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.

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.

A Rapid Method for Determination of Buprenorphine and Norbuprenorphine in Urine by UPLC-MS/MS

2020 ◽  
Vol 16 ◽  
Author(s):  
Aykut Kul ◽  
Murat Ozdemir ◽  
Selma Ozilhan ◽  
Olcay Sagirli
Keyword(s):  
Forensic Science ◽  
Rapid Method ◽  
Proficiency Testing ◽  
Mass Spectrometer ◽  
Illicit Market ◽  
Analysis Methods ◽  
Accuracy And Precision ◽  
Lower Limits

Background: Buprenorphine is quite common in the illicit market. Buprenorphine-containing drugs abuse is frequently encountered in patients. The analysis methods used to determine the abuse of buprenorphine and norbuprenorphine are important for forensic science. Buprenorphine is metabolized to norbuprenorphine by the liver. Objective: Therefore, the determination of buprenorphine and norbuprenorphine in urine is one of the methods to determine the abuse of buprenorphine. Methods: In this study, we have developed a precise, simple, and rapid ultra-performance liquid chromatographytandem mass spectrometer method for the determination of buprenorphine and norbuprenorphine simultaneously. Results: The developed method was validated in terms of selectivity and linearity, which was in the range of 9–1800 ng/mL for both buprenorphine and norbuprenorphine. The intra-assay and inter-assay accuracy and precision were found within acceptable limits of the EMA guideline. Lower limits of quantitation were 9 ng/mL for both buprenorphine and norbuprenorphine. Conclusion: The developed method was successfully applied for the determination of both analytes in the proficiency testing samples.

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