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Raoyang Sag Paleogene Sequence Stratigraphy And Subtle Reservoir Exploration

Posted on:2007-03-29Degree:DoctorType:Dissertation
Country:ChinaCandidate:R F ZhangFull Text:PDF
GTID:1110360218956723Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
According to the basic theory of sequence stratigraphy, the paper focuses on the palaeogene in Raoyang Depression and carries out the recognition of boundaries of sequence stratigraphic units of every order with the combination of data of seism, well-logging, core, paleontology and so on. And it also carries through single-well sequence stratigraphic analysis and the correlation of connecting-well sequence stratigraphic sections. In the way that goes from point to plane, it carries out the division of the sequences and system tracts in the whole area. During this research, three second-order sequences, ten third-order sequences and twenty-seven system tracts are plotted out. The third-order sequences are divided into lake facies sequence, river sequence and climate sequence, and further, representative characteristic analysis is done to sequence of every type and then the sequence stratigraphic frame of palaeogene stratum in Raoyang Depression is established. Based on the characteristic of tectonic development in Raoyang Depression, the tectonic units of four types are divided out in the block area: gentle slope belt, steep incline belt, uplift belt and sub-sag belt. It does some research on the sequence stacking patterns of different tectonic units, establishes the development model of system tracts and then analyzes the controlling effects of tectonic subsidence, sedimentary supply and the climate factor on sequence development. And during this process, it shows that toplap surface can't always serve as the recognition symbol for sequence boundaryes. In this research area, six sedimentary systems are identified: alluvial fan facies, river facies, fan delta facies, braided river delta facies, neritic underwater fan facies and lake facies.On the bases of the study of sequence stratigraphy and sedimentology. With the combined analysis of the core observation and description, the identification of rock slice, the well-logging data and the seismic data, it carries out the research systematically on sequence stratigraphic architecture of Raoyang Depression, the characteristics of sedimentary facies marks, he sedimentary facies types and the space-time distribution rules and on this basis, it also points out the stratum and the space position for the favorable reservoir. Raoyang Depression is a complex of faulted basin and faulted-depressed basin, which forms under the background of rifting. It is filled with relatively thick clastic rock.. During the fault dividing and filling up period of Raoyang Depression, it mainly develops alluvial fan facies, river facies and playa lake facies which develops in local area. During the expanding period of the fault, the sedimentary facies are shallow lake, braided river delta, fan delta and neritic underwater fan which develops in parts of Maxi sub-sag and so on. During the end of the period, the uplifting period, the sedimentary facies are braided delta and river. During the faulted-depressed deposits period, it mainly develops shallow lake facies, and braided river delta facies, lack of the deepwater deposits. During the end of this period, the sedimentary facies are braided river delta and river. Based on this, it discusses the controlling effects of tectonic movement on sedimentary system, shows the migration rules of sedimentary center and carries out the primary discussion the evolution characteristics of the sedimentary facies in longitudinal direction. There are two sets of source rocks in the whole area. And there are sand bodies of braided river delta of great amount which surrounds the source rock stratum, stacking during many periods and they develop in a good way and are the main reservoir. It focuses on the analysis of the development area for favorable reservoir in Sequence VII (1st number of Shahejie ) in Linxian Slope.The paper also analyzed the development of source rock, reservoir and cap rock of every sequence,puts forward that the Liuxi Area is the favorable areas for oil and gas. through exploration by one year and foundation 5000 X 104 t control reserves.
Keywords/Search Tags:Raoyang depression, Sequence stratigraphy, Development models, Controlling effects, Sedimentary facies
PDF Full Text Request
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