TOWARDS THE PRESENCE OF REGULARITIES BETWEEN THE FUNCTION OF INTERFACIAL INTERACTION AND THE FILTRATION CAPACITY PROPERTIES

2021 ◽  
Vol 7 (1) ◽  
pp. 92-111
Author(s):  
Sergey V. STEPANOV ◽  
Alexander B. SHABAROV
Keyword(s):  
Relative Phase ◽  
Laboratory Data ◽  
Interfacial Interaction ◽  
Pressure Curve ◽  
Phase Permeability ◽  
Interphase Interaction ◽  
Acceptable Error ◽  
Interaction Function ◽  
Relative Phase Permeability ◽  
Filtration Capacity

This paper discusses the results of identifying possible regularities between the parameters describing the function of interfacial interaction and filtration capacity properties of rocks. The studies have employed real laboratory data, forming four clusters. The capillary pressure curve data and relative phase permeability data were obtained on the same core samples. The authors describe the factors determining the interphase interaction during multiphase fluid flow in a porous medium. On this basis, a method for calculating discrete values of the interfacial interaction function based on the results of laboratory studies of relative phase permeability is proposed. For the approximation of the interfacial interaction function, the four-parametric formula following from derivative of Buckley — Leverett function at assignment of relative phase permeability functions by means of Corey functions is substantiated. The authors suggest two variants of interphase interaction function formulation. They prove that for the first variant, there is a stable dependence only for one parameter, and for the second variant — with three parameters. Thus, one of the parameters in all cases has appeared close to one. The results show that the error of the detected dependencies on the deviation of the parameters has a linear dependence, and for both variants of the interfacial interaction function, the ranking of the parameters is different according to their influence on the error. Using a test sample, the authors show that the dependencies obtained allow determining the parameters of the interphase interaction function with an acceptable error.

scholarly journals Approaches to determining the critical coefficients of water saturation Burdine formulas taking into account the differences in the limits of integration

2019 ◽  
pp. 30-39
Author(s):  
G. E. Stroyanetskaya
Keyword(s):  
Print Media ◽  
Relative Phase ◽  
Water Saturation ◽  
Phase Permeability ◽  
Saturation Ratio ◽  
Geophysical Research ◽  
Relative Phase Permeability ◽  
Definite Integrals ◽  
Lower Limits

The article is devoted to the determination of the critical water saturation ratio productive reservoirs. It is necessary to have information about these coefficients in order to interpret the geophysical research wells at the stage of exploration. The print media publish Burdine formulas, which contain definite integrals, to determine the coefficients that need to be solved. In this case, the upper and lower limits of the integrals in the works of different authors don't completely coincide. The author of this article analyses Burdine formulas, which have been published in various print media, and proposes Burdine formulas without integrals. As a result, it is established that Burdine formulas, which are presented in the work [6], are suitable for real conditions; but there should be taken into account the conditions under which the relative phase permeability of oil and water is equal to 0 and 1.  

Mathematical modeling of a well performance in view of nonequilibrium relative phase permeability

2020 ◽  
Vol 6 (1) ◽  
pp. 208-217
Author(s):  
Alexander V. Ivanov ◽  
Sergey V. Stepanov
Keyword(s):  
Relative Phase ◽  
Oil Field ◽  
Well Performance ◽  
Mathematical Methods ◽  
Hydrodynamic Models ◽  
Phase Permeability ◽  
Relative Phase Permeability ◽  
A Cell ◽  
Relationship Of ◽  
The Relationship

As it is well known, mesh refinement of hydrodynamic models to improve accuracy of well performance modeling results in a significant increase of the calculation time. That explains the relevance of developing mathematical methods that can increase the modeling adequacy without a detailed computation mesh. This article discusses using a well correcting function (CF) that presents the coordinated performance of a watercut in a calculated cell and a well. The distinctive feature of the introduced CF lies in it being defined by the saturation structure of the calculated cell which accounts for the disequilibrium of the relative phase permeability (RFP) function. At the same time, the RFP disequilibrium follows Barenblat’s model. This method is presented as a computer program, which has helped to determine that the watercut in a cell gravitates towards the well watercut when the redistribution time rises. This behavior agrees with the saturation contour, which accounts for the relationship of the width of stabilized zone with the driving velocity. The selection of CF was tested on four wells working in horizons AV1(3) of the Samotlor Oil Field. The retrospective analysis shows, that this method can be used for increasing the accuracy of well modeling.

scholarly journals Appearance of Capillary end Effects in Filtration Studies

2021 ◽  
Vol 21 (1) ◽  
pp. 23-27
Author(s):  
Ivan S. Putilov ◽  
◽  
Denis B. Chizhov ◽  
Evgeniy A. Kochergin ◽  
◽  
...  
Keyword(s):  
Relative Phase ◽  
Test Sample ◽  
Negative Influence ◽  
Core Sample ◽  
End Effect ◽  
End Effects ◽  
Experimental Conditions ◽  
The Core ◽  
Filtration Capacity ◽  
Capillary End Effect

From theoretical studies and experiments on the core, the so-called capillary end effect, or, as it is also called, the effect of phases capillary entrapment, is known. When carrying out laboratory experiments to determine the relative phase permeabilities, capillary end effects appear on the core models of the reservoir. These effects can occur as a result of capillary ruptures at the ends of the core sample, which leads to the accumulation of one phase in relation to the other, and thereby affects the movement and retention of the fluid. The region of capillary end effect, which occurs due to the rupture of capillaries at the exit from the sample, affects the change in pressure drop and saturation of a particular fluid. If the influence of capillary end effects is significant, then the experimental conditions are modeled incorrectly, which can lead to serious errors in predicting the productivity of the studied formation. This paper presents the results of studying the porosity-permeability properties of determining the relative phase permeabilities and the studies analysis of the capillary end effects influence mechanism on the filtration capacity of rock samples during laboratory studies using the example of terrigenous and carbonate types of the Pavlovskoye reservoir. According to the results of the studies, the significance of capillary end effects in filtration experiments was established using the example of determining the relative phase permeabilities. Recommendations are given with the aim of minimizing the negative influence of end effects. Capillary effects can be overcome by increasing the length of the test sample, as well as by increasing the flow rate of the fluid during a laboratory experiment to determine the relative phase permeabilities.

scholarly journals Prognostic Factors of Lymph Nodes in Colorectal Carcinoma

2020 ◽  
Vol 17 (5) ◽  
pp. 7-14
Author(s):  
Marilena Stoian ◽  
Lucia Indrei ◽  
Victor Stoica
Keyword(s):  
Lymph Node ◽  
Colorectal Carcinoma ◽  
Lymph Nodes ◽  
Primary Tumor ◽  
Regional Lymph Node ◽  
Laboratory Data ◽  
Lymph Node Involvement ◽  
Acceptable Error ◽  
Regional Lymph Node Involvement ◽  
Node Involvement

Abstract Background/Aims. The aim of this study was to establish whether, and to what extent, preand intraoperatively detected characteristics (demographic, anamnestic and laboratory data) and tumor characteristics can be used in the assessment of regional lymph node involvement in patients with colorectal carcinoma. The assessment also included the number of lymph nodes involved in patients with positive lymph nodes. Considering that the number of obtained lymph nodes is resected specimens, assessment parameters also included the percentage of the involved lymph nodes within the total population of lymph nodes. Methodology. From 2010-2019, 46 patients with carcinoma of the rectum and sigmoid colon were studied, with a total number of 736 lymph nodes evaluated. Out of the total number of lymph nodes, 577 (78.4%) were benign and 159 (21.6%), malignant. Data were analyzed by multi-variant statistical methods: discriminant analysis and multiple regression. Results. For this patient group, we evaluated the following potentially predictive factors for lymph node involvement: age; serum hemoglobin, albumin and alkaline phosphatase levels; weight loss; and the primary tumor localization characteristics: histological type, macroscopic growth pattern and depth of tumor invasion of the bowel wall. We found that there was no difference in the prediction of regional lymph node involvement between analysis of the aforementioned parameters and analysis of the isolated discriminators only. Conclusion. A predictability likelihood of 83.78% greatly surpasses the acceptable error tolerance level of 5%. Correlation of demographic, anamnestic and laboratory data about the patient and the characteristics of the primary tumor cannot be used in distinguishing malignant lymph nodes from benign ones. These data cannot be the basis for exact intraoperative staging and thus cannot be significant criteria foe decision-making about operative treatment modalities.

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