being employed in the work of forcing down the drive-pipe. The further operation of drilling is thus described by Mr. Carll: "When a sufficient depth has been reached by spudding, to admit of the introduction of a full string of tools,' the spudding machinery is abandoned. Now the coil of drilling cable is rolled into the derrick and set upon end. The free end in the centre of the coil is tied by a connecting cord to the rope just detached from the ring socket, and by it drawn up over the crown pulley and down to the bull-wheel shaft, where it is fastened; the bull rope is put in place, the engine started, and the men carefully watch and guide the cable as it is wound, coil after coil, smoothly and solidly upon the shaft. When this is done, the end of the cable depending from the crown pulley is secured to the rope socket, and the full set of tools is attached and swung up in the derrick. After carefully screwing up all the joints (the bull rope having been unshipped), the tools are lowered into the hole by means of the bull-wheel brake. The band-wheel crank is then turned to the upper centre; the pitman is raised and slipped upon the wrist pin, where it is secured by the key and wedges; the temper screw is hung upon the walking-beam hook, the slack in the cable is taken up by the bull wheels until the jars are known to be in proper position; the clamps are brought around the cable (after a wrapper has been put on it at the point of contact) and securely fastened by the set screw; the cable is slacked off from the bull wheels, and the tools are now held suspended in the well from the walking beam, instead of from the top of the derrick as before. Some 15 or 20 feet of slack cable should be pulled down and thrown upon the floor, to give free movement to the drill. When the drill is rotated in one direction for some time, the slack coils around the cable at the well mouth; if it becomes troublesome, the motion is reversed, and it uncoils. Only by this constant rotation of the drill can a round hole be ensured. "Having now made all the necessary connections, it only remains to give the engine steam, and the drill will rise and fall with each revolution of the band-wheel, and commence its aggressive work upon the rock below. From this point downward, the daily routine of the work is very monotonous, unless some accident occurs to diversify it. Day and night the machinery is kept in motion. One driller, and one engineer and tool dresser work from noon until midnight (the 'afternoon tour'), and another pair from midnight until noon (the morning tour'). Up and down goes the walking beam, while the driller, with a short lever inserted in the rings of the temper screw, walks round and round, first this way, then that, to rotate the drill. He watches the jar and, at proper intervals, lets down the temper screw as the drill penetrates the rock. When the whole length of the screw has been run out,' or the slow progress of the drill gives warning that it is working in hard rock and needs sharpening, he arranges the slack cable upon the floor, so that it will go up freely without kinks, and informs the engineer that he is ready to draw out.' After attending to the needful preliminaries, the driller throws the bull rope upon its pulley and quickly steps to the bull-wheel brake, while the engineer commands the throttle of the engine. The walking beam and the bull wheel are now both in motion, but at the proper moment, one man stops the engine and the other holds the bull wheels with the brake just when all the slack cable has been taken up, and the weight of the tools is thus transferred from the temper screw to the crown pulley. This is a performance requiring experience and good judgment, for should any blunder be made, a break-down must certainly result. "To loosen the clamps on the cable, and unlock the pitman from the wrist pin and lower it to the main sill, is but the work of a moment. Dropping the pitman raises the end of the walking beam with the temper screw attached to it, and throws them back from their former perpendicular over the hole, so as to allow the cable and tools to run up freely without interference with them. Steam is now turned on again and the tools come up. "When the box of the auger stem emerges from the hole, the engine is stopped. A wrench is slipped on the square shoulder of the bit, and the handle dropped behind a strong pin fixed for that purpose in the floor; another wrench is put on the shoulder of the auger stem; a stout lever is inserted in one of a series of holes bored in the derrick floor in a circle having a radius a little less than the length of the wrench handle, and it is brought up firmly against the upper wrench handle, thus making a compound lever of the wrench, and greatly increasing its power. Both men give a hearty pull on the lever, which 'breaks the joint,' or, in other words, loosens the screw joint connecting the bit with the auger stem, so that the bit can be unscrewed and taken off by hand after it has been brought up above the derrick floor. The wrenches are then thrown off, steam is let on again, and the bit rises from the hole. Now the driller throws off the bull rope by operating a lever with one hand, while with the other he catches the bull wheel with the brake, holding the tools suspended a few inches above the floor. At the same instant, the engineer shuts off the steam, or else, suddenly relieved of its heavy work by unshipping the bull rope, the engine would run away' with lightning speed. It now remains only to hook the suspended tools over to one side of the derrick, and the hole is free for the sand pump. "While the driller is sand pumping, the engineer unscrews the worn bit and replaces it by one newly dressed, so that there may be no delay in running the tools into the well again when sand pumping is finished. "The line' to which the sand pump is attached, as already described, passes over a pulley near the top of the derrick, and thence down to the sand-pump reel, which is operated from the derrick by means of the hand lever, v (Plate IX.), and connecting levers, u and t. While sand pumping, the pitman remains disconnected, the bull rope lies slack on its pulleys, and the band-wheel is kept constantly in motion. A slight pressure on the lever, v, brings the friction pulley, w, in contact with the band-wheel, and the pulley immediately revolves, the slack sand-pump line is quickly wound up, and the sand pump, which is usually left standing at one side of the derrick, swings out to the centre and commences to ascend. Just now the lever is thrown back, and the connection between the friction pulley and the bandwheel being thus broken, the sand pump commences to descend into the well by its own gravity. If it be likely to attain too great speed in its descent, a movement of the lever, to bring the pulley either forward against the band-wheel or backward against the brake post, will quickly check it, and thus the speed may be regulated at will. "As soon as the pump strikes bottom, additional steam is given to the engine, and the lever is brought forward and held firmly, while the sand pump rises rapidly from the well. The sand pump is usually run down several times after each removal of the tools, to keep the bottom of the hole free from sediment, so that the bit may have a direct action upon the rock. "After the hole has been set to one side, the drilling tools a d sufficiently cleansed, the sand pump is are unhooked and, swinging to their place over the well mouth, are let down a short distance by the brake, the wrenches are put on, and the lever is applied to set up' the joint connecting the replaced bit to the auger stem. Then removing the wrenches, the tools are allowed to run down to the bottom, under control of the bull - wheel brake. Connections are now made as before, the driller commences his circular march, the engineer examines the steam and water gauges and the fire, and then proceeds to sharpen the tool required for the next 'run,' and thus the work goes on from day to day until the well is completed." The manner in which the wrenches are used for tightening and loosening the screw joints of the drilling tools, as already described, is shown in Fig. 36. The wrench bar, c, which drops into one of a series of holes in an iron ring, b, fastened to the derrick floor, is used as a lever to move the wrenches, a. A wooden lever, d, is also employed when additional force is needed, and to this is sometimes attached a block and fall. Fig. 36. Instead of "tempering" the "jar" as it becomes feeble, by slightly lowering the temper screw, which practically increases the length of the cable, some experienced drillers rely upon the spring of the cable alone when a sufficient depth has been reached, the jars being only utilised when the drill jams. This operation is known as "bouncing' the drill. The bits are "dressed" by heating the cutting end in the forge which is attached to the derrick and hammering it out to a blunt edge, the width of which depends on the required diameter of the well. In drilling through a seam of hard rock, the drill frequently becomes much reduced in width, while the cutting edge is not necessarily blunted to a great extent. When the well is of considerable depth, the tools on being lowered, descend with a velocity which causes the derrick to vibrate to its foundation, but the operator keeps his hand on the brake, and carefully watching for a piece of string tied upon the cable at a certain point, is able to reduce the speed before the bottom is reached. The derrick is lighted by a primitive lamp burning crude petroleum, and resembling an iron kettle with a spout on each side. It is frequently warmed by a stove consisting simply of a sheet-iron cylinder, in which natural gas is burned. When gas issues in sufficient quantity from the well to furnish fuel for the boiler, it is conducted through a 2-inch pipe connected with the casing of the well, to the firebox, a 1-inch steam pipe fitted with an -inch jet being inserted into the gas pipe close to the firebox. This arrangement acts as an exhauster, to draw the gas from the well and prevent the flame from travelling back. The operation of drilling is frequently interrupted by the occurrence of an accident which necessitates the use of fishing tools. If the fishing operation is unsuccessful, the well has to be abandoned, often after months of labour, unless it is found possible to drill past the tools which have been lost. Well Records.-The following record, relating to a well drilled in the Bradford field, shows the time occupied in drilling a well to a depth of 1,700 feet, together with the accidents which were met with : DENNIS WELL, No. 1. situated on the Rogers Farm, three-quarters of a mile south, 25° west, of Bradford, M'Kean County, Pa. |