Industry Article: KOC Turns a Mutt into a Thoroughbred

After watching production in one Sabriyah field well drop to zero shortly after completion, Kuwait Oil Company used new technology to bring it back to life.

Publication: World Oil
Volume: July
Issue: 2007
Publication Date: 07/01/2007

An old expression says, “It’s best to let sleeping dogs lie.” Kuwait Oil Company (KOC) could have walked away from its Sabriyah SA210 well and chalked it up to a bad investment when it stopped flowing shortly after completion in 2004. Instead, the company tried a new technique to rejuvenate the failing well with good results. The SA210 was an openhole completion, J-type directional well. Kickoff point was at 6,264 ft (MD), and the well was landed at 8,376-ft MD (7,621-ft TVD), with a 1,337-ft stepout. A 7-in liner was run and cemented in place at an 8,162-ft MD (7,601-ft TVD). The 2,462-ft production section was drilled with a 61/8-in. bit to 10,838 ft (MD). Bottomhole pressure was about 3,093 psi, and temperature was 170 degF.
The target formation was the Mauddud Limestone, normally a prolific producer. It was, therefore, puzzling to everyone when the SA210 failed to produce. Openhole logs showed effective porosity averaged 20% to 24% across the entire interval. Clay volume was very low, building from almost zero at the heel to about 10% at the toe. Permeability at the formation interface was estimated to range from 5 mD to 20 mD in the lower target zone, but it was believed to range from 10 mD to 50 mD in two of the upper zones. A fourth zone’s permeability ranged to 100 mD. Later, log-derived permeabilities of the reservoir rock indicated an even rosier picture. The tight toe area was calculated to be 46 mD, and the heel zone was predicted to be almost 815 mD. In addition, the entire production zone was split by dozens of longitudinal and transverse natural fractures. So why wouldn’t the well produce?

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