Complex Structural Analysis
Lago specializes in the performance of integrated exploration and exploitation projects in complex structural regimes. These include strike-slip, compressional, and extensional tectonic settings. We have a history of success in locating previously unidentified reserves in these areas, largely as a result of rigorously integrating the work of industry experts in all key disciplines: reservoir engineering, structural geology, stratigraphy & sedimentology, geophysics, petrophysics, and geomechanics. Lago’s typical workflow includes the incorporation of surface geology, dipmeter and borehole image log data; tight integration of seismic horizon interpretations to well log picks; tying seismically identified faults to those identified in the wellbore and at the surface; and assuring that the structural interpretation is consistent with well tests, reservoir pressure analyses, fluid contacts, and microseismic observations. Attribute analysis and acoustic / elastic inversion of both 3D and 2D seismic datasets have allowed us to integrate petrophysical properties and depositional facies identified in well logs and core, and extrapolate them spatially to identify both sweet spots and drilling pitfalls in conventional and unconventional reservoirs.
Statistical Curvature Analysis Technique (SCAT), (Bengtson, 1981), is used in many of Lago’s projects. Using the calculated or interpreted wellbore dips from dipmeter and borehole image logs, we are able to perform macro-scale analyses of features encountered in the wellbore, and as a result, determine the genetic natures of geologic structures and structural trends. Employing this technique, Lago can perform critical three-dimensional characterizations such as the type of fold and fold form; the fold geometry and orientation, including details of the fold axes (transverse and longitudinal), and plunge rates; the locations of faults cutting the well, and identification of unconformities. It has also been used to restore depositional cross-bedding dip orientations in structurally rotated settings to reconstruct paleo-current direction and thereby predict fluid flow behavior or sand trend direction.
The most interesting aspect of SCAT work, is that the interpretations can be extended spatially beyond the wellbore. Lago typically begins a SCAT interpretation independently, then integrates the dataset with 3D and 2D seismic interpretation and surface geology calibrate faults and structural features to the ground truth of the wellbore. Lago has developed a method to assure that the dip magnitude and orientation identified from this technique is used during structural mapping, so consistency is maintained between the well data and resulting maps.
This rigorous approach has allowed us to identify prospects and recommend successful step-out drilling programs in conventional reservoirs.
*Bengtson, C.A., (1981), Statistical Curvature Analysis Techniques for Structural Interpretation of Dipmeter Data