# Analysis of Hydrocarbon Enrichment in Tight Sandstone Reservoirs in the Eastern Baiyun Depression
## 3 Structure and Multiple Reconstruction Characteristics of Eastern Baiyun Depression
### Tectonic Sedimentary Response  
The overall structure-sedimentary filling pattern is as follows: multiple sedimentary centers migrated and gradually evolved to form a single sedimentary center, small uplift structures and sub-depression structures gradually transformed to a single center of the main depression of the white cloud, small uplift structures gradually disappeared, the area of the sedimentary facies in the middle and deep lake gradually decreased, the protruding edges gradually submerged underwater, and braided-river delta and shoreline bar developed.  
During the Enping Formation, there was obvious inheritance with the upper Wenchang period, and the study area was transitioning to the faulting transition period. At the same time, the study area was still subjected to a certain degree of horizontal extension-dissociation and relatively weak magmatic floor invasion, and the secondary depression in eastern Baiyun continued to die out and the depositional center continued to migrate to the main depression. In the eastern Baiyun, the small-scale sub-depression is further reduced, the overall number of upper depressions continues to decrease and the depositional center continues to migrate from the secondary depression to the main Baiyun depression, gradually forming a single central deposit. The water body in the study area is relatively shallow and is mainly composed of braided river delta and shoreline shallow lake facies.  
The eastern Baiyun suffered from magmatic floor encroachment with different intensities, and the degree of floor encroachment results in a great difference in the distribution pattern and distribution of the sedimentary system in the study area: the magmatic floor encroachment intensity is large, and the direct erosion and denudation are the source; the intensity of magma floor invasion is from medium to small, which affects the degree of pinching of preexisting sediments and regulates the transport channels of Upper Wenchang and Enping sedimentary systems. At the same time, based on the study of the tectono-sedimentary response under complex fault-uplift joint control in the eastern Baiyun, it can be clear that the Lower Wenchang tectono-lithologic trap is mainly to find the large sedimentary development area under the control of large sources and sinks in the background of the uplift and depression. The upper Wenchang tectonic-lithologic trap is mainly to find the large sedimentary development area controlled by a large source and large sink and the lower Wenchang sedimentary transformation area under the background of the demolition-magmatic floor invasion.  
Since the Yundong low bulge was subjected to strong magma floor encroaching during the Chang-Enping Formation period above, the strata were then subjected to sedimentary uplift and exfoliation, and the area at the southern inclined end of the bulge was gradually submerged underwater. Due to the strong water energy, it was conducive to the formation of a shoreline beach bar facies storage collective.