The Formation Characteristic Of Natural Gas In Upper Paleozoic Of Ordos Basin And Development Strategies

This article is based on geological data, logging and log data interpretation, and core, thin sections and porosity, permeability test and analysis, to analyze the largest depth of source rocks in late early Cretaceous, the denudation since of the late Cretaceous and the biggest driving force distribution of the source area in the current construction phase,to analyze the distribution of natural gas in the basin,to discusses the biggest driving force source and the connectivity relations of natural gas and source rocks, reservoirs and compartments, based on the above analysis,to analyze the characteristics of upper Paleozoic of Ordos Basin gas reservoir, and discuss development strategies. The obtained knowledge are as the follows:1. The area of late early Cretaceous source rocks of the biggest driving force source in upper Paleozoic of Ordos Basin is maerzhuang-dabazui-duhoutan-jiayuan. The area of the denudation since of the late Cretaceous is Tiesukemiao in the northwest and shancheng in the southwest. The area of the biggest driving force distribution of the source area in the current construction phase is Tiekesumiao in the northwest.2. The natural gas found currently has a good connection relationship in different geological periods with the greatest driving force source, and the connectivity is mainly achieved through communication cracks. The average shale permeability with fractured parallel to the direction of layers is 311.74×10-3μm2, and the average penetration of fractured sandstone is 14279.2×10-3μm2.3. The sandstone reservoir and adjacent shale (source rocks, insulation layer) have a certain connectivity relation in Upper Paleozoic of Ordos Basin, and the connectivity relations are achieved through the communication cracks.4. In the gas reservoir development process, the fluid-driven of upper Paleozoic gas reservoir in Ordos Basin have closely relationship with the greatest driving force source, and through the cracks source rocks, reservoir and the insulation layer can achieve effective connectivity. Based on the above analysis, the connectivity relationships may result in supplement of the region outside the gas reservoir the gas layer in the compartment or the effective source rocks. When working out the gas reservoir development measures, this feature should be fully considered.