A NEW METHOD OF TIME-TEMPERATURE MODELING OF SEDIMENTARY BASINS

TIME-TEMPERATURE MODELING OF ORGANIC MATTER MATURATION HAS BECOME AN IMPORTANT TOOL IN PETROLEUM AND GAS EXPLORATION INRECENT YEARS. THE MOST SERIOUS DIFFICULTIES IN APPLYING THESE MODELS ARE: 1) OBTAINING ACCURATE DOWNHOLE GEOLOGICAL INFORMATION, AND 2) ESTIMATION OF KINETIC PARAMETERS. SINGLE COLLECTIVE KINETIC RATES ARE TYPICALLY MEASURED IN THE LABORATORY. THESE MUST THEN BE APPLIED ON MUCH LONGER GEOLOGICAL TIME SCALES. THE VALIDITY OF MAKING THESE EXTRAPOLATIONS IN TIME IS ALWAYS QUESTIONABLE. THE INNOVATION OFFERED IN THIS PROPOSAL IS THE DEVELOPMENT OF A COMBINED THEORETICAL AND EXPERIMENTAL METHODOLOGY FOR DETERMINING THE CHEMISTRY AND KINETICS OF THE MULTIPLE REACTIONS IN MACROMOLECULAR DECOMPOSITION TO OBTAIN A MORE VALID EXTRAPOLATION BETWEEN GEOLOGICAL AND LABORATORY TIME SCALES. THE METHODOLOGY COMBINES A UNIQUE MACROMOLECULAR NETWORK MODEL OF HYDROCARBON PYROLYSIS (FG-DVC) WITH A UNIQUE METHOD OF ANALYSIS (TG-FTIR) OF THE ORGANIC SAMPLES FROM THE BASIN. FG-DVC PROVIDES THE LINK BETWEEN OIL, TAR AND GAS GENERATION IN TERMS OF THE VARIATION WITH MATURATIONIN TMAX OF ALL SPECIES AND THE CROSSLINKING ASSOCIATED WITH CO2, CH4, AND H2. THE KINETIC RATE COEFFICIENTS FOR THE EVOLUTION OF ALL THESE SPECIES CAN BE DETERMINED WITH THE TG-FTIR. IN COLLABORATION WITH DR JEAN WHELAN OF WOODS HOLEOCEANOGRAPHIC INSTITUTE (WHOI), WE WILL STUDY TWO GEOLOGICALBASINS FOR WHICH STATE-OF-THE-ART TECHNIQUES HAVE ALREADY BEEN EMPLOYED TO OBTAIN THE BASIN'S PROPERTIES. SAMPLES WILL BE SUBJECTED TO TG/FTIR ANALYSIS. THE SAMPLES AND THE BASIN MODELING HISTORY WILL BE EMPLOYED TO DEVELOP A "FG-DVCMATURATION MODEL" TO PREDICT THE COMPOSITION OF KEROGENS IN THE BASIN. THESE PREDICTED COMPOSITIONS WILL THEN BE USED IN THE FG-DVC PYROLYSIS MODEL TO PREDICT THE BEHAVIOR UNDER THE TG-FTIR ANALYSIS. THE MATURATION CHEMISTRY IN THE MODELWILL BE REFINED BY COMPARING PREDICTED RESULTS TO THE ACTUALTG-FTIR ANALYSIS. IN ADDITION, SAMPLES FROM HYDROUS PYROLYSIS OF BASIN SAMPLES PERFORMED AT WHOI AND AT AFR WILLALSO BE TESTED BY TG-FTIR TO DETERMINE THE RATES AND MECHANISMS OF CHEMICAL TRANSFORMATION WHICH OCCUR.