Conveying a CMR string on Tool Taxis drastically reduced stick-slip motion and improved data quality
In an offshore well in Abu Dhabi, a CMR log was invalid due to the highly irregular motion of the tool in the wellbore (see tension log on left).
On the subsequent well the CMR was run on Tool Taxis, which oriented the tool pad down and ensured good contact with the wellbore. In a deviated well with Tool Taxis, the weight of CMR sonde provides sufficient contact force without the addition of bowsprings and PPCs. Removing the bowspring and PPC has the added benefit of helping to further reduce stick slip motion.
The data set was devoid of stick slip artifacts on the 2nd well and the log yielded excellent data (see tension log on right).
CMR data acquired in the previous well in the same field was unusable due to cyclic overpulls, which caused stick slip motion. Stick slip is common with services which require slow logging speeds such as CMR and MRX.
The CMR was run on Tool Taxis removing the need for bowsprings and PPCs. In a deviated well the weight of the CMR sonde provides sufficient force for good pad contact.
The log yielded a high quality data set and the stick slip motion was eliminated.
Holefinder system facilitates wireline logging in an ‘impossible well’ in Iraq
Near Vertical ‘Impossible Well’ Logged in Iraq
An operator in Iraq was combating major issues with wellbore ledges in a well with only 6 deg deviation. After two wireline runs which were held up at shallow depth, the operator undertook a wiper trip, only to experience similar problems again on the 3rd attempt. The decision was made to run a TLC operation, however this was also unsuccessful.
In all a total of 5 days of rig time had been lost trying to pass a 20” washout with associated ledge.
Frustrated with the lack of results from conventional wireline and TLC, the operator sought the expertise of Petromac to log this critical well. A total of 6 descents were made with Petromac Wireline Express – all seamlessly conveyed to TD.
Without a holefinder, wireline toolstrings are easily held up by ledges and washouts.
Using the Wireline Express holefinder, the toolstring does not loose any momentum as it slides over wellbore obstructions.
In ‘vertical’ wellbores large ledges will persistently holdup toolstrings, even on TLC operations.
Petromac Tool Taxis ensure that the angled holefinder is always oriented upwards, allowing the toolstring to slide seamlessly over ledges.
A well which could not be logged on TLC was subsequently logged using the Petromac holefinder system (6 successful runs in hole).