The instability of a vaporization front in hot porous rock

Nature ◽  
1994 ◽  
Vol 367 (6462) ◽  
pp. 450-453 ◽  
Author(s):  
Shaun D. Fitzgerald ◽  
Andrew W. Woods
Keyword(s):  
Porous Rock ◽  
Vaporization Front

scholarly journals Study on the Influence of Geometric Characteristics of Grain Membranes on Permeability Properties in Porous Sandstone

Membranes ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 587
Author(s):  
Run Shi ◽  
Huaiguang Xiao ◽  
Chengmeng Shao ◽  
Mingzheng Huang ◽  
Lei He
Keyword(s):  
Fluid Flow ◽  
Single Parameter ◽  
Control Group ◽  
Porous Rock ◽  
Permeability Characteristics ◽  
Natural Rock ◽  
Porous Sandstone ◽  
Novel Method ◽  
Boltzmann Method ◽  
Flow Laws

Studying the influence of grain characteristics on fluid flow in complex porous rock is one of the most important premises to reveal the permeability mechanism. Previous studies have mainly investigated the fluid flow laws in complex rock structures using an uncontrollable one single parameter of natural rock models or oversimplified control group models. In order to solve these problems, this paper proposes a novel method to reconstruct models that can independently control one single parameter of rock grain membranes based on mapping and reverse-mapping ideas. The lattice Boltzmann method is used to analyze the influence of grain parameters (grain radius, space, roundness, orientation, and model resolution) on the permeability characteristics (porosity, connectivity, permeability, flow path, and flow velocity). Results show that the grain radius and space have highly positive and negative correlations with permeability properties. The effect of grain roundness and resolution on permeability properties shows a strong regularity, while grain orientation on permeability properties shows strong randomness. This study is of great significance to reveal the fluid flow laws of natural rock structures.

A New Dynamic Wettability-Alteration Model for Oil-Wet Cores During Surfactant-Solution Imbibition

SPE Journal ◽  
2013 ◽  
Vol 18 (05) ◽  
pp. 818-828 ◽  
Author(s):  
M. Hosein Kalaei ◽  
Don W. Green ◽  
G. Paul Willhite
Keyword(s):  
Experimental Data ◽  
Oil Recovery ◽  
History Matching ◽  
Mechanistic Model ◽  
Surfactant Solution ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Wettability Alteration ◽  
Porous Rock ◽  
Surfactant Solutions

Summary Wettability modification of solid rocks with surfactants is an important process and has the potential to recover oil from reservoirs. When wettability is altered by use of surfactant solutions, capillary pressure, relative permeabilities, and residual oil saturations change wherever the porous rock is contacted by the surfactant. In this study, a mechanistic model is described in which wettability alteration is simulated by a new empirical correlation of the contact angle with surfactant concentration developed from experimental data. This model was tested against results from experimental tests in which oil was displaced from oil-wet cores by imbibition of surfactant solutions. Quantitative agreement between the simulation results of oil displacement and experimental data from the literature was obtained. Simulation of the imbibition of surfactant solution in laboratory-scale cores with the new model demonstrated that wettability alteration is a dynamic process, which plays a significant role in history matching and prediction of oil recovery from oil-wet porous media. In these simulations, the gravity force was the primary cause of the surfactant-solution invasion of the core that changed the rock wettability toward a less oil-wet state.

598 Temperature profiles of sunlight-exposed surfaces in a desert climate: Determining the risks for pavement burns.

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S150-S151
Author(s):  
Paul J Chestovich ◽  
Richard Z Saroukhanoff ◽  
Syed F Saquib ◽  
Joseph T Carroll ◽  
Carmen E Flores ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Solar Irradiance ◽  
Time Of Day ◽  
Temperature Measurements ◽  
Solar Irradiation ◽  
Porous Rock ◽  
Solid Materials ◽  
Contour Plots ◽  
Desert Climate ◽  
Sunlight Intensity

Abstract Introduction In the desert climates of the United States, plentiful sunlight and high summer temperatures cause significant burn injuries from hot pavement and other surfaces. Although it is well known that surfaces reach temperatures sufficient to cause full-thickness burns, the peak temperature, time of day, and highest risk materials is not well described. This work measured continuous temperature measurements of six materials in a desert climate over a five-month period. Methods Six different solid materials common in an urban environment were utilized for measurement. Asphalt, brick, concrete, sand, porous rock, and galvanized metal were equipped with thermocouples attached to a data acquisition module. All solid materials except metal were placed in a 2’x2’x3.5” form, and identical samples were placed in both shade and direct sunlight. Ambient temperature was recorded, and sunlight intensity was measured using a pyranometer. Measurement time interval was set at three minutes. A computational fluid dynamics (CFD) model was created using Star CCM+ to validate the data. Contour plots of temperature, solar irradiance, and time of day were created using MiniTab for all surfaces tested. Results 75,000 temperature measurements were obtained from March through August 2020. Maximum recorded temperatures for sunlight-exposed samples of porous rock was 170 F, asphalt 166 F, brick 152 F, concrete 144 F, metal 144 F, and sand 143 F. Peak temperatures were recorded on August 6, 2020 at 2:10 pm, when ambient temperature was 120 F and sunlight intensity 940 W/m2 (Table). Temperatures ranged from 36 F - 56 F higher than identical materials in the shade at the same time. The highest daily temperatures were achieved between 2:00 pm to 4:00 pm due to maximum solar irradiance. Contour plots of surface temperature as function of solar irradiation and time of day were created for all surfaces tested. Nearly identical results obtained from the CFD models to the experimentally collected data, which validated the experimental data. Conclusions Surfaces exposed to direct, continuous sunlight in a desert climate achieve temperatures from 143 F to 170 F in the early afternoon and are high enough to cause significant injury with sufficient exposure. Porous rock reached the highest temperature, followed closely by asphalt. This information is useful to inform the public of the dangers of exposed surfaces in a desert climate.

scholarly journals Direct measurement of the unjacketed pore modulus of porous solids

2018 ◽  
Vol 474 (2219) ◽  
pp. 20180602 ◽  
Author(s):  
Ali Tarokh ◽  
Emmanuel Detournay ◽  
Joseph Labuz
Keyword(s):  
Stress Measurement ◽  
Pressure Change ◽  
Porous Solids ◽  
Testing System ◽  
Effective Pressure ◽  
Porous Rock ◽  
Indirect Approach ◽  
Mineral Constituent ◽  
Solid Bulk ◽  
Skempton Coefficient

Pressure decline caused by the extraction of oil from deep sedimentary layers depends on the pore modulus K pp , a poroelastic parameter that characterizes the effect of pressure change on pore volume under constant mean stress. Measurement of K pp is difficult, however, as it requires calibration to account for fluid compressibility and compliance of the testing system. Nevertheless, knowing the easily measurable drained pore modulus K p and adopting an assumption on the unjacketed pore modulus K s ″, it is possible to determine K pp because these pore moduli are related. Previous work on indirectly estimating K s ″ claimed that K s ″ is strongly dependent on Terzaghi effective pressure P′ and therefore not a constant; also, K s ″ might be different from K s , the solid bulk modulus of the major mineral constituent. We overcome the limitations of the indirect approach by directly measuring K s ″. The experiments reveal that K s ″ is indeed a constant and that for an ideal porous rock, the assumption of K s ′ ′ = K s holds. Furthermore, a constant K s ″ implies that K p and K pp are functions of Terzaghi effective pressure only. These results provide a framework to accurately determine the Skempton coefficient B .

Internal friction and modulus dispersion in fluid saturated porous rock

1983 ◽  
Vol 74 (S1) ◽  
pp. S57-S57
Author(s):  
B. R. Tittman ◽  
J. R. Bulau ◽  
M. Abdel‐Gawad
Keyword(s):  
Internal Friction ◽  
Porous Rock
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