TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractSome of the horizontal wells that were drilled in the Saladin field on Thevenard Island in Western Australia have produced below expectations or have experienced sharp production declines. The reasons for this were not known, although the following were suspected to be contributing factors:• Reservoir quality could vary considerably.• The horizontal sections were intentionally drilled in a sinusoidal shape and the low points could become traps for sand and heavy fluids.