Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for determining gas saturation of shale gas reservoir by longitudinal-transverse wave time difference of dipole acoustic waves

A technology of dipole acoustic wave and shear wave time difference, which is applied in the direction of earthwork drilling and production, wellbore/well components, etc., and can solve problems such as large limitations, many formation parameters, and narrow application range

Active Publication Date: 2016-03-02
CHINA PETROCHEMICAL CORP +2
View PDF6 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional dipole acoustic wave shale gas reservoir gas saturation determination method is based on the elastic modulus method, which is only applicable to sandstone and carbonate reservoirs. The calculation requires many regional formation parameters, the method is complicated, and the scope of application is narrow , which has relatively large limitations in shale gas reservoirs and is basically not applicable

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for determining gas saturation of shale gas reservoir by longitudinal-transverse wave time difference of dipole acoustic waves
  • Method for determining gas saturation of shale gas reservoir by longitudinal-transverse wave time difference of dipole acoustic waves
  • Method for determining gas saturation of shale gas reservoir by longitudinal-transverse wave time difference of dipole acoustic waves

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0036] Example 1: Well A4 in the R area of ​​a shale gas field

[0037] 1) The gas saturation (Sg) of a total of 93 shale cores from 4 shale gas wells was obtained through core test analysis in the R work area of ​​a shale gas field, and the shear wave time difference (DTS) and compressional wave at the corresponding depth were obtained through dipole logging data. Time difference (DTC), and calculate the horizontal and vertical time difference ratio RMSC=DTS / DTC;

[0038] In the formula: the dipole acoustic shear wave time difference DTS dimension is μs / ft,

[0039] Dipole acoustic longitudinal wave time difference DTC dimension is μs / ft,

[0040] The horizontal and vertical time difference ratio RMSC is dimensionless;

[0041] 2) Obtain natural gamma ray (GR) at the corresponding depth of 93 shale cores through conventional logging data;

[0042] 3) The gas saturation (Sg) of the 93 cores, the time difference ratio RMSC and natural gamma ray GR of the 93 cores are calcula...

example 2

[0048] Example 2: Well A1-3HF, a horizontal well in the R area of ​​a shale gas field

[0049] 1) Well A1-3HF and well A4 in Example 1 are both wells in the R work area, so the model coefficients are the same, and the model coefficients of Example 1 can be used. The model coefficients are a=-159.123, b=-0.037, c=335.716 ;

[0050] 2) Obtain the natural gamma ray and lithology density of the A1-3HF well to be interpreted through the logging data, obtain the total hydrocarbon and methane content of the A1-3HF well to be interpreted through the gas logging data, and obtain the to-be-interpreted well through the geological logging data Cuttings and core lithology of well A1-3HF;

[0051]The depth interval of natural gamma ray and lithology density data of wells to be interpreted is 0.1m~1.0m, and saved in wis or txt format; the depth interval of gas logging full hydrocarbon and methane content is 1m or 0.5m, saved as wis or txt Format; the lithology data of geological cuttings a...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for determining gas saturation of shale gas reservoir by longitudinal-transverse wave time difference of dipole acoustic waves. The method comprises the following steps: obtaining shale gas saturation Sg by virtue of rock core test analysis, and obtaining the longitudinal-transverse wave time difference of the dipole acoustic waves of corresponding depth by virtue of co-well dipole logging information, and calculating a longitudinal-transverse time difference ratio; fitting by use of logging natural gamma of the corresponding depth, a longitudinal-transverse time difference ratio and gas saturation obtained by rock core test of the shale gas reservoir, establishing a model and determining a model coefficient; obtaining natural gamma and litho-density of a to-be-interpreted well, obtaining gas-logging total-hydrocarbon and methane content of the to-be-interpreted well by virtue of gas logging data, and obtaining rock debris and rock core lithology of the to-be-interpreted well by virtue of geological logging data; dividing the shale gas reservoir, and calculating the gas saturation of the divided shale gas reservoir; and outputting the calculated results. The method is simple and convenient, and is wide in scope of application. The method has been applied to 80 wells of certain shale gas field, and average errors determined by calculating do not exceed 10%, so that needs can be met.

Description

technical field [0001] The invention relates to a method for determining the gas saturation of a shale gas reservoir by dipole acoustic wave longitudinal and shear wave time difference. Background technique [0002] Shale gas gas saturation is an indispensable and important parameter for logging evaluation of shale gas reservoirs. The traditional dipole acoustic wave shale gas reservoir gas saturation determination method is based on the elastic modulus method, which is only applicable to sandstone and carbonate reservoirs. The calculation requires many regional formation parameters, the method is complicated, and the scope of application is narrow , which has relatively large limitations in shale gas reservoirs and is basically not applicable. Contents of the invention [0003] The purpose of the present invention is aimed at above-mentioned technical present situation, aims to provide a kind of simple and convenient, widely applicable, and the determined gas saturation ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): E21B49/00
CPCE21B49/00
Inventor 冯爱国张建平彭超石文睿赵红燕张占松任元张超谟石元会
Owner CHINA PETROCHEMICAL CORP