Chieftain International, Inc. has announced that its exploratory well on High Island Blocks A-510/A-531 offshore Texas has resulted in an oil and natural gas discovery. Drilled to a total depth of 11,107 feet, the well encountered more than 260 net feet of hydrocarbon bearing pay in multiple zones. Further drilling is planned in the area prior to the design and installation of production facilities. Chieftain International, Inc. as operator, has a 50% working interest in the well. Tana Oil and Gas Corporation holds the other 50% working interest. This well was drilled as part of Chieftain's 15-well program for the second half of 1999 in the Gulf of Mexico region, offshore and onshore. Drilling activity is currently under way at three other locations, two of which are onshore.