Analytical Model for the Waterflood Honouring Capillary Pressure (With applications to laboratory studies)

1996 ◽  
Author(s):  
P. Bedrikovetsky ◽  
J.R.P. Rodrigues ◽  
P.R.F. Britto
Keyword(s):  
Capillary Pressure ◽  
Analytical Model ◽  
Laboratory Studies

scholarly journals Testing an Analytical Model for Predicting Subsurface LNAPL Distributions from Current and Historic Fluid Levels in Monitoring Wells: A Preliminary Test Considering Hysteresis

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2404
Author(s):  
Robert Lenhard ◽  
John Rayner ◽  
J. García-Rincón
Keyword(s):  
Capillary Pressure ◽  
Analytical Model ◽  
Specific Volume ◽  
Preliminary Test ◽  
Contaminated Site ◽  
Monitoring Wells ◽  
Versus Main ◽  
Phase Liquid ◽  
Subsurface Light ◽  
Fluid Levels

Knowledge of subsurface light nonaqueous phase liquid (LNAPL) saturation is important for developing a conceptual model and a plan for addressing LNAPL contaminated sites. Investigators commonly predict LNAPL mobility and potential recoverability using information such as LNAPL physical properties, subsurface characteristics, and LNAPL saturations. Several models exist that estimate the LNAPL specific volume and transmissivity from fluid levels in monitoring wells. Commonly, investigators use main drainage capillary pressure–saturation relations because they are more frequently measured and available in the literature. However, main drainage capillary pressure–saturation relations may not reflect field conditions due to capillary pressure–saturation hysteresis. In this paper, we conduct a preliminary test of a recent analytical model that predicts subsurface LNAPL saturations, specific volume, and transmissivity against data measured at a LNAPL contaminated site. We call our test preliminary because we compare only measured and predicted vertical LNAPL saturations at a single site. Our results show there is better agreement between measured and predicted LNAPL saturations when imbibition capillary pressure–saturation relations are employed versus main drainage capillary pressure–saturation relations. Although further testing of the model for different conditions and sites is warranted, the preliminary test of the model was positive when consideration was given to capillary pressure–saturation hysteresis, which suggests the model can yield reasonable predictions that can help develop and update conceptual site models for addressing subsurface LNAPL contamination. Parameters describing capillary pressure–saturation relations need to reflect conditions existing at the time when the fluid levels in a well are measured.

Modeling of Spontaneous–Imbibition Experiments With Porous Disk—On the Validity of Exponential Prediction

SPE Journal ◽  
2017 ◽  
Vol 22 (05) ◽  
pp. 1326-1337 ◽  
Author(s):  
P. Ø. Andersen ◽  
S.. Evje ◽  
A.. Hiorth
Keyword(s):  
Experimental Data ◽  
Pressure Gradient ◽  
Capillary Pressure ◽  
Analytical Model ◽  
Time Scale ◽  
Flow Resistance ◽  
Equilibrium Points ◽  
Porous Disk ◽  
The Core ◽  
Capillary Pressure Gradient

Summary Imbibition experiments with porous disk can be used to derive accurate capillary pressure curves for porous media. An experimental setup is considered in which brine spontaneously imbibes cocurrently through a water-wet porous disk and into a mixed-wet core. Oil is produced from the core's top surface, which is exposed to oil. The capillary pressure is reduced in steps to determine points on the capillary pressure curve. A mathematical model is presented to interpret and design such experiments. The model was used to history match experimental data from Ahsan et al. (2012). An analytical model was then derived from a simplification of the general model, and validated by comparing the two by use of parameters from history matching. The main assumption of the analytical model is that the imbibition rate is sufficiently low, allowing fluids to redistribute inside the core, leading to a negligible capillary pressure gradient. This results in an exponential imbibition time profile with a time scale τ. Exponential matching has been applied earlier in the literature, but, for the first time, we derive this expression theoretically and provide an explicit formulation for the time scale. The numerical simulations show that, at low saturations, there can be a significant flow resistance in the core. A capillary-pressure gradient then forms, and the analytical solution overestimates the rate of recovery. At higher saturations, the fluids are more mobile, and imbibition rate is restricted by the disk. Under such conditions, the exponential solution is a good approximation. The demonstrated ability to predict the time scale in the late stage of the experiment is of significant benefit, because this part of the test is also the most time-consuming and most important to estimate. A method is presented to derive capillary pressure data point by point from measured imbibition data. It provides reliable data between the equilibrium points, and demonstrates consistent variations in flow resistance during the imbibition tests. Gravity had minor influence on the considered experimental data, but generally implies that equilibrium points have higher capillary pressure than the phase pressure difference defined by the boundary conditions.

An Analytical Model for Capillary Pressure–Saturation Relation for Gas–Liquid System in a Packed-Bed of Spherical Particles

2008 ◽  
Vol 77 (1) ◽  
pp. 17-40 ◽  
Author(s):  
Katja Lappalainen ◽  
Mikko Manninen ◽  
Ville Alopaeus ◽  
Juhani Aittamaa ◽  
John Dodds
Keyword(s):  
Capillary Pressure ◽  
Analytical Model ◽  
Packed Bed ◽  
Liquid System ◽  
Spherical Particles

Analytical Solution for Determining Fracture Attenuation

2021 ◽  
Author(s):  
Vadim Andreevich Rubailo ◽  
Kirill Dmitrievich Isakov ◽  
Anton Vyacheslavovich Shirobokov
Keyword(s):  
Analytical Solution ◽  
Hydraulic Fracturing ◽  
Analytical Model ◽  
Crack Width ◽  
Laboratory Studies ◽  
Crack Geometry

Abstract This work is devoted to the analytical solution of the damping of the fracture of the hydraulic fracturing. A solution is obtained for changing the dimensionless conductivity of the crack due to a decrease in the conductivity of the proppant and its removal from the crack. The considered crack geometry corresponds to the Perkins-Kern analytical model, which allows us to take into account the change in the crack width depending on its length. To calculate the proppant conductivity, laboratory studies were used, the data of which were extrapolated in order to predict the destruction of proppant balls during the operation of a well with a fractured hydraulic fracturing.

Hydrogen Cyanide Polymers from the Impact of Comet P/Shoemaker-Levy 9 on Jupiter

1997 ◽  
Vol 161 ◽  
pp. 179-187
Author(s):  
Clifford N. Matthews ◽  
Rose A. Pesce-Rodriguez ◽  
Shirley A. Liebman
Keyword(s):  
Amino Acids ◽  
Solar System ◽  
Hydrogen Cyanide ◽  
Nitrogen Heterocycles ◽  
Laboratory Studies ◽  
Heterogeneous Solids ◽  
The Many ◽  
Comet Halley ◽  
The Impact ◽  
By Products

AbstractHydrogen cyanide polymers – heterogeneous solids ranging in color from yellow to orange to brown to black – may be among the organic macromolecules most readily formed within the Solar System. The non-volatile black crust of comet Halley, for example, as well as the extensive orangebrown streaks in the atmosphere of Jupiter, might consist largely of such polymers synthesized from HCN formed by photolysis of methane and ammonia, the color observed depending on the concentration of HCN involved. Laboratory studies of these ubiquitous compounds point to the presence of polyamidine structures synthesized directly from hydrogen cyanide. These would be converted by water to polypeptides which can be further hydrolyzed to α-amino acids. Black polymers and multimers with conjugated ladder structures derived from HCN could also be formed and might well be the source of the many nitrogen heterocycles, adenine included, observed after pyrolysis. The dark brown color arising from the impacts of comet P/Shoemaker-Levy 9 on Jupiter might therefore be mainly caused by the presence of HCN polymers, whether originally present, deposited by the impactor or synthesized directly from HCN. Spectroscopic detection of these predicted macromolecules and their hydrolytic and pyrolytic by-products would strengthen significantly the hypothesis that cyanide polymerization is a preferred pathway for prebiotic and extraterrestrial chemistry.

Cognitive Aging in a Precision Sport Context

1996 ◽  
Vol 1 (3) ◽  
pp. 166-179 ◽  
Author(s):  
Bo Molander ◽  
Lars Bäckman
Keyword(s):  
Older Adult ◽  
Cognitive Abilities ◽  
Cognitive Aging ◽  
Motor Performance ◽  
Intervention Programs ◽  
Laboratory Studies ◽  
High Arousal ◽  
Memory And Attention ◽  
Age Related ◽  
Principal Finding

Highly skilled miniature golf players were examined in a series of field and laboratory studies. The principal finding from these studies is that young and young adult players (range = 15-38 years) score equally well or better in competition than in training whereas older adult players (range = 46-73 years) perform worse in competitive events than under training conditions. It was also found that the impairment in motor performance on the part of the older players is associated with age-related deficits in basic cognitive abilities, such as memory and attention. These results support the hypothesis that older players may be able to compensate for age-related deficits under relaxed conditions, but not under conditions of high arousal. The possibility of improving the performance of the older players in stressful situations by means of various intervention programs is discussed.

Sign in / Sign up

Export Citation Format

Share Document