Eccentered NMR tool successfully descended by gravity in high deviation well, while eliminating stick-slip motion thanks to Wireline Express conveyance system.
The logging program included an NMR tool (MRIL-XL) to be run in a highly deviated well (69°) in Mexico. With the conventional setup, the drag due to the weight of the magnet on finned standoffs, prevents gravity descent in deviations over 60deg. The normal “solution”, pipe conveyed logging, involves much more logging time, particularly as two latches were needed per descent in this instance. To save time, mitigate risks and improve data quality by eliminating stick-slip, the operator decided to convey the toolstring with Petromac’s conveyance system – Wireline Express.
This was the first time that a MRIL-XL was conveyed fully on wheels. A tailored configuration of Tool Taxis generated the optimum standoff, which allowed removal of the finned standoffs. This resulted in low drag coefficient (0.18), very smooth tool motion and much enhanced data quality.
By using Wireline Express the operator obtained an exceptional logging dataset while saving rig-time and controlling intrinsic operational risks.
MRIL-XL measurement is directional and must be run eccentered for optimal data quality. The standard configuration utilizing finned standoffs results in high drag and limits gravity descent at high deviations. Additionally, high drag induces stick-slip motion, further compromising data quality at slow logging speeds.
A bespoke configuration was designed to convey the whole toolstring on wheels with the Tool Taxis.
MRIL-XL descended by gravity to TD, while controlling operational risks such as differential sticking. Additionally, enhanced data was acquired thanks to smooth tool motion while logging up.
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).