Post Details

11 May 2015

Examples of Final Products

Qualitative interpretation overlay
The gravity and magnetics data can be used to interpret and map qualitative structure in the project area. Structural features include faults and anticlinal and synclinal trends. The DEM hillshade grids will be used to correlate & interpret structure and lineaments. The surface geology will be correlated with other data for interpretation. The final structural interpretation overlay will consist of faults, anticlines, synclines, and lineaments. Faults and lineaments will be represented in classes; e.g., certain (solid line and supported by multiple data) and inferred (represented by a dashed line).

Depth-to-magnetic basement
Because interpretation results are data quality and coverage dependent, a first step in this analysis is for IGC geophysicists to carefully scrutinize data. The depth analysis techniques are applied to the profile data; it is an interactive application of 2D spectral, 2D Euler, and Werner techniques to estimate depth to magnetic basement and/or major sedimentary magnetic features. IGC’s interpretation is generally in the form of a hand-contoured basement structure map that will include major fault trends and major igneous intrusives/extrusives. The contour interval is governed by the data coverage.

Depth-to-high density basement
Within certain geographical areas with substantial gravity coverage, it is possible to calculate a 3D Earth Model with the objective of determining the configuration and composition of the high-density basement horizon for the project area. Results are governed by the number of constraints made available such as, seismically interpreted sedimentary horizons, magnetic basement, velocity/sonic data, and/or lithology/density logs.

Magnetic susceptibility
The relative susceptibility or magnetization of the basement can be correlated to basement lithology. This has general interest to petroleum generation. This map has proven to be an aid to targeted exploration. High values correspond to mafic composition; lower values to felsic composition. A high-quality aeromagnetic survey is very important for best results.

  • Total magnetic intensity
  • Reduced-to-pole magnetics
  • Bouguer Gravity

These are qualitative trend enhancers that are generated with specific exploration objectives; such as directional filters applied to selected areas to delineate anomaly trends or edge/lineation indicators.

These targeted residuals can be used to isolate basement-related anomalies within the sedimentary section that may have exploration significance.

  • Targeted residual RTP magnetics maps
  • Targeted residual gravity maps

IGC can interpret 2D structural models based on aeromagnetic and gravity data integrated with seismic data, magnetic basement horizon, and geologic information provided by the client. Model traverses selections are made jointly by IGC and the client’s geophysicists. Structural models are plotted at a selected scale; usually seismic horizontal scale is used.

A gravity/magnetic/seismic velocity based 3D earth model is the product of a 3D gravity inversion method. The geophysical/geological three-dimensional model of the earth is best described in terms of its exploration objective. This means that when its geologic problem is determined, the model is designed to represent the geologic environment surrounding the prospective target. It is a pseudo-density model derived from a calibrated clastic sediment velocity volume representing the sedimentary section in multiple layers. At a minimum, the earth model is an accumulation of the results of multiple sciences approximating the earth’s lithology. At best—through the skilled interpretation of integrated sciences, it can bring new insight through further refinement of the salt configuration. The success of an integrated 3D earth model approach is dependent upon skilled interpreter and the quality of the data amassed to build the model.

  • Sediment Isopachs
  • Structural Elements and lineations
  • Tectonic interpretations
  • Isostatic residual gravity
  • GIS geology
  • Colored DEM Hillshade topography

IGC provides clients with a detailed narrative—a project summary or project report—covering methods and observations. Clients can receive either a paper copy or a PDF digital copy.

We provide your output and data in whatever format you require. To help clients manage their inventory of interpretations and data, we have developed a proprietary data-management solution.