阅读说明：本技术 基于声波波速各向异性的岩心室内定向方法 (Rock ventricle inner orientation method based on acoustic wave velocity anisotropy ) 是由 梁利喜 刘向君 庄大琳 熊健 张文 于 2019-10-26 设计创作，主要内容包括：本发明公开了一种基于声波波速各向异性的岩心室内定向方法。本发明基于钻井岩心与取心段地层的声波波速各向异性的相一致,建立了矿场声波测井与室内多方位岩样声波测试相结合实现岩心地面定向的方法,本发明不仅操作简单、且不受岩样岩性及矿物组成的影响,同时还可对取自同一层段的岩心实现批量定位。本发明具有结果可靠、操作便捷、经济高效、适用性广的特点。本发明对地层构造(裂缝)发育解释、油气运移方向分析、开发方案合理优化、老油田剩余油开发井部署优化等具有重要的基础指导价值。(The invention discloses a rock ventricle inner orientation method based on acoustic wave velocity anisotropy. The method for realizing the ground orientation of the rock core by combining the sound wave velocity anisotropy of the drilling rock core and the stratum of the coring section is established based on the consistency of the sound wave velocity anisotropy of the drilling rock core and the stratum of the coring section, the operation is simple, the influence of the lithology and mineral composition of the rock sample is avoided, and the batch positioning of the rock core from the same interval can be realized. The invention has the characteristics of reliable result, convenient operation, economy, high efficiency and wide applicability. The method has important basic guidance value for explaining the development of stratum structures (cracks), analyzing the migration direction of oil and gas, reasonably optimizing a development scheme, optimizing the deployment of residual oil development wells in old oil fields and the like.)

1. A rock ventricle inner orientation method based on acoustic wave velocity anisotropy is characterized by comprising the following steps:

s1, obtaining a fresh and complete cylindrical drilling core;

s2, observing the apparent structure of the rock core, and screening the rock core developing without cracks according to the observation result of the apparent structure of the rock core;

s3, marking the relative 0-degree position of the core along the radial direction, setting a test position interval, and sequentially determining the test position from the relative 0-degree position along the clockwise direction according to the test position interval;

s4, testing the sound wave velocity of the core along the diameter direction according to the test direction by a projection method from the direction opposite to 0 degree to obtain the sound wave velocity under different test directions;

s5, analyzing the relation between the wave speed and the test direction according to the wave speed of the sound waves in different test directions, and determining the maximum wave speed relative direction of the rock core;

s6, analyzing and acquiring anisotropic characteristics of the sound wave velocity of the well surrounding stratum based on the sound wave test well information, and determining the maximum direction of the wave velocity;

and S7, comparing the maximum wave speed relative orientation of the core with the maximum wave speed orientation, and determining the geographic orientation of the core.

2. A method for direction in a core chamber based on sonic anisotropy of its velocity as claimed in claim 1, wherein the cylindrical core in step S1 has a diameter of 4in or 2in and a height of 2-4 in.

3. A method for rock intra-ventricular orientation based on sonic anisotropy of claim 1, wherein the specific steps in step S2 are: and observing the bedding of the rock core and the development conditions of other weak structural planes, and screening the rock core which has a complete structure and uniform bedding and does not have an interlayer, a crack or the development of other structural planes.

4. A method for orientation in a rock ventricle based on sonic anisotropy of claim 1, wherein the test azimuth interval in step S3 is 5 °, 10 ° or 15 °.

5. A sonic anisotropy-based rock intra-ventricular orientation method as claimed in claim 1, wherein the sonic test well information in step S6 comprises XMAC, soniscan or DSI sonic test well information.

6. A method as claimed in claim 1, wherein the periwellic strata in the step S6 are strata without fault, interlayer and other heterogeneous structures corresponding to the core, and the thickness of the periwellic strata is not more than 25 m.

7. A method for rock intra-ventricular orientation based on acoustic wave velocity anisotropy according to claim 1, wherein the calculation method of the wave velocity maximum direction in step S6 is: extracting fast wave data and slow wave data from the acoustic testing well information, calculating an anisotropy coefficient through the fast wave data and the slow wave data, counting the fast wave azimuth and the slow wave azimuth of the interval according to the anisotropy coefficient, analyzing the anisotropy of the target interval according to the fast wave azimuth and the slow wave azimuth, and acquiring the wave speed maximum azimuth of the well-surrounding stratum.

8. A method for rock intra-ventricular orientation based on sonic anisotropy of claim 7, wherein the calculation formula of the anisotropy coefficient in step S6 is:

in the above formula, S is the anisotropy coefficient, V_fastFor fast-wave data, V_SlowIs slow wave data.

9. A method for rock core indoor orientation based on sound wave velocity anisotropy according to claim 1, characterized in that the determination method of the geographical orientation of the core in the step S7 is as follows: and subtracting the maximum wave velocity azimuth from the maximum wave velocity relative azimuth of the core to obtain the geographic azimuth of the core.

Technical Field

The invention relates to the technical field of oil and gas drilling, in particular to a method for orienting inside a karst chamber based on wave velocity anisotropy of sound waves.

Background

Well drilling coring is a direct and important carrier for researching deep stratum geological characteristic information. The core orientation is the basis for researching the structural characteristics, sedimentary facies, attitude, fracture development characteristics and ground stress core test evaluation of the stratum based on the core; in an oil field developed by water injection and gas injection, core orientation is helpful for scientifically and visually recognizing and analyzing the flow direction of oil, gas and water, and provides a basis for well pattern deployment and optimization. Therefore, scientific orientation of the drill core has great significance for oil and gas exploration and development.

However, a large number of drill cores are obtained by non-directional drilling, and the original orientations of the drill cores cannot be directly obtained through complex rotation in the coring process, so that a lot of geological information of the drill cores cannot be effectively utilized. Although the core orientation can be determined by the oriented coring (mechanical method) technology, the ancient geomagnetic core orientation, the imaging log image-based core orientation and other methods and technologies gradually developed from the 20 th century and the 60 th era, the application practice shows that the methods have the problems of complex operation process, high economic cost, poor reliability of analysis results and the like to different degrees.

Disclosure of Invention

Aiming at the defects in the prior art, the rock core intra-ventricular orientation method based on the acoustic wave velocity anisotropy solves the problems of complex operation process, high economic cost and poor reliability of analysis results in the core orientation.

In order to achieve the purpose of the invention, the invention adopts the technical scheme that: a rock ventricle inner orientation method based on acoustic wave velocity anisotropy comprises the following steps:

s1, obtaining a fresh and complete cylindrical drilling core;

s2, observing the apparent structure of the rock core, and screening the rock core developing without cracks according to the observation result of the apparent structure of the rock core;

s3, marking the relative 0-degree position of the core along the radial direction, setting a test position interval, and sequentially determining the test position from the relative 0-degree position along the clockwise direction according to the test position interval;

s4, testing the sound wave velocity of the core along the diameter direction according to the test direction by a projection method from the direction opposite to 0 degree to obtain the sound wave velocity under different test directions;

s5, analyzing the relation between the wave speed and the test direction according to the wave speed of the sound waves in different test directions, and determining the maximum wave speed relative direction of the rock core;

s6, analyzing and acquiring anisotropic characteristics of the sound wave velocity of the well surrounding stratum based on the sound wave test well information, and determining the maximum direction of the wave velocity;

and S7, comparing the maximum wave speed relative orientation of the core with the maximum wave speed orientation, and determining the geographic orientation of the core.

Further: in the step S1, the diameter of the cylindrical drill core is 4in or 2in, and the height of the cylindrical drill core is 2 in-4 in.

Further: the specific steps in step S2 are: and observing the bedding of the rock core and the development conditions of other weak structural planes, and screening the rock core which has a complete structure and uniform bedding and does not have an interlayer, a crack or the development of other structural planes.

Further: the test azimuth interval in step S3 is 5 °, 10 °, or 15 °.

Further: the sonic testing well information in the step S6 includes XMAC, soniscan, or DSI sonic testing well information.

Further: and the formation around the well in the step S6 is a formation without fault, interlayer and other heterogeneous structures corresponding to the core, and the thickness of the formation around the well is not more than 25 m.

Further: the method for calculating the maximum wave velocity azimuth in step S6 includes: extracting fast wave data and slow wave data from the acoustic testing well information, calculating an anisotropy coefficient through the fast wave data and the slow wave data, counting the fast wave azimuth and the slow wave azimuth of the interval according to the anisotropy coefficient, analyzing the anisotropy of the target interval according to the fast wave azimuth and the slow wave azimuth, and acquiring the wave speed maximum azimuth of the well-surrounding stratum.

Further: the calculation formula of the anisotropy coefficient in step S6 is:

in the above formula, S is the anisotropy coefficient, V_fastFor fast-wave data, V_SlowIs slow wave data.

Further: the method for determining the geographical position of the core in the step S7 includes: and subtracting the maximum wave velocity azimuth from the maximum wave velocity relative azimuth of the core to obtain the geographic azimuth of the core.

The invention has the beneficial effects that: the method for realizing the ground orientation of the rock core by combining the sound wave velocity anisotropy of the drilling rock core and the stratum of the coring section is established based on the consistency of the sound wave velocity anisotropy of the drilling rock core and the stratum of the coring section, the operation is simple, the influence of the lithology and mineral composition of the rock sample is avoided, and the batch positioning of the rock core from the same interval can be realized. The invention has the characteristics of reliable result, convenient operation, economy, high efficiency and wide applicability. The method has important basic guidance value for explaining the development of stratum structures (cracks), analyzing the migration direction of oil and gas, reasonably optimizing a development scheme, optimizing the deployment of residual oil development wells in old oil fields and the like.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is a diagram illustrating the variation of the wave velocity of a rock sample with the test azimuth, and the maximum wave velocity azimuth and the minimum wave velocity azimuth thereof according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating a fast wave azimuthal histogram of a formation in an embodiment of the present invention.

Detailed Description

The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.

As shown in FIG. 1, a method for orientation in a rock ventricle based on wave velocity anisotropy of sound waves comprises the following steps:

s1, obtaining a fresh and complete cylindrical drilling core; the diameter of the cylindrical well core is 4in or 2in, and the height is 2 in-4 in.

S2, observing the apparent structure of the rock core, and screening the rock core developing without cracks according to the observation result of the apparent structure of the rock core; the method comprises the following specific steps: and observing the bedding of the rock core and the development conditions of other weak structural planes, and screening the rock core which has a complete structure and uniform bedding and does not have an interlayer, a crack or the development of other structural planes.

S3, marking the relative 0-degree position of the core along the radial direction, setting test position intervals, wherein the test position intervals are 5 degrees, 10 degrees or 15 degrees, and sequentially determining the test positions along the clockwise direction from the relative 0-degree position according to the test position intervals;

s4, testing the sound wave velocity of the core along the diameter direction according to the test direction by a projection method from the direction opposite to 0 degree to obtain the sound wave velocity under different test directions;

s5, analyzing the relation between the wave speed and the test direction according to the wave speed of the sound waves in different test directions, and determining the maximum wave speed relative direction of the rock core;

s6, analyzing and acquiring anisotropic characteristics of the sound wave velocity of the well surrounding stratum based on the sound wave test well information, and determining the maximum direction of the wave velocity; the sonic test well information includes XMAC, SonicScan, or DSI sonic test well information. The stratum around the well is a stratum without fault, interlayer and other heterogeneous structures corresponding to the core, and the thickness of the stratum around the well is not more than 25 m. Extracting fast wave data and slow wave data from the acoustic testing well information, calculating an anisotropy coefficient through the fast wave data and the slow wave data, counting the fast wave azimuth and the slow wave azimuth of the interval according to the anisotropy coefficient, analyzing the anisotropy of the target interval according to the fast wave azimuth and the slow wave azimuth, and acquiring the wave speed maximum azimuth of the well-surrounding stratum.

And S7, comparing the maximum wave speed relative orientation of the core with the maximum wave speed orientation, and subtracting the maximum wave speed orientation from the maximum wave speed relative orientation of the core to obtain the geographic orientation of the core.

The embodiment of the invention is as follows:

s1, carrying out size test on the drilling core to be oriented, wherein the size test comprises diameters in different orientations (at least two orthogonal orientations);

s2, obtaining a mine field shale rock sample, observing and describing the mine field shale rock sample, and screening a core section with a complete and uniform structure;

s3, selecting a certain radial direction as a relative 0-degree orientation for the screened rock core, and calibrating one direction at a certain angle along the clockwise direction until a circle is marked (for example, at an interval of 30 degrees, respectively calibrating 0 degrees, 30 degrees, 60 degrees, 90 degrees, 120 degrees, 150 degrees and 180 degrees).

And S4, performing sound wave velocity test on the marked section core with the complete structure along the calibration direction from the 0-degree direction by adopting a transmission method.

And S5, analyzing the change of the wave velocity along with the test orientation according to the test results of the wave velocity of the sound waves in different orientations, and determining that the relative orientation of the maximum wave velocity and the relative orientation of the minimum wave velocity of the core are 90 degrees and 0 degree respectively, as shown in figure 2.

S6, respectively extracting fast waves and transverse waves by using DSI acoustic logging data, calculating and analyzing wave velocity anisotropy, and counting fast wave orientations, wherein the fast wave orientations are 90-105 degrees and the central orientation is 97.5 degrees as shown in figure 3.

And S7, comparing the maximum wave velocity relative orientation of the rock core obtained by indoor testing with the maximum wave velocity orientation of the peri-wellbore stratum obtained by analyzing logging data, determining the geographic orientation of the rock core, and realizing the orientation of the rock core.

Therefore, the maximum wave velocity relative position of the analyzed core is 90 degrees and corresponds to the underground actual geographic position of 97.5 degrees, namely the relative position of the core is minus 7.5 degrees and corresponds to the true north direction, and the relative position of the core is 82.5 degrees and corresponds to the true east direction, so that the indoor orientation of the core is realized.