Publications

Nuclear magnetic resonance (NMR) and tensor resistivity data (3DEXSM) were acquired in Peragam-5ST1 with the scope of accurately computing gas saturations in low-contrast and lowresistivity shaly sandstone formations, and also to provide information about formation dip and azimuth.Peragam-5 and -5T1 were drilled into the footwall of the Champion growth fault block to confirm commercial gas saturations in the intermediate (SU) and deep (V1-V5). While these formations have been identified as gas saturated, in the hanging wall fault block comprising the main Champion and Peragam fields, gas presence in the footwall block has yet to be appraised by drilling. Tensor resistivity data allowed quantification of vertical and horizontal resistivity and delivers improved identification and evaluation of hydrocarbon saturation and net pay computation since it allows the removal of resistivity suppression due to conductive shale laminations. It was also used to compute formation dip and azimuth that aided in more accurately positioning the location of faults. A laminated shaly sandstone interpretation was done based on resistivity anisotropy information, and helped compute accurate gas saturations. The laminated shaly sandstone interpretation was done with the integration of porosity from NMR measurement, and also compared against saturations computed from a 2D NMR (T1/T2app vs. T2app) evaluation. Conventional NMR processing converts the echo decay curve into a T2 value distribution array where different components of the pore volume (gas, oil, water) might overlap because of common T2 values. 2D NMR (T1/T2app vs. T2) interpretation method exploits the differences between T1 and T2 properties of the different components to compute gas saturation. This presentation proves how an integration of tensor resistivity and NMR data computes accurate gas saturations and helped structural geology interpretation in the structurally complex Champion growth fault bloc.