Description: Das Projekt "Entwicklung und Erprobung einer neuen Sonde fuer die in-situ Entgasung von Bodenproben fuer die geochemikalische Isotopenanalyse" wird vom Umweltbundesamt gefördert und von Geochemische Analysen durchgeführt. Objective: A new in-situ-degassing probe for the application in isotope-geochemical exploration for oil and gas should be developed and tested. The probe would enable the separation of free, mainly bacterial produced soil gas from absorbed gases formed in the deep subsurface by thermo catalytic reactions from organic source rocks, in one sampling step. A distinct reduction of cost for sampling and sample treatment for isotope-geochemical analysis in the field of oil and gas exploration is expected due to the lack of cost intensive drilling rigs, the storage of samples in liquid nitrogen and the separation and extraction of gases in the laboratory. General Information: A new probe for in-situ degassing of soil with acid treatment was constructed. The probe consists of a 2 m long stainless steel tube with two telescoping Teflon-tubes for acid injection and gas transportation of the liberated gases. The tip of the probe is closed by a varnished bottom plug and driven into the soil about maximal 2 m by means of a motor hammer or a heavy plastic hammer. Then the probe is lifted by 10 cm whereby the bottom is opened. In opened volume in the soil body phosphoric acid (85 per cent) is injected via the probe tip. The liberated gases and developed carbon dioxide of carbonates are stripping the gas to the outlet of the probe on the surface. In a connected gas preparation line the developed carbon dioxide of the sample gas is washed out by potassium hydroxide solution (50 percent). The remaining gas phase contains the liberated hydrocarbon gases of the soil. These gases are transferred by water into an evacuated gas container for further determination of the gas composition and 13C/12C-isotope ratio of methane. After testing the probe for material corrosion and leaks it was used in soil areas above an oil field near Lehrte. By parallel analysis of field samples and laboratory standard samples the results were compared with those of the conventional laboratory degassing method. It was found that both methods generate different isotope-geochemical data. The data of the conventional method fits very well with the expected data in the oil field and the laboratory standard. On the other hand the new developed acid-probe generally produced shifted data which are not useful for interpretation in the oil and gas exploration. Laboratory and blanc tests with the acid probe showed that the stainless steel produces high concentrations of hydrocarbon gases by the treatment with phosphoric acid. In the field work the gas composition and isotope ratios of this artificially formed gas is mixed with the soil gas. As the artificially formed gas part can not be controlled and in addition gas yields can't be determined due to the unknown degassed soil body, the acid-probe was found to be not useful for the given demand.
Types:
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Kalisalz ? Kunststoff ? Alicyclischer Kohlenwasserstoff ? Erdgas ? Erdöl ? Hydroxid ? Carbonat ? Lack ? Kohlenwasserstoff ? Erdölförderung ? Gasanalyse ? Stickstoff ? Bodeninformation ? Chemie ? Kohlendioxid ? Methan ? Probenaufbereitung ? Prospektion ? Transportbehälter ? U-Bahn ? Korrosion ? Chemische Analyse ? Deponie ? Edelstahl ? Gasförmiger Stoff ? Unterboden ? Analyseverfahren ? Bodenbewirtschaftung ? Geologie ? Vergleichsanalyse ? Kostensenkung ? Bodenuntersuchung ? Daten ? Motor ? Wasser ? Offshore-Technik ? Isotop ? Standardmethode ? Bodenprobe ? Probenahme ? in situ ? Verkehr ? Gestein ? Entgasung ? Isotopenverhältnis ?
Region: Lower Saxony
Bounding box: 9.16667° .. 9.16667° x 52.83333° .. 52.83333°
License: cc-by-nc-nd/4.0
Language: Deutsch
Time ranges: 1988-10-01 - 1989-09-30
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