Sand Channel Characterization and Fault Identification Utilizing Ultra-Deep Resistivity 3D Inversion in Complex Clastic Reservoirs

Abstract

Abstract Modifying the well position to maximize production requires both detailed reservoir characterization and mapping of sub-seismic features to identify and remain within the optimal zone. Sand channel characterization, including mapping their orientation, thickness and geometry is important to enable optimization of the well path in this complex environment to maximize the net to gross. Combining high Resolution Imaging tools used traditionally for sand channel characterization and fault identification with ultra-deep 3D electromagnetic inversion improves understanding and provides clear visualization of sand channel behavior. Advanced azimuthal ultra-deep resistivity tools with improved signal to noise ratio and processing techniques have enabled better reservoir visualization. Resistivity and geo-signal curves, images, raw components and associated inversions are provided which can be widely used for landing, geo-steering, geo-mapping and lithology identification (Anisotropy) or even petrophysical analysis (Far Field Saturation) at distance. Recent advances provide 3D Inversions, which can be used for sand channel characterization (mapping out the orientation, thickness, and geometry) and fault identification (dip, strike and amplitude) with confidence. In the candidate wells, 3D EM Inversion revealed sand channels distribution in the area for the target reservoir. An innovative workflow for Sand channel characterization and fault identification with ultra-deep resistivity 3D inversion in complex clastics reservoirs has been developed based on the acquired 3D Inversion data and combining multiple sources of data from near wellbore as well as offset logs. In the first field case two sand channels were identified, in the second field case a break with displacement (fault) dislocating the reservoir has been identified and characterized with dip, strike and amplitude values from the 3D Inversion. The 3D Inversion and proposed workflow could be used for optimizing current and future well placement by adjusting well azimuth while drilling, planning sidetracks and field studies incorporating the 3D data into seismic models. This paper demonstrates field cases utilizing ultra-deep resistivity 3D inversion for mapping out the orientation, thickness and geometry of the sand channels and fault identification in complex clastic reservoir to provide increased reservoir understanding.