US2991852A - Drilling rig and method of extending an upper section of the mast thereof - Google Patents

Drilling rig and method of extending an upper section of the mast thereof Download PDF

Info

Publication number
US2991852A
US2991852A US625119A US62511956A US2991852A US 2991852 A US2991852 A US 2991852A US 625119 A US625119 A US 625119A US 62511956 A US62511956 A US 62511956A US 2991852 A US2991852 A US 2991852A
Authority
US
United States
Prior art keywords
mast
sections
hinge
section
upper section
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US625119A
Inventor
Harold D Lee
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
C N HOUSH
Original Assignee
C N HOUSH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by C N HOUSH filed Critical C N HOUSH
Priority to US625119A priority Critical patent/US2991852A/en
Application granted granted Critical
Publication of US2991852A publication Critical patent/US2991852A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B15/00Supports for the drilling machine, e.g. derricks or masts

Definitions

  • This invention relates to drilling rigs and more particularly to drilling rigs designed to be easily and quickly transported between locations and erected. In one important aspect it relates to a means and method for extending sections of a telescoping mast. In another important aspect it relates to a telescoping mast in which the legs converge. in an upwardly direction. In a still third important aspect it relates to a collapsible base.
  • One form of popular portable mast employs, telescoping sections which extend to a suitable height for well operations but collapse to a length which is within road limits,
  • the previously successful masts of this type have employed parallel mast legsv notwithstanding the well known fact that a mast employing upwardly converging mast legs is stronger and, therefore, for a given rating can be less expensively manufactured.
  • the converging leg mast is extensively used in non-telescoping mast but has not been successfully applied to the telescoping mast, probably due to the diiliculty of obtaining rigidity in the mast when extended.
  • 'I lre substructure for supporting the mast is usually built up from a number of individual pieces and requires considerable time to assemble and disassemble. Across its narrowest dimension the substructure may be much larger than normal road limits permit and it cannot be transported across public roads without dismantling.
  • An object of this invention is to provide a method of raising and lowering a section of a telescoping mast in which there is provided as a part of the raising and lowering rigging a safety line to guard against dropping of the mast.
  • Another object is to provide a telescoping mast and method of raising and lowering a sect-ion of the mast in which there is no side pull on the mast.
  • Another object is to provide an apparatus and method for raising and lowering a section of a telescoping mast Patented July 11, 1961 in which the drill line is used instead of a telescoping line to avoid ball-ups of the line on the draw works:
  • Another object is to provide a telescoping mast in which the two legs of the mast converge upwardlyfand in which the legs of the mast are free, to tilt, relative to each other as the mast is raised and lowered in which the mast is automatically rigid when extended.
  • Another object is to provide a telescoping the preceding object in which inter-engaging stops provided which abut when the mast is. fully. extended to provide the desired stability for the mast. 4
  • Another object is to provide in combination a mast and substructure in which the legs of the mast converge toward each other when extended and when retracted permit the legs at their base to move inwardly tow d each other, the substructure having an intermediate tion which is collapsible to permit the two outer seen 11s to move toward each other with the legs for cj
  • Another object is to provide a base for a drilling rig which is collapsible for roading and which may belexjtended with eifort to provide a substructure for a drilling rig which is larger than can be transported over public roads.
  • Another object is to provide a base as. in the preced; ing object in which the base is collapsed without mantling the base.
  • Another object is to provide a substructure for a drill.- ing rig in which two structural sections each-of w h is designed to support a leg of a drilling mast are seicured together by a collapsible linkage.”
  • FIGS. through 4 are viewsin front elevation of a drilling rig constructed in. accordance with this inve 't' n with a portion of the lower section of the mast of 1 broken away for illustration of detail, and'showing progressively the steps of raising the upper section of the mast;
  • FIG. 5 is a view on an enlarged scale of the. hinge con neotion; between the substructure and the. legs of the t
  • FIG. 6i is a fragmentary view on. an enlarged scale oi. one. corner of the crown of the mast illustrating then anner of connecting the crown to the legs of thernast of providing a means for stabili 'ng. the mast once I been raised;
  • FIG. 7 is a view along the line 7,7 of FIG. 6 I
  • FIG. 8 is a plan view of the substructure for the drill i s
  • FIG. 9 is a view in side elevation of the substructure shown in FIG. 8;
  • FIG. 10 is a view along the. lines lik -:10, of 9,;
  • FIG. 11 is a plan view of the substructure wh col lapsed and showing, in part, the position of th structure when extended in dashed outline;
  • FIG. 12 is a side elevational view oi the drilling rig of this invention showing the trailer mounted draw in position;
  • FIG. 13 is a view on an enlarged scale of means tor interlocking the two structural sections of thesubst zucture together when collapsed.
  • Therig illustrated in the drawings includes .a substructure indicated generally at 10 and a telescoping mast indicated generally at 1 1. Power for the rigv is provided by a trailer mounted draw works indicated generally at 12
  • the mast 1 1 is a two-legged structural mast. The legs are made up of identical lower structural section s 13a and upper identical telescoping sections 14 and;
  • a novel apparatus and method for raising and lowering the upper sections of the mast is provided by utilizing the traveling block or similar weight for raising and lowering the mast.
  • a rigging between the telescoping sections of the mast with at least a two to one mechanical advantage is provided.
  • two riggings, one for each leg of the mast are utilized to avoid unequal stresses on the mast and to prevent the mast from falling in the event one rigging breaks or becomes inoperative in any way.
  • These riggings are identical and, therefore, only one will be described.
  • the rigging for raising and lowering the mast includes a pulley 15 on the inside top of lower section 13 of the mast.
  • a line 16 passes over this pulley and down to pulley means on the bottom of the upper section 14 of the same leg of the mast.
  • This pulley means should preferably transfer line 16 from the inside of the mast to the one of the other three sides of the mast to provide suflicient space for the rigging.
  • This pulley means may be provided by two small single pulleys 17 and 18 positioned at the inner and outer edge of the mast section 14 as illustrated.
  • the line 16 passes over pulleys 17 and 18 and thence upwardly to an anchor point on the lower section of the mast. As the dead line.
  • portion 16a of line 16 will be moved as hereinafter more fully explained, itis preferred to pass the line 16 over a pulley 19 at the upper end of section 13 of the mast and thence to an anchor means 20 just below pulley 19. With the dead line portion of line 16 secured to anchoring means 20, thefast line portion 16b of line 16 will be very short as indicated in FIG. 1. With the mast erected but collapsed as shown in FIG. 1, the drilling line 21 from drum 22 of draw works 12 will be fastened to the traveling block 23 in the usual manner. (The traveling block 23 and crown block 24 are provided with a number of sheaves and the drilling line is normally looped over these sheaves to provide a sub stantial mechanical advantage.
  • the drilling line is shown to pass over the crown block only one time and to be directly secured to the traveling block.
  • the traveling block 23 will be raised to a point adjacent the crown of the mast and the fast line portion 16b of line 16 secured to the traveling block.
  • the traveling block is usually a very heavy member and will often weigh more than one half the weight of the upper section of the mast. When this is true the weight of the block will be sufiicient to overcome the weight of the upper section of the mast and by lowering the traveling block with the drilling line 21 the upper section of the mast will be raised to the FIG. 2 position.
  • the rigging may be designed to increase the mechanical advantage as will be understood by those skilled in the art.
  • the upper section of the mast may be temporarily suspended in any desired conventional manner as diagrammatically illustrated by supports 25 releasably secured to lower mast section 13 and supporting the upper mast section.
  • the drilling line is taken in to raise the'traveling block to a position just below the pulley 15 at the top of the lower mast section.
  • The, dead line portion 16a of rigging line 16 is then removed from anchor 20 and the slack in the rigging taken up.
  • the dead line is made fast preferably by securing it to a second anchor means spaced from the first anchor means 20 such as anchor means 26.
  • This arrangement of the rigging is shown in FIG. 3.
  • the drilling line is payed out to lower traveling block 23 again. This raises 4 the upper section of the mast to its fully extended position as shown in FIG. 4.
  • the mast may then be latched in extended position in any convenient conventional manner and rigging line 16 removed from the traveling block and secured in an out-of-the-way position.
  • the drilling rig is now ready for use.
  • the lifting mechanism gives an automatic safety device and no additional auxiliary safety means are required.
  • a two-legged mast in which the legs converge upwardly toward the crown block is much stronger than a mast in which the legs are parallel to each other. Therefore, the converging leg mast is used whenever possible as it permits a lighter, cheaper mast.
  • For a telescoping mast to have converging legs necessitates that the legs be permitted to tilt toward and away from each other during raising and lowering of the mast.
  • the mast must be stable when in fully erected position.
  • the hinge means includes an upstanding base 28 carried by substructure 10.
  • the base 28 carries spaced hinge parts 29 and 30.
  • An in-line bore 31 extends through the hinge parts 29 and 30.
  • the lower ends of lower sections 13 and 13a are each provided with a hinge part 32 which fits loosely between the hinge parts 29 and 30 of the base.
  • the mast hinge part 32 has a bore 33 of smaller diameter than bore 31 through hinge parts 29 and 30.
  • a hinge pin provided by bolt 34 extends through bores 31 and 33.
  • the relationship of the hinge pin and two bores permits the mast legs to tilt toward and away from each other.
  • the bolt 34 fits snugly within bore 33 of the mast hinge part and loosely within bore 31 of the base hinge parts.
  • the hinge pins rest upon the bore in hinge part 30 but is not supported by hinge part 29 as shown in dashed outline at 35. With the mast fully extended the weight of the mast and the load imposed thereon will be squarely supported by both base hinge parts 29 and 30 in the same manner in which a hinge having a tight hinge pin would support a mast and this support.
  • the hinge 27 shown in FIG. 5 is provided at the front and rear of each mast leg and functions in each location as explained above.
  • connection between the crown and each mast leg is preferably provided by hinge means in association with stop means which provide a substantial rigid connection between the crown and mast legs when the mast is fully extended.
  • the connection is best shown in FIGS. 6 and 7.
  • the crown of the mast indicated generally at 36 is provided with depending spaced hinge parts 37 and 38, preferably on the front and rear side of each mast leg. While four hinges are used, they are identical and only one will be described. These hinge parts depend from the bottom of the crown beam 39. At a point spaced some distance from the crown beam, in-line bores 41 are provided in the hinge parts 37 and 38.
  • a hinge pin 42 is mounted in the bore 41 and passes through a hinge part 43 carried at the upper'end ofea-chnrast leg; The; hinge pin 42 extends fore and aft of the mast and the mast legs to rotate about the hinge pin and tilt toward and away from each other.
  • the hinge 'part 43 carried by the mast leg has a stopor abutment section 43a which extends beyond the'hinge 'pin' 42 and close to the bottom'face 39a of the crownfbeam 39.
  • plate 43a has a flat terminal portion 4312" which as gig-91,852
  • the mast tilts will engage the bottom surface 39a of the crown beam 39.
  • This plate should be designed to be in firm abutment at point 44 (FIG. 6) when the mast is fully extended.
  • these abutments will stabilize the mast and prevent further tilting or rocking of the mast.
  • eachstructural section carries supports 28 to which the lower sections of the mast are hinged as heretofore explained.
  • the structural sections are secured together by a-collapsible means extending therebetween whereby the substructure 'may be extended to the FIG. '8 relationship and collapsed to a size suitable for roading as for instance .as shown in FIG. 11.
  • Each structural section is built around skids 47 and 47a and may include any arrangement of beams desired such as. the vertical I-beams 48, 48a, 49, 49a, 50,. 50a, 51, and 51a, and the deck beams 52' and 53.
  • the sections may ,be cross braced by structural members such as. I-beams 60.
  • the collapsible linkage for securing; the substructure sections together may be provided in any convenient man,- ner such as by the I-beam'structural members54, 55, 56,
  • the linkage member 57 is bes t seen in FIG.
  • the linkage members have hingedconnections at each end with the respective structural sections 45 and 46. These hinged connections are identical and are indicated generally at 59.
  • the hinge pins 61 preferably are removable at least at a common end of the linkage members to provide an alternate means of collapsing the substructure. When the substructure is-delivered to a site, it is collapsed in the manner indicated in FIG. 11.
  • the linkage means holds the two structural sections. parallel to each other and permits them to move together and apart in the manner of parallel rulers. It will be noted-from FIG. 9 that the linkage members are staggered vertically so that they may be longer than the distance between adjacent hinges 5'9. 1
  • 'I'hesemembers include a box 62 projecting-outwardly from one structural section.
  • a bore-63 is provided in the outer extremity of the box for receiving a pin 64 i'car'ried by the other structural section.
  • the pin '64 is surrounded for a portion of its length by-a box 65.
  • interlocking means are spaced along the substructure at points opposite each other and are spaced apart along each structural section a distance equal the length of the interconnecting members 54, 55, etc. Thus, some of these interlocking means .will engage when the substructure-is collapsed in the manner indicated inFIG. 11 or when they-are collapsed in the manner explained below.
  • the pins 61 may be removed from the hinges at a common end of the interconnecting links to completely disengages the two structural sections 45 and 46.
  • the linkage members may be folded as in 'FIG. 11.
  • the structural members may then be skidded together until the interlocking means provided by the, confronting pins 64 and sockets 63 are engaged.
  • the substructure may befi'rinly secured together by wrapping chains around it if desired.
  • FIG. 11 When the rig is delivered on location, the collapsed substructure of FIG. 11 is expanded to the dotted line position of FIG. '11 or the position shown in FIG. 8-. Here the connecting links are fully extended.
  • a turntable indicated generally at 66 may be installed.
  • a ramp indicated generally at 67 may be built up on one end of the substructure. It will be noted that there is no interconnecting linkage between the two structural sections at the top of the substructure above platform 67. permits the trailer mounted draw works indicated generally at 12 to be backed onto the ramp 67 in a position for use as indicated in FIG. 12.
  • the mast will be brought in on a separate lowboy truck and a pair of hinges 27 will be utilized to connect one side of the mast to the substructure. Thereafter'the mast may be raised to a vertical position in any desired manner and the other two hinge connections made'up. 'A-t'this time the upper section of the mast may be extended in the manner heretofore explained and the rig is ready for use.
  • the rig When it is desired to change locations the rig may be dismantled by reversing the procedure just explained. However, if it is desired to move the rig only a short distance such as, for instance, in the same field and it is not "It will be recalled that the crown of the mast is hinged for limited movement to the two legs and, therefore, although the connections of the legs to the crown prevent the lower ends of the legs from moving closer together when they are extended, the bottoms of the two legs may be moved in toward each other when they are telescop'ed. With the two structural sections of the substructure .close to each other they may be secured together by chains or the like and the mast and substructure skiddedacross country to a new location. Furthermore,because the two legs of the mast may be telescoped to diiferent degrees,
  • the two sections of the substructure may even be moved toward each other and longitudinally of each other when the mast is reclining, without disconnecting the hinge pins 61.
  • the rig may be skidded between obstructions or over a narrow roadway.
  • a drilling rig comprising, a pair of rectangular substructural sections, collapsible spaced links between the sections selectively holding them in spaced-apart relationship and collapsible, topermit the sections to be moved toward andaway from each other, a two-legged telescoping mast each leg of which is comprised of an upper and a lower section, spaced lower hinge means securing the lower section of each leg of the mast to one of the rectangular substruotural sections, a mast crown, upper hinge pins securing the crown to the upper sections of the mast, the hinge. pins of said upper hinge means extending fore and aft of the mast to permit slight tilting movement.
  • a drilling rig comprising, a pair of rectangular substructural sections, collapsible spaced links pivotally connecting the sections for selectively holding them in spacedapart relationship and collapsible to permit the sections to. be moved toward and away from each other and longitudinally with respect to one another without disconnecting said links, a. two-legged telescoping mast each leg of which is comprised of upper and lower sections, spaced lower hinge means securing the lower section of each leg oi the mast to one of the.
  • the method of raising the telescoping upper section of a telescoping mast which comprises rigging a weight hoisting apparatus to the upper end of the uppersection while the two sections are 'telescoped relative to each other, rigging tackle between the upper end of the lower section and the lower end of the upper section of the mast with a part adjacent the upper end of the lower sec ion; of which a downward movement will result in raising the; upper section, by said hoisting apparatus, and with said sections upright, hoisting to a point adjacent the upper end of the lower section a weight sufficient to act through said tackle to substantially overcome the weight of said upper section, connecting.
  • said weight to said part of; said tackle adjacent the upper end of the lower section, lowering the weight to raise the upper section, supporting said upper section against retrograde movement when it has been raised a predetermined amount within the limits of downward movement of said weight, releasing the weight from the tackle, again hoisting said weight, by said hoisting apparatus to a point, adjacent the top of the lower section, again connecting it to the tackle at such point, and repeating the, weight lowering and raising, releasing and connecting and the upper section supporting steps until said upper section is at the desired level.
  • the method of raising the telescoping upper section of a, telescoping mast which comprises rigging a weight hoisting apparatus to the upper end of the upper section while. the two sections are telescoped relative to each other, rigging tackle between the upper end of the lower section and the lower end of the upper section of the mast with a part adjacent the upper end of the lower section of which a downward movement will result in raising the upper section, by said hoisting apparatus and with said sections upright hoisting to a point adjacent the upper end of the lower section a weight sufficient to act through said tackle to substantially overcome the weight of said upper section, connecting said weight to said part of said tackle adjacent the upper end of the lower section, and lowering the weight to raise the upper section, said hoisting apparatus being the apparatus with which the mast is operated in use after its erection.
  • the method of raising the telescoping upper section of a telescoping mast which comprises rigging a weight hoisting apparatus to the upper end of the upper section while the two sections are telescoped relative to each other, rigging tackle between the upper end of the lower section and the lower end of the upper section of the mast with a part adjacent the upper end of the lower section of which a downward movement will result in raising the upper section, by said hoisting apparatus and with said sections upright hoisting to a point adjacent the upper end of the lower section a weight sufiicient to act through said tackle to substantially overcome the weight of said upper section, connecting said weight to said part ofsaid tackle adjacent the upper end of the lower section, and lowering the weight to raise the upper section, said weight being the traveling block with which the mast is operated in use after its erection.

Landscapes

  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)

Description

July 11, 1961 H. D. LEE 2,991,852
DRILLING RIG AND METHOD OF EXTENDING AN UPPER SECTION OF THE MAST, THEREOF Filed Nov. 29, 1956 4 Sheets-Sheet 1 Harv/o fl. Lee INVENTOR.
July 11, 1961 H. D. LEE 2,991,852
DRILLING RIG AND METHOD OF EXTENDING AN UPPER SECTION OF THE MAST THEREOF Filed Nov. 29, 1956 4 Sheets-Sheet 2 fiaro/a l7. lee
INVENTOR.
July 11, 1961 H. D. LEE 2,991,852
DRILLING RIG AND METHOD OF EXTENDING AN UPPER SECTION OF THE MAST THEREOF Filed Nov. 29, 1956 4 Sheets-Sheet 3 zfl 29 a 26 I 35 50a Haro/a fl. Lee
INVENTOR. ,15 47 47a BY July 11, 1961 LEE 2,991,852
DRILLING RIG AND METHOD OF EXTENDING AN UPPER SECTION OF THE MAST THEREOF Filed Nov. 29, 1956 4 Sheets-Sheet 4 Hora/J17. Lee
INVENTOR.
United States l atent Oflice 2 991,852 DRILLING RIG AND"METHOD F EXT-ENDING AN UPPER SECTION OF THE MAST THEREOF Harold D. Lee, Houston, Tex., assignor to. "C. N. Housh, Houston, Tex. Filed Nov. 29, 1956, :Ser. No. 625,119
' 6 Claims. (Cl. 189-44) This invention relates to drilling rigs and more particularly to drilling rigs designed to be easily and quickly transported between locations and erected. In one important aspect it relates to a means and method for extending sections of a telescoping mast. In another important aspect it relates to a telescoping mast in which the legs converge. in an upwardly direction. In a still third important aspect it relates to a collapsible base.
Modern drilling practice presents a number of instances in which it is desirable to use a portable mast. One form of popular portable mast employs, telescoping sections which extend to a suitable height for well operations but collapse to a length which is within road limits, The previously successful masts of this type have employed parallel mast legsv notwithstanding the well known fact that a mast employing upwardly converging mast legs is stronger and, therefore, for a given rating can be less expensively manufactured. The converging leg mast is extensively used in non-telescoping mast but has not been successfully applied to the telescoping mast, probably due to the diiliculty of obtaining rigidity in the mast when extended.
In extending the telescoping mast it is customary to employ a fast line wrapped around the drum of the draw works for the rig. The mast has been extended with a number of various types of rigging. The fast lines so used will usually not spool well'due to the smaller size of this line than the drill line which is wrapped on the spool under the fast line and the fact that it first passes over a pulley pinned to the platform close to the Thus, there has been a tendency in the past for the. fast line to ball-up on the draw works and give trouble.
In the event the fast line parts or in some way becomes disengaged either from the draw works or the mast, there is nothing to support the telescoping section and it will fall. This possibility has been guarded against by providing auxiliary safety equipment, but this is both expensive and creates dead weight in the mast which must be supported. The prior art methods have also sometimes created abnormal side pull on the mast while it was being extended.
'I lre substructure for supporting the mast is usually built up from a number of individual pieces and requires considerable time to assemble and disassemble. Across its narrowest dimension the substructure may be much larger than normal road limits permit and it cannot be transported across public roads without dismantling.
Even when the rig is to be moved only a short distance to another location in the same field, it must be dismantled and disassembled before it can be moved unless the rig is built about a vehicle mounted on wheels which vehicle provides the substructure. A vehicular substruclure cannot, due to road limits provide a mast with a broad base.
An object of this invention is to provide a method of raising and lowering a section of a telescoping mast in which there is provided as a part of the raising and lowering rigging a safety line to guard against dropping of the mast.
Another object is to provide a telescoping mast and method of raising and lowering a sect-ion of the mast in which there is no side pull on the mast.
Another object is to provide an apparatus and method for raising and lowering a section of a telescoping mast Patented July 11, 1961 in which the drill line is used instead of a telescoping line to avoid ball-ups of the line on the draw works:
Another object is to provide a telescoping mast in which the two legs of the mast converge upwardlyfand in which the legs of the mast are free, to tilt, relative to each other as the mast is raised and lowered in which the mast is automatically rigid when extended.
Another object is to provide a telescoping the preceding object in which inter-engaging stops provided which abut when the mast is. fully. extended to provide the desired stability for the mast. 4
Another object is to provide in combination a mast and substructure in which the legs of the mast converge toward each other when extended and when retracted permit the legs at their base to move inwardly tow d each other, the substructure having an intermediate tion which is collapsible to permit the two outer seen 11s to move toward each other with the legs for cj Another object is to provide a base for a drilling rig which is collapsible for roading and which may belexjtended with eifort to provide a substructure for a drilling rig which is larger than can be transported over public roads.
Another object is to provide a base as. in the preced; ing object in which the base is collapsed without mantling the base.
Another object is to provide a substructure for a drill.- ing rig in which two structural sections each-of w h is designed to support a leg of a drilling mast are seicured together by a collapsible linkage."
Other objects, features'and advantages of this invention; will be apparent from the drawings, the fi fi fig i' tion and the claims.
In the drawings wherein there is shown an illust tiyo embodimentof this invention. and wherein like re rice numerals, indicate like partsr FIGS. through 4 are viewsin front elevation of a drilling rig constructed in. accordance with this inve 't' n with a portion of the lower section of the mast of 1 broken away for illustration of detail, and'showing progressively the steps of raising the upper section of the mast;
FIG. 5 is a view on an enlarged scale of the. hinge con neotion; between the substructure and the. legs of the t FIG. 6i is a fragmentary view on. an enlarged scale oi. one. corner of the crown of the mast illustrating then anner of connecting the crown to the legs of thernast of providing a means for stabili 'ng. the mast once I been raised;
FIG. 7 is a view along the line 7,7 of FIG. 6 I
FIG. 8 is a plan view of the substructure for the drill i s FIG. 9 is a view in side elevation of the substructure shown in FIG. 8;
FIG. 10 is a view along the. lines lik -:10, of 9,;
FIG. 11 is a plan view of the substructure wh col lapsed and showing, in part, the position of th structure when extended in dashed outline;
FIG. 12 is a side elevational view oi the drilling rig of this invention showing the trailer mounted draw in position; and
FIG. 13 is a view on an enlarged scale of means tor interlocking the two structural sections of thesubst zucture together when collapsed.
Therig illustrated in the drawings includes .a substructure indicated generally at 10 and a telescoping mast indicated generally at 1 1. Power for the rigv is provided by a trailer mounted draw works indicated generally at 12 The mast 1 1 is a two-legged structural mast. The legs are made up of identical lower structural section s 13a and upper identical telescoping sections 14 and;
3 The upper sections of the mast slide within the hollow columns formed by the lower sections of the mast.
A novel apparatus and method for raising and lowering the upper sections of the mast is provided by utilizing the traveling block or similar weight for raising and lowering the mast. A rigging between the telescoping sections of the mast with at least a two to one mechanical advantage is provided. Preferably, two riggings, one for each leg of the mast, are utilized to avoid unequal stresses on the mast and to prevent the mast from falling in the event one rigging breaks or becomes inoperative in any way. These riggings are identical and, therefore, only one will be described.
The rigging for raising and lowering the mast includes a pulley 15 on the inside top of lower section 13 of the mast. A line 16 passes over this pulley and down to pulley means on the bottom of the upper section 14 of the same leg of the mast. This pulley means should preferably transfer line 16 from the inside of the mast to the one of the other three sides of the mast to provide suflicient space for the rigging. This pulley means may be provided by two small single pulleys 17 and 18 positioned at the inner and outer edge of the mast section 14 as illustrated. The line 16 passes over pulleys 17 and 18 and thence upwardly to an anchor point on the lower section of the mast. As the dead line. portion 16a of line 16 will be moved as hereinafter more fully explained, itis preferred to pass the line 16 over a pulley 19 at the upper end of section 13 of the mast and thence to an anchor means 20 just below pulley 19. With the dead line portion of line 16 secured to anchoring means 20, thefast line portion 16b of line 16 will be very short as indicated in FIG. 1. With the mast erected but collapsed as shown in FIG. 1, the drilling line 21 from drum 22 of draw works 12 will be fastened to the traveling block 23 in the usual manner. (The traveling block 23 and crown block 24 are provided with a number of sheaves and the drilling line is normally looped over these sheaves to provide a sub stantial mechanical advantage. For clarity of the drawings the drilling line is shown to pass over the crown block only one time and to be directly secured to the traveling block.) l In raising the upper section ofthe mast, the traveling block 23 will be raised to a point adjacent the crown of the mast and the fast line portion 16b of line 16 secured to the traveling block. The traveling block is usually a very heavy member and will often weigh more than one half the weight of the upper section of the mast. When this is true the weight of the block will be sufiicient to overcome the weight of the upper section of the mast and by lowering the traveling block with the drilling line 21 the upper section of the mast will be raised to the FIG. 2 position. j If the weight of the traveling block is not greater than the weight of the upper section of the mast by an amount suflicient to overcome the weight of the upper mast section and friction in the rigging, additional weight may be added to the traveling block. As an alternative, the rigging may be designed to increase the mechanical advantage as will be understood by those skilled in the art. With the mast raised to the position shown in FIG. 2, the upper section of the mast may be temporarily suspended in any desired conventional manner as diagrammatically illustrated by supports 25 releasably secured to lower mast section 13 and supporting the upper mast section.
With the mast in partial raised position, the drilling line is taken in to raise the'traveling block to a position just below the pulley 15 at the top of the lower mast section. The, dead line portion 16a of rigging line 16 is then removed from anchor 20 and the slack in the rigging taken up. The dead line is made fast preferably by securing it to a second anchor means spaced from the first anchor means 20 such as anchor means 26. This arrangement of the rigging is shown in FIG. 3. The drilling line is payed out to lower traveling block 23 again. This raises 4 the upper section of the mast to its fully extended position as shown in FIG. 4. The mast may then be latched in extended position in any convenient conventional manner and rigging line 16 removed from the traveling block and secured in an out-of-the-way position. The drilling rig is now ready for use.
As two riggings are used there is no side thrust on the mast during raising or lowering and in the event of malfunction of one of the riggings, the other rigging will prevent falling of the upper section of the mast. Therefore, the lifting mechanism gives an automatic safety device and no additional auxiliary safety means are required.
It would, of course, be possible to use a separate line from a separate power source to raise or lower the traveling block. It would also be possible to unrig the traveling block and wrap a telescoping line about the drill line on drum 22 and use this line to raise and lower the traveling block. The method illustrated is preferred 'as the traveling block remains riggedat all times thereby saving considerable manhours of work. Furthermore, the drilling line will spool properly and there is little chance of a ball-up on the draw works.
A two-legged mast in which the legs converge upwardly toward the crown block is much stronger than a mast in which the legs are parallel to each other. Therefore, the converging leg mast is used whenever possible as it permits a lighter, cheaper mast. For a telescoping mast to have converging legs necessitates that the legs be permitted to tilt toward and away from each other during raising and lowering of the mast. On the other hand, the mast must be stable when in fully erected position.
Provisions are made for tilting of the mast legs toward and away from each other by special hinge means at the top and bottom of the mast. Referring particularly to FIG. 5, one of the four bottom hinge means indicated generally .at 27 is shown. This hinge means permits the hinge pin to rock longitudinally and as the pin extends across the mast, the leg of the mast will be permitted to tilt. The hinge means includes an upstanding base 28 carried by substructure 10. The base 28 carries spaced hinge parts 29 and 30. An in-line bore 31 extends through the hinge parts 29 and 30. The lower ends of lower sections 13 and 13a are each provided with a hinge part 32 which fits loosely between the hinge parts 29 and 30 of the base. The mast hinge part 32 has a bore 33 of smaller diameter than bore 31 through hinge parts 29 and 30. A hinge pin provided by bolt 34 extends through bores 31 and 33. The relationship of the hinge pin and two bores permits the mast legs to tilt toward and away from each other. In the preferred form shown, the bolt 34 fits snugly within bore 33 of the mast hinge part and loosely within bore 31 of the base hinge parts. As the mast is lowered and tilts inwardly, the hinge pins rest upon the bore in hinge part 30 but is not supported by hinge part 29 as shown in dashed outline at 35. With the mast fully extended the weight of the mast and the load imposed thereon will be squarely supported by both base hinge parts 29 and 30 in the same manner in which a hinge having a tight hinge pin would support a mast and this support.
for the mast will be stable. The hinge 27 shown in FIG. 5 is provided at the front and rear of each mast leg and functions in each location as explained above.
The connection between the crown and each mast leg is preferably provided by hinge means in association with stop means which provide a substantial rigid connection between the crown and mast legs when the mast is fully extended. The connection is best shown in FIGS. 6 and 7. The crown of the mast indicated generally at 36 is provided with depending spaced hinge parts 37 and 38, preferably on the front and rear side of each mast leg. While four hinges are used, they are identical and only one will be described. These hinge parts depend from the bottom of the crown beam 39. At a point spaced some distance from the crown beam, in-line bores 41 are provided in the hinge parts 37 and 38. A hinge pin 42 is mounted in the bore 41 and passes through a hinge part 43 carried at the upper'end ofea-chnrast leg; The; hinge pin 42 extends fore and aft of the mast and the mast legs to rotate about the hinge pin and tilt toward and away from each other. I
In order to stabilize the mast when erected, 'the hinge 'part 43 carried by the mast leg has a stopor abutment section 43a which extends beyond the'hinge 'pin' 42 and close to the bottom'face 39a of the crownfbeam 39. Brieferably, plate 43a has a flat terminal portion 4312" which as gig-91,852
the mast tilts will engage the bottom surface 39a of the crown beam 39. This plate should be designed to be in firm abutment at point 44 (FIG. 6) when the mast is fully extended. As identical hinges and stops are providedon opposite sides of the mast, these abutments will stabilize the mast and prevent further tilting or rocking of the mast.
Referring now to the substructure indicated generally at 10, it will be seen to include spaced structural sections indicated generally at 45 and 46'. Eachstructural section carries supports 28 to which the lower sections of the mast are hinged as heretofore explained. The structural sections are secured together by a-collapsible means extending therebetween whereby the substructure 'may be extended to the FIG. '8 relationship and collapsed to a size suitable for roading as for instance .as shown in FIG. 11.
Each structural section is built around skids 47 and 47a and may include any arrangement of beams desired such as. the vertical I- beams 48, 48a, 49, 49a, 50,. 50a, 51, and 51a, and the deck beams 52' and 53. The sections may ,be cross braced by structural members such as. I-beams 60. The two structural sectionsflare mir'rorimages.
The collapsible linkage for securing; the substructure sections together may be provided in any convenient man,- ner such as by the I-beam'structural members54, 55, 56,
.57 and 5 8. The linkage member 57 is bes t seen in FIG.
10. The linkage members have hingedconnections at each end with the respective structural sections 45 and 46. These hinged connections are identical and are indicated generally at 59. The hinge pins 61 preferably are removable at least at a common end of the linkage members to provide an alternate means of collapsing the substructure. When the substructure is-delivered to a site, it is collapsed in the manner indicated in FIG. 11. The linkage means holds the two structural sections. parallel to each other and permits them to move together and apart in the manner of parallel rulers. It will be noted-from FIG. 9 that the linkage members are staggered vertically so that they may be longer than the distance between adjacent hinges 5'9. 1
In folded position the two sections are preferably interlocked by a plurality of pin and socket connections carried by the structural members and best "shown in FIG. 13. 'I'hesemembers include a box 62 projecting-outwardly from one structural section. A bore-63 is provided in the outer extremity of the box for receiving a pin 64 i'car'ried by the other structural section. The pin '64 is surrounded for a portion of its length by-a box 65. With the substructure folded as shown in FIG. 11, the boxes 62 and 65 are in abutment. The nose of the pin 64 is beveled as at 65a for ease of insertion into box 62. It will be noted that these interlocking means are spaced along the substructure at points opposite each other and are spaced apart along each structural section a distance equal the length of the interconnecting members 54, 55, etc. Thus, some of these interlocking means .will engage when the substructure-is collapsed in the manner indicated inFIG. 11 or when they-are collapsed in the manner explained below.
As an alternative means of collapsing the substructure, the pins 61 may be removed from the hinges at a common end of the interconnecting links to completely disengages the two structural sections 45 and 46. The linkage members may be folded as in 'FIG. 11. The structural members may then be skidded together until the interlocking means provided by the, confronting pins 64 and sockets 63 are engaged. The substructure may befi'rinly secured together by wrapping chains around it if desired.
When the rig is delivered on location, the collapsed substructure of FIG. 11 is expanded to the dotted line position of FIG. '11 or the position shown in FIG. 8-. Here the connecting links are fully extended. A turntable indicated generally at 66 may be installed. A ramp indicated generally at 67 may be built up on one end of the substructure. It will be noted that there is no interconnecting linkage between the two structural sections at the top of the substructure above platform 67. permits the trailer mounted draw works indicated generally at 12 to be backed onto the ramp 67 in a position for use as indicated in FIG. 12.
The mast will be brought in on a separate lowboy truck and a pair of hinges 27 will be utilized to connect one side of the mast to the substructure. Thereafter'the mast may be raised to a vertical position in any desired manner and the other two hinge connections made'up. 'A-t'this time the upper section of the mast may be extended in the manner heretofore explained and the rig is ready for use.
' When it is desired to change locations the rig may be dismantled by reversing the procedure just explained. However, if it is desired to move the rig only a short distance such as, for instance, in the same field and it is not "It will be recalled that the crown of the mast is hinged for limited movement to the two legs and, therefore, although the connections of the legs to the crown prevent the lower ends of the legs from moving closer together when they are extended, the bottoms of the two legs may be moved in toward each other when they are telescop'ed. With the two structural sections of the substructure .close to each other they may be secured together by chains or the like and the mast and substructure skiddedacross country to a new location. Furthermore,because the two legs of the mast may be telescoped to diiferent degrees,
two sections of the substructuremay even be moved toward each other and longitudinally of each other when the mast is reclining, without disconnecting the hinge pins 61. By providing for collapse of the substructure before skidding, the rig may be skidded between obstructions or over a narrow roadway. i
From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus and method. 60
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.
As many possible embodiments may be madeof the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted illmelt the. sections to be positioned side, by side for transportins, a, w egsed t lesc p ng ach leg f. h c 5 comprised Qf. an upper and a lower section, spaced lower hinge means, securingthe, lower section of each leg of the mast to one of the rectangular structural sections, a mast crown, and hinge means securing the crown to the upper sections of the mast, the hinge pins of said last mentioned in e ea s x nding fore and aft of he ma t to perrnit slight tilting movement of the legs of the mast toward and away from each other and permitting the structural sections to be moved toward; and away from each other while the mast is secured to one of the pair.
2. A drilling rig comprising, a pair of rectangular substructural sections, collapsible spaced links between the sections selectively holding them in spaced-apart relationship and collapsible, topermit the sections to be moved toward andaway from each other, a two-legged telescoping mast each leg of which is comprised of an upper and a lower section, spaced lower hinge means securing the lower section of each leg of the mast to one of the rectangular substruotural sections, a mast crown, upper hinge pins securing the crown to the upper sections of the mast, the hinge. pins of said upper hinge means extending fore and aft of the mast to permit slight tilting movement. of the legs of the mast toward and away from each other during extension and retraction of the mast, and stop means carried by the upper section of each leg of the mast and the crown, said stop, means being engageable to lock the mast legs against tilting movement when the mast is fully extended, and means releasable when the mast is in a retracted position to free the. mast legs for said tilting movementv to permit said suhstructural sections to be moved toward and away from each other while each leg of the mast is connected to one of said structural sections byone of said hinge means.
3, A drilling rig comprising, a pair of rectangular substructural sections, collapsible spaced links pivotally connecting the sections for selectively holding them in spacedapart relationship and collapsible to permit the sections to. be moved toward and away from each other and longitudinally with respect to one another without disconnecting said links, a. two-legged telescoping mast each leg of which is comprised of upper and lower sections, spaced lower hinge means securing the lower section of each leg oi the mast to one of the. rectangular substructural sections, a mast crown, upper hinge means securing the crown to the upper sections of the mast, the hinge pins of said upper hinge means extending fore, and aft of the mast to, permit slight tilting movement of the legs of mast toward and away from each other during extension 'and retraction of the mast, and stop means carried by the upper section of each leg of themast and the crown, said stop means being engageable to lock the mast legs against tilting movement when the mast is fully extended, and releasable when the mast is in a retracted position to free the mast legs, for said tilting movement to permit said substructural sections, to be moved toward and away from each other and longitudinally with respect to one another while the mast is connected thereto and without requirement of disconnecting'said collapsible spaced links.
4. The method of raising the telescoping upper section of a telescoping mast, which comprises rigging a weight hoisting apparatus to the upper end of the uppersection while the two sections are 'telescoped relative to each other, rigging tackle between the upper end of the lower section and the lower end of the upper section of the mast with a part adjacent the upper end of the lower sec ion; of which a downward movement will result in raising the; upper section, by said hoisting apparatus, and with said sections upright, hoisting to a point adjacent the upper end of the lower section a weight sufficient to act through said tackle to substantially overcome the weight of said upper section, connecting. said weight to said part of; said tackle adjacent the upper end of the lower section, lowering the weight to raise the upper section, supporting said upper section against retrograde movement when it has been raised a predetermined amount within the limits of downward movement of said weight, releasing the weight from the tackle, again hoisting said weight, by said hoisting apparatus to a point, adjacent the top of the lower section, again connecting it to the tackle at such point, and repeating the, weight lowering and raising, releasing and connecting and the upper section supporting steps until said upper section is at the desired level.
5. The method of raising the telescoping upper section of a, telescoping mast, which comprises rigging a weight hoisting apparatus to the upper end of the upper section while. the two sections are telescoped relative to each other, rigging tackle between the upper end of the lower section and the lower end of the upper section of the mast with a part adjacent the upper end of the lower section of which a downward movement will result in raising the upper section, by said hoisting apparatus and with said sections upright hoisting to a point adjacent the upper end of the lower section a weight sufficient to act through said tackle to substantially overcome the weight of said upper section, connecting said weight to said part of said tackle adjacent the upper end of the lower section, and lowering the weight to raise the upper section, said hoisting apparatus being the apparatus with which the mast is operated in use after its erection.
6. The method of raising the telescoping upper section of a telescoping mast, which comprises rigging a weight hoisting apparatus to the upper end of the upper section while the two sections are telescoped relative to each other, rigging tackle between the upper end of the lower section and the lower end of the upper section of the mast with a part adjacent the upper end of the lower section of which a downward movement will result in raising the upper section, by said hoisting apparatus and with said sections upright hoisting to a point adjacent the upper end of the lower section a weight sufiicient to act through said tackle to substantially overcome the weight of said upper section, connecting said weight to said part ofsaid tackle adjacent the upper end of the lower section, and lowering the weight to raise the upper section, said weight being the traveling block with which the mast is operated in use after its erection.
References Cited in the file of this patent- UNIT ED. STATES PATENTS 282,703 Collins; Aug. 7, 1883 1,006,842 Phelps Aug. 15, 1911 1,063,156 Cohen et' al May 27, 1913 1,119,734. Van Giesen Dec. 1, 1914 1,586,424 Gilowitz May 25, 19.26 2,283,049- Corrnier May 12, 1942 2,331,559 McEwen Oct. 12, 1943 2,463,841 Woolslayer et a1 Mar. 8, 1949 2,470,998 McPherson May 24, 1949 2.6921031 Woolslayer et a1 Oct. 19, 1954 2,763,339, North Sept. 18, 1956 2,781,108; Selberg Feb. 12, 1957
US625119A 1956-11-29 1956-11-29 Drilling rig and method of extending an upper section of the mast thereof Expired - Lifetime US2991852A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US625119A US2991852A (en) 1956-11-29 1956-11-29 Drilling rig and method of extending an upper section of the mast thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US625119A US2991852A (en) 1956-11-29 1956-11-29 Drilling rig and method of extending an upper section of the mast thereof

Publications (1)

Publication Number Publication Date
US2991852A true US2991852A (en) 1961-07-11

Family

ID=24504672

Family Applications (1)

Application Number Title Priority Date Filing Date
US625119A Expired - Lifetime US2991852A (en) 1956-11-29 1956-11-29 Drilling rig and method of extending an upper section of the mast thereof

Country Status (1)

Country Link
US (1) US2991852A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3228151A (en) * 1962-02-15 1966-01-11 Moore Corp Lee C Drilling apparatus for deep oil wells
US3365008A (en) * 1965-06-23 1968-01-23 Kerr Mc Gee Oil Ind Inc Ultra-large diameter drilling structure and method
US4598509A (en) * 1985-06-24 1986-07-08 Lee C. Moore Corporation Method and apparatus for raising and lowering a telescoping mast
US20110056168A1 (en) * 2009-09-10 2011-03-10 National Oilwell Varco, L.P. Windmill installation system and method for using same
US20120131880A1 (en) * 2009-09-09 2012-05-31 National Oilwell Varco, L.P. Method and apparatus for wind turbine erection
US9650840B2 (en) 2015-04-27 2017-05-16 National Oilwell Varco, L.P. Method and apparatus for erecting a drilling rig

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US282703A (en) * 1883-08-07 Fire-escape
US1000842A (en) * 1911-03-11 1911-08-15 Eligah Harris Phelps Scaffold.
US1063156A (en) * 1910-11-03 1913-05-27 Pennsylvania Steel Company Mechanism for lifting heavy weights.
US1119734A (en) * 1913-11-18 1914-12-01 Joseph S Van Giesen Concrete-construction form.
US1586424A (en) * 1925-02-21 1926-05-25 Harry Goldstein Fire escape
US2283049A (en) * 1941-05-16 1942-05-12 Jr Gustave J Cormier Derrick
US2331559A (en) * 1941-07-26 1943-10-12 Int Stacey Corp Portable derrick
US2463841A (en) * 1947-05-22 1949-03-08 Moore Corp Lee C Folding substructure
US2470998A (en) * 1945-10-08 1949-05-24 Robert H Mcpherson Portable mast
US2692031A (en) * 1950-10-18 1954-10-19 Moore Corp Lee C Oil derrick substructure with tilting deck section
US2763339A (en) * 1950-01-20 1956-09-18 Universal Mfg Co Elevating tower
US2781108A (en) * 1956-03-30 1957-02-12 Dresser Equipment Company Self-erecting derrick

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US282703A (en) * 1883-08-07 Fire-escape
US1063156A (en) * 1910-11-03 1913-05-27 Pennsylvania Steel Company Mechanism for lifting heavy weights.
US1000842A (en) * 1911-03-11 1911-08-15 Eligah Harris Phelps Scaffold.
US1119734A (en) * 1913-11-18 1914-12-01 Joseph S Van Giesen Concrete-construction form.
US1586424A (en) * 1925-02-21 1926-05-25 Harry Goldstein Fire escape
US2283049A (en) * 1941-05-16 1942-05-12 Jr Gustave J Cormier Derrick
US2331559A (en) * 1941-07-26 1943-10-12 Int Stacey Corp Portable derrick
US2470998A (en) * 1945-10-08 1949-05-24 Robert H Mcpherson Portable mast
US2463841A (en) * 1947-05-22 1949-03-08 Moore Corp Lee C Folding substructure
US2763339A (en) * 1950-01-20 1956-09-18 Universal Mfg Co Elevating tower
US2692031A (en) * 1950-10-18 1954-10-19 Moore Corp Lee C Oil derrick substructure with tilting deck section
US2781108A (en) * 1956-03-30 1957-02-12 Dresser Equipment Company Self-erecting derrick

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3228151A (en) * 1962-02-15 1966-01-11 Moore Corp Lee C Drilling apparatus for deep oil wells
US3365008A (en) * 1965-06-23 1968-01-23 Kerr Mc Gee Oil Ind Inc Ultra-large diameter drilling structure and method
US4598509A (en) * 1985-06-24 1986-07-08 Lee C. Moore Corporation Method and apparatus for raising and lowering a telescoping mast
US20120131880A1 (en) * 2009-09-09 2012-05-31 National Oilwell Varco, L.P. Method and apparatus for wind turbine erection
US8601748B2 (en) * 2009-09-09 2013-12-10 National Oilwell Varco, L.P. Method and apparatus for wind turbine erection
US20110056168A1 (en) * 2009-09-10 2011-03-10 National Oilwell Varco, L.P. Windmill installation system and method for using same
US8801330B2 (en) 2009-09-10 2014-08-12 National Oilwell Varco, L.P. Windmill installation system and method for using same
US9650840B2 (en) 2015-04-27 2017-05-16 National Oilwell Varco, L.P. Method and apparatus for erecting a drilling rig

Similar Documents

Publication Publication Date Title
US3483933A (en) Oil derrick erection and support system
US2345253A (en) Portable derrick
US3942593A (en) Drill rig apparatus
US4021978A (en) Mast assembly
CA2523505C (en) Fast moving drilling rig
US3228151A (en) Drilling apparatus for deep oil wells
US4221088A (en) Low lift, elevatable high floor drilling mast and substructure arrangement therefor
US3922825A (en) System for erecting an oil well derrick
US4109800A (en) Multi-stage well-drilling mast assembly
US3033527A (en) Portable rig, mast and substructure
US2993570A (en) Portable trailer-mounted derrick
US4138805A (en) Wheeled portable trailer substructure for elevatable drawworks, masts and setback tower
US4489526A (en) Drill rig elevating floor structure
US2781108A (en) Self-erecting derrick
US3739853A (en) Rig substructure and method of moving the same
US2594847A (en) Drilling rig substructure
US2332479A (en) Mast structure
US3101816A (en) Drilling and servicing mast
US3817397A (en) Telescopic masts or towers
US2663375A (en) Portable rig mount
US2920725A (en) Portable collapsible derricks
US4305237A (en) Compact sectionalized drilling mast, power arrangement and support means therefor
US2991852A (en) Drilling rig and method of extending an upper section of the mast thereof
US2210407A (en) Portable derrick
US2306311A (en) Bridge construction