3类不同来源侵蚀性酸性流体的的完整接力过程并不是发育在所有深层油气储层

The complete relay process of the three types of erosive acid fluids from different sources is not developed in all deep oil and gas reservoirs, and is complete only when specific geological backgrounds are met. For example, the large-scale delta sedimentary sand bodies of the Paleogene Zhuhai Formation and Enping Formation in Baiyun Sag, during the depositional period and the shallow burial stage, the thick sand bodies experienced the leaching of atmospheric fresh water, and the feldspar dissolved to form porosity-increasing secondary pores; During the diagenetic B-middle diagenetic stage, the source rocks thermally evolved to generate acidic fluids such as organic acids, which dissolved feldspar minerals, accompanied by the precipitation of kaolinite and quartz. Thermal cracking and water evolution acid generation occurred, and acidic fluids such as CO2 continued to dissolve feldspar to form secondary pores, and accompanied by the precipitation of some illite and quartz, these secondary pores were effectively superimposed, forming the dominant type of dissolved pores in deep feldspar today. Low permeability-medium and low porosity oil and gas reservoirs.

The complete relay process of three types of erosive acid fluids from different sources is not developed in all deep oil and gas reservoirs, but only when they meet the specific geological background. For example, in the Paleogene Zhuhai Enping formation large delta sedimentary sand body of Baiyun Sag, in the sedimentary period shallow burial stage, the thick sand body experienced the leaching of atmospheric fresh water and the dissolution of feldspar to form pore increasing secondary pores; In the early diagenetic b-middle diagenetic stage, the thermal evolution of source rocks generated acid fluids such as organic acids, dissolved feldspar minerals and precipitated kaolinite and quartz; In the process of deep burial after hydrocarbon filling, it enters the B stage of middle diagenesis. The hydrocarbons undergo thermal cracking and water evolution to generate acid. CO2 and other acidic fluids continue to dissolve feldspar to form secondary pores, accompanied by the precipitation of some illite and quartz. These secondary pores are effectively superimposed, forming the low-permeability medium and low porosity oil and gas reservoir dominated by deep feldspar solution pores.

The complete relay process of three types of corrosive acid fluids from different sources is not developed in all deep oil and gas reservoirs, but only when the specific geological background is met. For example, in the large delta sedimentary sand bodies of Paleogene Zhuhai Formation-Enping Formation in Baiyun Sag, during the sedimentary period-shallow burial period, thick sand bodies experienced atmospheric fresh water leaching, and feldspar dissolved to form pore-increasing secondary pores; In the early diagenesis B- middle diagenesis period, the thermal evolution of source rocks generated acidic fluids such as organic acids, which eroded feldspar minerals, accompanied by the precipitation of kaolinite and Shi Ying. During the process of deep burial after hydrocarbon filling, it entered the middle diagenesis stage B, and the hydrocarbon underwent thermal cracking and water evolution to generate acid. Acidic fluids such as CO2 continued to corrode feldspar to form secondary pores, accompanied by the precipitation of part of illite and Shi Ying. These secondary pores were effectively superimposed, forming the low permeability-middle low porosity oil and gas reservoir dominated by the dissolution of deep feldspar.