scholarly journals Experimental Methods for the Quantitative Assessment of the Volume Fraction of Movable Shale Oil: A Case Study in the Jimsar Sag, Junggar Basin, China

2021 ◽  
Vol 9 ◽  
Author(s):  
Xia Luo ◽  
Zhongying Zhao ◽  
Lianhua Hou ◽  
Senhu Lin ◽  
Feifei Sun ◽  
...  
Keyword(s):  
Aromatic Hydrocarbon ◽  
Crude Oil ◽  
Sequential Extraction ◽  
Quantitative Assessment ◽  
Volume Fraction ◽  
Saturated Hydrocarbon ◽  
Junggar Basin ◽  
Shale Oil ◽  
Extract Content ◽  
Jimsar Sag

Deep insights into the movability of the retained shale oil are of great significance to shale oil. Rock and crude oil samples were collected from well J174 in the Jimsar Sag, Junggar Basin. Rock samples were subjected to different extraction followed by analysis of the component in the extracts, and measurement of porosity in conjunction with nuclear magnetic resonance and high-pressure mercury injection analysis. The results of these analyses were used to establish an experimental method for quantitative assessment of movable shale oil. The extract content of the component varied among different extraction and between mud shale and non-mud shale samples. The saturated hydrocarbon in the extracts of the mud shale was similar to those of the non-mud shale after extraction with CHCl3 alone or after sequential extraction with nC6 + CHCl3. The aromatic hydrocarbon in the extract were significantly lower for the mud shale than for the non-mud shale after extraction with nC6, but the opposite was observed after sequential extraction with nC6 + CHCl3. The contents of the non-hydrocarbon in the extract were significantly lower for the mud shale than for the non-mud shale after extraction with nC6, but the opposite was observed after extraction with CHCl3 or nC6 + CHCl3. The contents of the asphaltene in the extract were not significantly different for the mud shale and non-mud shale after extraction with nC6, but the contents were higher for the mud shale than for the non-mud shale after extraction with nC6 + CHCl3 or CHCl3. The viscosity of the crude oil was negatively correlated with the saturated hydrocarbon, was positively correlated with the aromatic hydrocarbon and non-hydrocarbon, and was not correlated with the asphaltene. For the mud shale and non-mud shale, their porosity after extraction with nC6 or CHCl3 was higher than their original porosity. Moreover, their porosity after extraction with CHCl3 was higher than after extraction with nC6. The movable oil was significantly correlated with the lithology, with sandstone allowing for a higher fluid movability than mud shale and dolomite allowing for a higher fluid movability than siliceous rocks.

Characteristics of Micro/Nano Pores and Hydrocarbon Accumulation in a Continental Shale Oil Reservoir—A Case Study of the Lucaogou Formation in the Jimsar Sag, Junggar Basin, Northwest China

2021 ◽  
Vol 21 (1) ◽  
pp. 262-273
Author(s):  
Jun Jin ◽  
Zhao Yang ◽  
Xuekun Chen ◽  
Lulu Li ◽  
Hongxia Yang ◽  
...  
Keyword(s):  
Junggar Basin ◽  
Ct Scanning ◽  
Northwest China ◽  
Oil Reservoir ◽  
Shale Oil ◽  
Pore Characteristics ◽  
Mercury Analysis ◽  
Lucaogou Formation ◽  
Jimsar Sag ◽  
Intercrystalline Pores

This paper comprehensively studies the micro- and nanometer-scale pore characteristics and structure of the Lucaogou Formation shale oil reservoir in the Jimsar Sag using high-pressure mercury analysis, field emission scanning electron microscopy and nano-CT scanning technology. In addition, the occurrence states of crude oil in pores are analyzed combined with macro–micro characteristics. The results show that there are various reservoir types; the main reservoir pore structure is on the micron and nanometer levels, with other void spaces including intergranular pores, interparticle dissolution pores, intercrystalline pores and microfissures. Nanopores are generally oil-bearing and mostly in the adsorption state, which changes the traditional understanding that micron pores are the only microscopic pores in the reservoir and confirms that shale oil exists in ‘sweet spots’ and mud-shale sections of the Lucaogou Formation.

scholarly journals Characteristics and Genetic Mechanism of Pore Throat Structure of Shale Oil Reservoir in Saline Lake—A Case Study of Shale Oil of the Lucaogou Formation in Jimsar Sag, Junggar Basin

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8450
Author(s):  
Xiaojun Zha ◽  
Fuqiang Lai ◽  
Xuanbo Gao ◽  
Yang Gao ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Sedimentary Environment ◽  
Junggar Basin ◽  
Genetic Mechanism ◽  
Formation Mechanisms ◽  
Oil Reservoir ◽  
Shale Oil ◽  
Pore Throat ◽  
Delta Front ◽  
Lucaogou Formation ◽  
Jimsar Sag

The shale oil reservoir of the Lucaogou Formation in the Jimsar Sag has undergone tectonic movement, regional deposition and complex diagenesis processes. Therefore, various reservoir space types and complex combination patterns of pores have developed, resulting in an intricate pore throat structure. The complex pore throat structure brings great challenges to the classification and evaluation of reservoirs and the efficient development of shale oil. The methods of scanning electron microscopy, high-pressure mercury injection, low-temperature adsorption experiments and thin-slice analysis were used in this study. Mineral, petrology, pore throat structure and evolution process characteristics of the shale oil reservoir were analyzed and discussed qualitatively and quantitatively. Based on these studies, the evolution characteristics and formation mechanisms of different pore throat structures were revealed, and four progressions were made. The reservoir space of the Lucaogou Formation is mainly composed of residual intergranular pores, dissolved pores, intercrystalline pores and fractures. Four types of pore throat structures in the shale oil reservoir of the Lucaogou Formation were quantitatively characterized. Furthermore, the primary pore throat structure was controlled by a sedimentary environment. The pores and throats were reduced and blocked by compaction and cementation, which deteriorates the physical properties of the reservoirs. However, the dissolution of early carbonate, feldspar and tuffaceous minerals and a small amount of carbonate cements by organic acids are the key factors to improve the pore throat structure of the reservoirs. The genetic evolution model of pore throat structures in the shale oil reservoir of the Lucaogou Formation are divided into two types. The large-pore medium-fine throat and medium-pore medium-throat reservoirs are mainly located in the delta front-shallow lake facies and are characterized by the diagenetic assemblage types of weak compaction–weak carbonate cementation–strong dissolution, early medium compaction–medium calcite and dolomite cementation–weak dissolution. The medium-pore fine throats and fine-pore fine throats are mainly developed in shallow lakes and semi-deep lakes. They are characterized by the diagenetic assemblage type of strong compaction–strong calcite cementation–weak dissolution diagenesis. This study provides a comprehensive understanding of the pore throat structure and the genetic mechanism of a complex shale oil reservoir and benefits the exploration and development of shale oil.

Impact of Shale Oil Supply Shock on US Crude Oil and Gasoline Prices

2018 ◽  
Vol 31 (4) ◽  
pp. 1375-1393
Author(s):  
Jong Cheol Yoon ◽  
Jun Kim ◽  
Sang Young Jei
Keyword(s):  
Crude Oil ◽  
Gasoline Prices ◽  
Shale Oil ◽  
Oil Supply ◽  
Supply Shock

scholarly journals Modeling of Two-Phase Flow in Rough-Walled Fracture Using Level Set Method

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Yunfeng Dai ◽  
Zhifang Zhou ◽  
Jin Lin ◽  
Jiangbo Han
Keyword(s):  
Crude Oil ◽  
Level Set Method ◽  
Level Set ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Contact Angles ◽  
Immiscible Fluids ◽  
Water Volume ◽  
Phase Flow ◽  
Two Phase

To describe accurately the flow characteristic of fracture scale displacements of immiscible fluids, an incompressible two-phase (crude oil and water) flow model incorporating interfacial forces and nonzero contact angles is developed. The roughness of the two-dimensional synthetic rough-walled fractures is controlled with different fractal dimension parameters. Described by the Navier–Stokes equations, the moving interface between crude oil and water is tracked using level set method. The method accounts for differences in densities and viscosities of crude oil and water and includes the effect of interfacial force. The wettability of the rough fracture wall is taken into account by defining the contact angle and slip length. The curve of the invasion pressure-water volume fraction is generated by modeling two-phase flow during a sudden drainage. The volume fraction of water restricted in the rough-walled fracture is calculated by integrating the water volume and dividing by the total cavity volume of the fracture while the two-phase flow is quasistatic. The effect of invasion pressure of crude oil, roughness of fracture wall, and wettability of the wall on two-phase flow in rough-walled fracture is evaluated.

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