Next Article in Journal
A Coupled, Semi-Numerical Model for Thermal Analysis of Medium Frequency Transformer
Next Article in Special Issue
Environmental and Operational Performance of CO2-EOR as a CCUS Technology: A Cranfield Example with Dynamic LCA Considerations
Previous Article in Journal
Environmental Performance of Effluent Conditioning Systems for Reuse in Oil Refining Plants: A Case Study in Brazil
Previous Article in Special Issue
Experimental Investigation on Microscopic Residual Oil Distribution During CO2 Huff-and-Puff Process in Tight Oil Reservoirs
Article

Experimental Investigation on the Effects of CO2 Displacement Methods on Petrophysical Property Changes of Ultra-Low Permeability Sandstone Reservoirs Near Injection Wells

by 1,2, 1,2,*, 3, 1,2, 1,2 and 1,2
1
State Key Laboratory of Petroleum Resources and Engineering, China University of Petroleum (Beijing), Beijing 102249, China
2
School of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China
3
State Key Laboratory of Enhanced Oil Recovery, Beijing 100083, China
*
Author to whom correspondence should be addressed.
Energies 2019, 12(2), 327; https://doi.org/10.3390/en12020327
Received: 11 December 2018 / Revised: 3 January 2019 / Accepted: 18 January 2019 / Published: 21 January 2019
(This article belongs to the Special Issue CO2 EOR and CO2 Storage in Oil Reservoirs)
The petrophysical properties of ultra-low permeability sandstone reservoirs near the injection wells change significantly after CO2 injection for enhanced oil recovery (EOR) and CO2 storage, and different CO2 displacement methods have different effects on these changes. In order to provide the basis for selecting a reasonable displacement method to reduce the damage to these high water cut reservoirs near the injection wells during CO2 injection, CO2-formation water alternate (CO2-WAG) flooding and CO2 flooding experiments were carried out on the fully saturated formation water cores of reservoirs with similar physical properties at in-situ reservoir conditions (78 °, 18 MPa), the similarities and differences of the changes in physical properties of the cores before and after flooding were compared and analyzed. The measurement results of the permeability, porosity, nuclear magnetic resonance (NMR) transversal relaxation time (T2) spectrum and scanning electron microscopy (SEM) of the cores show that the decrease of core permeability after CO2 flooding is smaller than that after CO2-WAG flooding, with almost unchanged porosity in both cores. The proportion of large pores decreases while the proportion of medium pores increases, the proportion of small pores remains almost unchanged, the distribution of pore size of the cores concentrates in the middle. The changes in range and amplitude of the pore size distribution in the core after CO2 flooding are less than those after CO2-WAG flooding. After flooding experiments, clay mineral, clastic fines and salt crystals adhere to some large pores or accumulate at throats, blocking the pores. The changes in core physical properties are the results of mineral dissolution and fines migration, and the differences in these changes under the two displacement methods are caused by the differences in three aspects: the degree of CO2-brine-rock interaction, the radius range of pores where fine migration occurs, the power of fine migration. View Full-Text
Keywords: CO2 displacement method; ultra-low permeability sandstone; permeability; pore size distribution; fines migration CO2 displacement method; ultra-low permeability sandstone; permeability; pore size distribution; fines migration
Show Figures

Figure 1

MDPI and ACS Style

Wang, Q.; Yang, S.; Han, H.; Wang, L.; Qian, K.; Pang, J. Experimental Investigation on the Effects of CO2 Displacement Methods on Petrophysical Property Changes of Ultra-Low Permeability Sandstone Reservoirs Near Injection Wells. Energies 2019, 12, 327. https://doi.org/10.3390/en12020327

AMA Style

Wang Q, Yang S, Han H, Wang L, Qian K, Pang J. Experimental Investigation on the Effects of CO2 Displacement Methods on Petrophysical Property Changes of Ultra-Low Permeability Sandstone Reservoirs Near Injection Wells. Energies. 2019; 12(2):327. https://doi.org/10.3390/en12020327

Chicago/Turabian Style

Wang, Qian, Shenglai Yang, Haishui Han, Lu Wang, Kun Qian, and Jieqiong Pang. 2019. "Experimental Investigation on the Effects of CO2 Displacement Methods on Petrophysical Property Changes of Ultra-Low Permeability Sandstone Reservoirs Near Injection Wells" Energies 12, no. 2: 327. https://doi.org/10.3390/en12020327

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop