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High Resolution Sequence Stratigraphy Analysis From Well Logging Data

Posted on:2009-03-05Degree:DoctorType:Dissertation
Country:ChinaCandidate:X H LiFull Text:PDF
GTID:1100360245472934Subject:Mining engineering
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Tengge'er formation, as one of the three favorable hydrocarbon source rocks and three oil-bearing strata in Baiyinchagan depression, Erlian basin, shows great potential to exploration and development. This thesis, aimed at the questions of fine strata correlation, sedimentary features, regular pattern of sand-body distribution and combination of Tengge'er formation, beginning with methods and quantification techniques study of high resolution sequence stratigraphy analysis from well logging data, making use of the basic theories in fields of well logging geology and petrophysics, have done some research in high resolution sequence stratigraphy analysis on Tengge'er formation. After doing this, the author hope that the achievements laid cornerstone for the exploration and development in Baiyinchagan dpression, and have great effects to promote the quantification of high resolution sequence stratigraphy analysis. Main achievements in the research are as the following:(1)Based on mathematic methods, parameters, which used to high resolution sequence stratigraphy analysis from well logging data, have been extracted from log curves, the parameters includes amplitude parameters, the parameters that can reflect sedimentary characters, the interpretation parameter sets that can be used on lithology discrimination, best eigenvalue, high and low frequency parameter values.(2)Lithology discrimination of Tengge'er formation has been done by using non-linear lithology discrimination model that established from support vector machines. The results show that the parameter sets, which combined with average, extreme difference and variance parameters of nature gamma, sonic, density, and neutron curve is suitable to lithology discrimination.(3)It's first time that the function of characteristic classification have been used on identification and quantification of transformation boundaries, under different values of that, transformation surfaces which reflect sequence boundaries such as base value alternation of log curves, large scale riverway erosion, progradation(aggradation) with retrogradation have been identified.(4)Log curve shapes and strata stacking patterns have been judged automatically though curves simulation, using the coefficient of independent variable in the highest rank which derived from mathematic expression of the simulated curve.(5)Litho-electric property relationship has been established from the data of cores and well logging, joining with the establishment of log-facies models of fan delta and braided delta in Tengge'er formation, log-facies of Tengge'er formation have been analyzed.(6)According to A/S (Accommodation/Supply) variation, based on analysis results of cycle properties and its stacking patterns of well logging, short-term base lever cycle sequences have been divided into three main types including up-deeping asymmetry, up-shallowing asymmetry and symmetry, and seven secondly types. Under curve variation trend in low frequency that come from wavelet transformation, mid-term cycles number of Tengge'er formation have been confirmed to seven(MSC1-MSC7) by using curve a7 as an reference. Tengge'er formation was a long-term cycle which composed with ascending and descending semi-cycle, according to transformation boundary of ascending and descending semi-base lever cycle in MSC4.(7)Under short-term base lever cycle,sand-body growths mainly in bottom of ascending base lever cycles and top of descending base lever cycles. Under same time strata framework of mid-term base lever cycles, Tengge'er formation in Daerqi area have been divided into 4 different provenance, in which, middle-east provenance have a long extension, at the end of it, turbidite fan developed, strata sedimentary of MSC4 in mid-term base lever cycles show lake transgressive characters. Under long-term base lever cycles, at the beginning of ascending base lever cycles, strata stacking types show the trend of aggradation to retrogradation, at the time of descending base lever cycles, strata stacking types show the trend of slightly progradation or aggradation, oil formation below is higher than oil formation upside in characters of sand-body thickness, grain size and oil-bearing.(8)Tengge'er formation shows low to middle porosity and low to extra-low permeability characters, formation geophysical properties show notability differentiation and extra heterogeneity in portrait and lateral, in which, geophysical properties in microfacies of subaqueous distributary channel and mouth bar are best.
Keywords/Search Tags:Geophysical logging, High resolution sequence stratigraphy, Log-facies, Wavelet transformation, Support vector machine, Sequence boundary
PDF Full Text Request
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