The oil-gas accumulation zone in the coquina limestone of the Da'anzhai segment, North Sichuan

摘要

The prediction of oil-gas accumulation zone in lamina limestone is a worldwide problem. Because the limestone of Da'anzhai segment is extremely tight, it is generally thought that the main factor of controlling oil-gas accumulation is fracture. After analyzing the sequence stratigraphy and studying the sedimentary environment of Da'anzhai biogenic coquina limestone, it is found that the solution and ablation is probably the main factor of hydrocarbon accumulation, and the effect of the fracture is secondary or one of necessary conditions. By using relevant seismic parameters, such as mutation exponent and amplitude, it is possible to find the oil-gas abundance zone. The theoretical result based on our study is in good agreement with the practical data obtained from the field drilling, and the result based on our study has been applied in development and exploration in practice.