Palaeostructure, evolution and tight oil distribution of the Ordos Basin, China

International audienceWhether or not the tight oil in the Triassic Yanchang Formation of the Ordos Basin is controlled by structural factors is a controversial issue, the relationship between the structural factors of the strata and the distribution of tight oil is limited to the study of current structures. The traditional view is that structural factors have no obvious control over the formation and distribution of the oil reservoir. Taking the Chang 8 member of the Triassic Yanchang Formation in the Ordos Basin as an example, this paper studies respectively the burial of strata-hydrocarbon generation history of the individual well and the structural evolution history of strata in the basin by using software tools of the Genex burial-hydrocarbon generation history restoration and TemisFlow evolution of stratigraphic structures. It is considered that the hydrocarbon generation period of the source rock of the Triassic Yanchang Formation in the Ordos Basin is from early Middle Jurassic to end of Early Cretaceous. By reconstructing the evolution and structure of the Chang 8 member during the hydrocarbon accumulation period, combined with a comprehensive analysis on the distributional characteristics of the Chang 8 oil reservoir, we found the palaeoslopes and palaeohighs of the Chang 8 reservoir to represent areas in which tight oils were distributed. Palaeo-structural characteristics of the target layer exhibit control over the Chang 8 reservoir. The new theory underlying tight oil exploration, which is based on the recovery of the palaeogeomorphology of the target layer during the hydrocarbon generation period, incorporates the vital roles of key controlling factors over tight oil accumulation, so that the mind-set on tight oil exploration in the Ordos Basin has evolved

Palaeostructure, evolution and tight oil distribution of the Ordos Basin, China

Whether or not the tight oil in the Triassic Yanchang Formation of the Ordos Basin is controlled by structural factors is a controversial issue, the relationship between the structural factors of the strata and the distribution of tight oil is limited to the study of current structures. The traditional view is that structural factors have no obvious control over the formation and distribution of the oil reservoir. Taking the Chang 8 member of the Triassic Yanchang Formation in the Ordos Basin as an example, this paper studies respectively the burial of strata-hydrocarbon generation history of the individual well and the structural evolution history of strata in the basin by using software tools of the Genex burial-hydrocarbon generation history restoration and TemisFlow evolution of stratigraphic structures. It is considered that the hydrocarbon generation period of the source rock of the Triassic Yanchang Formation in the Ordos Basin is from early Middle Jurassic to end of Early Cretaceous. By reconstructing the evolution and structure of the Chang 8 member during the hydrocarbon accumulation period, combined with a comprehensive analysis on the distributional characteristics of the Chang 8 oil reservoir, we found the palaeoslopes and palaeohighs of the Chang 8 reservoir to represent areas in which tight oils were distributed. Palaeo-structural characteristics of the target layer exhibit control over the Chang 8 reservoir. The new theory underlying tight oil exploration, which is based on the recovery of the palaeogeomorphology of the target layer during the hydrocarbon generation period, incorporates the vital roles of key controlling factors over tight oil accumulation, so that the mind-set on tight oil exploration in the Ordos Basin has evolved

Chloridobis(1,10-phenanthroline-κ2 N,N′)copper(I) dichloridocopper(II)

The asymmetric unit of the title compound, [CuCl(C12H8N2)2]·[CuCl2], contains two complex Cu(II) cations and two cuprate(I) anions. The Cu(II) atom is coordinated by two phenanthroline (phen) mol­ecules and one chloride anion in a distorted trigonal–bipyramidal geometry. The Cu(II) complex cations form layers through π–π stacking [interplanar distance = 3.481 (2) Å]. The dichloridocuprate(I) anions are located between the layers, forming a sandwich-like structure

2-Amino-4-(2-chloro­phen­yl)-5-oxo-5,6,7,8-tetra­hydro-4H-chromene-3-carbonitrile ethanol monosolvate

In the title compound, C16H13ClN2O2·C2H6O, the fused cyclo­hexene and pyran rings adopt envelope and flattened boat conformations, respectively. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the chromene and ethanol solvent mol­ecules into infinite chains along the c axis, and N—H⋯N hydrogen bonds link these chains into a three-dimensional framework. Weak C—H⋯π inter­actions are also present

A new approach for optimising GNSS positioning performance in harsh observation environments

Maintaining good positioning performance has always been a challenging task for Global Navigation Satellite Systems (GNSS) applications in partially obstructed environments. A method that can optimise positioning performance in harsh environments is proposed. Using a carrier double-difference (DD) model, the influence of the satellite-pair geometry on the correlation among different equations has been researched. This addresses the critical relationship between DD equations and its ill-posedness. From analysing the collected multi-constellation observations, a strong correlation between the condition number and the positioning standard deviation is detected as the correlation coefficient is larger than 0·92. Based on this finding, a new method for determining the reference satellites by using the minimum condition number rather than the maximum elevation is proposed. This reduces the ill-posedness of the co-factor matrix, which improves the single-epoch positioning solution with a fixed DD ambiguity. Finally, evaluation trials are carried out by masking some satellites to simulate common satellite obstruction scenarios including azimuth shielding, elevation shielding and strip shielding. Results indicate the proposed approach improves the positioning stability with multi-constellation satellites notably in harsh environments

CNV discovery for milk composition traits in dairy cattle using whole genome resequencing

General statistics of 487 differential CNVRs between high and low group based on UMD3.1. (XLSX 28 kb

Carbonization Resistance of Reinforced Concrete under Bending Load

Fly ash has been used more and more often to take the place of cement as the admixture of concrete in the construction of concrete buildings. However, with the increase of the carbon dioxide (CO2) concentration in the atmosphere, carbonization damage has become an essential factor affecting the durability of fly ash concrete. Here a long-term bending load device was developed to explore how the pouring surface and the bending load affect the carbonization resistance of reinforced concrete under rapid carbonization. In addition, the relationship between the bending-tension and bending-compression loads with respect to the carbonization damage of test blocks was also investigated. Due to the differences in the concrete compactness, the carbonization depth of the pouring surface was found to be greater than that of the bottom at the same position. To a certain extent, with the increasing bending-load stress, different carbonization resistances were observed in the bending-tension zone and the bending-compression zone of the concrete test blocks. Meanwhile, to study the relationship between the carbonization damages in the bending-tension zone and the bending-compression zone of concrete test blocks, a carbonization influence coefficient of bending tension-compression load was proposed, which provides a convenient and scientific guidance for the detection and evaluation of concrete carbonization damages in practical engineering. &nbsp