Dual stripper apparatus

Patent metadata

Field	Value
Publication number	US-9874065-B2
Application number	US-201515128581-A
Country	US
Kind code	B2
Filing date	Mar 24, 2015
Priority date	Mar 25, 2014
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

A workover riser arrangement designed to allow installation/retrieval of a coiled tubing suspended Electrical Submersible Pumps (ESP) into live wells is described. The installation takes place by the use of a coiled tubing as a running string that extends through respective apparatuses in said workover riser arrangement and further down towards the well bottom. The workover riser apparatus comprises a first (upper) dual stripper apparatus through which said coiled tubing is to extend, a second (lower) dual stripper apparatus through which said coiled tubing is to extend, a surface BOP, if required, and a surface flow tree arranged between the first and second dual stripper apparatus, an EDP, LRP and an XMT arranged below the second dual stripper apparatus.

First claim

The invention claimed is:

1. A workover riser arrangement designed to allow installation/retrieval of a coiled tubing suspended Electrical Submersible Pump (ESP) into a live well defined by an internal wall of a production tubing, by use of a coiled tubing as a running string to be extended through respective apparatuses in said workover riser arrangement and further down towards a bottom of the well, wherein said workover riser arrangement comprises an upper dual stripper apparatus, positioned at an upper end of the workover riser arrangement, through which said coiled tubing is to be extended, a lower dual stripper apparatus, positioned at a lower end of the workover riser arrangement, through which said coiled tubing is to be extended, a surface blowout preventer (BOP) and/or a surface flow tree arranged either between the upper and lower dual stripper apparatuses or above the upper dual stripper apparatus, an emergency disconnect package (EDP), a lower riser package (LRP) and a Christmas tree (XMT) arranged in series below the lower dual stripper apparatus.

2. The workover riser arrangement according to claim 1 , wherein said upper and lower dual stripper apparatuses are designed to both seal against a slick surface and still being able to let through an object of larger diameter, each apparatus comprises two independent seal blocks, said seal blocks being located adjacent to each other and retaining respective split seals that are spaced a distance apart from each other and leaving a cavity there between, the cavity is in communication with a high viscosity fluid supply device in order to fill said cavity with high viscosity fluid and pressurize said cavity to form a dual seal.

3. The workover riser arrangement according to claim 1 , wherein said upper and lower dual stripper apparatuses comprising two independent seal blocks, the seal blocks are divided in two halves, each half being moveable towards and away from each other.

4. The workover riser arrangement according to claim 3 , wherein each seal half is moveable by respective pipe actuators.

5. The workover riser arrangement according to claim 2 , wherein each seal is a dynamic seal able to dynamically seal against well pressure.

6. The workover riser arrangement according to claim 1 , wherein said ESP has a connected power/signal cable extending inside the coiled tubing between the surface and the ESP.

7. The workover riser arrangement according to claim 1 , wherein an isolation plug, or hanger plug, is connected to a plug running tool connected to the coiled tubing, the isolation plug is suspended in the running tool and arranged to be hung off either in a wellhead at the top of the well or the XMT.

8. The workover riser arrangement according to claim 1 , wherein one of the upper or lower dual stripper apparatuses is placed at a distance above an EDP valve at least equal to the length of the ESP, in order to enable lowering the ESP through EDP/LRP while keeping pressure control with one of the upper or lower dual stripper apparatus above the ESP.

9. The workover riser arrangement according to claim 1 , wherein spacing between the upper or lower dual stripper apparatuses is equal to or greater than the length of a hanger plug and a hanger plug running tool, in order to enable sluicing through the plug and running tool while keeping pressure control with one of the upper or lower dual stripper apparatus.

10. The workover riser arrangement according to claim 2 wherein said upper and lower dual stripper apparatuses comprising the two independent seal blocks, the seal blocks are divided in two halves, each half being moveable towards and away from each other.

11. The workover riser arrangement according to claim 10 wherein each seal half is moveable by respective pipe actuators.

12. The workover riser arrangement according to claim 2 wherein each seal is a dynamic seal able to dynamically seal against well pressure.

13. The workover riser arrangement according to claim 3 wherein each seal is a dynamic seal able to dynamically seal against well pressure.

14. The workover riser arrangement according to claim 4 wherein each seal is a dynamic seal able to dynamically seal against well pressure.

15. The workover riser arrangement according to claim 2 wherein said ESP has a connected power/signal cable extending inside the coiled tubing between the surface and the ESP.

16. The workover riser arrangement according to claim 3 wherein said ESP has a connected power/signal cable extending inside the coiled tubing between the surface and the ESP.

17. The workover riser arrangement according to claim 4 wherein said ESP has a connected power/signal cable extending inside the coiled tubing between the surface and the ESP.

18. The workover riser arrangement according to claim 2 , wherein said slick surface is a coiled tubing string.

19. A method for installing a coiled tubing suspended Electrical Submersible Pump (ESP) into a live well defined an internal wall of a production tubing, the method uses a coiled tubing string as a running string to be extended through a workover riser arrangement and further down towards a bottom of the well, the workover riser arrangement includes an upper dual stripper apparatus positioned at an upper end of the workover riser arrangement, through which said coiled tubing is to extend, a lower dual stripper apparatus positioned at a lower end of the workover riser arrangement, through which said coiled tubing is to extend, a surface blowout preventer (BOP) and/or a surface flow tree arranged between the upper and lower dual stripper apparatuses, an emergency disconnect package (EDP), a lower riser package (LRP) and a Christmas tree (XMT) arranged in series below the lower dual stripper apparatus, wherein said method comprises the following steps:
1. lowering the ESP through the upper dual stripper apparatus while both upper and lower dual stripper apparatuses are open and EDP/LRP valves are closed and the ESP is lowered to above the EDP;
2. closing the upper dual stripper apparatus, pressurize the workover riser arrangement to well pressure, open the EDP/LRP valves and lowering the ESP through the EDP/LRP;
3. continue the lowering of the ESP until a hanger plug arrives at the upper dual stripper apparatus;
4. the lower dual stripper apparatus closes around the coiled tubing while the riser between the upper and lower dual stripper apparatuses are bled off and circulated to monoethylene glycol (MEG);
5. the upper dual stripper apparatus is opened, the hanger plug with associated running tool is lowered through and past the upper dual stripper apparatus;
6. the upper dual stripper apparatus is closed, the pressure between the upper and lower dual stripper apparatuses is increased to equalize the well pressure; and
7. the lower dual stripper apparatus is opened, the hanger plug and running tool is lowered until the hanger plug is landed in the XMT, and the hanger plug is locked to the XMT.

20. The method according to claim 19 , wherein the method further includes a step 8:
to retrieve the running tool above the EDP/LRP, close the EDP/LRP valves, bleed off and circulate the riser to MEG, and finally open the upper dual stripper apparatus and retrieve CT and running tool to the surface.

Assignees

• Aker Solutions As

Inventors

• Christensen Kim W

Classifications

• E21B43/128

  Adaptation of pump systems with down-hole electric drives · CPC title

• E21B33/064 Primary

  specially adapted for underwater well heads · CPC title

• E21B33/035

  specially adapted for underwater installations (E21B33/043, E21B33/064, E21B33/076 take precedence) · CPC title

• E21B33/076 Primary

  specially adapted for underwater installations · CPC title

• E21B17/01

  Risers · CPC title