Application of Non-Destructive Continuous Motion X-Ray Analysis for Petrophysical Reservoir Characterization Studies

摘要

Case studies are used to illustrate the value of applying continuous motion x-ray analysis for selecting routine,special core analysis,and geomechanical core samples for subsurface evaluations.This technique has been successfully used on a wide range of petrophysical rock types including unconsolidated reservoirs,high porosity chalks,low permeability systems,naturally fractured reservoirs and mixed lithology systems.Continuous motion x-ray analysis or digital fluoroscopy is a non-destructive,inexpensive,and precise x-ray core imaging method.This process produces a real time continuous high-resolution core image that measures volumetric density contrast viewed through 360 degrees of rotation.Fluoroscope imaging provides investigators the ability to visualize depositional and structural features within the internal structure of a sample.Continuous rotation of whole core or core plugs provides information on size,density contrast,spatial distribution and orientation of framework features.Often these events are visible in a narrow range of azimuths.Results show that it is common to find up to 50% of core plugs unsuitable for testing,because of small-scale heterogeneities such as micro fractures,fine scale faults,laminae,and burrowing.When extracting core plugs from conventional cores in directional wellbores,proper orientation of the core plug is simplified by using the full motion fluoroscopy method.This technique is complimentary to X-Ray Computed Tomography.Screening core samples for internal consistency with the fluoroscopy method significantly reduces the uncertainty associated with laboratory measurements.Thus,interpretations can apply the measurement results with a greater degree of confidence.These images are cost effective and improve subsurface evaluation cycle time.Repeat measurements due to poor sample integrity is costly to both the vendor and sponsoring asset team.Our results show that improved sample quality control,selection,improved subsequent measurement precision,and effective cost control are essential elements for securing management support to obtain laboratory data.