US 12,291,933 B2
Method for clearing flexible lines using coiled tubing from a well intervention rig
João Marcelo Mussi Baptista, Rio de Janeiro (BR); Paulo Igor Barbosa Martins, Rio de Janeiro (BR); Rossano Renir Comunelo, Florianópolis (BR); Andre Luiz Bevilaqua Santana, Macaé (BR); George Souza Costa, Rio de Janeiro (BR); Carlos Alberto Teles Borges, Macaé (BR); Julio Maia Gouvea, Niterói (BR); Fernando Koiti Higashi Nakashima, Ribeirão Preto (BR); Ana Karla Melle Soares, Rio de Janeiro (BR); Paulo Tavares Fernandes, Rio de Janeiro (BR); Anderson Meireles Palmeira, Rio de Janeiro (BR); Nilton de Lima França, Macaé (BR); and Jose Augusto Pinto Padilha, Rio de Janeiro (BR)
Assigned to Petróleo Brasileiro S.A.—Petrobras, Rio de Janeiro (BR)
Appl. No. 17/782,810
Filed by Petróleo Brasileiro S.A.—Petrobras, Rio de Janeiro (BR)
PCT Filed Dec. 2, 2020, PCT No. PCT/BR2020/050511
§ 371(c)(1), (2) Date Jun. 6, 2022,
PCT Pub. No. WO2021/108880, PCT Pub. Date Jun. 10, 2021.
Claims priority of application No. 10 2019 025811 0 (BR), filed on Dec. 5, 2019.
Prior Publication US 2023/0349244 A1, Nov. 2, 2023
Int. Cl. E21B 19/22 (2006.01); B63B 21/50 (2006.01); E21B 37/00 (2006.01)
CPC E21B 19/22 (2013.01) [B63B 21/50 (2013.01); E21B 37/00 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of clearing flexible pipes using flexitube from an intervention rig in wells, the method comprises the following steps:
a. opening a flanged connection (10) at a location between two flanges (13 and 15) of two legs (12 and 14) of a submarine pipe (40) and installing a pull head (16 and 17) in each of these legs (12 and 14), in which the step of opening the flanged connection (10) and installing the pull heads (16 and 17) comprises attaching floats (18 and 19) in each of the legs (12 and 14), so that each leg (12 and 14) has a curved section towards a surface of a body of water, wherein a hood (08) and shuttle tank (09) to collect oily fluid are used in case of leakage;
b. moving a rig (120) to the location;
c. assembling a hoisting assembly (58) for hoisting the leg (14) of the submarine pipe (40) with a drill string (50);
d. descending the drill string (50) with the hoisting assembly (58) and engage a hook (56) to the pull head (17);
e. hoisting the leg (14) of the submarine pipe (40) through an end of the leg using the hoisting assembly (58) coupled to the pull head (16);
f. anchoring the end of the leg (14) of the submarine pipe (40) on a rotary table (60) of the rig (120) using a side door elevator (47);
g. draining an internal pressure of the pipe by means of a connection of a tube (67);
h. disconnecting the pull head (17) and assembling a Surface Flow Tree (70) at the end of the leg (14) of the submarine pipe (40), and optionally to connection adapters (90) and (91) to match the end of the leg with the Surface Flow Tree (70);
i. assembling the Flexitube (101) on the Surface Flow Tree (70) and surface lines (105 and 106);
j. carrying out the operation of clearing the leg (14) of the submarine pipe (40) with the Flexitube (101);
k cleaning the leg (14) of the submarine pipe (40) with high flow rate seawater circulation;
l. Disassembling the Flexitube (101), the surface lines (105 and 106) and the Surface Flow Tree (70) pieces of equipment;
m. installing the pull head (16) at the end of the leg (14) of the cleared submarine pipe (40), assembling the hoisting assembly (58) for hoisting the leg (14) of the submarine pipe (40) with the drill string (50), and descending the leg (14) of the submarine pipe (40) to the seabed, where the leg (12) of the submarine pipe (40) is located;
n. removing the pull heads (16 and 17) from the legs (12 and 14) of the submarine pipe (40) and connecting the legs (12 and 14) via the flanged connection (10).