DRILLING FOR PETROLEUM.

Taranaki Herald, Volume LX, Issue 143771, 20 April 1912, Page 7

DRILLING FOR PETROLEUM.

DESCRIPTION OF THE HERMANW’EGER DEEP WELL BORING PLANT.

The plaut designed by Messrs. Herman aud Weger has been devised with the object of simplifying and economising the operations of deep well boring iu sinking oil bores, artesian bores or other bores. The" plant possesses a considerable number of advantages over tlio plants now iu use, and these,advantages will be made manifest in a consideration of the construction.

The most important advantage, however, is one by means of which the system of boring may be quickly changed from the “rotary'’ to the “cable” system' aud vice versa, with a minimum of trouble and inconvenience. In the working of the plant the use of an inner tube to cany the rotary is dispensed with, and tile boring casing rotated, a bit of special design being provided for lowering through the casing and looking to ils bottom end when the rotary drilling is to be carried on. This hit may then be withdrawn, and the cable tools lowered through the casing, when “cable” drilling is required, so that only the time tifkeu in lilting the hit through the boro, aud lowering the cable down through it, or vice versa, will be taken up in making a change, as compared'with the present necessity of removing the inner rotary casing or replacing it to make a change. A further advantage of importance is that by, which the whole plant is self-contained upon a single platform, so that it may bo shifted over a rich! without dismantling aud may re-start boring with loss ol time. The dilfcrent parts are, however, so connected that they may be taken for transport and ro-assomhlcd again with a minimum of trouble.

The plaut consists of a derrick constructed with four legs of girder iron, extending upwards from a framework base, also of girder iron. The deri.ci; legs are arranged at the four corners of the base and converge together at their top ends above the venire of the base. The width of the base is approximately 20 feet and the full height of the derrick, 60 feet. The derrick legs arc made up of lengths of sin by Ipm girder iron bolted to them. The base is composed of Bin by 4in girder beams, strengthened by cross beams bolted to them.

In the toil of the derrick the sheave wheels for carrying respectively the drill line and the sand pump line, and the pulley block wheels of the casing lifting line are all so journalled as to suspend their respective appliances in a line with the boro.

The gear for operating the drill is all built upon an extension of the base so that it will act to steady the derrick in the working of the plant. This gear comprises the usual rocking beam for use in cable drilling, such beam being supported upon the top end of a frame marie of Sin by Tin girder iron uprights bolted to the base. This frame forms portion of the gcai supporting framework that is erected on the base and marie up of side cheeks formed of girder iron uprights and cross beams. The rocking beam is driven by a pitman actuated in the usual way by a crank mounted on a main shaft and the pitman is connected to the crank pin by special eccentric gripping means so designed as to allow for it being quickly removed from the crank when such operation is to bn re-commenced. The crunk is made with a variable throw in order to vary the rise and fall of the rocking beam and drill. In this plant special means are included for the lending of the drill from the rocking beam. These means consist of a chain having an eccentric clutch on its end to grip the cable, amt hung over the end of the beam. ’1 be other end oT this chain is fastened to a piston rod mounted in a cylinder arranged along the beam and this piston rod moved along its cylinder under the action of a fluid pumped into the front end of the cylinder so as to draw the chain mi, and is then allowed lo move out again at intervals by relieving the fluid pressure and thus to loner tbo chain and cable bit by bit as required. When the piston has moved out ro its maximum tbo weight oi the cable is taken by its winch the clutch is releasee! therefrom, the piston forced back and then a fresh hold taken on the cable and'tbo weight thrown on to the chain and the rocking beam. The boro casing is fed in through a gripping ring attached to a crown gear wheel tTmt is supported upon antifriction rollers in the centre of the derrick base and the centre of which is cut away to permit of the casing passing down through it. The/grips for locking the casing to the ring consist of small rollers on horizontal axes mounted on opposite side of the casing and adapted to he forced inward by means of right and left hand screws to grip with their peripheries against the casing sufficiently to cause the casing to revolve with the crown wheels. The grip of these rollers is such that the casings as the boring proceeds, will pass down into the boro in the required manner. V-The crown wheel receives its rotation from a bevil gear wheel driven by chain and sprocket gearing from the main shaft. The cable employed for lowering the cable drill through the casing is wound upon a. drum mounted at the rear of the pitman shaft in the gearing framework and driven by friction gear from the main pitman shaft. Below the pitman shaft a winch barrel for the sand pump line is mounted and in front of it the casing line which is mounted. These are each adapted to be driven by. friction gearing with the pitman shaft. The friction gearing governing the several winch drums is adapted to be actuated by suitable eccentric bearings which are rotated by means of crank, arms. Each of these arms is actuated by a separate hand lever arranged adjacent to the bore, so that an attendant may throw any one into gear wjthont leaving the boro. The pitman shaft receives its rotation from a motor, such as an oil or steam engine, erected on the base of the derrick and transmitting its power by cotton driving ropes. The boring hits for , locking to the casing for rotary boring,, are mounted in a head that may be lowered down through the casing and are specially constructed to automatically lock therewith when fully lowered.' The hits are also so constructed as to boro beyond the edge of the casing and thus afford the necessary clearance for the escape of the silt and sludge outside the casing to the top of the bore. In operating the plant, the cable drill is operated in the usual way by lowering it through the casing, the rotation of which is stopped. When a change to tho rotary is required, the pitman is disconnected from the pitman shaft and the cable drill is drawn up and removed from the cable.. The drill head for locking to the easing is then lowered through it and released, and the rotary gear sot in motion. The sand pump may he lowered into the bore casing and raised therefrom whenever required. This sand pump when not in use remains suspended

from its cable, but drawn across to one side of the derrick.

- A sludge pump for pumping sludge down through the casing and then up round the inside of the bore to line it and prevent the soakage of water into the bore, is provided and connected with a special fitting upon the" top section of the casing. This pump is arranged upon the base of the derrick. 1 The plant is provided with a channel spudder apparatus for use in starting the bore through soft ground. This consists of a frame of bell crapk shape arranged on a pivot and having its arms extending radially with the cable winding drum. A pulley sheave is mounted on the outer end of one arm. The other arm is connected by a connecting rod with the pitman shaft crank, so that an up aud down movement is imparted to the arm having the pulley sheave thereon. The drill cable as it passes from its drum is carried round this sheave so that the movement of the arm will impart a tamping movement to the drill as its cable is paid out.