SCSSV Flapper Milling using E-line Solution

Abstract

This paper discusses the success of an operation involving E-line unit to mill Surface Controlled Subsurface Safety Valve (SSCSSV) flapper on a well, which has been detached from its hinge. The flapper has become obstruction to well intervention activity on this well, as a zone shifting job was planned on this well which will triple its oil production.

The SCSSV flapper becoming a restriction was identified from slickline tubing clearance job, but the fact that it has been detached from its hinge was learned after getting the result from running downhole camera. The objective of the operation is regaining access to the zone below SCSSV for zonal isolation and perforation. The bit was specially designed to mill the flapper while minimizing the flapper rotating action that might have caused by the milling, hence increasing the milling effectiveness. As this is the first loose SCSSV flapper milling for Medco E&P Natuna Ltd. (MEPN), a System Integrity Test (SIT) was conducted at Service Company facility with actual flapper of the same type to prove the method would work, prior to the actual job onsite.

E-line milling with special designed bit was proven to be the effective method to solve the restriction issue in this well. The restriction was able to be milled, and rotational movement of the flapper which could have impeded the milling operation was minimized. A full-bore access was made available upon the milling job completion, which allow for future intervention work.