Ensure cement bond before completion
To optimize gas production from the Raudhatain
Field’s tight carbonate reservoirs, Kuwait Oil
Company (KOC) was preparing for a multistage,
horizontal well completion. As part of its
completions process, the operator needed to
evaluate cement bond quality and ensure the
integrity of the 75/8-in liner in the zone of interest
before drilling out the shoe.
Convey cement bond logging tools
The inclination angle of the 7 5/8-in liner reached
up to 90°—preventing conventional wireline
logging tools from reaching the desired depth.
In previous high-deviation wells, KOC acquired
the cement bond log by using drillpipe to
move the required wireline logging tools.
While necessary to ensure the success of
the planned completion, pipe-conveyed logging
operations add time and costs to the project.
Conduct efficient cement evaluation
Schlumberger proposed using the cement
evaluation component of the SonicScope multipole sonic-while-drilling service, which
verifies cement quality without the additional
runs and rig time of conventional cement
bond logging tools. The SonicScope service
uses both the amplitude of the casing arrival
and its attenuation rate across the receiver
array to derive a quantitative bond index (QBI)
measurement equivalent to a conventional
cement bond log.
Saved 4 days and USD 340,000
KOC ran the SonicScope service for a total of 500 ft within the 75/8-in liner, successfully acquiring
the high-quality waveform from monopole high frequency needed to compute the QBI. By conducting
cement evaluation while drilling, the operator eliminated the need for a separate cement bond log run.
As a result, KOC cut wireline costs and 4 days of rig time, saving USD 340,000.