SU1670557A1 - Method of gas-air mixture analysis in well logging - Google Patents

Abstract

This invention relates to gas analysis in gas cutting research. The aim of the invention is to increase the reliability of the interpretation of the results of the total gas indications and to facilitate the work with the chromatograph. For this purpose, in the gas-air system of the gas-cutting station, the conductometric amount of hydrogen is additionally measured at the temperature of the heating element of the sensitive element, close to 43 ° C, at which the detector responds only to hydrogen, not reacting to methane. According to the difference in the readings of the total gas analyzer and the hydrogen indicator, the dosing column of the chromatograph is working in the required volume. 4 ill., 1 tab.

Description

one

(21) 4619609/25

(22) 12/13/88

(46) 08/15/91. Bul Nh30

(75) G.R.Rozanov

(53) 543.544 (088 8)

(56) Levitat L.M. Gas analysis and degassing in the development of oil, gas and coal deposits. M .: Nedra, 1974, p. 120-123

Pomeranets LI. Gas logging M: Nedra, 1982, p. 70

(54) METHOD OF ANALYSIS OF A GAS AIR MIXTURE AT CARRIAGE WORKS

(57) The invention relates to gas analysis in gas cutting research.

The aim of the invention is to improve the accuracy of interpretation of the results of the total gas indications and facilitate work with the chromatograph. For this, in the gas-logging system of the logging station, the amount of hydrogen at the heating temperature of the sensing element close to 43 ° C is additionally measured, at which the detector reacts only For hydrogen, not reacting to methane. According to the difference in the readings of the total gas analyzer and hydrogen indicator, the required volume of the dosing column is chosen. and operating discretely yl 4., 1 tab.

This invention relates to gas analysis in downhole geochemical studies.

The purpose of the invention is the accuracy of the interpretation of the total gas indications and the efficiency of the analysis at high methane concentrations in the mixture of the analyzed sample and sharply different hydrogen content.

Fig, 1 shows a diagram of the device that implements this method; in fig. 2 is a plot of the indications of the hydrogen indicator for a given voltage supply on the sensitive elements when analyzing the gas / air mixture with a methane concentration of 6.3%. The abscissa shows the values in volts. The ordinate axis plots the distance of the recorder carriage deviation from zero in millimeters.

with

WITH

FIG. Figure 3 shows a graph of standardization of a hydrogen indicator with a voltage supply of sensitive elements equal to 1.4 V, which establishes the dependence of the hydrogen indicator readings on the concentration of hydrogen in the gas-air mixture. The abscissa axis shows the distance of the recorder carriage deviation from zero in millimeters. The ordinate shows the concentration of hydrogen in the gas-air mixture in percent by volume.

FIG. 4 shows graphs showing the change relative to the air, thermal conductivity of methane, hydrogen and air, with a change in temperature of these gases 0-100 ° C. The relative thermal conductivity in arbitrary units is plotted along the abscissa axis. The ordinate shows the temperature in degrees Celsius. Metao Heat Conduction Graphics

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air and air intersect at temperatures close to 43 ° C. The thermal conductivity of methane at this temperature is equal to the thermal conductivity of air, whereas the thermal conductivity of hydrogen differs by almost 7 times. On the basis of this, the temperature of the sensitive elements of the detector of the hydrogen indicator was experimentally established close to 43 ° C.

The device consists of a degasser 1 installed at the wellhead, from which the mixture is fed simultaneously to the thermoconductor detector of the total gas analyzer 2 of the type DGRP-2, the metal case of which has two measuring chambers, inside which are pulled tungsten filaments (sensitive elements), operating temperature which is close to 297 ° С, and in the thermoconductometric detector of hydrogen indicator 3, which has a plastic case with two chambers, inside which are inserted cylindrical perforated ebonito s ear, on the outer side are tensioned tungsten filament (sensing elements), the operating temperature of the filament is close to 43 ° C, at which the detector responds only to hydrogen does not react with methane.

Based on the difference in the readings of the total gas analyzer and the hydrogen indicator, the desired volume of the chromatograph of the chromatograph, operating discretely, is selected.

The hydrogen content was determined during gas cutting operations at the Kuzbass coal deposits, for example, at the well 8790 of the Tomsk section and at the well 8897 of the Shelkanovsky section. For this purpose, a hydrogen indicator was connected to the gas-air system of the AGKS-4ATS gas-cutting station, whose thermoconductor detector has sensitive elements with a heat temperature close to 43 ° C. At the same time, for the purpose of control, samples of the gas-air mixture were taken with subsequent analysis in the analytical laboratory. 36 measurements were carried out using this method, 9 measurements from them were certified by laboratory analyzes. Below are the comparative results.

Using the proposed method

analysis of the gas-air mixture during gas-cutting works at coal deposits provides, in comparison with the existing methods, the following

Advantages: increase in reliability when interpreting the results of total gas indications in the presence of hydrogen in the gas-air mixture; the ability to choose the right dosing column

work with the chromatograph, and, therefore, the exclusion of rejected measurements by the chromatograph, in the presence of hydrogen in the gas-air mixture; an increase in the number of points tested for hydrogen

wellbore (up to continuous recording); reduction of the cost of determining the hydrogen in the gas-air mixture; more reliable determination of hydrogen in the gas-air mixture, since the transportation of some of the hydrogen from the sample may be lost.

Claims (1)

Claims, Method for analyzing gas-air mixture during logging works by delivering a dose the mixture is divided into a chromathrograph, the measurement of the total signal from all components of the mixture is thermoconductometric and the determination of the relative amounts of each of the components of the gas-air mixture, characterized in that, in order to increase the accuracy, reliability and operability of the determination, with a high methane content and abrupt hydrogen content in the mixture, a thermoconductometric signal is additionally determined at a temperature of sensitive elements below 43 ° C, which is proportional to the hydrogen content, determine the total signal of all components without hydrogen, the value of which determines the order of methane concentration in the mixture and corrects the dose of the mixture fed to the separation chromatograph. / i NW SI J / yo Vue.1 MM MO 210 180 150 120 90 SO 30 0.5 1.0 Jt5 2.0 2.5 3.0 3.5 4.06 FIG. 2 1 21 18 15 12 9 6. U 20 JO W 50 60 70mm Fig.Z five §§§ & §§ h; § H . esi "