LWT FAQs

LWT Answers

Q. Do Cordax LWT Logs meet industry data standards and comply with regulatory requirements?

Yes. Cordax LWT Logs are API (American Petroleum Institute) calibrated open hole logging measurements which fully comply with submission standards set by government regulatory bodies.

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Q. How do LWT log responses compare to conventional Wireline logs?

Cordax LWT logs overlay conventional wireline data, as proven on several wells where both methods were run to provide a comparison. Data overlay logs are presented on the LWT Resources page of this site.

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Q. Do we need a dedicated pipe trip to add the LWT collars to the BHA?

No. The LWT collar can be put into the BHA at the most convenient time for the well operator including the bit trip, wiper trip, or reamer run. LWT tools are then pumped down to the LWT collar at TD and record data during the normal pipe trip out with little impact on overall operations.

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Q. What happens if the drill string gets stuck, can the logging tools and radioactive sources be retrieved?

Yes. Unlike pipe conveyed methods, LWT logging tools are safely housed within the LWT collars at all times during operations and are fully retrievable if the BHA becomes stuck downhole. The LWT tools have a standard wireline fishneck on top for retrieval.

Q. How much time will LWT add to our drilling operations?

Q. How much time will LWT add to our drilling operations?

A typical LWT run will add a few hours to normal tripping operations to allow for tool pump-down and slightly reduced tripping speeds during logging. This time is significantly less than the additional day(s) required for other methods requiring a change of BHA or hole conditioning prior to logging.

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Q. How slow do we need to pull the pipe to allow logging measurements?

For proper tool response on nuclear measurements the pipe should be pulled out at 9 -12 m/min (30 - 40 ft/min).

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Q. Can we drill or ream with the Cordax Composite collar?

Yes. Cordax LWT collars are most commonly used on reaming runs. The collars are drilling rated and are often used to drill final intervals prior to logging tool deployment. The decision to employ LWT collars for drilling is made on a well by well basis after an assessment of anticipated drilling conditions.

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Q. Does it matter what type of mud is in the wellbore?

No. Cordax LWT tools perform well in all conventional mud types including fresh, invert, KCl, and high salinity.

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Q. How do you acquire depth?

Cordax LWT uses the rig's Electronic Drilling Recorder (EDR) or an encoder on the drilling cable drum. This depth info is recorded in time and is merged with time indexed logging data from the memory tools to produce a standard well log.

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Q. How do we know if the tools land in the Cordax LWT Composite Collar during pumping?

Cordax LWT provides a 56 mm (2.2 in) drift to ensure the tools will pass through the drilling assembly. After the tools are deployed into the drill pipe, a pressure pulse at surface confirms the tools have landed in the collar restriction and the swab cup has shifted on the pump-down assembly, allowing flow past and circulation/rotation.

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Q. What is the temperature rating of the Cordax LWT tool string?

All LWT tools are rated to 150 deg C (302 deg F), including the battery.

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Q. What is the total length and diameter of the Cordax LWT string?

The total length of the LWT triple-combo tool suite is 8.7 m (28.7 feet), with a maximum diameter of 52 mm (2.0 in). The addition of SGR to the standard suite increases the length to 9.74 m (31.9 ft).

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Q. What is the deepest well that Cordax LWT has logged?

Cordax LWT regularly acquires logs on deep horizontal wells over 4,500 m (14,763 ft) measured depth. The deepest well logged by LWT to date is 6,420 m (21,062 ft) measured depth in Western Canada.