US2712921A - Drilling well head - Google Patents

Description

July 12, 1955 c. L. REDMAN DRILLING WELL HEAD Filed Jan. 25, 1951 FIG. 2

United States Patent() DRILLING W'ELL HEAD Cecil L. Redman, Tulsa, Okla., assgnor to Shell Development Company, Emeryville, Calif., a corporation of Delaware Application January 23, 1951, Serial No. 207,401 2 Claims. (Cl. Z55-24) This invention relates to the art of well drilling and pertains more particularly to an apparatus designed for use with rotary drilling equipment when air, rather than a drilling mud, is used to lift drill cuttings out of a well borehole.

in normal rotary drilling operations, a drilling mud is circulated down through the drill string and up the annular space between the borehole wall and the drill string at a rate sufiicient to carry the drill cuttings away from the drill bit, up the borehole and through a discharge pipe to a settling pit some distance from the well borehole. It has now been found that shallow wells and shot-holes used in geophysical exploration work may be drilled rapidly, efficiently and less expensively by ernploying air instead of mud as a drilling fluid.

in drilling well boreholes by this method, the air is piped under pressure down the drill string where it is discharged through the drill bit and escapes up the borehole, having sucient velocity to carry the drill cuttings with it. As the mixture of air, dust and cuttings issues from the top of the borehole, it creates an objectionable and hazardous condition in that the cuttings are blown all over the drilling machinery and operating crews. in time, the cuttings pile up around the top of the borehole and have to be moved away.

It is the primary object of the present invention to provide an apparatus for diverting drill cuttings away from the mouth of a well borehole during rotary Well-drilling operations when air is being used as the drilling huid.

It is also an object of this invention to provide an apparatus for closing the top of a well borehole While pro viding a uid seal through which a drill string or kelly may extend vertically while rotating with slight random displacements during drilling operations.

Another object of this invention is to provide an apparatus for closing the top of a well borehole, said apparatus being formed to provide a large diameter liuid seal through which a drill string and a bit attached thereto may be inserted or withdrawn when it is necessary to change a bit during drilling operations.

These and otherobjects of this invention will be understood from the following description of a preferred embodiment of the invention as shown in the accompanying drawing, wherein:

Figure l is a view in vertical elevation of the present apparatus when positioned in a well borehole shown in cross section.

Figure 2 is a view in vertical cross the line 2--2 of Figure 1.

Figure 3 is a plan View of the present apparatus illustrating the eccentric position of the discharge conduit.

Figure 4 is a view in vertical cross section diagram rnatically illustrating the present apparatus of Figures l to 3 together with a portable drill rig and a source of compressed air.

Figure 5 is an enlarged view taken in cross section, showing the downwardly-sloping fiuid injection ports 21 in the upper portion 14 of the cylindrical body member.

section 'taken along Figure 5a is an enlarged view taken in vertical section showing the downwardly-sloping uid injection ports 21 in the upper portion 14 of the cylindrical body member.

Referring to Figures 1 and 2 of the drawing, the

present apparatus is shown as comprising a cylindrical housing or body member 11 open at the upper and lower ends 12 and 13 thereof, respectively. Preferably, the upper and lower portions 14 and 15 of the cylindrical housing 11 are of smaller diameter than the central portion 16. In fabricating the cylindrical housing 11, the small diameter upper and lower portions 14 and 15 may be attached to the central portion 16 in any desired manner; thus, the upper portion 14 is shown welded directly to central portion 16 as at 17 (Figure 2), while a waged nipple 18 is shown interposed as between the central portion 16 and the lower portion 15. The inside diameter of the upper and lower portions 14 and 15 of the cylindrical body member 11 is slightly larger than the drill bit to be passed therethrough during drilling operations.

As shown in Figures l and 3, the cylindrical housing 11 is provided with a conduit 19 for discharging air and drill cuttings carried thereby through the side of the housing. Preferably, the discharge conduit 19 is eccentricaily positioned with regard to the housing 11 and also is sloped at an angle of about from 30 to 45 degrees to the horizontal as shown.

Mounted preferably on the outside wall of the upper section 14 of the housing 11 in any suitable manner, as by welding, is an annular pipe member of hollow jet ring 29. A plurality of air injection ports 21, preferably from 4 to 40 in number depending on the diameter of the housing 11, are provided for communication through the wail of housing section 14 between the bore 22 of said section and the annular space 23 Within the jet ring 2@ as shown in Figure 2.

The air injection ports 21 may extend horizontally through the wall of thc housing 11 but are preferably drilled so that they slope downwardly at an angle of from 30 to 60 degrees to the vertical axis of the housing 11. Although the air ports 21 may extend radially through the wall of the housing 11, they are preferably formed at an angle to radial lines, so that an extension of the axis of each injection port 21 does not intercept the axis of the housing 11, but would pass to one side thereof, whereby air streams injected through these ports impart a clockwise or a counter-clockwise motion to the contents of the central section 16 of the housing 11. Since an eccentric discharge conduit 19 is employed in the present device as shown in Figure 3, the axes of the air ports 21 are arranged tangentially at such an angle as to impart a clockwise rotation to the cuttings in the honsing 11 and to discharge them through said conduit 19 more readily.

A second annular hollow jet ring 24 may be secured in a similar manner to the `cylindrical housing 11 at any point below the discharge conduit 19. In the embodiment of Figure 2, the ring 24 is welded to the lower section 15 of the housing 11 and the air injection ports 25 therefrom slope upwardly at about a 30 to 60 degree angle to the Vertical axis through the housing 11. These air ports 25 also may be directed in a manner previously described to give a swirling action to the contents of the housing 11.

A third jet ring 26 may be positioned at the end of the discharge conduit 19 with an extension pipe 27 being welded to said ring 26 to form an extension to the discharge conduit 19. if desired, the axis of the discharge air ports 2S from this jet ring 26 may be parallel to the axis of the discharge conduit 19, as shown in Figure l. If all three jet rings 20, 24 and 26 are included in the apparatus, air may be supplied to all of them from any thereby are forced up the borehole 39 lecting chamber of the housing 52. Since the downpreferable to the use suitable source, such as a portable compressor 46 (Fig. 4) having a suitable manifold device for connecting the jet rings to the compressed air supply conduit 29. The compressor maybe the same that is used for drilling, that is, for supplying air pressure to the drill Abit through the drill string. As illustrated in Figures 1 and 3, the manifold -device mayV comprise a four-way T 3l) attached to the supply conduit 29 with and 33, having control valves 34, 35 and 36 for the individual jet rings 20, 24 and 26, respectively.

. To stabilize the present apparatus during drilling operations, the housing 11 is provided with a base plate support means 37 which extends radially and horizontally from said housing 11. The base plate 37 is secured, as by welding, to the outside of said housing 11 below Vthe discharge conduit 19. As shown in Figure 2, the base plate 37 is preferably equipped vwith a downwardly extending rim or skirt 38.l

In drilling with the present earth diverter well head, a drill rig is set upV and a hole about a foot deep is drilled. As shown in Figure 4, the drill rig may comprise a portable derrick 40 mounted on a truck bed 41 together with individual conduits 31, 32.

` bers. Likewise, while the present suitable Yrotating and hoisting equipment, diagrammativ cally represented by elements 42 and 43 respectively, for actuating a drill string 44 and the bitv45 attached to the lower end thereof. The compressor 46 and its compressed air supply tank 47 may be positioned adjacent the drill rig. One conduit 48 leads from the supply tank 47 to a swivel 49 afxed to the top of the drill string 44. 'e The other conduit 56 is in communication with the top jet ring 51 of another embodiment of thepresent earth diverter well head 52 which employs a single jet ring. After a shallow hole has been drilled, the earth diverter 52 is placed in the hole with the base plate 53' on top of the ground and the rim 54 firmly embedded in the top soil,` as shown in Figure 4. The bit 45 and drill string 44 may then be passed down through the open housing 11 for drilling a borehole 39. Y

Before drilling is started, valve 55 is opened to admit air Afrom conduit 50 into jet ring 51. The air is injected through the air ports 21 so that a downwardly directed cone of air impinges on the outer surface of the drill string 44. As drilling is commensed, using air instead of mud as the drilling fluid, air is pumped down through the drill'string 44 and the air and the cuttings carried into the central colure 2) to assist in lifting the drill cuttings into thecham-` ber 16 and discharging them through conduit 19.

If desired, valve 36 may also be opened to admit air through conduit 33 to jet ring 26 where it is exhausted into the discharge conduit extension 27 to aid in blowing the cuttings further from the drill rig. From the above description, it is evident that the present earth diverter may operate effectively when air is being supplied to the upper jet ring 20 above so as to form a fluid seal at the top of the apparatus. The air being circulated down the drill string and up the borehole 29 is normally su'icient to blow the drill cuttings up the borehole and out the discharge conduits 19 and 27V of the diverter. Auxiliary jet rings'24 and 26 may be used as desired ,or they may be entirely eliminated.

By use of a base plate 53 with a downwardly extending rim 54, the possibility of airY escaping from around the diverter housing at the mouth of the Vborehole is prevented. In certain circumstances, however, such as on very hard top-soil, the base plate 53 may be eliminated or, if desired, replaced with radially extending bar memearth diverter is shown in Figure 4 as having a substantial portion of the cylindrical housing 11 extending below the base plate 53, it is realized that the present apparatus will also operate etectively withV little or none of the housing extending below i the base plate 53.

wardly directed air streams from the air ports of jet ring 51 may be said to form a seal about the drill string, the air used in drilling and the cuttings cannot escape upwardly through the upper open end of the housing 52 but are directed out the side of the housing and through the discharge conduit 56.

The use of an air seal formed by air being discharged from the jet ring 51 is especially important and far of any shield or packing material in that the air seal formed according to the present invention allows free horizontal movement of the drill string passing vertically through the housing 52. Because of the nature of drilling operations, a drill string is normally subject toV considerable wobbling as it is rotated. An air seal Vat jet ring 571 permits horizontal movement of the drill string while at the same time forming an effective seal therearound. Y

With the discharge conduit 19 sloped at an angle as shown in Figure 1, and the tubular member 27 given any desired length, the cuttings are blown a number of feet away from the site of drilling operations, thus removing dust and cuttings from the working areal and preventing Y cuttings from piling up around the mouth of the bore- It is understood that although air was referred to as a normal medium of fluid pressure, other fluids, such as natural gas, may as well be used for the purposes of this invention.

I claim as my invention:

l. An apparatus for use during rotary well-drilling operations, said apparatus comprising a cylindrical housing adapted to be positioned at the mouth of a well borehole coaxially therewith, said housing being open at its upper and lower ends to receive a drill string and drill bit therethrough, elongated Vdischarge conduit means tangentially opening to said housing through the wall thereof, said conduit means'sloping upwardly away from said housing, downwardly-sloping upperV port means through the wall of said housing above said discharge conduit and below the openV top'of said housing, Vupwardly-sloping lower port means'throughitheV wall of said housing below said'discharge conduit, port means through'the wall of said discharge conduit intermediate the ends thereof, the axes of saidport means sloping toward the discharge end of said discharge conduit, each of said port means being arranged in a circumferentialrline and the axis of each of said port means through the wall of said housing being arranged at an angle tothe radii thereof, conduit means in communication between said port means and a supply of pressure gas and horizontal base plate means affixed to the outer wall of said housing below said discharge conduit for supporting the housing over a well borehole.

2. An installation for drilling a well with a pressure gas as drilling uid, said installation comprising a drill string having a drill bit connected to its lower end, means comprising a source of pressure gas connected to its upper end for circulating pressure gas down the drill string, out through the drill bit and up the annular space between the drill string and the borehole walls, a tubular housing surrounding the drill string at the surface, said tubular housing being open at the top and at the bottom to a diameter permitting a drill bit to pass therethrough,

ra pluraliy-of ports through the wall of said tubular memof'said ports and said Y the drill string and the inner wall and an exhaust conduit periph- Wards he of the housing and at an angle to the radii thereof, whereby the pressure gas jets arrest the upward axial motion of cuttings hrcugh said housing and create a swirling gaseous ow tending to eject said cuttings through said exhaust conduit.

Referers-ces Cited in the ie of this patent UNITED STATES PATENTS Baumeister et a1. May 26, 1936 Kelley Dec. 12, 1939 Mcntyre May 21, 1940 Burch et al Aug. 24, 1943

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