are down 100 to 200 feet, run it all the way down to the top of our socket, marking that location on our sand line. If the drill tools are down really deep, it is a good idea run our rope knife assembly down perhaps a quarter of the way, pull it out, run it half way, pull it out, then three-quarters of the way, and finally all the way to the socket of our stuck string.
At this point we will assemble our rope knife, making sure that it is good and clean and lubricated with some light oil. We will then lower our rope knife into the hole. Here a very loud caution is included: At this point, we do not want to take more tension on the drilling line or attempt to remove our knife assembly until we have contacted the stuck socket. Our drilling line is severed or cut by taking a slight tension on our sand line and then rapping quickly upward, letting the fishing jars do their job. It should only take a few strokes to cut the drilling line, and when it is cut it is very obvious at the top of the ground. We will then pull the drilling line followed by the sand line with our rope knife assembly attached. We now have an open hole down to our stuck tools and only open hole, but we still have a lot of work to do.
We now assemble our fishing string and at the top we will have another wire line socket. Most tool companies recommend that this be the solid-type socket that does not allow our fishing string to rotate. I have fished with swivel sockets with no adverse affect, but if the driller has a solid socket in stock it is probably a good idea to use that type. Next comes a drill stem, and this should be as long as practical considering our mast height and the weight capacity of our drill rig. The next item is very important, and that is a good set of fishing jars. It is extremely important that the stroke of our fishing jars be longer than the stroke that our rig is adjusted to. For just about any fishing job, the rig stroke should be adjusted to the shortest one possible and on most water well rigs this would be 24 to 28 inches. With our machine set to a 24-inch stroke, we would use fishing jars with at least a 30-inch stroke or perhaps even a 36-inch stroke. The reason for this caution is that if our fishing jars have a shorter stroke than our machine is set to, we will be hitting “both ways.” Hitting both ways will probably result in breaking the hold of our fishing tool and possibly breaking the tool itself. Also, severe damage to the drilling tools can result, making future attempts at recovery much more difficult.
The last tool in our fishing string and the first thing into the hole is a combination socket. An additional point is that our fishing tools will usually be the same diameter as the tools we are fishing for. With our fishing string assembled, BUT WITHOUT THE SLIPS INSTALLED, we will lower it into the hole and go all the way to the socket of our stuck string. The fishing string is then removed and a soft wood stick is wedged across the mouth of the socket. The tools are then run into the hole again and removed. If the stick is broken or has disappeared, it is a pretty good indication that the combination socket went down over the fishing neck of the drilling string socket.
At this point, just like our rope knife procedure, we will clean and oil the combination socket and assemble it with the slips. Various sizes of slips are available for each size combination socket, and it is important to keep a record of the exact size of the fishing neck on our drilling string socket. We will want to use the proper size slips to catch that neck. It is also very important not to let this neck become battered at the top like a chisel sometimes does from bumping pipe out of the hole. A battered fishing neck can make things very complicated.
Having taken all these precautions, we now lower our fishing string into the hole, noting from our flagged line that we are on the drilling string. It is then a good idea to jar down lightly to make sure we have full contact with our fish. We then take some tension on the fishing line and, as the tools we are after are stuck, we will start the spudder mechanism and start jarring upward. Short and quick jarring is preferable to long hard jarring, and patience is a requirement here.
If we are fortunate, our stuck string will come loose within a few minutes and we can lift the fishing string and the drilling string out of the hole. I cannot say here how long it might take to loosen any drilling string in whatever condition. If after several hours of light jarring we have no results, then we have no choice but to go to longer and harder jarring-though this harder jarring increases the danger of a broken hitch or of breaking the fishing tools. If, after a long session of jarring upward, it is obvious that the drilling tools cannot be retrieved, we have no choice but to try to break the hitch. This is done by jarring both up and down as I have written about earlier in this article. This, too, can result in broken fishing tools and parts left in the hole. We will have to set our drilling rig to a longer stroke to do this.
If we have been successful, we can remove the combination socket from the fishing neck of the drill string socket, take our fishing string off our drilling line, reset our drilling line into the socket of the drill string, go back to drilling and hopefully we won’t get stuck again.
If you get the impression that this is a hard, complicated and time consuming process, you are absolutely right. It is best to avoid this situation in the first place but, like anything in drilling, sometimes you have to do difficult things. Remember too, please, that the foregoing is a history of my experience retrieving stuck tools and I make no guarantees express or implied about what procedure to use yourself. If you can get a hold of a old Acme Cable Tool or Rampp Cable Tool catalog, reading them can be very worthwhile. I don’t know if these are printed anymore, but I believe these companies still exist under different names and you might be able to get these catalogs.
Here in Michigan, we have had a month of fairly light snows from 2 to 4 inches then, after it is plowed and melts off, a few days or a week later we get 2 to 4 more inches. We had a particular nasty snow a few days ago, and it was the wet slippery kind that is hard to plow and dangerous to shovel. Next time, we will do some more fishing.