US2268978A - Apparatus for recovering sulphur - Google Patents

Description

Jal 6, 1942- J. P. WHITE APPARATUS FOR RECOVERING SULPHUR 2 Sheets-Sheet l Filed Feb. e, 1941 I rentar Jan. 6, 1942. J. P. WHITE l APPARATUS FOR RECOVERING SULPHUR Filed Feb. 6, 1941 2 Shee'cs--Sheell 2 Im'entor Patented Jan. 6, 1942 UNITI-:Dv STATES PATENT OFFICE mf.f.lf l

Application February 6,1941, Serial No. 377,734

v(ci. 26a- 3) 2 Claims.

My invention relates to improvements in apparatus for the recovery of sulphur from wells by combined application of electrically generated heat and fluid pressure to the contents of the well, whereby the sulphur bearing matter is rendered into fluid form and hydraulically lifted to the surface of the earth, and the primary object of my invention is to provide simple and eiiicient arrangements of this character.

Other important objects and advantages of my invention will be apparent from a reading of the following description taken in connection with the appended drawings, wherein preferred embodiment of the apparatus of the invention is shown.

In the drawings:

Figure 1 is a general fragmentary and vertically contracted sectional elevational view taken through a well and a portion of the casing.

Figure 2 is an enlarged fragmentary longitudinal transverse sectional view taken through the heating means.

Figure 3 is an enlarged horizontal sectional view taken through Figure 2 along the line 3 3.

Figure 4 is an enlarged horizontal sectional view taken through Figure 1 along the line 1 4.

Figure 5 is an enlarged horizontal sectional view taken through Figure 2 along the line 5 5.

Referring in detail to the drawings, and particularly to Figure 1 thereof, the method of the present invention is carried out by drilling a well hole 5 to the top 6 of the sulphur bearing formation 1, the hole 5 being of sufficient diameter to accommodate permanent setting of the steel casing 8 which is preferably 12 inches in diameter. Below and permanently sealed to the lower end of the casing 5 by means of a lead seal 9 is a perforated steel pipe I0, commonly referred to as a liner, which extends into the sulphur bearing formation 1. Within the liner I0 and casing 8 is suspended a pipe II, preferably about 3 inches in diameter, commonly referred to as tubing,to the lower end of which is attached the heating unit which is generally designated I2. The tubing II and the heating unit I2 are arranged to be raised or lowered inside the well casing and liner and suspended at any desired level. Methods in common use for raising and lowering the same, such as used in oil or sulphur well drilling and operating, are satisfactory for the purpose.

Strapped or otherwise attached as indicated by the numeral I3 to the outside of the tubing II is a conduit I4 containing two electrical conducheating unit I2. The conduit protects these cables against fouling or jamming against the sides of the casing or liner, the elements I3 acting as guards and being conveniently spaced along the outside of the tubing.

The heating unit I2 is constructed of two concentrically spaced cylinders I5 and I6 which are hermetically sealed, providing an annular space in which the longitudinally arranged electrical heating coils I'I are supported for generating the heat necessary for the liquefaction of the sulphur in the formation 'I. The inner cylinder I6 is similar in form to the tubing II and a sleeve I8 threadably connects the upper end of the inner cylinder I8 and the lower end of the tube II as shown in Figure 2. The outer cylinder I5 is considerably larger than the inner cylinder, being preferably about 8% inches inside diameter, being swedged at its top and bottom to the inner cylinder I6, or equivalently is threadably connected by tapering elements I9 and 20, respectively. As indicated in Figure 3 of the drawings the various heating coils I1 are supportably located in flutes or grooves 2| in a suitable cylindrical insulator 22 surrounding the inner cylinder I6, the heating coils being connected in series to upper and lower conductor rings 23 and 24, respectively, to which the conductors 25 and 26 in the cable conduit' I4 are respectively connected. The cable I4 passes through a grommet 21 in the upper tapered element I9 shown in Figure 2.

Secured to the lower end of the inne'fcylinder I6 below the taper 20 is a perforated bull plug 30 to act as a strainer to exclude solids and foreign bodies which might otherwise jam the tubing Il or the jet line 3| which extends down through the tubing II and the inner cylinder I6 to a position within the bull plug shown in Figure 2.

The heating unit attached to the tubing II is suspended inside the perforated liner I0 as described above, the perforations in the liner permitting the water in the formation 1 to enter the liner. This sub-surface water being under considerable pressure may consequently be raised to a very much higher temperature than its boiling point at atmospheric pressure, without vaporzing. By contact with the heating unit I2 this sub-surface water is raised to a temperature above the melting point of the sulphur. Therefore, cold water from without will tend to displace the heated water inside the liner, and the circulation thus established will bring the hot tor cables for supplying electric current to the water into contact with,4and thereby liquefy the sulphur in place in the sulphur-bearing formation. The molten sulphur, being heavier than the water, will sink to the bottom of the formation, from which point it is raised to the surface of the earth in a manner t'o be described below.

The jet line 3i extends from the bull plug 30, through the tubing il to the top of the well where it traverses the cap 32 closing the upper end of the tubing il and is connected to an air compressor 33 supported on the surface 34 of the earth. The .compressor 33 is arranged to force hot compressed air, at a temperature above the melting point of the sulphur, down the jet line 3l at a pressure suiilcient to raise the molten sulphur in liquid form to the surface of the earth. This molten sulphur is raised through the tubing il outside of the jet line. A convenient method of obtaining compressed air at the desired temperature is heating of the air by the same Diesel power unit used for generating electric power for the heating unit. The hot compressed air forced down through the jet line forces the molten sulphur from the bottom of the well upwardly on the same principle that oil or water wells are jetted. As the molten sulphur moves upwardly, a suction is set up which draws more ofthe molten substance, liqueed by the hot water circulation, to the jet, at the bottom of the heating unit. The numeral 35 generally designates diagrammatically suitable rigging for operating the device described. In addition there is shown a flexible tube 36 connected by a gooseneck 31 to the cap 32 of the tubing whereby the molten sulphur is led off to the flow line, from whichthe molten sulphur is discharged into pits. The generator of the electric power supply unit is generally designated by the numeral 38, the conduit I4 being shown run over pulleys 39 and 4l) on the rig 35.

An upper packer 4I of conventional arrangement is placed around the portion of the inner cylinder of the heating unit extending above the upper taper I9 to seal the unit in the liner I0 and the lower packer or back pressure valve 42 seals the outer cylinder of the heating unit in the perforated liner I0. Vertically spaced spacers 43 and 44 are mounted on the tubing Il to concentrically space the tubing Il from the sides of the casing 8 when raising and lowering the heating unit.

Although I have shown and described herein a preferred embodiment of the apparatus and of the method of the present invention, it is to be understood that I do not wish to limit the application o1 the invention thereto, beyond the scope of the subjoined claims.

Having described the invention, claimed as new is:

1. In combination, a drill hole extending to the top of a sub-surface sulphur bearing formation containing water, a casing lining said hole, a perforated liner sunk in said formation and sealed to the lower end of said casing, a heating unit situated within said perforated liner in said formation, said heating unit containing heat generating means for contact heating of the Water from said formation entering said perforated liner to a temperature above the melting point of the sulphur, said heating unit comprising an inner cylinder surrounded by said heat generating means and open at its lower end, tubing connected to the upper end of said inner cylinder and extending upwardly in spaced relation to said casing to the surface of the earth, means sealing said unit in said perforated liner, a jetting pipe depending within said tubing and through said inner cylindenand a source of hot air connected to the upper end of said jetting pipe for applying air to the molten sulphur below said heating unit at a temperature higher than the melting point of the sulphur and at sufficient pressure to force the molten sulphur through said inner cylinder and tubing to the surface of the earth.

2. The combination recited by claim 1 wherein said heat generating means comprises electriwhat is cal heating coils, a. jacket enclosing said heating coils, a protected conduit containing conductors to the coils, said conduit being connected to the outer side of said tubing. and extending to the surface of the earth, and current supplying means connected to said conductors.

JOHN PATRICK WHITE.

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