Probably the most common mishap that occurs in drilling a well is that due to a break in the drilling or sand-lines. If this has not happened directly where the line is attached to the tools or bailer, it is recovered by either the common rope-spear (Fig. 169), in which the wickers or spurs for the line point out from a single bar, or the rope-grab (Fig. 170) with the wickers pointing in from two or three bars that spring sufficiently to press against the casing or the sides of the hole. The is also used where pieces of loose rope or wire are to be caught and withdrawn. In some cases the lost tools become lodged at the bottom of the hole so tightly that they cannot be freed by pulling with the rope spear, and it becomes necessary to break the drilling-line at the point where it enters the rope-socket before the tools may be loosened by some other method. This is done, after the rope has become entangled in the rope-spear, by lowering the fishing-tools until just sufficient slack is in the lost line so that when the ' fishing-tools are given the walking-beam motion, the lost line becomes taut at the high point in the swing of the beam. They are then jarred, sometimes for several days before the slight jar applied to the lost line at each stroke of the beam eventually breaks the lost line at the socket.
In cases where the sand-line has broken and the bailer is held too tightly to be pulled out by the rope-spear, the line is jarred as described above, until it is pulled away from the bailer, either alone or bringing with it the bail which not infrequently pulls away from the body of the bailer. If the bail remains intact a latch or boot-jack (Fig. 171) is run. This is a fork-shaped tool, often made from the upper half of an old set of jars, with a small bar or latch at the lower end, swinging on a pin set in one of the forks. When horizontal it rests at the other end in a recess in the second fork. When this is run for a bailer and the lower ends of the forks are passing the bail, one on each side of it, it pushes up the latch and goes by it. The latch then falls back to a horizontal position and holds the bail when the fishing-tools are pulled up. The latch-jack is also often used for the work customarily done by the rope-spear, when the latter is not avail able, by running it in and driving the rope down until the coils have become tangled in the forks and latch so that they hang to it while being withdrawn.
Occasionally the bail may be pulled away in the course of trying to jar the bailer free, leaving the body of the bailer still in the hole. In such a case an ordinary bulldog-spear (Fig. 172) may be run into the bailer and jarred, although this step is seldom suc cessful, as the spear is more liable to split the pipe of which the bailer is made than it is to dislodge it. When conditions permit, a casing-bowl (Fig. 173) large enough to run over the bailer may be tried and if this fails a bell, or mandrel-socket (Fig. 174) may catch the bailer. The bell-socket is essentially a bar or mandrel with an enlarged end, and a hood or bell-shaped piece that is free to move up and down on the mandrel. When used for fishing
a bailer, the ball on the end of the mandrel enters the body of the bailer and the fishing tools are jarred down, forcing the bell down over the top of the bailer so that it takes the shape of the inside of the bell. When the tools are pulled up the mandrel passes up through the opening in the bell until the ball at the end of the mandrel reaches the inside of the bent portion of the bailer (Fig. 175), which is then grasped between the ball and the bell and is pulled out. This socket is also of considerable value when fishing for broken and odd-shaped pieces of tubing or loose pieces of casing.
Should all the methods outlined for recovering the lost bailer fail, then about the only move remaining is to run in the drilling tools and drill it up. Those unacquainted with the details of drilling practice frequently express surprise on learning that when iron or steel tools cannot he recovered, it does not necessarily mean the abandonment of the hole. While such is more apt to be the case with rotary wells than not, the cable tools find com paratively little difficulty in either drilling through metal pieces of quite fair size or in side-track ing these, i.e., pushing them off into the side of the hole, where the ground is soft and permits it. In such work the bit is dressed with a chisel-point or other suit able edge and a suction-bailer of the type shown in Figs. 88, 156 and 157 used to withdraw the pieces of iron as they become small enough to be drawn tip into the bailer. The work is often tedious, especially if the piece to be drilled is an under reamer lug or some other such tool made from extra hard steel, but it is far from impracticable and few cable-tool wells are up by reason of their being plugged by tools, although this does happen occasionally.
When a line has been pulled from the rope-socket, leaving the entire string of drilling tools in the hole, they may be recov ered by one of several types of fishing-tools, the most effective of which is the slip-socket (Fig. 176). This consists of a strong body with a lower opening suffi ciently large to admit the top of the lost tool. If necessary a bowl of suitable size for guiding the lost tool up to the opening is attached to the lower outer edge. Two slips, usually made part of a U-shaped rein, are placed in it as shown in Fig. 177, with a small piece of wood pressing them against the tapering in side-face of the socket. A wood block is also driven between the top of the rein and the top of the two outside openings, in order to prevent the slips from rising when the top of the lost tool passes up between them. When it does so, it pushes away the light piece of wood that holds the slips apart, and when the fishing tools are then lifted the slips bind on the lost tool and hold it while it is being withdrawn. The merit of the slip-socket lies in its simplicity, as well as in the fact that as the pull necessary to dislodge the lost tools becomes greater, the hold of the slips on it increases.