Tool Taxis prevent differential sticking for imaging, sampling and coring tools in a highly overbalanced well (ΔP 5000psi)
The Gulf of Mexico is known for some of the toughest drilling and wireline logging conditions in the world. An operator drilled a challenging 8.5” deviated well to 33,000 ft in a field where virgin pressures in adjacent zones can differ by over 5000psi.
The first wireline run in hole was an oil based mud imaging tool (without Petromac Taxis) which became stuck across one of the problematic low pressure sands and had to be fished. As a consequence the operator insisted on using Petromac for all remaining runs. When the imaging tool was re-run it recorded outstanding data with no sticking, overpulls or spiraling – the smooth tool motion resulted in clear, crisp images.
On the same job, Wireline Express successfully conveyed a 7500lbs reservoir sampling string with the probe oriented to the high side of the wellbore – enabling fast build ups and sample clean ups, with one sampling station setting an industry record of 12,000 psi ΔP (flowing).
After the final reservoir sample was taken from this problematic low pressure sand, the sampling string became temporarily stuck. However because the tool was oriented probe-up the toolstring weight ‘peeled’ the probe from the high side of the wellbore and the tool was immediately able to move up and down freely.
The final run was a sidewall coring tool. An 85% recovery rate was achieved despite the high overbalance (1000-5000 psi) – another industry record.
Petromac wheels reduce borehole contact and by orienting the probe to high side helps peel off a station
A local geological regression produces adjacent zones with , ΔP 5000psi. The first run in hole was stuck and fished across one of these ‘pseudo-depleted’ zones.
After the fishing job the operator ran Petromac Tool Taxis on all subsequent runs with a goal of eliminating sticking.
No sticking was encountered on the imaging run (which was previously fished) – data quality was outstanding.
The sampling tool became temporarily stuck after a 12,000 psi ΔP (flowing) station. Orientation of the probe to the high side caused the tool weight to ‘peel’ the probe off the station, avoiding another costly fishing operation.
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).