The sequence stratigraphy theory and method system formed in the 1980s and has been gradually mature, becoming the most striking modern stratigraphy and sedimentology theory and method of the system.Aiming at sequence stratigraphic classification of putaohua oil layers in Talaha Changjiawezi area, as sequence stratigraphy, sedimentology and petroleum geology theory the instruction, comprehensive use of various materials, depthly analysising the division of stratigraphic units in the study area, the sequence identification marks and the establishment of sequence stratigraphic framework.Established the sequence stratigraphic frame work and the sequence stratigraphic model in the study area.
Talaha Changjiaweizi area is located in the central depression area within the first-order tectonic units, across Longhupao bubble-Da’an terraces, Qijia-Gulong sag and daqing placanticlin three second-order tectonic units in China.The formation from the old to the new develop Quantou formation,Qingshankou formation, Yaojia, Nenjiang group, Sifangtai, MingShui, Taikang group and Quaternary strata, lack of Tertiary Yi’an group and Da’an group formation. Lithology is mainly sandstone and mudstone and the sedimentary facies are mainly fluvial facies, delta facies and lacustrine facies.Fluvial and delta facies form the oil and gas reservoir and lake facies form favorable source rocks and seal, making the sag develop many sets of oil and gas combination under the cretaceous period. According to the traditional stratigraphic theory, the target stratum is the first member of Yaojia formation(XIV). Through the research, LST of sequence XIV(Y1L) is formed under the background of forced lacustrine regression ,made up of three type prograde quasi sequence sets. TST(Y1T) is made up of three type retrogradation of quasi sequence set.HST (Y1H) is given priority to with accretion. After detailed analysis, research, stratigraphic classification and correlation, research area can be divided into SQ1, fo SQ2 and SQ3 from bottom to up, corresponding P13, P12 and P11 reservoir group.P11 reservoir group is distributed in the whole region,with northern formation thicker and average thickness 16.3m, formation thickness concentrated near 17 m.Similarly,P12 reservoir group is distributed in all the region,with the formation thickness thicker in the northeast and thinner in the southwest,and mostly near 18 m.While P13 has missing group in the northwest, formation thickness changing fast, in addition,most formation thickness is about 26m. In conclution,the results enrich the continental lacustrine basin sequence stratigraphy and sedimentology theory.
Topics: Lacustrine sedimentation , Topics: Sequence stratigraphy , Topics: Geophysics and geophysical methods in sedimentology
