Based on the theory of superimposed deformation and the regional tectonic background, the multi-phase non-coaxial superimposed structures in Junggar Basin were systematically analyzed using seismic interpretation, field outcrop observation, and paleo-stress field recovery methods according to the characteristics of the current tectonic framework. Moreover, the tectonic evolution process of the basin was reconstructed using sandbox analogue modelling technology. The results showed that the study area has experienced five phases of non-coaxial deformation with superimposition: The first phase of deformation (D₁) is characterized by NNE-SSW extension during late Carboniferous to early Permian, which formed large graben, half graben and other extensional structure style around the basin. The second phase of deformation (D₂) is represented by NE-SW compression during the middle to late Permian, and it comprised numerous contraction structures that developed based on D₁. The basic form of the entire basin is alternating uplift and depression. The third phase of deformation (D₃) is the NW-SE transpressional strike-slip in the Triassic-Jurassic, which produced numerous strike-slip structural styles in the middle part of the basin. The fourth phase of deformation (D₄) is the uniform sedimentation during Cretaceous, and the fifth phase (D₅) is the compression along NNE-SSW due to the North Tianshan northward thrust, which produced three rows of fold thrust belts and tear faults in the front of the mountain in the southern margin of the basin. The newly established three-dimensional tectonic evolution model shows that, based on the large number of NW-trending grabens and half grabens in the Carboniferous basement of Junggar Basin, multiple level NE trending uplifts have formed with the joint superposition of the late structural inversion and multiple stress fields. This has resulted in the current tectonic units of alternating uplifts and depressions in different directions in the study area.

The evolution of faults within the same stress field is frequently influenced by numerous factors, involving the reactivation of pre-existing structures, stress transmission through ductile detachment layers, and the growth, interaction, as well as linkage of new fault segments. This study analyses a complex multi-phase oblique extension fault system in the Nanpu Sag (NPS) of the Bohai Bay Basin (BBB), China. High-resolution three-dimensional (3D) seismic data and analogue modelling indicate that the oblique extensional reactivation of pre-existing structures governs the sequential arrangement of fault segments in the caprock, and they dip synthetically to the reactivated fault at depth. During the NW–SE extension in the Eocene, the predominant movement of the pre-existing fault is strike-slip. Subsequently, during the N–S extension since the Oligocene, inclined at 20° to the pre-existing fault, forming splay fault segments and ultimately creating large en-échelon arcuate faults linked by relay ramps. Using fault throw-distance (T-D) and laser scanning, we reconstructed the fault evolution model of oblique extension reactivation in the presence of a ductile detachment basement. Our study illustrates that the arcuate faults can be categorized into linear master fault segments controlled by pre-existing structures, bending splay faults in the termination zone, and normal fault segments responding to the regional stress field. The interaction between faults occurs among normal faults and strike-slip faults, and the kinematic unification of the two fault systems is accomplished in the intersection zone. As the faults continue to evolve, the new fault segments tend to relinquish the control of pre-existing structures and concentrate more on the development of planar and continuous major faults. The ductile detachment layer significantly contributes to the uniform distribution of strain, resulting in narrow shear zones and discontinuous normal faults in its absence.

Currently, the lower Paleogene Wenchang formation in the Lufeng Depression is the primary focus of reservoir development. The structural fractures that have formed inside of it not only serve as the principal path for oil migration, but also as oil storage space. As a result, the distribution features of structural fractures are crucial for future petroleum exploration and development in the Lufeng Depression. At the same time, with the quantity of conventional reservoirs in the Lufeng Depression on the decline, it is critical to determine the fracture distribution criteria for deep unconventional reservoirs. In this work, the lower Paleogene Wenchang formation in the Lufeng Depression is used as the research stratum. Then, based on existing logging data for the research region, the distinct physical properties of different rock kinds are calculated. The simulation results of the paleotectonic stress field in the study area using the finite element numerical simulation software ANSYS show that the high-value areas of maximum principal stress are the high-value areas of the uplift belt and low uplift, and the areas with low maximum principal stress are the low-value areas of Lufeng 13 Sag and the gentle slope belt in the north of Lufeng middle-low uplift. The fracture density is quantitatively predicted after the stress field simulation, which shows good agreement between the anticipated and actual observed values, and an average error of 13.61%. The predicted findings may provide new ideas for future petroleum exploration.

In this paper, taking the Lufeng Depression as the study object, the distribution characteristics and reservoir-controlling conditions of palaeo-uplift are analyzed from both qualitative and quantitative perspectives. The distribution characteristics of the three-level palaeo-uplift structural pattern are elucidated, which show that the palaeo-uplifts went through three structural evolutionary stages: Eocene, Early-Middle Miocene, and Late Miocene, with long-term inherited development characteristics. Palaeo-uplift controls the distribution of hydrocarbon planes, the direction of dominant hydrocarbon transport, the development of various traps, and the types of hydrocarbon reservoirs. Applying the principle and method of "multi-element matching reservoir formation model", the corresponding geological and mathematical models are established, which indicate that 86.29% of the number of reservoirs are distributed on the top and slope of the palaeo-uplift, and the reserves and number decrease with the distance to the top of the palaeo-uplift. Based on the palaeo-uplift control model, four high-probability areas for palaeo-uplift control in the Wenchang and Enping Fms are predicted, which are mainly located in the Lufeng middle-low uplift, the Dongsha uplift, and uplifts within the depression.