Conventional offshore 3D acquisition is still being performed mainly with narrow azimuth streamer configurations, even in structurally complex areas. Attempt at breaking this paradigm have been recently made by the industry through the successful acquisition of some unconventional "Multi-Azimuth" (MAZ), "Wide-Azimith" (WAZ) and "Rich Azimuth" (RAZ) marine surveys. Eni Indonesia and WestenGeco conducted "the first of its kind" full 3D Circular Shooting survey (Coil) over the Tulip Discovery in Indonesia between August and September 2008. Circular Shooting is a technique developed to acquire a full azimuth dataset with a single vessel towed streamer operation: this is achieved sailing in circles. The circular geometry introduces several differences and a number of new challenges in the whole modeling, acquisition and processing workflow. This paper describes the experience made on the Tulip discovery, focusing primarily on the acquisition planning, deployment efficiency, special QC phases and preliminary processing results. This paper demonstrates also that despite the new technical challenges inherent to circular shooting, it was possible to achieve since the "fast track" volume results, a superior imaging of the Tulip discovery, comparing with the conventional techniques. The improved imaging led interpreters to place with confidence a new appraisal well.
展开▼
