US2725213A - Oil well drilling drawworks - Google Patents

Description

Nov. 29, 1955 s. w. WEBSTER 2,725,213

OIL WELL DRILLING DRAWWORKS Filed April 16, 1951 IN VEN TOR. SAMUEL M4 WEBSTER. DECEASED. 5) /DA E. M ELVY WEBSTER, EXECUTE/X.

United States Patent Ofiice 2,725,213 Patented Nov. 29, 1955 1 2,725,213 OIL WELL DRILLING DRAWWORKS Samuel W. Webster deceased late of Dallas Tex b Ida E. McElvy Vlebster, eriecutrix, Dallas, Tex as signer to Emsco Manufacturing Company, Los Angeles, Cal1f., a corporation of California Application April 16, 1951, Serial No. 221,159 5 Claims. (Cl. 254187) This invention relates in general to well drilling equipment and relates in particular to a drawworks for deep Well drilling. y

In' the drilling of Wells to great depth, for example from 16,000 feet to 20,000 feet, a number of restrictin factors have been encountered. One of these was strength of drill pipe. This restriction has been satisfactorily overcome by improvement in the strength and durability of drill pipe intended for deep well drilling. Another restric'ting factor is extreme wire line wear resulting princ ipally' from the destructive action of one layer of wire l ne superimposed upon another layer on the spooling drum of the drawworks. invention to provide a rotary drawworks having a number of simplifications and improvements over existing drawworks and which eliminates the extreme" wire line wear mentioned in the foregoing.

It is an object of the invention to provide a drawworks havmga drum or spool, of a size to accommodate in a single layer the spooling portion of a cable or wire line comprising a part of the hoisting apparatus of the derrick. In derriclts employed for deep drilling of Wells it is almost universally the practice to use hoisting equipment comprising a block and tackle arrangement consisting-of a crownblcck and a' travelling block interconnected bya plurality of loops of a continuous cable. One end of this wire line is connected to an anchor in one corner of It is an object of the present of brake bands or brake rims does not require removal of spool since the brake mechanism is not mounted on the ends of the spool. The gear through which the spool is driven is connecteddirectly thereto and the spool may be-keyed' onto a shaft which rotates in bearings, which" bearings maybe replaced as becomes necessary without removal of the spool from its position in* the drawworks structure.

A further object of the inventionis to provide a draW-" works for deep well drilling which do not require acable guide for controlling the spooling of the line on the spool. The spool is of such diameter and such length that the spooling portion of the line is wound on the spool so as to lie in a single layer resting in a continuous helical chanhe] in the cylindric wall of the spool. This arrangementlends itself to the useofa control which will automatically stop the rotation of the spool at either limit ofthe spooling or unspooling of the line thereon. With this arrangement it is impossible for the driller to inadvertently cause the travelling block tonbump the crown block.

Further objects and advantages of the invention will be brought out in the following part of the specification wherein in detail is describeda preferred embodiment of the invention for purpose of disclosure without limiting. the scope of the invention or the range of equivalence embraced'in the accompanying claims;

Referringv to the drawing which is for illustrative pur poses only: I

Fig. 1 isa schematic elevational view showing a heavy dutydrawworks, according to the invention in a derrick; and

'Fig. 2 is a:- plan view, to enlarged scale, showing the mechanical elements of the drawworks, without the lions the derrick and the other end ofthe wire line is connected to a spool so as to be wound there m The spoolingportion of the line, therefore, is that por-' tion of the line which must be wound onto the spool in order to raise the travelling block a predetermined distance in the derrick. In an 186 foot derrick having ten lines, or five complete cable loops connecting the ground block and the travelling block, theisp'o'oling portion of the line may be about 1,800 feet. It isan object of the invention to provide a drawworks'wherein there is a spool capable of carrying the spooling portion of the linein a single layer on the spool so that the're' never exists a'condition wherein one turn of the" line rides on anoth'er t'urn of the line, this spool being driven through a relatively high speed shaft which is" directly connected to the spool through a s'tepdown transmission, such as a relatively small pinion" driving a larger gear which is connected to the spool, there being a brake to-control the speed of the s,iian and thereby control the s'pee'd' of the spool.

Irf thisariang'e'rtient a brake of relatively small size as compared to the diameter of the'spobl, may be employed,

and this'brak'e' may be" placed with rel'ation to an end r 0f the high speed shaft so as to be expedientl'y e uipped with a brali'e'rirh cooling system.

It the anobje'ct of the'invention to provide anew work's having a drum of the character" described in the foregetirg; in which draww'orks a power ab'sb'fheflgs'ii'ch as a indignant brake, is connected to the spo'ounren g'h arra'nsniission air'ange'cl so that the rotating par let the power absorber rotate at a' speed much higher than the speed of the spool. Not only is it possible to use a hydromatic Brake or other power absorber ofsmaller size, but the sensitivity ofth'e control exeited by the power absorber isincreased.

1" It is an object of the invention to provide a' difawworks? of simplified construction wherein removal of thisfibbl is-never necessary. For example, replacement ing employed to shield the mechanical element's. H

In Fig. l a drawworks 10 is shown mounted at one side of a derrick 11 having a crown block 12 at its" upper end. This crown block 12 comprises part of the hoisting equipment for the derrick, which hoisting equipment includes a travelling block-13 and a steel cable or wire line 14. The travelling block 13 is shown with a liftinglmeans consisting of a hook 15 engaging a-ro'tary swivel 16. from which'a Kelly bar 17; is connected.

As shown in Figs: 1 and 2,. the drawworks 10 has a spool-18 on which a portion 19 of the line 14 is wound. As this portion 19 of the line 14 is woundupon the spool 18;. the line 14-- will be pulled outof the derrick 1 1, lifting the-travelling block 13 within the derrick. Likef wise, whenthe portion 19 of the line 14 is'uns'pooled from the spool. 18 it will be fed over the crown block 12 into the derrick 1 1 ,tl1e'reby lowering the travelling block 13'Wllhl1'1 ih8 derrick 11. It will belunderstood' that in order to lift the travelling block 13 from its lowest predetermined, point in the derrick to its highest position in the derrick will require winding of a. related length of'line onto the spool 1-8 Hereinthis length of line is referred toyas the spooling portion of the line sinceit is that portion of the line which winds onto and off of the spool in causing. movement of the travellingblocklS fromone extreme position in the derrick-11 to the other extreme position therein. v

As shown in Fig. 2-, the spool 18 has a cylindric wall 20 with a helical groove 21 having a length gr'ea'te'i" than the length of the spooling portion of the line 14, orhavin'g' alength at least aslong as the length of the spooling portion of the line 14 so that when the entire length of the spooling portion of the-line 14 is wound on the spool 18, it'will'be disposed in asingle layer on the wall 20 of the sm lls, arid no mm of the line will lie upon or ress radiallyjnwardly upon another turn of the line on' the spool 18.

stub" shaft elements 22 projecting frorn'theeiids thereof into bearings 23. A so-called highspeed shaft 24 is mounted adjacent the drum 18 and a drive connection is provided between this shaft 24 and the drum 18, such drive connection being shown as a pinion 25 fixed on the shaft 24 and being arranged to drive the larger gear 26 which is fixed on an end of the spool 18. The shaft 24 is mounted in bearings 27 and is arranged to be driven at different selected speeds from a line shaft 28 which may be driven from a power source through chain 29 and sprocket 30.

Sprockets 31, fixed on the end 32 of the shaft 28 through chains 35 drive sprockets 33 which are turnable on the near end of the shaft 24. An air operated clutch 34 is arranged to connect the sprockets 33 to the shaft 24, thereby driving the shaft 24 at one speed. In order that the shaft 24 may be driven at another speed from the shaft 28, a dual sprocket 36 is turnably mounted on the far end of the shaft 28 and an air operated clutch 37 is provided for connecting the dual sprocket 36 directly to the shaft 28 so that it will be rotated thereby.

Chains 38 are arran ed to drive a dual sprocket 39 which is fixedon the shaft 24 adjacent the pinion 25. Brake drums 40 are fixed on the far end of the shaft 24 and brake bands or shoes 41 are disposed around these drums 40 in the customary manner so as to provide means for producing a frictional braking action or actual stopping of the shaft 24 at any time desired. A clutch element 42 is mounted at the far end of the shaft 24. This clutch element rotates with the shaft 24 and is adapted to engage the clutch element 43 of a power absorbing device 44, such as a hydromatic brake, operative during the time a string of drill pipe is being lowered and during which time the cable portion 19 is being unwound from the drum 18. The power absorber 44 exerts a reacting force to reduce the speed of the shaft 24 during the unwinding of cable from the drum 18, thereby minimizing wear upon the frictional parts of the brake elements 40 and 41.

A further advantage of this drawworks is the arrangement which makes possible the placing of the catheads 45 forwardlv in the drawwork structure as shown in Fig. l. A further feature of the drawworks is in the arran ement of the large diameter drum so that the line 19. Fig. l, is taken off from the backside of the spool 18 and extends up the rear base of the derrick 11 instead of within the derrick. This leaves a space at the front of the drawworks for the cathead shaft 46, Fig. 2, above the rightward portion of the spool 18. Chain and s rocket means 47 are rovided for driving the catshaft 46 from the line shaft 28, a clutch 48 being provided for connecting the chain and sprocket means 47 to the shaft 28. For driving a rotarv machine 49, mounted on the floor of the derrick, drive shaft 50 is provided which extends to a gear box 51 mounted within the drawwork structure. Power for rotation of the shaft 50 is carried from the line shaft 28 to the gear box 51 through a chain 52 which runs over a sprocket 53 mounted on the shaft 28 and the sprocket 54 mounted on the power input shaft 55 of the gear box 51.

What is claimed is:

1. In a drawworks for use in a derrick having a crown block, a travelling block and a line having a soooling portion: supporting means: a spool rotatably carried by said supporting means, said s ool having a snoolin surface of a size to accommodate said soooling portion of said line in a single laver; a line shaft: a driving shaft for said spool; speed chan e means through which said driving shaft is driven at different speeds from said line shaft; a speed reducing transmission connection between said driving shaft and said spool whereby said spool is driven at a speed slower than the speed of said driving shaft; a friction brake for controlling the rotation of said spool connected to said driving shaft; a power absorber for controlling the rotation of said spool; and means for connecting said power absorber to said driving shaft so that the power absorber will be operated at a speed higher than the speed of said spool.

2. In a drawworks for use in a derrick having a crown block, a travelling block and a line having a spooling portion: supporting means; a spool rotatably carried by said supporting means, said spool having a spooling surface of a size to accommodate said spooling portion of said line in a single layer; a driving shaft supported in operative relation to said spool; a speed reducing transmission connection between said driving shaft and said spool whereby said spool is driven at a speed slower than the speed of said driving shaft; a friction brake for controlling the rotation of said spool connected by said driving shaft; a power absorber for controlling the rotation of said spool; and means for connecting said power absorber to said driving shaft so that the power absorber will be operated at a speed higher than the speed of said spool.

3. In a drawworks for use in a derrick having a crown block, a travelling block and a line having a spooling portion: supporting means; a spool rotatably carried by said supporting means, said spool having a spooling surface of a size to accommodate said spooling portion of said line in a single layer; a line shaft; :1 driving shaft for said spool; speed change means through which said driving shaft is driven at different speeds from said line shaft; a speed reducing gear train connecting said driving shaft and said spool whereby said spool is driven at a speed slower than the speed of said driving shaft; a friction brake for controlling the rotation of said spool connected to said driving shaft; a power absorber for controlling the rotation of said spool; and means for connecting said power absorber to said driving shaft so that the power absorber will be operated at a speed higher than the speed of said spool.

4. In a drawworks for use in a derrick having a crown block, a travelling block and a line having a spooling portion: supporting means; a spool rotatably carried by said supporting means, said spool having a spooling surface of a size to accommodate said spooling portion of said line in a single layer; a driving shaft supported in operative relationto said spool; a speed reducing gear train connecting said driving shaft and said spool whereby said spool is driven at a speed slower than the speed of said driving shaft; a friction brake for controlling the rotation of said spool connected to said driving shaft; a power absorber for controlling the rotation of said spool; and means for connecting said power absorber to said shaft so that the power absorber will be operated at a speed higher than the speed of said spool.

5. In a vdrawworks for use in a derrick having a crown block, a travelling block and a line having a spooling portion: supporting means; a spool rotatably carried by said supporting means, said spool having a spooling surface of a size to accommodate said spooling portion of said line in a single layer; a line shaft; a driving shaft for said spool; speed change means through which said driving shaft is driven at different speeds from said line shaft; a speed reducing transmission connection between said driving shaft and said spool whereby said spool is driven at a speed slower than the speed of said driving shaft; a friction brake for positively controlling the rotation of said spool; transmission means connecting said friction brake to said spool to operate said brake at a higher speed than said spool; a power absorber; and means for connecting said power absorber to said driving shaft so that the power absorber will be operated at a speed higher than the speed of said spool.

References Cited in the file of this patent UNITED STATES PATENTS

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