ELEVATOR

Abstract: An elevator for lifting at least one tubular in an oil or gas rig, said elevator comprising at least two body parts (14, 16) which together define an opening, characterised in that said at least two body parts (14, 16) are hinged at least two opposing ends thereof. An elevator for lifting at least one tubular in an oil or gas rig, characterised in that said elevator comprises at least one roller (46, 46') disposed therein, such that, in use, said at least one roller (46, 46') facilitates movement of a tubular arranged in said elevator. An apparatus for lifting at least one tubular in an oil or gas rig, said apparatus comprising an elevator (12) and means for supporting said elevator characterised in that said means comprises an elastic strap (50).

Description: ELEVATOR This invention relates to an elevator, an apparatus and a method for lifting at least one tubular in an oil or gas rig. Lifting tubulars to be connected to or disconnected from a string of tubulars is vital to the operation of an oil or gas rig. For connecting a stand or a single joint of tubular to a string of tubulars, a single joint elevator is lowered to a storage rack. The single joint elevator is opened and placed around the top of a single joint or stand of tubulars located in the rack. The single joint elevator is closed providing a loose fit around the tubular. The elevator is lifted until the elevator abuts a box of the single joint or stand of tubulars. The elevator is lifted together with the tubular to the well centre. A pin of the single joint or stand of tubulars is stabbed into a box of the string of tubulars held in the well. The connection is made with the aid of tongs. The string is subsequently lowered into the well using the primary elevator. A rig worker known as a stabber stands on a stabbing board located on the rig approximately 10m from the rig floor. The stabber aligns the single joint or stand of tubulars with the string of tubulars . The stabber also opens the single joint elevator, guides a swivel supporting the single joint elevator to the correct side of the string, and communicates to the driller the proper settting position of the primary elevator. The entire string of tubulars is then lowered using the primary elevator. For disconnecting a single joint or stand of tubulars to a string of tubulars, a single joint elevator is lowered to a close proximity of the top of the string of tubulars. The stabber places the single joint elevator around the top of the string of tubulars . The stabber closes the single joint elevator. The single joint or stand of tubulars is disconnected from the string of tubulars with the aid of a tong and lifted to a storage rack by the single joint elevator. The primary elevator is used to lift the string of tubulars into a position for removal of further joints or stands of tubulars. Problems have been observed with prior art elevators. In particular, the stabber has a very difficult job opening and closing the elevator. According to a first aspect of the invention there is provided an elevator for lifting at least one tubular in an oil or gas rig, said elevator comprising at least two body parts which together define an opening, characterised in that said at least two body parts are hinged at at least two opposing ends thereof. Other features of the first aspect of the invention are set out in claims 2 to 4. There is also provided a method using an elevator in accordance with the first aspect of the invention comprising the step of opening said elevator and placing a tubular in an opening defined therein . * * * The elevator is placed around the tubular providing a loose fit therearound. The tubular is less likely to be in central alignment with the string of tubulars and more likely to cause damage between the two. The stabber has to ensure alignment and hence his job is strenuous and therefore there is a high risk of danger to the stabber and a probability of damage to the tubular is high. Damage to the tubular can also result from relative movement between the elevator and the tubular. According to a second aspect of the invention there is provided an elevator for lifting at least one tubular in an oil or gas rig, characterised in that said elevator comprises at least one roller disposed therein, such that, in use, said at least one roller facilitates movement of a tubular arranged in said elevator. Other features of the second aspect of the invention are set out in claims 7 to 9. There is also provided a method using an elevator in accordance with the second aspect of the invention comprising the step of placing a tubular in said elevator and moving said elevator relative to said tubular until said elevator abuts or is a predetermined distance from the top or box of said tubular. * * * Relative movement between tubulars can result in damage thereto if the tubulars collide. Handling of joints of tubulars is very difficult when they are in close proximity. According to a third aspect of the invention there is provided an apparatus for lifting at least one tubular in an oil or gas rig, said apparatus comprising an elevator and means for supporting said elevator characterised in that said means comprises an elastic strap . Other features of the third aspect of the invention are set out in claims 12 to 15. There is also provided a method using an apparatus in accordance with the third aspect of the invention comprising the step of placing a tubular in said elevator, lifting said elevator and said tubular on said elastic strap. For a better understanding of the invention, reference will now be made, by way of example, to the accompanying drawings, in which: Fig. 1A is a front view of an apparatus according to a first aspect of the present invention with a hidden part shown in dotted lines; Fig. IB is a side view of an elevator of Fig. 1A with hidden parts shown in dotted lines ; Fig. 1C is a top view of the elevator of Fig. 1A; Fig. 2 is a partial side view of an elevator according to a second aspect of the present invention; and Fig. 3 is a perspective view of a system according to third aspect of the present invention. Referring to Figures 1A to 1C there is shown an apparatus generally identified by reference numeral 10. The apparatus 10 has an elevator 12 comprising two parts 14 and 16. The two parts 14 and 16 are generally semicircular in cross-section and together make up a hollow cylinder. The two parts 14 and 16 are each provided with two bosses 18,20 and 18' ,20' at the top and bottom of opposing ends of the two parts 14 and 16 respectively and one central boss 32 and 32' on the other opposing ends. The elevator 12 is shown with pins 26 and 26' inserted through eyes 36 and 36' through the central bosses 32 and 32' and eyes 22,24 and 22' ,24' through the bosses 18,20 and 18' ,20' . The two parts 14 and 16 are hingable about removable pins 26 and 26' upon removal of the other of said pins 26,26' . Lifting ears 28 and 28' are provided on each side of the elevator 12. The elevator 12 may be selectively opened from either side as desired by removing one of the pins 26 and 26' opening the parts 14 and 16 about the other of the pins 26. Elastic straps (which straps may be elastic cables or elastic wires) 40 and 40' with connectors 42 are connected to each pin 26 and 26' . The elastic straps 40 and 40' may be used to move the elevator 10 and/or to remove the pins 26. Removal of the pins 26 and 26' can be carried out from below if the straps are looped over an item arranged above the pins 26 and 26' . A tubular resides in an opening 38 defined between inner surfaces of the two parts 14 and 16. Referring now to Figure 2 , there is shown an elevator in accordance with a second aspect of the present invention which has rollers 46 and 46' rotatably mounted to the elevator 12 to facilitate movement of a tubular 48 with respect to the elevator 12. The rollers may be arranged in openings 44 in the elevator 12, and/or on lugs 45 external to the elevator 12. The rollers 46 and 46' are preferably cylindrical or conical to conform to the outer surface of the tubular 48. However, the rollers 46 and 46' may comprise a plurality of ball bearings. The rollers 46 and 46' facilitate longitudinal movement of the tubular 48, although they may also be arranged to facilitate rotation of the tubular 48. The rollers 46 and 48 are provided in, preferably longitudinal rows spaced about the tubular. Preferably, the roller 46 and 46' protrudes from the opening defined by the elevator 12 to contact the tubular 48. Referring now to Fig. 3, an elevator 12 is shown positioned in a rig 60 with elastic straps 50 (which straps may be elastic cables or elastic wires) connecting the elevator 12 to a swivel 52 and with straps 54 connecting the swivel 52 to a primary elevator 56. The primary elevator is used to lower or raise the entire string of tubulars once the at least one tubular is disconnected therefrom or connected thereto. A system 70 as shown in Fig. 3 according to the present invention includes a mechanized stabbing device 64 secured to the rig 60 and a remote controlled spider 66 with a safety interlock system.

Claims: Claims : 1. An elevator for lifting at least one tubular in an oil or gas rig, said elevator comprising at least two body parts (14,16) which together define an opening, characterised in that said at least two body parts (14,16) are hinged at at least two opposing ends thereof. 2. An elevator as claimed in Claim 1 , wherein said at least two body parts comprise interengaging bosses (18,18' ,20,20' ,32,32') . 3. An elevator as claimed in Claim 2 , wherein said interengaging bosses (18, 18' ,20,20' ,32 , 32' ) comprise eyes (22,22' ,24,24' ,36,36') . 4. An elevator as claimed in Claim 3 , further comprising removable pins (26,26') insertable through said eyes (22 ,22' ,24 ,24' ,36,36' ) to lock said at least two body parts (14,16) together and to provide means for said at least two body parts (14,16) to hinge about. 5. A method for lifting at least one tubular in an oil or gas rig using the elevator as claimed in any of Claims 1 to 4, said method comprising the step of opening said elevator and placing a tubular in an opening defined therein . * * * 6. An elevator for lifting at least one tubular in an oil or gas rig, characterised in that said elevator comprises at least one roller (46,46') disposed therein, such that, in use, said at least one roller (46,46') facilitates movement of a tubular arranged in said elevator . 7. An elevator as claimed in Claim 6, wherein said at least one roller (46,46') is arranged in an opening (44) in said elevator. 8. An elevator as claimed in Claim 6 or , wherein said at least one roller (46,46') is arranged on a lug (45) . 9. An elevator as claimed in Claim 6 , 7 or 8 , wherein comprising a plurality of rollers (46,46') spaced about said elevator. 10. A method for lifting at least one tubular in an oil or gas rig using the elevator as claimed in any of Claims 6 to 9, said method comprising the step of placing a tubular in said elevator and moving said elevator relative to said tubular until said elevator abuts or is a predetermined distance from the top or box of said tubular . * * * 11. An apparatus for lifting at least one tubular in an oil or gas rig, said apparatus comprising an elevator (12) and means for supporting said elevator characterised in that said means comprises an elastic strap (50) . 12. An apparatus as claimed in Claim 11, wherein said elastic strap (50) is connected above said elevator (12) to a swivel (52) . 13. An apparatus as claimed in Claim 12 , wherein said swivel (52) is supported from a primary elevator (56) . 14. An apparatus as claimed in Claim 13, wherein said swivel (52) is supported from said primary elevator (56) by elastic straps (54) . 15. An apparatus as claimed in Claim 11, 12, 13 or 14 wherein said elastic straps are connected via ears (28,28') on said elevator (12). 16. A method for lifting at least one tubular in an oil or gas rig, said method comprising the steps of placing a tubular in said elevator, lifting said elevator and said tubular on said elastic strap. * * * 17. An elevator as claimed in any of Claims 1 to 4 combined with the features of any of claims 6 to 9. 18. An apparatus as claimed in any of Claims 11 to 15 using an elevator as claimed in any of Claims 1 to 4 or 6 to 9 or 17.

Inventors: HOLLINGSWORTH JIMMY LAWRENCE, HOLLINGSWORTH, JIMMY, LAWRENCE
Applicants: LUCAS BRIAN RONALD, WEATHERFORD LAMB, LUCAS, BRIAN, RONALD, WEATHERFORD/LAMB, INC.
Application year: 1999
Main classification: E21B19
IPC codes: E21B19