InterPore2022

Micro experimental study on residual oil of marine carbonate rocks during water flooding based on CT scanning

1 Jun 2022, 09:20

1h 10m

Poster Presentation (MS09) Pore-scale modelling Poster

Speaker

Wenlong Jing

Description

At present, carbonate reservoirs mainly rely on primary and secondary oil recovery. However, the complex pore structure leads to large production decline in the early stage of depletion development, and the distribution of oil and water in the reservoir is very uneven in the process of water injection. The key to solve these series of problems is to clarify the micro occurrence characteristics and laws of residual oil in carbonate reservoir. In this study, the natural cores of marine carbonate reservoir were used to carry out water flooding experiment based on CT scanning. We obtained the CT scanning results of oil saturated cores and cores after water flooding 3, 5, 10 and 20 PV (pore volumes), and established digital cores. According to the difference of gray value, the oil and water in pores were extracted respectively. The pore network models were then established, and the relevant parameters of pore structure, residual oil shape factor and Euler number were calculated. The distribution of remaining oil in cores at different displacement stages was described qualitatively and quantitatively. It is found that the oil saturation decreases with the water flooding. After injection of 20PV of water, all oil with a radius greater than 20μm is basically displaced, and there is only a small amount of residual oil with a radius of 3μm~ 10μm. In the process of water flooding, the main distribution type of remaining oil is isolated droplet. The remaining oil of other types is less, and the proportion remains basically unchanged with the water flooding.