Surface Geochemical Exploration (SGE) is a petroleum prospecting tool based on the premise that upward migrated petroleum from deep source rocks and reservoirs can be detected in near-surface sediments and used to evaluate exploration potential. Typically, geophysical surveys are used to select coring locations based on surface expression of faults and other features related to conduits for upward migration of hydrocarbons.

This video represents oil droplets from an active ocean floor seep rising to the surface in greater than 2,000 meters of water in northern Angola during the TDI-Brooks 2000 Angolan Consortium SGE Study. Video of surface seepage slicks Choose format to view video clip: Quick Time format (~1.2mb) Microsoft AVI format (~1.0mb) TDI-Brooks International performs surface geochemical surveys using a vessel outfitted to perform heavy piston coring. The 1,000 kg piston coring rig used by TDI-Brooks is capable of obtaining 9m ocean sediment samples in water depths up to 4,000m. Three deep sections per piston core are sampled and analyzed, allowing for the determination of depth trends in measured parameters.
Total Scanning Fluorescence (TSF), C15+-Hydrocarbon Gas Chromatographic Analysis (C15+GC), and Headspace Gas Analysis (HS) are performed on each core section to evaluate each core for the presence of migrated mature hydrocarbons. Samples believed to contain migrated petroleum are then analyzed for saturate and aromatic biological markers and stable carbon isotopes. These more detailed analyses can usually confirm the presence of migrated petroleum and are often used to match hydrocarbons in the sediment extract with a specific produced oil and/or source rock.

Piston Coring For Surface Geochemical Exploration

Site Surveys Using Chirp II Sub Bottom Profiler

Extraction of Hydrocarbons From Sediments

Total Scanning Fluorescence

C15+-Hydrocarbon Gas Chromatographic Analysis

Headspace Gas Analysis

Surface Geochemical Surveys Available From TDI-Brooks Int'l