THE IRRIGATION AGE. 



1099 



METHODS OF CONSTRUCTION OF WELLS.* 



A number of deep wells of larger diameter have also 

 been drilled. Some of these were put down by the rail- 

 road company; others were test wells sunk by the State 

 of Utah; and still others were oil prospects sunk by dif- 

 ferent concerns. 



The large dug wells with tunnels or infiltration gal- 

 leries are a special type adapted to special conditions. 

 They are found chiefly at Eureka and Homansville where 

 it is important to obtain as large supplies as possible from 

 the meager seepage out of the decomposed igneous rock 

 and overlying loose waste. 



The wells on the alluvial slopes are, almost without 

 exception, of the dug type, but in some respects drilled 

 wells with iron casings 4 to 6 inches in diameter would 

 be better adapted to the conditions. They could easily 

 be sunk to greater depths than the dug wells and thus they 

 would frequently find water where the dug wells are 

 failures. They would not, like the dug wells, end in the 

 first water-bearing bed encountered, which is generally 

 weak; but could be carried to deeper horizons where large 

 supplies would be found. They would also be better 

 protected from pollution and would therefore furnish 

 cleaner and safer water for drinking and culinary use. 

 If the labor required in digging a well is not considered, 

 a dug well is, of course, much less expensive than a 

 drilled one would be, but if the labor were paid for at a 

 fair wage the dug well would probably not be cheaper. 

 Since the digging is frequently done at times when there 

 is no other work, the actual cost of many of the dug wells 

 is not great. For drilling on the bench lands the light 

 jetting rigs used on the flats would not be adequate, but 

 heavy rigs, such as are used in sinking oil wells, are not 

 necessary. A portable rig with cable and 4-inch or 6-inch 

 percussion drill, built to go to depths of several hundred 

 feet, will be serviceable for this kind of work. Such a 

 machine can be purchased at a moderate price and oper- 

 ated with only moderate expense. If bowlders too large 

 to be pushed aside by the drill are struck it may be pos- 

 sible to shatter them by use of explosives, or, if the 

 drilling has not progressed far, a new hole can be started 

 with no great loss of time. 



Wherever irrigation with ground water is undertaken 

 wells of large diameter should be drilled. These wells 

 should be drilled deep enough into the unconsolidated 

 sediments to tap water-wearing beds that have not been 

 reached in ordinary drilling, and they should admit water 

 at as many levels as practical. Since in the localities 

 where the ground water is near the surface the unconsol- 

 idated sediments are easily penetrated with a drill, and 

 since rock drilling is not involved, the difficulty of making 

 these larger irrigation wells will not be as great as might 

 be supposed. With the proper type of machine and with 

 some experience in operating it, the work can be done 

 rapidly and with few mishaps. The adoption of better 

 methods than now prevail will lead to lower costs and to 

 kirger yields from both flowing and pumped wells, and 

 may make practical the development of ground waters in 

 areas where their development is now impracticable. 



The California or "Stovepipe" Method of Well 

 Construction. 



In California, where irrigation water is very extensive- 

 ly drawn from unconsolidated valley-fill material similar 

 to that in which most of the valuable Utah ground waters 

 occur, a special type of well has been evolved. In the be- 

 lief that the California method of well construction can be 

 used with advantage in the valleys of Utah, the following 

 description is quoted from a paper by Charles S. Slichter: 



Conditions in California. 



The valleys in southern California are filled with 

 deposits of mountain debris, gravels, sand, bowlders, clays, 

 etc., to a depth of several hundred feet, into which a con- 

 siderable part of the run-off of the mountains sink. The 

 development of irrigation upon these valleys soon became 

 so extensive that it was necessary to supplement more 

 and more the perennial flow of the canyon streams by 

 ground water drawn from wells in the gravels. This 

 necessity was greatly accentuated by a series of dry years, 



Abstract of Water Supply Paper No. 277, by Oscar Meinzer, 1911. 



so that the ground waters became a most valuable source 

 of auxiliary supply for irrigation in the important citrus 

 areas in southern California. The type of well that 

 came to the front and developed under these circumstances 

 is locally known as the "stovepipe" well. It seems to 

 suit admirably the conditions prevailing in southern Cal- 

 ifornia. In producing water for irrigation the item of 

 cost is, of course, much more strongly emphasized than 

 in obtaining water for municipal use. The drillers ot 

 wells in California were not only confronted with a mater- 

 ial which is almost everywhere full of bowlders and 

 similar mountain debris, but also by a high cost of labor 

 and of well casings. It was undoubtedly these difficulties 

 that led to the very general adoption in California of the 

 "stovepipe" well. 



Fig. 1. Perforator for slitting stovepipe casing. 



Description of Apparatus and Methods. 



The wells are put down in the gravel and bowlder 

 mountain outwash or other unconsolidated material to 

 any of the depths common in other localities. One 

 string of casing in favorable location has been put down 

 over 1,300 feet. The usual sizes of casings are 7, 10, 12 

 and 14 inches, or ever larger. A common size is 12 

 inches. The well casing consists of, first, a riveted sheet- 

 steel "starter," from 15 to 25 feet long, made of two or 

 three thicknesses of No. 10 sheet steel, with a forged 

 steel shoe at lower end. In ground where large bowlders 

 are encountered these starters are made heavier, the shoe 

 1 inch thick and 12 inches deep, and three-ply instead of 

 two-ply No. 10 sheet-steel body. 



The rest of the well casing, above the starter, con- 

 sists of two thicknesses of No. 12 sheet steel made into 

 diveted lengths, each 2 feet long. One set of sections is 

 made just enough smaller than the other to permit them 

 to telescope together. Each outside section overlaps the 

 inside section 1 foot, so that a smooth surface results 

 both outside and inside of the well when the casing is 

 in place, and so that the break in the joint is always op- 

 posite the middle of a 2-foot length. It is these short 

 overlapping sections which are popularly known as "stove- 

 piping." 



The casing is sunk by large steam machinery of the 

 usual oil-well type, but with certain very important modi- 

 fications. In ordinary material the "sand pump" or 

 "sand bucket" is relied upon to loosen and remove the 

 material from the inside of the casing. The casing itself 

 is forced down, length by length, by hydraulic jacks, 

 buried in the ground, and anchored to two timbers 14 

 by 14 inches and 16 inches long, which are planked over 

 and buried in 9 or 10 feet of soil. These jacks press 

 upon the upper sections of the stovepiping by means of a 

 Suitable head. The driller, who stands at the front of 

 the rig, has complete control of the engine, the hydraulic 

 pump, and the valves by which pistons are moved up or 

 down, and also of the lever that controls the two clutches 

 which cause tools to work up and down or to be hoisted. 



The sand pumps used are usually large and heavy. 

 For 12-inch work they vary in length from 12 to 16 feet, 

 are 10^4 inches in diameter, and weigh, with lower half 

 of jars, from 1,100 to 1,400 pounds. 



After the well has been forced to the required depth, 

 a cutting knife is lowered into the well and vertical slits 

 are cut in the casing where desired. A record of material 

 encountered in digging the well is kept and the perfora- 

 tions are made opposite such water-bearing materials as 

 may be most advantageously drawn upon. A well 500 

 feet deep may have 400 feet of screen if circumstances 

 justify it. 



The perforator (see fig. 1) for slitting stovepipe casing 

 is handled with 3-inch standard pipe with 54-inch standard 

 pipe on the inside. In going down or in coming out of 



