百色盆地百49块百岗组三段高分辨率层序地层学分析

以高分辨率层序地层学理论为指导，通过地表露头、岩芯、测井资料的综合研究，并结合地震剖面资料，分析了百色盆地塘寨油田百49块古近系百岗组三段不同级别的层序界面和湖泛面特征及识别标志，划分出1个长期、3个中期、14个短期基准面旋回层序。在此基础上，详细讨论了各级次基准面旋回层序的垂向序列、岩性岩相组合、结构类型及更加样式等特征，并探讨了高分辨率层序地层学的研究成果在区块油气开发工程中的应用前景。

ANALYSIS OF HIGH-RESOLUTION SEQUENCE STRATIGRAPHY OF THE THIRD SECTION OF BAIGANG FORMATION IN BLOCK BAI-49 OF TANGZHAI OIL FIELD

Through the comprehensive analysis of outcrops, rock cores, well logs, seismic interpretation and ESR data, and under the guidance of the theory and technology of the high resolution sequence stratigraphy, this paper studies the characteristics of the different grade sequence interfaces of the third section of Baigang Formation of Tangzhai oil field in Baise basin. According to the identification sign of the sequence interface and lake flood sedimentation, three grade base level cycle sequences (short term, middle term, long term cycle sequences) are divided, and one long term, three middle term, and fourteen short term base level cycle sequences are recognized. On the basis of these studies, the vertical sequence, facies association, lithologic composition, structure type and stacking pattern are discussed in detail. Among these sequences, the short term cycle sequence may be divided into three basic types of structure, that is, up deepening non symmetric structure, up shallowening non symmetric structure, and symmetric structure from up deepening to up shallowening, and furtherly into six subtypes of low or high accommodation and non complete or nearly complete symmetric structure. These basic sequence types and subtypes are of various superposition and distribution patterns. The structure type and superposition pattern of the middle term cycle sequence are the same that of the short term cycle sequence. The long term cycle sequence is of symmetric structure which develops a complete depositional sequence of lacustrine transgressive regressive cycle, which is a fast rate type. In this paper, the application of these different grade base level cycle sequences to the oil bed correlation, the foundation of sequence stratigraphic framework and the understanding of sandbodies distribution rule are probed in the light of these sequence characteristics.