scholarly journals On the Imbibition Model for Oil-Water Replacement of Tight Sandstone Oil Reservoirs

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiong Liu ◽  
Desheng Zhou ◽  
Le Yan ◽  
Shun Liu ◽  
Yafei Liu
Keyword(s):  
Osmotic Pressure ◽  
Relative Permeability ◽  
Capillary Force ◽  
Water Phase ◽  
Dimensionless Time ◽  
Water Displacement ◽  
Replacement Rate ◽  
Tight Sandstone ◽  
Water Replacement ◽  
Oil Water

A model suitable for evaluating a tight sandstone reservoir is established. The model includes two oil-water replacement modes: capillary force mode and osmotic pressure mode. The relationship between oil-water displacement rate and dimensionless time under different parameters is drawn considering the influence of capillary force, osmotic pressure, production pressure difference, and starting pressure gradient. Results indicate that the higher the relative permeability of the water phase, the lower the relative permeability of the oil phase, the smaller the oil-water viscosity ratio, and the higher the oil-water replacement rate. The relative permeability of the water phase also affects the infiltration stabilization time. Low salinity fracturing fluid infiltration helps to improve the oil-water replacement rate.

scholarly journals Analysis and Evaluation of Oil-water Relative Permeability Curves

2015 ◽  
Vol 8 (1) ◽  
pp. 181-185
Author(s):  
Yang Manping ◽  
Xi Wancheng ◽  
Zhao Xiaojing ◽  
Cheng Yanhong
Keyword(s):  
Relative Permeability ◽  
Water Phase ◽  
Core Flooding ◽  
Displacement Efficiency ◽  
Analysis And Evaluation ◽  
Different Types ◽  
Oil Displacement Efficiency ◽  
Oil Water ◽  
Relative Permeability Curves ◽  
The Relationship

Oil-water relative permeability curves are the characteristic curves of evaluating the oil-water infiltrating fluid and also are an important part of reservoir engineering studies. Through a large number of core flooding experiments, based on the establishment of oil-water relative permeability calculation models, the use of the function of the relative permeability curves divided these into the water phase concave, water phase convex and a water phase linear categories. The relationship between different types of relative permeability curves with reservoir characteristics, moisture content, common infiltration points, common permeation range and oil displacement efficiency have been evaluated. Analysis the distribution of the reservoir usable remaining oil and reservoir irreducible oil of different types of relative permeability curves.

Recirculation versus flow-through rainbow trout laboratory Flavobacterium columnare challenge

2020 ◽  
Vol 139 ◽  
pp. 213-221
Author(s):  
C Birkett ◽  
R Lipscomb ◽  
T Moreland ◽  
T Leeds ◽  
JP Evenhuis
Keyword(s):  
Rainbow Trout ◽  
Environmental Parameters ◽  
Cumulative Effects ◽  
Flavobacterium Columnare ◽  
Replacement Rate ◽  
Bacterial Concentration ◽  
Water Replacement ◽  
Dose Concentration ◽  
Flow Through ◽  
And Control

Flavobacterium columnare immersion challenges are affected by water-related environmental parameters and thus are difficult to reproduce. Whereas these challenges are typically conducted using flow-through systems, use of a recirculating challenge system to control environmental parameters may improve reproducibility. We compared mortality, bacterial concentration, and environmental parameters between flow-through and recirculating immersion challenge systems under laboratory conditions using 20 rainbow trout families. Despite identical dose concentration (1:75 dilution), duration of challenge, lot of fish, and temperature, average mortality in the recirculating system (42%) was lower (p < 0.01) compared to the flow-through system (77%), and there was low correlation (r = 0.24) of family mortality. Mean days to death (3.25 vs. 2.99 d) and aquaria-to-aquaria variation (9.6 vs. 10.4%) in the recirculating and flow-through systems, respectively, did not differ (p ≥ 0.30). Despite 10-fold lower water replacement rate in the recirculating (0.4 exchanges h-1) compared to flow-through system (4 exchanges h-1), differences in bacterial concentration between the 2 systems were modest (≤0.6 orders of magnitude) and inconsistent throughout the 21 d challenge. Compared to the flow-through system, dissolved oxygen during the 1 h exposure and pH were greater (p ≤ 0.02), and calcium and hardness were lower (p ≤ 0.03), in the recirculating system. Although this study was not designed to test effects of specific environmental parameters on mortality, it demonstrates that the cumulative effects of these parameters result in poor reproducibility. A recirculating immersion challenge model may be warranted to empirically identify and control environmental parameters affecting mortality and thus may serve as a more repeatable laboratory challenge model.

Gas-Water Flow Behaviour During Mutual Displacement in Porous Media

2017 ◽  
Vol 10 (1) ◽  
pp. 13-22
Author(s):  
Renyi Cao ◽  
Junjie Xu ◽  
Xiaoping Yang ◽  
Renkai Jiang ◽  
Changchao Chen
Keyword(s):  
Porous Media ◽  
Relative Permeability ◽  
Gas Storage ◽  
Fluid Distribution ◽  
Water Displacement ◽  
Phase Zone ◽  
Two Phase ◽  
Flow Process ◽  
Single Well ◽  
Mutual Displacement

During oilfield development, there exist multi-cycle gas–water mutual displacement processes. This means that a cycling process such as water driving gas–gas driving water–water driving gas is used for the operation of injection and production in a single well (such as foam huff and puff in single well or water-bearing gas storage). In this paper, by using core- and micro-pore scales model, we study the distribution of gas and water and the flow process of gas-water mutual displacement. We find that gas and water are easier to disperse in the porous media and do not flow in continuous gas and water phases. The Jamin effect of the gas or bubble becomes more severe and makes the flow mechanism of multi-cycle gas–water displacement different from the conventional water driving gas or gas driving water processes. Based on experiments of gas–water mutual displacement, the changing mechanism of gas–water displacement is determined. The results indicate that (1) after gas–water mutual displacement, the residual gas saturation of a gas–water coexistence zone becomes larger and the two-phase zone becomes narrower, (2) increasing the number of injection and production cycles causes the relative permeability of gas to increase and relative permeability for water to decrease, (3) it becomes easier for gas to intrude and the invaded water becomes more difficult to drive out and (4) the microcosmic fluid distribution of each stage have a great difference, which caused the two-phase region becomes narrower and effective volume of gas storage becomes narrower.

A high precision computing method for heat transfer in the process of oil-water displacement

2021 ◽  
Vol 33 (5) ◽  
pp. 958-969
Author(s):  
Pan-pan Han ◽  
Ke Chen ◽  
Dong-xi Liu ◽  
Yun-xiang You ◽  
Jin Wang
Keyword(s):  
Heat Transfer ◽  
High Precision ◽  
Water Displacement ◽  
Oil Water ◽  
Computing Method

scholarly journals Productivity Influence Factors of Tight Sandstone Gas Reservoir with Water Produced

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yongchao Xue ◽  
Qingshuang Jin ◽  
Hua Tian
Keyword(s):  
Pressure Gradient ◽  
Relative Permeability ◽  
Gas Flow ◽  
Influence Factors ◽  
Stress Sensitivity ◽  
Consumption Pattern ◽  
Tight Sandstone ◽  
Gas Reservoir ◽  
Two Phase ◽  
Start Up

Finding ways to accelerate the effective development of tight sandstone gas reservoirs holds great strategic importance in regard to the improvement of consumption pattern of world energy. The pores and throats of the tight sandstone gas reservoir are small with abundant interstitial materials. Moreover, the mechanism of gas flow is highly complex. This paper is based on the research of a typical tight sandstone gas reservoir in Changqing Oilfield. A strong stress sensitivity in tight sandstone gas reservoir is indicated by the results, and it would be strengthened with the water production; at the same time, a rise to start-up pressure gradient would be given by the water producing process. With the increase in driving pressure gradient, the relative permeability of water also increases gradually, while that of gas decreases instead. Following these results, a model of gas-water two-phase flow has been built, keeping stress sensitivity, start-up pressure gradient, and the change of relative permeability in consideration. It is illustrated by the results of calculations that there is a reduction in the duration of plateau production period and the gas recovery factor during this period if the stress sensitivity and start-up pressure gradient are considered. In contrast to the start-up pressure gradient, stress sensitivity holds a greater influence on gas well productivity.

A FRACTAL MODEL FOR WATER FLOW THROUGH UNSATURATED POROUS ROCKS

Fractals ◽  
2018 ◽  
Vol 26 (02) ◽  
pp. 1840015 ◽  
Author(s):  
BOQI XIAO ◽  
XIAN ZHANG ◽  
WEI WANG ◽  
GONGBO LONG ◽  
HANXIN CHEN ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Pore Size ◽  
Capillary Pressure ◽  
Water Flow ◽  
Relative Permeability ◽  
Fractal Model ◽  
Water Phase ◽  
Porous Rocks ◽  
Proposed Model ◽  
Flow Through

In this work, considering the effect of porosity, pore size, saturation of water and tortuosity fractal dimension, an analytical model for the capillary pressure and water relative permeability is derived in unsaturated porous rocks. Besides, the formulas of calculating the capillary pressure and water relative permeability are given by taking into account the fractal distribution of pore size and tortuosity of capillaries. It can be seen that the capillary pressure for water phase decreases with the increase of saturation in unsaturated porous rocks. It is found that the capillary pressure for water phase decreases as the tortuosity fractal dimension decreases. It is further seen that the capillary pressure for water phase increases with the decrease of porosity, and at low porosity, the capillary pressure increases sharply with the decrease of porosity. Besides, it can be observed that the water relative permeability increases with the increase of saturation in unsaturated porous rocks. This predicted the capillary pressure and water relative permeability of unsaturated porous rocks based on the proposed models which are in good agreement with the experimental data and model predictions reported in the literature. The proposed model improved the understanding of the physical mechanisms of water flow through unsaturated porous rocks.

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