Influences of Tibetan Plateau uplift on provenance evolution of the paleo-Pearl River

A comparative analysis of the geochemical characteristics of sediments from the Oligocene Zhuhai Formation(32-23.8 Ma),the Miocene Zhujiang Formation(23.8-16.5 Ma),and the Hanjiang Formation(16.5—10.5 Ma) and a comprehensive analysis of the geochemical characteristics of rocks surrounding the paleo-Pearl River drainage contribute to understanding the influences of the Tibetan Plateau uplift on provenance evolution of the paleo-Pearl River.The results show that the geochemical characteristics of sediments from the Oligocene Zhuhai Formation are very different from the geochemical characteristics of sediments from the Miocene Zhujiang and Hanjiang Formations.The ∑ rare earth elements(REE) of mudstone is relatively high in the Zhuhai Formation,204.07-293.88 ppm(average 240.46 ppm),and low in the Zhujiang and Hanjiang Formations,181.32-236.73 ppm(average 203.83 ppm) and 166.84-236.65 ppm(average199.04 ppm),respectively.The chemical index of alteration(CIA) for these samples has a similar trend to the∑ REE:the CIA of the Zhuhai Formation is relatively high and the CIA of the Zhujiang and Hanjiang Formations is relatively low.The uplift of the Tibetan Plateau is crucial to the westward expansion of the paleo-Pearl River drainage.

Accounting and Tax Planning for High Technology Enterprises

In recent years,the importance of science and technology,as the first productive force,has been gradually highlighted.China pays great attention to high-tech enterprises and strongly supports them in fiscal and taxation policies to promote their development effectively.In responding to national policies,high-tech enterprises also continue to improve their efficiency,so the accounting and tax planning work of enterprises is mandatory.However,combined with the status quo of accounting and tax planning of high-tech enterprises,there is something to be improved in both aspects,which makes the enterprises’financial and taxation risks higher and is not conducive to their normal operation.Based on this,the article will focus on the accounting and tax planning of high-tech enterprises as the main object of research.

Analysis of the Sedimentary Characteristics of a Modern Distributive Fluvial System:A Case Study of the Great Halten River in the Sugan Lake Basin,Qinghai,China

Understanding controls on river planform changes can help to build predictive models for distributive fluvial systems,and then guide the oil and gas exploration.To do this we have undertaken a detailed investigation of the modern Great Halten River distributive fluvial system from the Sugan Lake Basin,Qinghai,China.Unmanned aerial vehicle(UAV) photography,satellite remote sensing data and elemental analysis were used to determine differences in the sedimentary characteristics of the distributive fluvial system.From the apex to the toe,the changes in the slope,river morphology,sedimentary characteristics and element content in different regions were determined and three facies belts:“proximal”,“medial” and “distal” were identified.We found that the sedimentary structure and elemental content characteristics of each facies differ greatly.We compare the large-scale evolution of rivers from braided to meandering rivers,and the fine description of sedimentary characteristics in combination with each observation,we strengthen our overall understanding of the modern DFS from macro to micro scale.At the same time,we summarize the sedimentation model of the Great Halten River DFS,and our study provides a reference for establishing the sedimentary model in continental petroliferous basins.

Diagenesis and diagenetic stages prediction of Ed2 reservoir in the west of Bozhong sag

Diagenesis of clastic rock and hydrocarbon generating capacity are closely related with diagenetic stages.Based on diagenetic evolution,reservoir diagenetic stages prediction method is proposed through making a contrastive study of simulation results and test results using core measurement data.The essence of this method is illustrated and its effectiveness is demonstrated using Ed2 clastic sandstones in the west of Bozhong sag,Bohai Bay Basin,China.Measurement of paleo temperature(T),vitrinite reflectivity(Ro%)and the proportion of smectite in illite/smectite interstratified minerals(I/S-S%)indicate that there are there types of diagenetic stages in the study area,including early diagenetic stage B,middle diagenetic stage A1 and middle diagenetic stage A2.When only considering T index for diagenetic stages prediction,the simulation results are more conservative than measured data with some situations,and the simulation result using Ro%for diagenetic prediction is less than measured data in some wells.When I/S-S%is used,the two situations above both exist.Because depth,temperature,time duration,pressure and some chemical variables can change synchronously or asynchronously,it is difficult to attribute with certainty the parameters that affect the apparent diagenetic stages evolution series.Diagenetic stage variations can be significantly different in different parts of one sedimentary basin.A synthetic indexes method considering T,Ro%,I/S-S%to predict its distribution,and the simulation result has proved that the reliability of the model has greatly improved.

Bedding-parallel fractures in ultradeep tight sandstone reservoirs in Jurassic and Cretaceous of Yongjin Oil Field,Junggar Basin,China

Bedding-parallel fractures are fractures that are parallel to rock bedding structure planes and have been widely accepted as a key factor for oil and gas production in tight sandstone and shale reservoirs.However,the formation mechanisms of these parallel-bedding fractures are still under debate.In this study,bedding-parallel fractures in Yongjin Oil Field were analyzed using methods including core and microscopic observations,element geochemistry,and carbon and oxygen isotope analysis.Their origin and relations to reservoir quality,faults,and rock mechanical properties were examined.The discovery of bedding-parallel fractures in both the Upper Jurassic and Lower Cretaceous formations indicates that the BPFs are generated later than the early Cretaceous.The filling state of bedding-parallel fractures that with no bitumen and carbonate cement indicate that they formed after oil charging and carbonate cementation.The tensile fracture characteristics in core and thin section observa-tions,and the fact that overburden stress exceeds the pore pressure indicate that the bedding-parallel fractures were neither generated from tectonic compression nor over-pressure.The most likely generation mechanism is stress relief during core drilling under high in situ stress conditions.High in situ stress and low tensile strength lead to thinner fracture spacing.The existence of high bedding-parallel fracture density is an indicator of good reservoir quality and result in high oil/gas production.