Abstract
JAPEX has drilled two wildcat wells with a semi-submersible rig in the offshore Browse Basin Permit AC/P 29 of Australian Timor Sea during the year 2000. They were remotely located at 730km from Darwin that is the capital in the State of Northern Territory. The range of water depth was from 300m to 410m. During this drilling campaign, it was happened that Sub-sea Blow Out Preventers (BOP) were dropped unexpectedly to the seafloor from the sea level in the process of the Riser Dump Valve (RDV) function test. Fortunately there were no personnel injuries or near misses during the incident. Then immediately after the incident a special investigation team was organized and the BOP were recovered from seafloor and repaired successfully according to the plan. This paper describes not only this BOP incident itself but also the following key items related to the incident:
1. Flush Mounted Spider (FMS) bottom guide lost in hole
2. Riser-less temporary Plugged and Abandonment (P & A) operations
