scholarly journals Effect of the Heterogeneity on Sorptivity in Sandstones with High and Low Permeability in Water Imbibition Process

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 260 ◽  
Author(s):  
Yang Wu ◽  
Yixin Zhao ◽  
Peng Li
Keyword(s):  
Oil And Gas ◽  
Neutron Radiography ◽  
Pore Space ◽  
Oil Fields ◽  
Low Permeability ◽  
Wetting Front ◽  
Gas Reservoirs ◽  
X Ray Imaging ◽  
Front Position ◽  
Quantitative Results

Capillary imbibition in unsaturated rocks is important for the exploitation of tight reservoirs, such as oil and gas reservoirs. However, the physical properties of natural rocks tend to be relatively uneven, mainly in the heterogeneity of material composition and pore space. Reservoir heterogeneity is an important factor affecting the exploitation of oil fields and other reservoirs, which can be evaluated by the pore structure tortuosity fractal dimension DT of rock. The greater the value of DT, the stronger the heterogeneity of sandstone. Two types of sandstone with high and low permeability were selected to study the effect of heterogeneity on the imbibition behavior by using high-resolution X-ray imaging and neutron radiography. Quantitative results of the wetting front position for each specimen were extracted from the neutron images. The wetting front advanced linearly with the power index of time t1/(2DT). Different values of DT were selected to estimate and discuss the effect of the heterogeneity on sorptivity. A modified L-W equation was employed to predict the sorptivity. Comparing with the experimental results, the heterogeneity plays a significant role in determining the sorptivity. The modified model provides a reference for the prediction of the sorptivity of the same types of sandstones studied in this paper.

The effect of the pore space microstructure on hydrophobization of oil and gas reservoirs

2016 ◽  
Vol 71 (6) ◽  
pp. 436-444 ◽  
Author(s):  
N. N. Mikhailov ◽  
V. A. Kuz’min ◽  
K. A. Motorova ◽  
L. S. Sechina
Keyword(s):  
Oil And Gas ◽  
Pore Space ◽  
Gas Reservoirs ◽  
Oil And Gas Reservoirs

scholarly journals GEOLOGICAL CONDITIONS OF SECONDARY POROSITY FORMATION AND ITS DISTRIBUTION IN ROCKS

2018 ◽  
pp. 37-41
Author(s):  
H. M. Bondar
Keyword(s):  
Oil And Gas ◽  
Pore Space ◽  
Effective Porosity ◽  
Gas Reservoirs ◽  
Secondary Porosity ◽  
Geological Conditions ◽  
Main Component ◽  
Filtration Properties ◽  
Sedimentation Processes

The paper presents the problem of collectors secondary porosity, which is the main component of the total effective porosity. Different aspects of this problem are considered: the origin and distribution of secondary porosity in the rock, the dependency between the structure of the pore space and its filtration properties, the formation of hydrocarbons deposits at great depths, the role of post-sedimentation processes in the formation of secondary porosity and fractures, as well as the issue of secondary porosity prediction and its role in prospecting secondary oil and gas reservoirs.

scholarly journals Experimental evaluation of compressibility coefficients for fractures and intergranular pores of an oil and gas reservoir

2021 ◽  
Vol 251 ◽  
pp. 658-666
Author(s):  
Vitaly Zhukov ◽  
Yuri Kuzmin
Keyword(s):  
Stress State ◽  
Oil And Gas ◽  
Pore Space ◽  
Total Porosity ◽  
Gas Reservoirs ◽  
Gas Reservoir ◽  
Intergranular Porosity ◽  
Hydrocarbon Fields ◽  
Oil And Gas Reservoir

The paper is devoted to studies of the volumetric response of rocks caused by changes in their stress state. Changes in the volume of fracture and intergranular components of the pore space based on measurements of the volume of pore fluid extruded from a rock sample with an increase in its  all-round compression have been experimentally obtained and analyzed.  Determination of the fracture and intergranular porosity components is based on the authors' earlier proposed method of their calculation using the values of longitudinal wave velocity and total porosity. The results of experimental and analytical studies of changes in porosity and its two components (intergranular and fractured) under the action of effective stresses are considered. This approach allowed the authors to estimate the magnitude  of the range of changes in the volumetric compressibility of both intergranular pores and fractures in a representative collection of 37 samples of the Vendian-age sand reservoir of the Chayanda field. The method of separate estimation of the compressibility coefficients of fractures and intergranular pores is proposed, their values and dependence on the effective pressure are experimentally obtained. It is determined that the knowledge of the values of fracture and intergranular porosity volumetric compressibility will increase the reliability of estimates of changes in petrophysical parameters of oil and gas reservoirs caused by changes in the stress state during the development of hydrocarbon fields.

scholarly journals Multi-objective optimization and experiment of nylon cord rubber in expandable packer

2021 ◽  
Author(s):  
Yan-Wen Zhang ◽  
Han-Xiang Wang ◽  
Jia-Qi Che ◽  
Ming-Chao Du ◽  
Hong-Jie Zhang
Keyword(s):  
Response Surface ◽  
Oil And Gas ◽  
Structural Parameters ◽  
Residual Deformation ◽  
Surface Model ◽  
Low Permeability ◽  
Gas Reservoirs ◽  
Sealing Performance ◽  
Oil And Gas Reservoirs ◽  
Sealing Pressure

AbstractNylon cord rubber has the advantages of small residual deformation and is easy to lift and lower the tubing string in low-permeability oil and gas reservoirs. However, it is associated with low-pressure resistance and poor sealing performance. To enhance the performance of nylon cord rubber, a three-dimensional numerical model of the nylon cord rubber was established and its accuracy experimentally determined. The Plackett–Burman test, the Steepest climbing test and the Response surface method were used to acquire the polynomial response surface model connecting structural parameters with bearing and sealing pressure. Using genetic algorithms, optimal structural parameters of nylon cord rubber were determined depending on field operation. The reliability of the optimized results was verified by laboratory tests. It was shown that after optimization, the bearing capacity of the expandable packer increased by 25% while the sealing performance increased by 66%. In addition, the bearing pressure was 70 MPa while the sealing pressure was 50 MPa. These measurements effectively met the on-site requirements of high-pressure and fine fracturing in low-permeability oil and gas reservoirs.

scholarly journals INFLUENCE OF INCLINATION ANGLE OF THE BOREHOLE AXIS ON THEPOSSIBLE MANIFESTATIONS OF RESERVOIR WATER

2018 ◽  
pp. 54-59
Author(s):  
V. P. Ovchinnikov ◽  
D. S. Gerasimov ◽  
F. A. Agzamov ◽  
P. V. Ovchinnikov ◽  
V. V. Saltykov ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Oil And Gas ◽  
Low Permeability ◽  
Clay Layer ◽  
Gas Reservoirs ◽  
Reservoir Water ◽  
Inclination Angles ◽  
Oil And Gas Reservoirs ◽  
Water Saturated

Secondary opening of productive oil and gas reservoirs by using cumulative and bullet perfo-ration methods in directional wells with high values of inclination angles (40-60º) requires a solution of technological problems caused by the justification of the interval of their implementation. This is especially important for multi-layered reservoirs with alternating water saturated and oil saturated horizons and the absence of an insulating low-permeability screen, for example, a clay layer (tire). The article makes an attempt to attract geological services, owners of companies that develop deposits with such conditions, in order to increase the requirements for the appointment of a perforation interval. The authors give some proposals based on the actual results of well con-struction.

Advanced Remedial Methods for Metals and Radionuclides in Vadose Zone Environments

2010 ◽  
Author(s):  
Dawn M. Wellman ◽  
Shas V. Mattigod ◽  
Susan Hubbard ◽  
Ann Miracle ◽  
Lirong Zhong ◽  
...  
Keyword(s):  
Vadose Zone ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Low Permeability ◽  
Arid Environments ◽  
Pressure Gradients ◽  
Wetting Front ◽  
Gas Industry ◽  
Shear Thinning Fluids

Functionally, the methods for addressing contamination must remove and/or reduce transport or toxicity of contaminants. This problem is particularly challenging in arid environments where the vadose zone can be up to hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through injection of aqueous remedial solutions. However, heterogeneous vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones which frequently contain the majority of the contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to underlying aquifers prior to stabilization. Development of innovative, in-situ technologies may be the only way to meet remedial action objectives and long-term stewardship goals. Shear-thinning fluids (i.e., surfactants) can be used to lower the liquid surface tension and create stabile foams, which readily penetrate low permeability zones. Although surfactant foams have been utilized for subsurface mobilization efforts in the oil and gas industry, so far, the concept of using foams as a delivery mechanism for transporting reactive remedial amendments into deep vadose zone environments to stabilize metal and long-lived radionuclide contaminants has not been explored. Foam flow can be directed by pressure gradients, rather than being dominated by gravity; and, foam delivery mechanisms limit the volume of water (< 20% vol.) required for remedy delivery and emplacement, thus mitigating contaminant mobilization. We will present the results of a numerical modeling and integrated laboratory-/intermediate-scale investigation to simulate, develop, demonstrate, and monitor (i.e. advanced geophysical techniques and advanced predictive microbial markers) foam-based delivery of remedial amendments to remediate metals and radionuclides in vadose zone environments.

Evaluation of Well Performance for the Slot-Drill Completion in Low and Ultra-Low Permeability Oil and Gas Reservoirs

2013 ◽  
Author(s):  
Thomas Blasingame ◽  
Olufemi Olorode ◽  
Tioluwanimi Oluwagbemiga Odunowo ◽  
George Moridis ◽  
Craig Matthew Freeman
Keyword(s):  
Oil And Gas ◽  
Low Permeability ◽  
Well Performance ◽  
Gas Reservoirs ◽  
Oil And Gas Reservoirs

Foam: Novel Delivery Technology for Remediation of Vadose Zone Environments

2011 ◽  
Author(s):  
Danielle Jansik ◽  
Dawn M. Wellman ◽  
Shas V. Mattigod ◽  
Lirong Zhong ◽  
Yuxin Wu ◽  
...  
Keyword(s):  
Vadose Zone ◽  
Oil And Gas ◽  
Multiple Scales ◽  
Predictive Biomarkers ◽  
Primary Source ◽  
Oil And Gas Industry ◽  
Low Permeability ◽  
Wetting Front ◽  
Contaminant Migration

Deep vadose zone environments can be a primary source and pathway for contaminant migration to groundwater. These environments present unique characterization and remediation challenges that necessitate scrutiny and research. The thickness, depth, and intricacies of the deep vadose zone, combined with a lack of understanding of the key subsurface processes (e.g., biogeochemical and hydrologic) affecting contaminant migration, make it difficult to create validated conceptual and predictive models of subsurface flow dynamics and contaminant behavior across multiple scales. These factors also make it difficult to design and deploy sustainable remedial approaches and monitor long-term contaminant behavior after remedial actions. Functionally, methods for addressing contamination must remove and/or reduce transport of contaminants. This problem is particularly challenging in the arid western United States where the vadose zone is hundreds of feet thick, rendering transitional excavation methods exceedingly costly and ineffective. Delivery of remedial amendments is one of the most challenging and critical aspects for all remedy-based approaches. The conventional approach for delivery is through heterogeneous deep vadose zone environments present hydrologic and geochemical challenges that limit the effectiveness. Because the flow of solution infiltration is dominantly controlled by gravity and suction, injected liquid preferentially percolates through highly permeable pathways, by-passing low-permeability zones that frequently contain the majority of contamination. Moreover, the wetting front can readily mobilize and enhance contaminant transport to the underlying aquifer prior to stabilization. Development of innovative in-situ technologies may be the only means to meet remedial action objectives and long-term stewardship goals. Surfactants can be used to lower the liquid surface tension and create stabile foams, which readily penetrate low permeability zones. Although surfactant foams have been used for subsurface mobilization efforts in the oil and gas industry, thus far the concept of using foams as a delivery mechanism for transporting remedial amendments into deep vadose zone environments to stabilize metal and long-lived radionuclide contaminants has not been explored. Foam flow can be directed by pressure gradients, rather than being dominated by gravity; and foam delivery mechanisms limit the volume of water (< 5% vol.) required for remedy delivery and emplacement, thus mitigating contaminant mobilization. We will present the results of a numerical modeling and integrated laboratory-/intermediate-scale investigation to simulate, develop, demonstrate, and monitor (i.e., advanced geophysical techniques and advanced predictive biomarkers) foam-based delivery of remedial amendments to remediate metals and radionuclides in vadose zone environments.

scholarly journals Geodynamic and hydrodynamic conditions of the Urna and Ust‐Tegus oil fields

2019 ◽  
Vol 10 (4) ◽  
pp. 1011-1027
Author(s):  
A. R. Kurchikov ◽  
A. G. Plavnik ◽  
D. A. Kurchikov
Keyword(s):  
Oil And Gas ◽  
Pore Space ◽  
West Siberia ◽  
Oil Fields ◽  
Hydrodynamic Conditions ◽  
Reservoir Properties ◽  
Additional Tool ◽  
Oil And Gas Fields ◽  
Spatial Consistency ◽  
Geodynamic Processes

This paper discusses the productive beds of the Urna and Ust‐Tegus oil fields (West Siberia, Russian) and permeability and capacity properties that are influenced by geodynamic processes. Strong tectonic processes, accompanied by periodic magma intrusions, produced numerous fractures and faults in the Jurassic sediments, which act as conduits for groundwater flows, and thus led to the hydrothermal alteration of rocks and changes in the pore space. The data presented in the paper testify to the manifestation of these processes in the modern hydrogeochemical and geothermal conditions of the Jurassic‐Cretaceous sediments within the two oil fields and their vicinity. The petrophysical studies of the core samples and the hydrodynamic studies in the wells confirm that the reservoir properties of the productive strata are considerably heterogeneous. Despite the significant effect of the geodynamic factors, the analysis of the tracer data has not revealed any apparent spatial consistency of the presence (or absence) of a hydrodynamic connection between the wells and the locations of fractured and dynamically stressed zones. In our study, we have proposed and tested a method based on the analysis of morphotectonic features detectable in the depth maps of reference surfaces. This method is a useful additional tool for discovering and analyzing the relationships between the tectonic and hydrodynamic conditions of oil and gas fields.

scholarly journals A Complex Network Model for Analysis of Fractured Rock Permeability

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Xinmin Zhu ◽  
Guannan Liu ◽  
Feng Gao ◽  
Dayu Ye ◽  
Jixi Luo
Keyword(s):  
Complex Network ◽  
Fractured Rocks ◽  
Oil And Gas ◽  
Power Index ◽  
Fracture Network ◽  
Low Permeability ◽  
Self Similarity ◽  
Gas Reservoirs ◽  
Oil And Gas Reservoirs ◽  
Relationship Of

Fractured rocks exist widely in nature. The fracture network is an effective storage space and main seepage channel of low-permeability oil and gas reservoirs, which controls the seepage system of low-permeability oil and gas reservoirs. The connection characteristics of fracture networks are complex and evolve dynamically with time. The rise of complex network research can provide reliable analysis for the relationship between network structures and network behaviors. In this work, the fracture network is considered as a hierarchical network with self-similarity, and complex network theory is applied to analyze the permeability of fractured rocks. According to the power-law relationship of degree distribution of network nodes, the number of nodes is corresponding to the number of network edges and a new power-law distribution relationship of edges with degree of nodes is proposed. Eventually, the permeability model of fractured rocks is derived and it is found that permeability of fractured rocks is a function of degree of maximum node k max , self-similarity index γ , power index d k , and other structural parameters. Compared with the existing numerical simulations, the validity of the model is verified. By calculating the influence of model parameters on the permeability, the following results are obtained: (1) fracture porosity is directly proportional to permeability; (2) fracture surface density is linearly increasing with permeability; (3) power index is inversely proportional to permeability; and (4) permeability is exponentially increasing with the maximum degree of a node.

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