Papers by Keyword: Sequence Stratigraphy

Abstract: Zhunzhong area Qingshui River group has top and bottom boundaries,which are not clear,and research on the evolution of the lack in sequence stratigraphic framework of deposition and on the reservoir sand body types do not have a clear understanding problem.In seismic interpretation, core description and based on the analysis of the related test,combining with the mud logging and well logging data,for the redefinition of Qingshui River group on the top and bottom boundaries,it identifies 6 time significance of sequence boundary,taking Qingshui River group can be divided into 2 sequences, 5 system tracts;clear and definite the study area mainly developed delta lacustrine depositional system,which can be further divided into the delta front subfacies, beach bar facies and semi deep lake subfacies. It takes an analysis on the sedimentary characteristics and distribution rules of different types, and it controls effect of topography and hydrodynamic conditions on deposition system, and then puts forward the corresponding sedimentary patterns.

Abstract: Carbonate reef reservoir buried deeply, show great heterogeneity, Therefore, effective reservoir prediction is the key to the biohermal reservoir. In practical research, based on of the single well sequence stratigraphic framework, combined with these sequence stratigraphic framework and seismic section, found the reservoir development area in the longitudinal, which sq1-HST and sq3-HST is the main period of reservoir development, and then through the seismic Seismic multiple-attribute inversion, predicted porosity of system tracts of reservoir development in the sequence stratigraphic framework. Porosity inversion results shown, Changxing formation reservoir is mainly distributed in the central and north-central of Jiannan area.

Abstract: Based on the study of drilling, well logging and seismic profile, the Jurassic strata of the study area can be divided in to 2 2^nd-order and 4 3^rd-order sequences. The same formation in different regions unevenly distributed in study area due to sedimentary environment, sedimentary palaeotopography, post-depositional uplift and different degree of erosion. 4 3rd-order sequence boundaries can be recognized in this study, the results shown that the sequence boundaries used to be on the abrupt change point of the logging curve and are characterized by the bottom of large size braided channel scouring.

Abstract: This document studies the deposition condition in northeast Jizhong depression by using relevant data of cores, logging and scanning electron microscope. The result indicates that the study area has 7 kinds of lithofacies, including conglomerate, sandstone, siltstone, mudstone, bauxite, carbonate rock and coal seam . Bottom-up development in the study area cover tidal flat, lagoon, delta, meandering river and braided river, a total of five kinds of sedimentary facies. Benxi Formation, Taiyuan Formation and Shanxi Formation deposited in transitional facies, which has high generation potential of Hydrocarbon. Lower and upper Shihezi Formation is mainly a set of river deposition as a good reservoir. The top of upper Shihezi Formation and Shiqianfen Formation are mainly mudstone, which is conducive to seal oil and gas.

Abstract: By using geological and geophysical data and according to the basic characteristics of sequence boundary, Putaohua Reservoir in Daan Oilfield is divided into a rise hemicycle in long-term cycles, a full middle-term cycle, nine short-term cycles and a number of ultra-short-term cycles.The high-resolution sequence stratigraphic framework of Putaohua reservoir under monosandbody rank is established, and a set of techniques and methods to high-resolution sequence stratigraphy correlation in shallow delta is summed up.

Abstract: By using the data of core, geological log and seism and the theory of sedimentology and sequence stratigraphy , the sequence of Shahezi formation in Xujiaweizi depression are divided into five third-order sequence, they are SQ1, SQ2, SQ3, SQ4 and SQ5 up towards. The range of SQ1 is limited, influenced by palaeogeomorphology. SQ5 are greatly influenced by the late sedimentary denudation, now only in the northwest of the study area can be seen, other part is missing in this layer. SQ1, SQ2, SQ3 are onlap filled. There are defective area in SQ4 and SQ5.

Abstract: Sequence stratigraphic features of the Jurassic succession in Central Junggar Basin were investigated by integrating multiple materials including cores, well and seismic data. Due to their unique formation mechanism, sequences of the target interval were analyzed with a binary systems tract mode (each complete sequence contains a transgressive systems tract and a highstand systems tract) rather than the traditional one. Basic principles and analytical methods of high-resolution sequence stratigraphy were also applied to this research. By adopting cyclic correlation and hierarchical control techniques, eight sequences (Sq1-Sq8) were identified in the target interval. Especially, coal seams are of great significance in the sequence identification and they were considered to be closely relevant to maximum flooding surfaces (mfs).

Abstract: Sequence is a relatively conformable succession of genetically related strata bounded by unconformities or their correlative conformities. The correct identification of sequence boundaries is the key to the success of the sequence stratigraphic approach. Stratigraphic boundaries provide the fundamental framework for the genetic interpretation of any sedimentary succession, irrespective of how one may choose to name the packages of strata between them. Sequence stratigraphy of main research content is mainly chronohorizon (unconformity or conformity) identification, and to determine its causes and characteristics. Then, the key to sequence stratigraphy is identification unconformity and their correlative conformities. Unconformity and their correlative conformities on the seismic profiles, well logs, lithology, paleontology, and geochemical data have distinctive sequence boundaries mark characteristics.

Abstract: A total of two third-order sequences are subdivided in Late Permian. Sequence 1 is from the bottom of the Longtan Formation to the bottom of C₁₆ coal in Longtan Formation,representing a transgressive to regressive cycle,and the Sequence 2 is from the bottom of C₁₆ coal in Longtan formation to the top of the Changxing Formation. From Maokou formation to the first flooding surface (the bottom of the C₂₅) is the low systems tract in sequence 1(the earlier stage of coal accumulation). The palaeogeographic map has been reconstructed based on the contour maps of a variety of palaeogeographic parameters including total thickness of strata,thickness of sandstone,thickness of mudstone,and sandstone-mudstone ratio. The paleogeographic units include lowlandhighland eluvial plain and bay-lagoon-tidal. The transgression comes from south and the sediment provenances are mainly from the Kangdian old land in the west.

Abstract: Based on the theory of sequence stratigraphy, sequence stratigraphy framework of is established in this paper by comprehensively search of core, logging and 3-D seismic data. Zhalainuoer group in Cano Depression is divided into 5 3rd-order sequences: Sq1、Sq2、Sq3、Sq4、Sq5 from down to up. Based on the division and comparison of sequence formation, the sedimentary facies and the depositional system are proposed to study in the paper, and the main depositional systems are detailed explained. The distribution of these depositional systems is controlled by the sequence framework.