Putaohua Oil Layers Of Sequence Stratigraphic Analysis And The Research Of Sedimentary Facies In Northern Chang Ling Sag

Based on the high resolution sequence stratigraphy and sedimentology theory as the instruction,and using the data of core, drilling, logging, etc, sequence stratigraphy analysis and sedimentary facies were researched to putaohua oil reservoir in northern of changling depression. It, whose sand body is non-development, is seemed to deep lake development zone of songliao basin for the long-term exploration. The study found that sedimentary body of putaohua reservoir is given priority to with delta front facies, sand body of development. That provide good preservation for oil and gas gathering place.Based on the high resolution sequence stratigraphy and sedimentology theory as the instruction,and using the data of core, drilling, logging, etc, sequence stratigraphy analysis and sedimentary facies were researched to putaohua oil reservoir in northern of changling depression. It, whose sand body is non-development, is seemed to deep lake development zone of songliao basin for the long-term exploration. The study found that sedimentary body of putaohua reservoir is given priority to with delta front facies, sand body of development. That provide good preservation for oil and gas gathering place.Putaohua reservoir formed in first member of the Yaojia formation. During this period, the lake area contracts, then slowly spreads. The base level transformats from down to up. The sedimentary evolution shows characteristics of water subsidence to water transgressive in vertical.The middle base level cycle of putaohua reservoir is regarded as water subsidence. Based on the analysis of single well cycle, reunification of the regional cycle is achieved. That is the putaohua oil layer of changling sag northern is divided into a medium cycle and 8 short half cycle. Through analyzing of sequence stratigraphy, the reservoir is divided into three sand groups, including up, middle and down. The middle sand group, which has the characteristics of smaller values of the A/S, sediment supply relatively abundant and sand body development, is in late fall to rise early of datum. The sand body distribution of up and down is smaller.On the whole, the sand body of north is superior to the south. the development. According to the thickness of sandstone, sediment granularity, heavy mineral content and transverse changes and longitudinal superimposed of the lithological facies, etc, source direction has been defined. It is mainly controlled by the north provenance, which is composed of three palaeocurrent. South of the work area is affected by the southern provenance. The ancient landform is relatively flat, and it is mainly for the shallow water delta deposits. Through the source, single well facies, section facies and phase plane, sedimentary environment and sedimentary-facies distribution of putaohua reservoir are analyzed carefully from point to surface. It mainly includes underwater distributary channel, distributary bay, sand sheet, sheet sand microfacies of delta front. From vertical: since the putaohua oil layer at the bottom of the yao â†' middle â†' upper â†' 2 + 3 period,Vertical phase sequence by former delta subfacies and delta front sand sheet to delta front underwater distributary channel, delta front sand sheet- front delta subfacies.Again based on aggregation characteristics of reservoir and its main control factors, division of favorable zones for oil and gas gathering and guidethe oilfield development.