A look at welded casing.

In my last column, I wrote that this time I would include some more thoughts about well casing. I’m going to do that, but I want to take a small digression on the subject of safety on well drilling sites.

In the August issue of National Driller, there is an article about some fellows drilling wells in Central America. Now this is a wonderful thing, and certainly people in many parts of the world are in dire need of a good safe water supply. However, the picture that covers most of page 10 is very disturbing. Two of the fellows working on the drill rig pictured there are wearing baseball caps, and two are hatless. This is a very unsafe situation. Our industry has preached safety, safety and more safety for years, yet in almost every industry publication I see pictures of folks on drill rigs without a hard hat.

Continuing for just a short while on my soap box, yes, I am aware the hard hats are uncomfortable and sometimes hot; that steel-toed shoes are heavier than regular shoes; that safety glasses and goggles fog up, and are a pain to wear; and that hearing-protection ear muffs and ear plugs are uncomfortable and inconvenient. However, all these items will save an injury to important parts of your bodies, drillers, and maybe even save your life. My late father, whom I reference frequently in these articles, was a talented mechanic and a professional tradesman. He got clunked on the head once with part of a set of light drive clamps, and he was wearing, you guessed it, a baseball-style cap. He received a bad cut – it required stitches to close – but he really was quite lucky in that he easily could have been killed. I don’t mean to harp on this, but fellows and gals, it’s only our lives we are protecting with proper safety wear.

Back to the subject of casing, let’s talk a little bit about welded casing. Almost all of the casing that I ever used was joined with couplings on threaded pipe. I do know some fellows who used welded casing, especially in sizes of 6 inches and larger. Certainly, welded casing with the absence of couplings would drive easier than threaded and coupled types, and in some holes, this could be a big advantage. About the only thing I can say about welded casing is that the driller had better be a pretty good welder, or joint quality will suffer. Now I know some drillers who are pretty darn good welders, and others who have talents in this field that are somewhat lacking. I’ve talked with contractors who have reported that welded casing that they have used had a somewhat shorter service life than threaded and coupled casing. I don’t know the reason for this, and neither did they. I do know that many codes require multiple pass welding, especially as sizes get larger, and I have seen some fellows use a single pass and put her in. Lest you think I am opposed to welded casing joints, one of the wells on my property has 6-inch steel casing, and it has welded joints.

I mentioned in my last column that one could get into an interesting discussion about the advantages and disadvantages of black steel vs. galvanized steel casing. An equally debatable topic back in the days when the spudder was popular was what length casing was the best to use. I knew fellows who used nothing but full or 21-foot lengths, and I knew another driller who ordered a whole truckload of casing in exactly 8-foot, 9-foot and 10-foot lengths – and I mean exactly. In-between, we had fellows using half lengths, which were 10.5 feet, 12-footers, 14-footers, 16-footers and 18-footers. I personally liked to start the hole with a full or 21-foot length, and then use as many 16-foot lengths as I could.

In this part of southern Michigan, we drill primarily wells in the drift, as it is plenty deep. One of the tricks we spudder drillers used was to use an oversized temporary surface casing, and use a work pipe anywhere from 2 feet to 8 feet long. We would tighten the work pipe only slightly more than hand-tight, and then drive the upper section of our permanent casing down into our surface casing. When we were ready to go deeper, we would remove the work pipe, and tighten in the next joint of our permanent casing. Although it would seem we couldn’t get this joint very tight, in actuality, we could, and it was plenty adequate from both a watertight and a mechanical standpoint. This practice made the use of 16-, 18- and 21-foot joints of casing workable.

I have been told by drillers who drilled in areas where the geology was pretty tough that they would never consider a semi-tight joint, as breakage during hard driving would result if they did not make their joints up to full tightness. Actually, I sometimes wondered if the putting on work joints, taking them off, using the temporary surface casing and all that was worth it. I know at least one drill rig manufacturer that said the smart way to do a good job and make time with a spudder was just to use half lengths (10.5-ft.) and be done with it. Using the temporary surface casing, we had to pull this when the job was done, and sometimes they pulled darn hard. We usually filled the annular space with cuttings or any handy soft earth – a practice that is highly frowned upon in 2012; proper grouting is required. Well, I still have several subjects about casing to write about, including exotic materials and the effect of casing size on well capacity.

I got a nice letter from a driller in Pennsylvania asking about fishing for cable tools. This is a subject that I have not covered, but one that surely will be worthy of some future columns, as this is a topic that can be discussed seemingly forever.

In my monthly weather report, the terrible heat we experienced earlier this summer has abated, and we have had some warm, but very nice days with cool nights, which is typical of Michigan in August. Our lawns have turned green and are ready to be mowed, but our field crops basically are gone, with a few exceptions, especially where they were irrigated. Until next time, remember what I said at the beginning of this column, and wear that safety equipment – I want all you readers to be around to read my future efforts. 
ND