Quantitative evaluation of the diagenesis and porosity evolution of tight sandstone reservoirs: A case study of the Yanchang formation in the Southern Ordos basin, China

  • Meng Xiao PetroChina Research Institute of Petroleum Exploration and Development
  • Dawei Chen PetroChina Research Institute of Petroleum Exploration and Development
  • Guiqiang Qiu SINOPEC Exploration Production Researcher Institute
  • Xuanjun Yuan PetroChina Research Institute of Petroleum Exploration and Development
  • Chunfang Chen SINOPEC Exploration Production Researcher Institute
Keywords: Reservoir Characteristics, Diagenesis, Pore evolution, Ordos Basin

Abstract

Evaluation of the pore evolution is key to gaining a better understanding of oil migration and accumulation in tight oil exploration for tight sandstone; to study the diagenesis and porosity evolution of tight sandstone reservoirs, we analysed the 8th member of the Yanchang Formation by core observation, thin section observation, cathodoluminescence, scanning electron microscopy, and logging data analysis. The following conclusions can be drawn (1) In the typical tight sandstone reservoir, numerous secondary pores developed at burial depths in the range of 1300 m to 1400 m, and approximately 1500 m to 1600 m. (2) Compaction was the most influential factor of reservoir density and decreased the average pore size by 24.8%. Carbonate cementation decreased the porosity by 8.2%. The most important diagenetic process for increasing the reservoir porosity was dissolution, which increased the pore size by 5.1%. In addition, chlorite played an active role in inhibiting secondary quartz growth and preserving primary pores. (3) The early gas invasion can inhibit diagenesis, and the organic acids produced by the later oil can increase dissolution, so that the high oil saturation phenomenon becomes more obvious.

How to Cite
Xiao, M., Chen, D., Qiu, G., Yuan, X., & Chen, C. (2019). Quantitative evaluation of the diagenesis and porosity evolution of tight sandstone reservoirs: A case study of the Yanchang formation in the Southern Ordos basin, China. CT&F - Ciencia, Tecnología Y Futuro, 9(1), 15-26. https://doi.org/10.29047/01225383.148

Downloads

Download data is not yet available.
Published
2019-05-10
Section
Scientific and Technological Research Articles