Base-line caliper log for casing wear analysis

20 April 2013 Hi folks,

At a recent (HPHT) DWOP, we got 'round to discussing casing wear analysis for the critical casing string.

The deeper section of the well design has a full string of 14" casing, then 11¾" liner and 9⅝" liners installed before drilling to TD in 8"" hole size.

There's a plan to run a (64-arm) multi-finger caliper log (MFCT) across the 14" casing once the 10⅝" x 12¼" section has been drilled and open-hole logs are being acquired, in order to determine residual casing wall thickness of the 14" casing string; because 14" integrity is required when drilling the 8"" section to well TD.

Due to the high mud-weights in use, the conventional tools that could be used to determine wall-thickness cannot be used. So it will have to be inferred by caliper-ing the ID of the casing.

We talked about whether or not a base-line log should be run immediately after the 14" casing has been run, before any drillstring rotation has occurred, to determine the initial diameter profile ('original state') -  it is not currently planned to do make a dedicated wireline run on this $1.2 million per day operation.

One option is to run the caliper onshore in the pipe-yard before sending the string out; it's been reported that an MFCT tool has been run through pipe onshore.

We'd really value the experiences of members in this regard, especially anyone who has developed and implemented a cost-effective way to determine wall-thickness and/or gather 'original state' data.

Many thanks

Dave

11 Answer(s)

---