A method for evaluating the hydration characteristics of layered hard and brittle mud shale

A technology of shale hydration and evaluation method, which is used in earth-moving drilling, analysis of solids using sonic/ultrasonic/infrasonic waves, wellbore/well components, etc. , inaccurate evaluation results, etc., to achieve the effect of simple and easy-to-understand evaluation methods, high repeatability, and prevention of wellbore instability

Active Publication Date: 2018-07-27
CHINA UNIV OF PETROLEUM (BEIJING)
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since the core is crushed, the micro-cracks existing in the original core are destroyed, so this method ignores the expansion of the micro-cracks in the original rock when it encounters water, and cannot truly restore the expansion state of the rock
In particular, there are micro-fractures of graptolite in marine sedimentary shale, the width of which is extremely small and difficult to observe with the naked eye, but these micro-fractures are severely swelled by water.
In addition, in the process of evaluating the hydration characteristics of layered hard and brittle mud shale, there is no reasonable evaluation device at present, which leads to inaccurate evaluation results, large errors, and high cost

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
  • A method for evaluating the hydration characteristics of layered hard and brittle mud shale
  • A method for evaluating the hydration characteristics of layered hard and brittle mud shale
  • A method for evaluating the hydration characteristics of layered hard and brittle mud shale

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0057] Such as figure 1 As shown, a method for evaluating the hydration characteristics of layered hard and brittle mud shale includes the following steps in sequence:

[0058] Step 1: After describing the rock, take the core and prepare the core sample;

[0059] Step 2: Restoring the core sample to the in-situ pore fluid saturation state of the formation;

[0060] Step 3: Test the compressional wave velocity and the shear wave velocity of the core sample under the in-situ state of the formation, then change the properties of the pore fluid, and test the compressional wave velocity and the shear wave velocity of the core sample after changing the properties of the pore fluid;

[0061] Step 4: Evaluate the hydration characteristics of layered hard and brittle shale according to the changes of the compressional wave velocity and shear wave velocity of the core samples under different pore fluid properties.

[0062] In step 1, there is a group of joints in the rock, and the inc...

Embodiment 2

[0081] A method for evaluating the hydration characteristics of layered hard and brittle mud shale, its steps, principles, evaluation devices used and beneficial effects are the same as those in Example 1, except that:

[0082] In step one, three core samples were drilled. The shape of the core sample is cylindrical and the length is 3 times the diameter. After grinding, the diameter is 25mm and the length is 75mm. The diameter of the core sample is 20 times the diameter of the largest grain in the rock. Two mutually perpendicular diameters are measured at the bottom, middle and upper part of each core sample, and the average value of the measurement results is the final diameter of the core sample.

[0083]In step 2, the method for restoring the core sample to the saturated state of the in-situ pore fluid in the formation is to prepare a potassium chloride solution with the same properties as the pore fluid in the in-situ state of the formation, vacuumize the core sample an...

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 discloses an evaluation method for hydration characteristics of layered hard brittle mud shale. The evaluation method comprises the following steps: describing the rock, then coring the rock, and preparing a rock core sample; restoring the rock core sample to a stratum in-situ porosity fluid saturation state; testing a longitudinal wave speed and a transverse wave speed of the rock core sample under the stratum in-situ state condition, then changing the porosity fluid character, and testing the longitudinal wave speed and the transverse wave speed of the rock core sample after the porosity fluid character is changed; evaluating the hydration characteristics of the layered hard brittle shale under the variation situation of the longitudinal wave speed and the transverse wave speed of the rock core sample under different porosity fluid character conditions. The evaluation method is simple, easy to understand, convenient to operate and capable of quantitatively evaluating the hydration characteristics of the rock, the scientific evidence can be provided for stably control of the well wall when the layered hard brittle mud shale is drilled, the instability of the well wall can be better prevented, and the underground complicated situation can be prevented.

Description

technical field [0001] The invention belongs to the technical field of oil and gas drilling engineering, and relates to a method for evaluating the hydration characteristics of mud shale, in particular to a method for evaluating the hydration characteristics of layered hard and brittle mud shale. Background technique [0002] In recent years, the wellbore stability encountered in layered hard and brittle shale during drilling has always been a major problem in oil and gas drilling engineering. The layered hard and brittle shale has abnormal bedding development and high expansive clay content, which can easily lead to serious wellbore instability during drilling, such as wellbore shrinkage, wellbore collapse, drilling fluid loss and reservoir damage And other issues. Therefore, it is of great economic and social significance to evaluate the hydration characteristics of layered hard and brittle shale. [0003] At present, the evaluation method for the expansion characteristi...

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
Patent Type & Authority Patents(China)
IPC IPC(8): E21B49/00
CPCG01N29/07
Inventor 卢运虎陈勉董京楠金衍刘铭侯冰杜晓雨
Owner CHINA UNIV OF PETROLEUM (BEIJING)
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products