|| Prudhoe Bay, Alaska
WELL COMMANDER drilling valve
7,975 ft (2,431 m) MD
8,174 ft (2,491 m) MD
12.3. lb/gal (1.48 SG)
8,156 ft (2,486 m) MD
|Top of Source
8,089 ft (2,466 m) MD
|Inclination at Source
While drilling the 6 1/8 in. section, the rig experienced a drilling
break and then took at kick at 8,175 ft (2,492 m) MD. The rig pulled up 20 ft
(6 m) off bottom and the well was shut in. It was confirmed that that well was
not static and the well was taking gains. To control the well, kill mud was
mixed and pumped. During circulation on bottom after the well kill, the rig
tried to pull on the drill string, and the BHA was determined to be
The engineers started the source stuck Emergency Response Plan (ERP).
After notifying all parties, the engineers talked with the company man on site
and offered advice and recommendations on how to deal with the lost radioactive
(RA) source situation. Once the rig had completed 100 jarring cycles, the
engineers, company man and personnel in town made the decision to attempt
fishing the RA source through the BHA, including the 5 in. WELL COMMANDER
ball-activated drilling valve and BYPASS BALL CATCHER device.
As this section of the well was relatively shallow, the operator had few
options if the sources had to be left in the hole. The regulatory mandate of a
200 ft (61 m) cement plug on top of the sources will partially condemn the
A mixed team of Schlumberger D&M, Slickline and M-I SWACO engineers
tested the fishing assembly to be used in the Alaskan M-I SWACO shop with a
similar 5 in. WELL COMMANDER valve and BYPASS BALL CATCHER device combination
to confirm the assembly will go through. After demonstrating that the selected
1.31 in. OD fishing assembly would pass through the 1 1/2-in. drift of the
ball catcher the operation to fish the RA sources commenced.
The WELL COMMANDER drilling valve is the only drilling valve available
in the industry that will allow pass through it even if a ball has been
dropped. This unique design advantage allows the operator to run free point
tools, back off bars, RA sources fishing assemblies as well as to run/activate
ball operated tools below even after a ball has been dropped. Note: no balls
were dropped to the WELL COMMANDER valve in this particular well.
The RA sources were successfully fished through the 5 in. WELL COMMANDER on the second attempt, allowing the client to sidetrack the well and continue drilling adverting major complications with the well and regulatory authorities. The BHA was backed off on top of the ball catcher and portion of it was left in the hole after being cemented.
The key for the success of the operation was proper preparation, the
fishing gear was taken to the M-I SWACO shop in Alaska and tested on a spare
WELL COMMANDER valve and BYPASS BALL CATCHER to ensure it would go through.
A typical retrieval BHA comprises several things, including: fishing
overshot, bow spring centralizer, spring jars, weight bars, xo, cable head back