Influence of Pressure Generation Rate on Both Pore Size Distribution Measured by Mercury Porosimetry and Predicted Permeability

DOI Web Site Web Site 27 References

Bibliographic Information

Other Title
  • 水銀圧入式ポロシメータを用いた岩石の空隙径分布の昇圧速度依存性と浸透率の推定
  • スイギン アツニュウシキ ポロシメータ オ モチイタ ガンセキ ノ クウゲキケイ ブンプ ノ ショウアツ ソクド イソンセイ ト シントウリツ ノ スイテイ

Search this article

Abstract

<p>The pore size distribution within rock materials is an important geometric parameter to control fluid transport through pores and cracks. Measurement via mercury injection capillary pressure is a simple and popular method to obtain the pore size distribution with high replicability. However, the influence of the pressure generation rate on the results has not been investigated strictly. In the present study, pore size distribution, porosity, and permeability calculated from pore size data were investigated for four rock specimens at various pressure generation speeds. There was no significant difference between the results obtained from a continuous pressure generation mode and those from a pressure step increase mode. Even though the low porosity rocks show very low permeability, the volumetric ratio of large pores（>10 µm） was found to be high. The large pores detected by the mercury injection method are considered to reflect the rough surfaces of specimens that are disconnected from fluid flow pathways. The permeability predicted using the modified pore size distribution that disregards surface pores based on the percolation model and the hydraulic radius model is in agreement with the measured permeability. An increase in effective porosity with decreasing pressure generation rate was observed, and the largest effective pore diameter and the representative pore diameter increased with an increase in generation rate for sandstone. This result suggests that it takes some time for mercury to intrude fully into the small pores that are equivalent to intruded pressure. Therefore, lower pressure generation speed is recommended to measure small pore size for low permeable rocks.</p>

Journal

References(27)*help

See more

Keywords

Details 詳細情報について

Report a problem

Back to top