Coiled tubing workover riser
First Claim
1. An apparatus for performing workover operations on a subsea well comprising:
- a lower riser portion for connecting to a subsea production tree, said lower riser portion having a production passage adapted to register with the production passage of said tree, and an annulus access passage adapted to register with an annulus access passage in said tree;
a monobore riser extending upward from the lower riser portion to the surface;
a string of tubing extending from the surface through said monobore riser, defining an inner riser passage and annular riser passage; and
a circulation plug secured proximate a lower end of the tubing and landed in said lower riser portion, said circulation plug having a first passage communicating the production passage in said lower riser portion with one of the riser passages, and a second passage communicating the annulus access passage in said lower riser portion with the other of the riser passages.
2 Assignments
0 Petitions
Accused Products
Abstract
An apparatus for performing workover operations on a subsea well that has a subsea production tree with a production passage and an annulus access passageway. The subsea production tree is secured to a lower riser portion. The lower riser portion connects to the tree and has a production passage which registers with a production passage of the tree. The apparatus also has an annulus access passage which registers with the annulus access passage of the tree. The apparatus further includes a monobore riser which extends downward from the surface. A string of tubing, preferably coiled tubing, extends through the monobore riser and defines an inner riser passage and an annular riser passage. A circulation plug is secured proximate a lower end of the coiled tubing and is landed in the lower riser portion of the subsea well. The circulation plug communicates the inner riser passage with the annulus access passage. A flow-by passage is provided in the circulation plug to communicate the production passage with the annular riser passage.
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Citations
14 Claims
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1. An apparatus for performing workover operations on a subsea well comprising:
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a lower riser portion for connecting to a subsea production tree, said lower riser portion having a production passage adapted to register with the production passage of said tree, and an annulus access passage adapted to register with an annulus access passage in said tree; a monobore riser extending upward from the lower riser portion to the surface; a string of tubing extending from the surface through said monobore riser, defining an inner riser passage and annular riser passage; and a circulation plug secured proximate a lower end of the tubing and landed in said lower riser portion, said circulation plug having a first passage communicating the production passage in said lower riser portion with one of the riser passages, and a second passage communicating the annulus access passage in said lower riser portion with the other of the riser passages. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for performing workover operations on a subsea well comprising:
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a lower riser portion for connecting to a subsea production tree said lower riser portion having a production passage adapted to register with a production passage of said tree, and an annulus access passage adapted to register with an annulus access passage of said tree, wherein said lower riser portion has a landing profile; a monobore riser portion extending upward from the lower riser portion to the surface; a string of coiled tubing extending from the surface through said monobore riser, defining inner and annular riser passages; and a circulation plug secured to a lower end of the tubing and landed in the production passage in said lower riser portion, said circulation plug having a flow-by passage which communicates said production passage of said lower riser portion below said circulation plug with said annular riser passage and having a lateral annulus access passageway which communicates said annulus access passage of said lower riser portion with said inner riser passage, said circulation plug having a lock member that engages said landing profile. - View Dependent Claims (10, 11, 12)
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13. A method for performing workover operations on a subsea well having a subsea production tree comprising the steps of:
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connecting a monobore riser to a lower riser portion, which has a production passage adapted to register with a production passage of the tree, and an annulus access passage adapted to register with an annulus access passage of the tree; lowering the monobore riser and connecting the lower riser portion to the subsea production tree; engaging a circulation plug which has first and second passages to a string of tubing; lowering the string of tubing and the circulation plug through the monobore riser and landing the circulation plug in the lower riser portion, defining an inner riser passage in the string of tubing and an annulus riser passage surrounding the string of tubing; and with said first passage, communicating the annular access passage of said lower riser portion with one of the passages in said monobore riser and with said second passage, communicating the production passage of said lower riser portion with the other of the passages in said monobore riser. - View Dependent Claims (14)
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Specification