Intervention system with dynamic seal

Abstract

A technique for subsea intervention operations incorporates use of a compliant guide that extends between a surface location and a subsea installation. The technique facilitates deployment of tool strings into a subsea well. A dynamic seal can be conveyed through the compliant guide to a desired subsea location. At this location, the dynamic seal is locked into place to provide a subsea dynamic seal that can be used to facilitate the intervention operations.

1 . A system for use with a subsea well, comprising:
 a tubular member extending between a surface location and a subsea installation;   a dynamic seal sized for movement through the tubular member to a desired location; and   a locking mechanism to lock the dynamic seal at a desired location.   
   
   
       2 . A system as claimed in  claim 1 , wherein dynamic seal comprises the locking mechanism. 
   
   
       3 . A system as claimed in  claim 1 , wherein the tubular member is a compliant guide extending between a surface location and a subsea installation. 
   
   
       4 . A system as claimed in  claims 1 , which further comprises a conveyance on which the dynamic seal is transported through the tubular member. 
   
   
       5 . A system as claimed in  claim 4 , which further comprises an attachment mechanism for attaching the dynamic seal to the conveyance. 
   
   
       6 . A system as claimed in  claim 4 , wherein the dynamic seal seals against the conveyance during movement of the conveyance through the dynamic seal. 
   
   
       7 . A system as claimed in  claim 6 , wherein the dynamic seal seals against the conveyance by means of at least one dynamic seal member, the dynamic seal member being hydraulically operable. 
   
   
       8 . A system as claimed in  claim 7 , wherein the dynamic seal member is operable through a hydraulic activation system. 
   
   
       9 . A system as claimed in  claim 8 , wherein the hydraulic activation system is used in combination with a hydraulic ram system. 
   
   
       10 . A system as claimed in any one of  claim 7 , wherein the dynamic seal includes two dynamic seal members. 
   
   
       11 . A system as claimed in  claim 10 , wherein the two dynamic seal members each have their own hydraulic activation systems. 
   
   
       12 . A system as claimed in  claim 10  wherein the two dynamic seal members use the same hydraulic activation system. 
   
   
       13 . A system as claimed in  claim 1 , wherein the dynamic seal is positionable within a lower end of the tubular member so as to form a sealing contact with the tubular member when positioned at the desired location. 
   
   
       14 . A system as claimed in  claim 1  wherein the dynamic seal is positionable proximate the lower end of the tubular member. 
   
   
       15 . A method for intervening in a subsea installation, comprising:
 coupling a tubular member between a surface location and a subsea installation;   moving a dynamic seal down through the compliant guide to a desired subsea location; and   locking the dynamic seal into an operative position at the desired subsea location.   
   
   
       16 . A method as claimed in  claim 15 , which further comprises releasing the dynamic seal and then retrieving it through the tubular member following an intervention operation. 
   
   
       17 . A method as claimed in  claim 15 , wherein moving of the dynamic seal down through the tubular member to a desired subsea location is accomplished by moving the dynamic seal through the tubular member on a conveyance. 
   
   
       18 . A method as claimed in  claim 17 , wherein the conveyance is moved through the dynamic seal in sealing engagement with the dynamic seal. 
   
   
       19 . A method as claimed in  claim 17 , wherein the sealing engagement is provided by at least one dynamic seal member in the dynamic seal. 
   
   
       20 . A method as claimed in  claim 15 , wherein the locking is obtained by locking the dynamic seal within a lower end of the tubular member. 
   
   
       21 . A method as claimed in  claim 15 , which further comprises activating the dynamic seal to seal against the conveyance, opening the subsea well, and delivering an intervention tool into the subsea well via the conveyance. 
   
   
       22 . A method as claimed in  claim 15  wherein the seal is adjusted between the conveyance and the dynamic seal by adjusting the differential pressure above and below the dynamic seal. 
   
   
       23 . A method as claimed in  claim 15  wherein the seal is adjusted between the conveyance and the dynamic seal by adjusting the hydraulic pressure that controls the activation of the dynamic seal. 
   
   
       24 . A method for intervening in a subsea well comprising deploying a dynamic seal through a tubular member with a conveyance, positioning the dynamic seal at a desired subsea location and releasing the conveyance to enable movement of the conveyance through the dynamic seal while retaining a seal between the conveyance and the dynamic seal. 
   
   
       25 . A method as claimed in  claim 24 , wherein the deployment step is done by using a cable-type conveyance. 
   
   
       26 . A method as claimed in  claim 24 , wherein positioning includes positioning the dynamic seal above a subsea installation. 
   
   
       27 . A method as claimed in  claim 24 , wherein positioning includes positioning the dynamic seal in a lower portion of the tubular member. 
   
   
       28 . A method as claimed in  claim 24 , which further comprises sealing the dynamic seal to the tubular member. 
   
   
       29 . A method as claimed in  claim 24 , which further comprises adjusting a differential pressure acting on the dynamic seal. 
   
   
       30 . A method as claimed in  claim 24 , which further comprises opening the subsea well, delivering an intervention tool into the subsea well, conducting an intervention operation and retrieving the intervention tool to a surface location. 
   
   
       31 . A method for intervening in a subsea well comprising:
 coupling a spoolable compliant guide between a surface location and a subsea installation;   delivering a dynamic seal through the spoolable compliant guide via a conveyance; and   adjusting the seal formed between the conveyance and the dynamic seal.   
   
   
       32 . A method as claimed in  claim 31 , which comprises changing the pressure acting on the dynamic seal for adjusting the seal formed between the conveyance and the dynamic seal. 
   
   
       33 . A method as claimed in  claim 32 , wherein the pressure changing is accomplished remotely from a surface location. 
   
   
       34 . A method as claimed in  claim 31 , wherein the coupling step includes coupling the spoolable compliant guide between a surface vessel and the subsea installation. 
   
   
       35 . A method as claimed  claim 31 , wherein delivering the dynamic seal through the spoolable guide via the conveyance includes the use of a cable-type conveyance that delivers the dynamic seal through the spoolable compliant guide.