Simulation and Analysis of Long-Term CO2 Trapping for the Shenhua CCS Demonstration Project in the Ordos Basin

The Shenhua CO2 capture and sequestration (CCS) project has achieved its goal of injecting 100,000 tons/year CO2 into the saline aquifers of the Ordos Basin. This study analyzes the geochemical interactions between CO2, formation fluid, and host rock of the major formations in the Ordos Basin, assesses the CO2 trapping capabilities, and predicts the final mineral forms of injected CO2. Reactive transport simulations are performed using a 2D radial model, which represents a homogeneous formation. The results show that 80% of injected CO2 remains as free supercritical gas in each formation after injection, while most of CO2 is sequestrated in different carbonate mineral assemblages after 10,000 years. The CO2 mineral trapping capacities of the Shiqianfeng and Shihezi formations are smaller than the Liujiagou formation. Calcite, dawsonite, and siderite are stable CO2 trapping minerals, while dolomite, ankerite, and magnesite are not. The increase in porosity and permeability of the three formations in the first 100 years agrees with the observation from the Shenhua CCS Project. Also the decrease in porosity and permeability after 100 years shows agreement with other modelling studies using the similar methods. These results are useful for the evaluation of the geochemical process in long-term CO2 geological storage.

Download Full-text

Fractal Characterization of Nanopore Structure in Shale, Tight Sandstone and Mudstone from the Ordos Basin of China Using Nitrogen Adsorption

Energies ◽

10.3390/en12040583 ◽

2019 ◽

Vol 12 (4) ◽

pp. 583 ◽

Cited By ~ 10

Author(s):

Xiaohong Li ◽

Zhiyong Gao ◽

Siyi Fang ◽

Chao Ren ◽

Kun Yang ◽

...

Keyword(s):

Pore Structure ◽

Pressure Range ◽

Ordos Basin ◽

Fractal Dimensions ◽

Nitrogen Adsorption ◽

Relative Pressure ◽

Tight Sandstone ◽

Porosity And Permeability ◽

The Ordos Basin ◽

Nanopore Structure

The characteristics of the nanopore structure in shale, tight sandstone and mudstone from the Ordos Basin of China were investigated by X-ray diffraction (XRD) analysis, porosity and permeability tests and low-pressure nitrogen adsorption experiments. Fractal dimensions D1 and D2 were determined from the low relative pressure range (0 < P/P0 < 0.4) and the high relative pressure range (0.4 < P/P0 < 1) of nitrogen adsorption data, respectively, using the Frenkel–Halsey–Hill (FHH) model. Relationships between pore structure parameters, mineral compositions and fractal dimensions were investigated. According to the International Union of Pure and Applied Chemistry (IUPAC) isotherm classification standard, the morphologies of the nitrogen adsorption curves of these 14 samples belong to the H2 and H3 types. Relationships among average pore diameter, Brunner-Emmet-Teller (BET) specific surface area, pore volume, porosity and permeability have been discussed. The heterogeneities of shale nanopore structures were verified, and nanopore size mainly concentrates under 30 nm. The average fractal dimension D1 of all the samples is 2.1187, varying from 1.1755 to 2.6122, and the average fractal dimension D2 is 2.4645, with the range from 2.2144 to 2.7362. Compared with D1, D2 has stronger relationships with pore structure parameters, and can be used for analyzing pore structure characteristics.

Download Full-text

Establishment of Models for Tight Sandstone Formation Evaluation in the Ordos Basin of Northwest China

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.989-994.1372 ◽

2014 ◽

Vol 989-994 ◽

pp. 1372-1375 ◽

Cited By ~ 2

Author(s):

Xiao Lei Wei ◽

Jun Li ◽

Rui Xu ◽

Ling Ling Zhi

Keyword(s):

Ordos Basin ◽

Northwest China ◽

Tight Sandstone ◽

Reserve Estimation ◽

Formation Evaluation ◽

Porosity And Permeability ◽

Important Input ◽

The Ordos Basin ◽

Sandstone Formation ◽

Relative Errors

Porosity and permeability are two important input parameters in formation evaluation. However, It faces a great challenge for formation porosity and permeability estimation in tight sandstone reservoirs in the Ordos basin of northwest China due to the greater contribution of rock matrix and complicated pore structure. In this paper, based on the analysis of conventional log responses and 324 core samples drilled from the target formations in different wells, the estimation models of reservoir porosity and permeability are established, and the reliability of these models are verified by comparing the calculated porosity and permeability by using the established models with core analyzed results. The absolute errors between these two kinds of porosities are all lower than 0.64%, and the relative errors between them are lower than 7.1%, these are coincided with the requirement of reserve estimation.

Download Full-text

Numerical simulation of long-term storage of CO2 in Yanchang shale reservoir of the Ordos basin in China

Chemical Geology ◽

10.1016/j.chemgeo.2016.08.002 ◽

2016 ◽

Vol 440 ◽

pp. 288-305 ◽

Cited By ~ 17

Author(s):

Danqing Liu ◽

Yilian Li ◽

Ramesh K. Agarwal

Keyword(s):

Numerical Simulation ◽

Ordos Basin ◽

Long Term Storage ◽

The Ordos Basin ◽

Shale Reservoir ◽

Term Storage

Download Full-text

Numerical Investigation into the Impact of CO2-Water-Rock Interactions on CO2 Injectivity at the Shenhua CCS Demonstration Project, China

Geofluids ◽

10.1155/2017/4278621 ◽

2017 ◽

Vol 2017 ◽

pp. 1-17 ◽

Cited By ~ 3

Author(s):

Guodong Yang ◽

Yilian Li ◽

Aleks Atrens ◽

Ying Yu ◽

Yongsheng Wang

Keyword(s):

Reactive Transport ◽

Ordos Basin ◽

Selective Dissolution ◽

Mineral Dissolution ◽

Demonstration Project ◽

Flow Paths ◽

Porosity And Permeability ◽

The Impact ◽

Oil Gas ◽

And Storage

A 100,000 t/year demonstration project for carbon dioxide (CO2) capture and storage in the deep saline formations of the Ordos Basin, China, has been successfully completed. Field observations suggested that the injectivity increased nearly tenfold after CO2 injection commenced without substantial pressure build-up. In order to evaluate whether this unique phenomenon could be attributed to geochemical changes, reactive transport modeling was conducted to investigate CO2-water-rock interactions and changes in porosity and permeability induced by CO2 injection. The results indicated that using porosity-permeability relationships that include tortuosity, grain size, and percolation porosity, other than typical Kozeny-Carman porosity-permeability relationship, it is possible to explain the considerable injectivity increase as a consequence of mineral dissolution. These models might be justified in terms of selective dissolution along flow paths and by dissolution or migration of plugging fines. In terms of geochemical changes, dolomite dissolution is the largest source of porosity increase. Formation physical properties such as temperature, pressure, and brine salinity were found to have modest effects on mineral dissolution and precipitation. Results from this study could have practical implications for a successful CO2 injection and enhanced oil/gas/geothermal production in low-permeability formations, potentially providing a new basis for screening of storage sites and reservoirs.

Download Full-text

Control of differential diagenesis of tight sandstone reservoirs on the gas–water distribution: A case study on the Upper Paleozoic He 8 Member in the northern Tianhuan depression of the Ordos Basin

Energy Exploration & Exploitation ◽

10.1177/01445987211034590 ◽

2021 ◽

pp. 014459872110345

Author(s):

Xinshe Liu ◽

Xing Pan ◽

Huitao Zhao ◽

Zhenliang Wang ◽

Peilong Meng ◽

...

Keyword(s):

Water Distribution ◽

Ordos Basin ◽

Gas Reservoirs ◽

Reservoir Heterogeneity ◽

Upper Paleozoic ◽

Medium Strength ◽

Porosity And Permeability ◽

Differential Diagenesis ◽

The Ordos Basin ◽

Diagenetic Facies

The sandstone reservoirs in the Upper Paleozoic He 8 Member in the northern Tianhuan depression of the Ordos Basin are vastly different and feature particularly complex gas–water distributions. Scanning electron microscopy, fluorescence, Raman spectroscopy inclusions, relative permeability analysis, and nuclear magnetic resonance were utilized in this study based on core data, identification statistics, and various thin-section microscope measurements. Samples from the Upper Paleozoic He 8 Member in the northern Tianhuan depression were collected to study the characteristics of reservoir heterogeneity and gas–water distribution, which were controlled by differential diagenesis. The results indicate that compaction and dissolution are the two most important factors controlling reservoir heterogeneity. Large differences in diagenesis–accumulation sequences and pore structure characteristics affect reservoir wettability, irreducible water saturation, and gas displacement efficiency, thereby controlling the gas–water distribution. The He 8 Member is a gas reservoir that is densified because of accumulation. Reservoirs can be divided into three types based on the relationship between diagenetic facies and gas–water distribution. Type I is characterized by weak compaction, precipitate or altered kaolinite cementation, strong dissolution of diagenetic facies, and high porosity and permeability. This type is dominated by grain-mold pores and intergranular dissolution pores and produces gas reservoirs with high gas yield. Type II is characterized by medium-strength compaction, altered kaolinite or chlorite cementation, weak dissolution of diagenetic facies, and medium porosity and permeability. This type is dominated by residual intergranular pores, a few residual intergranular pores, and dispersed dissolution pores, producing gas reservoirs with low gas yield. Type III is characterized by medium-strength compaction, altered kaolinite cementation, and medium-strength dissolution of diagenetic facies. This type is dominated by kaolinite intercrystal pores and dispersed dissolution pores, producing gas reservoirs with high water yield.

Download Full-text