The last four columns have discussed tools needed for a successful cable-tool drilling operation (that is, in addition to a drill rig, casing and, oh yes, a job to go on). As I will describe many more tools in the future, I have decided to number these columns.
After selecting a tool string and tools needed to drive casing, we next need a way to raise casing sections from horizontal to vertical. For a small-diameter well, such as a 3- or 4-inch, using 10.5-foot casing sections, we may stand these up by hand — especially if we have a helper and thread them to casing already in the ground. The “by-hand” approach may not prove easy or practical for welded casing, since you need to clamp the sections together to keep them straight during welding. In my area, we join very little 3- and 4-inch casing by welding, so I will limit my remarks to threaded and coupled casing.
The easiest and simplest way to raise casing to vertical involves wrapping a chain around it below the coupling. You would form it into a loop, wrap it around the casing and attach it to the casing line, presuming you have one. The casing reel would then raise it to a vertical position so you can attach it to the next lower casing. This method has the advantage that if we release the casing reel brake, the casing hook or traveling block to which the chain attaches will probably fall to waist level. You can then easily remove the chain from the casing and begin driving. (If it does not come down by its own weight, somebody has to climb the mast and either loosen the chain or remove it.) I don’t see why, these days, one couldn’t use a fabric strap like those used to tow vehicles if it had the proper length.
An elevator offers a better and safer way to raise casing. The hinged device has a circular portion, which fits the outside diameter of the casing closely, but not nightly, right next to the hinge pin. An elevator is also equipped with a hollow square “flipper,” which keeps it together and has a small portion held in place by the casing’s coupling. After the lowered casing attaches to the casing string, if you lower the elevator (even 1 inch) this “flipper” rotates 180 degrees and the elevator falls free of the casing.
Elevators come in a wide variety of sizes and capacities. One manufacturer makes a light pattern for pipe as small as ½-inch diameter standard pipe. These very small elevators have a capacity of 3,000 pounds. Manufacturers make elevators for pipe sizes up through 12 inches, which can handle 32,000 pounds. All elevators have links that, for light-duty elevators, vary in size from ½- to 1½-inch diameter. They attach the elevator itself to the lifting device.
The manufacturer I mentioned also makes heavy pattern elevators for standard 4-inch pipe all the way up to 20-inch OD pipe. The smallest 4-inch elevators have a capacity of 26,000 pounds. The largest have a capacity of 80,000 pounds. The links on these heavy elevators range from 1.375 to 2.5 inches. Needless to say, elevators for 20-inch OD pipe are heavy — about 700 pounds each. However, if you drill a 20-inch hole, I would assume you have a heavy rig with a multi-part casing line to handle these heavy elevators.
Elevators for plain-end pipe with welded joints share a similar design, but the halves of the elevator fit tightly to the OD of the casing and secure with a bolt.
Drillers, of course, can readily find all types of elevators advertised in today’s industry magazines. You’ll see elevators for PVC casing heavily advertised, since that is a popular casing in 2022. (Needless to say, one does not drive PVC casing with a cable-tool rig.)
One downside of all elevators? When the operator adds the next section to the casing string, somebody has to climb the mast and flip the “flipper” to allow removal from the casing. Elevators are, however, the safest way to handle casing or, for that matter, the smaller pipe used for both test and permanent pumps. For that smaller pipe, which may range from 1 to 2 inches, it’s fairly easy to fabricate a lifting device. For example, you could weld a steel loop to a short section of schedule 80 pipe and thread it into the top coupling. This would attached to the casing line to the pipe to vertical. I have these built in four sizes for from 1- to 2-inch pipe, and even made one each for 3-, 4- and 6-inch pipe. I did this by attaching a steel bushing to smaller-diameter pipe (2½ inches for a 4-inch lifter) and then attaching a clevis through a hole in the smaller pipe. These lifters work fine for lighter duty, but I do not consider them nearly as safe as an elevator.
One huge downside to these lifters happens when the hook on the casing line does not swivel. When tightening the pipe to the next lower section, you could easily unthread the lifting plug or, worse yet, almost unthread it. Then, when you pick up the string of pipe and remove its support, just a little jarring could release it and the whole darn thing would go flying down the casing. This did not have to happen very often to make one aware of whether the lifter rotates as the pipe it holds also does. This can’t happen with a set of elevators — one of the main reasons they are safer than lifting plugs. I did get a lot of use, though, out of the plugs I had made.
Next time, I will write about tools needed to remove casing driven tight into the ground. As I write this in early June, we have had some nice spring weather with many days in the 70s and only a few hot, humid days in the high 80s. We have had enough rain to keep my infamous lawn looking green and I mow it regularly. The farmers in the area seemed to get a late start but the corn crop looks good. I do see plenty of fallow fields, so perhaps high cost have pushed some farmers to just not plant this spring. Until next time, keep working and keep your eye on those lifting devices above your head.
For more John Schmitt columns, visit www.thedriller.com/schmitt.