Visualization of the morphology and mode of occurrence of Cenomanian rudists within a drillcore by X-ray CT scanning and 3D modeling

摘要

Rudists are a group of bizarrely shaped marine bivalves that lived in the Tethys Ocean from the Late Jurassic to the latest Cretaceous. They are morphologically variable, including snail-like, cup-like, and horn-like shapes. In the Middle East, Cretaceous carbonates with rudists and rudist fragments are well exposed in many outcrops as well as oil and gas fields. For rudist-bearing carbonates in the subsurface, knowledge of rudist morphology and mode of occurrence must be derived from observation of drillcores; however, understanding the three-dimensional (3D) geometry of rudists from observation of core surfaces is difficult. In paleontological studies of rudists, X-ray computerized tomography (CT) scans have been carried out to reconstruct the inside texture of rudist shells for the purpose of taxonomic research. In contrast, in the oil and gas industry, application of X-ray CT scanning technology is generally focused on direct measurement of reservoir properties. Studies of rudist fossils within drillcores by means of X-ray CT have not yet been conducted. We have developed a new protocol to observe core interiors using X-ray CT. We obtained high-resolution 3D images of rudists in a drillcore by means of surface rendering, volume rendering, and 3D printing. X-ray CT and 3D modeling is a novel method for non-destructive analyses of the morphology and mode of occurrence of fossils within drillcores.