Hongtao Zhu

Seismic-based sediment provenance analysis in continental lacustrine rift basins: An example from the Bohai Bay Basin, China

By using recently acquired three-dimensional seismic data, a seismic-based sediment provenance analysis was conducted in the late Paleogene sequence of the western slope of the Bozhong sag, Bohai Bay Basin, where the main depositional center was between the Shaleitian uplift and the Shijiutuo uplift. Three styles of sediment-transport pathways were identified in the study area, including sediment transport via (1) faulted troughs, (2) incised valleys, and (3) structural transfer zones. The Paleogene deposits in the study area were primarily controlled by the faulted-trough pathways, which are northeast–southwest oriented in between different northeast–southwest-trending faults with sediments derived primarily from the Shaleitian uplift. The sediments to the east of the Shaleitian uplift were interpreted to have sourced via relatively long-distance transportation and deposited along the northeast–southwest-trending faulted troughs, forming a deltaic sediment belt. In contrast, sediments derived from the Shijiutuo uplift, which were transported by the incised-valley pathways and deposited in the southern margin of the uplift, formed proximal fan-deltas. The depositional systems in the study area are characterized by the coupling of source–faulted-trough pathway–deltaic–lacustrine deposits in the eastern margin of the Shaleitian uplift and that of source–incised-valley-pathway–fan-deltaic–lacustrine deposits near the southern margin of the Shijiutuo uplift. The proposed spatial distribution of the sand bodies extends the distribution range for potential reservoir sand bodies beyond the currently exploration area. This work may serve as a useful reference for sedimentary provenance analysis in other types of sedimentary basins.

Seismic interpretation of tectonic and paleogeomorphologic controls on sediment dispersal patterns in a continental rift basin: A case study from the Bohai Bay Basin, China

AbstractTectono-paleogeomorphologic frameworks exert a major control on sediment dispersal patterns and types of depositional systems, both of which influence reservoir geometry and quality. In this study, we analyze the framework of the Ed3 Member of the Dongying Formation in QHD29-2 Block, Bohai Bay Basin, China. The framework is constructed through (1) conventional sedimentologic study of single-well facies, cumulative frequency curves, and thin section analysis, (2) seismic stratigraphic interpretation of sectional seismic facies, and (3) seismic sedimentologic mapping through stratal slicing and seismic multiattribute analysis. The structural system is marked by a master boundary fault in the Shijiutuo Uplift that has greater displacement at its center than at the propagating fault tips. The resulting paleogeomorphologic architecture is characterized by a steep slope in the central part of the boundary fault and two gentle slopes at fault tips. Sediment dispersal patterns indicate that fan-shaped and...

Effects of low- to high-angle normal faults on sedimentary architectures in the Eocene Wenchang Formation, Enping Sag, Pearl River Mouth Basin, South China Sea

ABSTRACT The effects of low- to high-angle (>30°) normal faults on sedimentary architectural units in the Eocene Wenchang Formation, Enping Sag, Pearl River Mouth Basin (PRMB), South China Sea were investigated utilising a high-quality 3D seismic data set and restored paleogeomorphology. It has been shown that sequence stratigraphic units and sedimentary architecture are significantly controlled by the low- to high-angle normal faults. The Wenchang Formation, a second-order sequence, can be subdivided into two para-second-sequences (the Lower and Upper Wenchang sequences, E2WL and E2WU) and seven third-order sequences (from base to top: SQ1∼SQ7). The low-angle fault confined sequence architecture of the Wenchang Formation is mainly characterised by lateral stacking with the ratio of the vertical subsidence (V) to horizontal slip (H) being reduced from 1/2 for E2WL to 1/6 for E2WU. In contrast, the high-angle fault confined sequence is characterised by vertical stacking with the ratio of V/H close to 1 for sequences SQ1 to SQ7. In the 3D seismic area, the features of sediment-dispersal pattern were interpreted based on an integrated analysis of paleogeomorphology, seismic reflection characteristics, stratal thickness distribution and multiple attribute clustering. The results show that the large-scale fan delta, belt-shape lacustrine deposit and bird-foot braided delta systems mainly developed in the low-angle fault confined sequences, whereas small-scale fan delta, rhombus-shaped lacustrine deposit and lobe-shaped braided delta systems inherited tectono-sedimentary architectures in the high-angle fault confined sequences.

Introduction to special section: Source-to-sink system analysis of petroliferous and other sedimentary basins

The source-to-sink system comprises all areas that contribute to erosion, transportation, and deposition of sediments within an erosional-depositional system. The source-to-sink system is often described in terms of its dynamic drivers producing unsteady (allogenic) and steady (autogenic) responses

Differential source-to-sink system analysis for three types of stepped terrains in China

AbstractThe terrains of China, showing a trend of being high in the west and low in the east, can be categorized largely into three types of stepped terrains that consist of different geomorphic units — namely, glaciers and mountains (the first [highest] step), basins and plateaus (the second [less high] step), and plains (the third [lowest] step). The source-to-sink systems in the first and second steps are closed systems from land to lake, whereas those of the third step are mainly open systems from land to ocean. We have based our analytical methods mainly on the parameters of the source-to-sink systems for the three types of stepped terrains using the Google Earth database. We acquired data for the catchment area in the source unit, the longest channel and coefficient of river-network development in the conduit unit, the fan area and fan length: width ratio in the sink unit, and the gradient of the entire system. On the basis of our comparison of these parameters in the three types of stepped terrains...

Pore Fluid Evolution Influenced by Volcanic Activities and Related Diagenetic Processes in a Rift Basin: Evidence from the Paleogene Medium-Deep Reservoirs of Huanghekou Sag, Bohai Bay Basin, China

Volcanic activities exert a significant influence on pore fluid property and related diagenetic processes that substantially controlled reservoirs quality. Analysis of Paleogene medium-deep sandstones on the Huanghekou Sag provides insight into relating the diagenetic processes to pore fluid property evolution influenced by volcanic activities. Three distinct types of pore fluids were identified on the basis of an integrated and systematic analysis including core and thin section observation, XRD, SEM, CL, and trace element. Alkaline aqueous medium environment occurred in E2s1