scholarly journals The distribution of sand void diameter by air intrusion method and moisture characteristic curve method.

1998 ◽  
pp. 35-44 ◽  
Author(s):  
Takao Uno ◽  
Kohji Kamiya ◽  
Kohji Tanaka
Author(s):  
Ying-xian Liu ◽  
Jie Tan ◽  
Hui Cai ◽  
Yan-lai Li ◽  
Chun-yan Liu

AbstractThe water flooding characteristic curve method is one of the essential techniques to predict recoverable reserves. However, the recoverable reserves indicated by the existing water flooding characteristic curves of low-amplitude reservoirs with strong bottom water increase gradually, and the current local recovery degree of some areas has exceeded the predicted recovery rate. The applicability of the existing water flooding characteristic curves in low-amplitude reservoirs with strong bottom water is lacking, which affects the accurate prediction of development performance. By analyzing the derivation process of the conventional water flooding characteristic curve method, this manuscript finds out the reasons for the poor applicability of the existing water flooding characteristic curve in low-amplitude reservoir with strong bottom water and corrects the existing water flooding characteristic curve according to the actual situation of the oilfield and obtains the improvement method of water flooding characteristic curve in low-amplitude reservoir with strong bottom water. After correction, the correlation coefficient between $$\frac{{k_{ro} }}{{k_{rw} }}$$ k ro k rw and $$S_{w}$$ S w is 95.92%. According to the comparison between the actual data and the calculated data, in 2021/3, the actual water cut is 97.29%, the water cut predicted by the formula is 97.27%, the actual cumulative oil production is 31.19 × 104t, and the predicted cumulative oil production is 31.31 × 104t. The predicted value is consistent with the actual value. It provides a more reliable method for predicting low-amplitude reservoirs' recoverable ability with strong bottom water and guides the oilfield's subsequent decision-making.


2020 ◽  
Vol 213 ◽  
pp. 02020
Author(s):  
Fachao Shan ◽  
Lun Zhao ◽  
Anzhu Xu ◽  
Bing Bo ◽  
Gang Ma ◽  
...  

Generally the dynamic methods are used to calculate the oil increase after flooding control in the oilfield, but the evaluation results of different methods are quite different, and the evaluation results are uncertain. Therefore, for flooding control well groups in heavy oil reservoirs, the water flooding characteristic curve method, decline method and net oil increase method are used to calculate the oil increase, and the influence of the method parameter values on the results are analyzed, and the parameter value limits and calculation errors of each method are determined. Based on this, the adaptability of each method is proposed. The results show that the effect evaluation of the whole region flooding control is suitable to use the water flooding characteristic curve method or the decline method, the effect evaluation of the single well group flooding control is more suitable to use the decline method, the net oil increase method is not recommended. The application range and parameter value limit of the effect evaluation method of flooding control are put forward, which can guide the actual production effect evaluation in the oilfield.


1986 ◽  
Vol 66 (2) ◽  
pp. 249-259 ◽  
Author(s):  
G. D. BUCKLAND ◽  
D. B. HARKER ◽  
T. G. SOMMERFELDT

Saturated hydraulic conductivity (Ks) and drainable porosity (f) determined by different methods and for different depths were compared with those determined from the performance of drainage systems installed at two locations. These comparisons were made to determine which methods are suitable for use in subsurface drainage design. Auger hole and constant-head well permeameter Ks were 140 and 110%, respectively, of Ks determined from subsurface drains. Agreement of horizontal or vertical Ks, from in situ falling-head permeameters; to other methods was satisfactory providing sample numbers were large. Ks by Tempe cells was only 3–10% of drain Ks and in one instance was significantly lower than Ks determined by all other methods. At one site a profile-averaged value of f determined from the soil moisture characteristic curve (0–5 kPa) of semidisturbed cores agreed with that determined from drainage trials. At the other site, a satisfactory value of f was found only when the zone in which the water table fluctuated was considered. Results indicate that Ks determined by the auger hole and constant-head well permeameter methods, and f determined from the soil moisture characteristic curve of semidisturbed cores, are sufficiently reliable and practical for subsurface drainage design. Key words: Subsurface drainage, hydraulic conductivity, drainable porosity


2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Qinghe Yao ◽  
Xin Pan ◽  
Qingyong Zhu

A parallel characteristic curve method is applied in domain decomposition system to simulate the dispersion behavior of hydrogen in this work. The characteristic curve method is employed to approximate the Navier-Stokes equations and the convection diffusion equation, and the feasibility of solving complex multicomponent flow problems is demonstrated by the numerical simulation of hydrogen dispersion in a partially open space. An analogy of the Boussinesq approximation is applied and numerical results are validated by comparing them with the experimental data. The dilution effect of ventilation is investigated. The transient behavior of hydrogen and the process of accumulation in the partially open space are discussed.


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