Advanced Ultrasonic technology measuring annulus thickness and detecting formation collapse on casing

Summary This paper describes a technology used in detecting a formation collapse on a casing in a deviated well in the Great Burgan Field in Kuwait. The Greater Burgan field is located in the south eastern part of Kuwait, the field contain several reservoirs in the Cretaceous and Jurassic formations. The intermediate section that is of interest in this paper is drilled across the Cretaceous and Tertiary shallow formations. This section is typically drilled using 16 in. bit and cased with 13 3/8 in. casing; the landing point of the section is typically planned at the top of Ahmadi shale formation. Since most of this interval is carbonate, the mud used to drill the section is water-based mud ranging from 8.8 to 9.1 ppg; the mud window is kept small to prevent losses across the loss prone highly fractured carbonate (Tayarat & Damam) formations.