Organic Matter Maturity And Its Relation To Time, Temperature And Depth In The Bengal Foredeep, Bangladesh
Journal Article: Organic Matter Maturity And Its Relation To Time, Temperature And Depth In The Bengal Foredeep, Bangladesh
AbstractAbout 350 vitrinite reflectance data on conventional cores and cuttings are available from 18 boreholes in the Tertiary sediments of the major tectonic elements of the Bengal Foredeep. The recorded bottom-hole temperature corrected by using Horner's plot and measured vitrinite reflectance (R0%) data have been utilized for the present study. The R0 values have been correlated with present temperature and depth, and a relationship between them has been established individually for each of the five sites located on three major tectonic elements of the region. Variation of present day temperature in relation to R0 in the basinal part of the foredeep enables the assessment the paleotemperature history of the sedimentary cover. Geothermal gradients presented in the form of an isogeothermal map show a general increase from north to south. The low geothermal gradients and high rate of subsidence of the region are responsible for the considerable extension of the catagenetic zone of organic matter maturation and petroleum formation at depth. The obtained data on individual sites allow an assessment of the maturity of organic matter and transformation of its associated products, as well as the delineation of the depth limit in each area where oil, wet gas and dry gas can be generated. The study reveals that in the northern part of the region (Sylhet Trough), the potential liquid hydrocarbon-bearing zone could be extended downwards to a considerable depth of about 8000 m, and this zone becomes gradually deeper from the north to the south of the Bengal Foredeep.
- M. Ismail and A. H. M. Shamsuddin
- Published Journal
- Journal of Southeast Asian Earth Sciences, 1991
M. Ismail,A. H. M. Shamsuddin. 1991. Organic Matter Maturity And Its Relation To Time, Temperature And Depth In The Bengal Foredeep, Bangladesh. Journal of Southeast Asian Earth Sciences. (!) .