CN-121995505-A - Method and device for identifying stratum lithology interface

CN121995505ACN 121995505 ACN121995505 ACN 121995505ACN-121995505-A

Abstract

The invention discloses a method and a device for identifying a stratum lithology interface. The method comprises the steps of obtaining a crustal electric field lithology test CYT curve obtained by measuring an underground target by utilizing an electric field lithology detector, carrying out interface processing calculation on the obtained CYT curve to obtain a lithology interface curve, and identifying stratum parts, which are larger than a preset cutoff value and correspond to the cutoff value, in the lithology interface curve as lithology interfaces. The invention provides a method for identifying the depth of lithology interface by utilizing the deep and ultra-deep CYT detection technology to process data of a CYT curve and setting a quantitative mode of judging a cut-off value, which has simple implementation means and can achieve higher precision.

Inventors

LI CHANG
QIAO ZHANFENG
SHEN JINLONG
CHEN JIAJUN

Assignees

中国石油天然气集团有限公司

Dates

Publication Date: 20260508
Application Date: 20241105

Claims (10)

1. The method for identifying the stratum lithology interface is characterized by comprising the following steps of; acquiring a crustal electric field lithology test CYT curve obtained by measuring an underground target by using an electric field lithology detector; performing interface processing calculation on the CYT curve to obtain a lithology interface curve; and identifying stratum parts larger than the cut-off value in the lithology interface curve as lithology interfaces according to the preset cut-off value.
2. The method of claim 1, wherein performing an interface processing calculation on the CYT curve to obtain a lithology interface curve comprises: For each sampling point of the CYT curve measured by the electric field lithology detector, sequentially calculating the ratio of the CYT value of each sampling point to the CYT value of the last sampling point according to the sequence from the ground to the underground to obtain the value of each point on the lithology interface curve; and generating the lithology interface curve according to the values of all points on the lithology interface curve.
3. The method of claim 1, wherein the interface processing the calculated formula comprises: wherein i represents the number of sampling points measured by the instrument, the value of i is from 1 to N, the measurement is started from the ground, i represents the ith sampling point, and i+1 represents the (i+1) th sampling point. CYT (i) represents the CYT curve value corresponding to the ith sampling point, and ith (i) is the ith point on the lithology interface curve.
4. The method of claim 1, wherein identifying the portion of the lithology interface curve corresponding to the formation greater than the cutoff value as a lithology interface according to a preset cutoff value comprises: comparing each point value on the lithology interface curve with the preset cut-off value; uniformly correcting the value of the lithology interface curve larger than the cutoff value to be a first preset value; the first preset value is used for representing that the stratum where the point is located is a lithology interface, and the depth corresponding to the point is the depth of the lithology interface.
5. The method as recited in claim 4, further comprising: uniformly correcting the value of the lithology interface curve smaller than or equal to the cutoff value to a second preset value, wherein the second preset value is unequal to the first preset value; the second preset value is used for representing that the stratum where the point is located is a non-lithology interface, and the depth corresponding to the point is the depth of the non-lithology interface.
6. The method of claim 4, wherein the cutoff value ranges from 2.5 to 10.
7. An identification device for a formation lithology interface, comprising: The geotechnical field lithology test CYT curve acquisition module is used for acquiring a CYT curve obtained by measuring an underground target by using an electric field lithology detector; The data processing module is used for performing interface processing calculation on the obtained CYT curve to obtain a lithology interface curve; And the identification module is used for identifying stratum parts which are larger than the cut-off value and correspond to the cut-off value in the lithology interface curve as lithology interfaces according to the preset cut-off value.
8. A server comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method of identifying a stratigraphic lithology interface according to any one of claims 1 to 6 when the program is executed.
9. A computer readable storage medium, characterized in that the computer readable storage medium stores a computer program which, when executed by a processor, implements a method for identifying a lithology interface of a strata according to any one of claims 1-6.
10. A computer program product, characterized in that the computer program product comprises a computer program which, when executed by a processor, implements a method of identifying a formation lithology interface according to any one of claims 1-6.

Description

Method and device for identifying stratum lithology interface Technical Field The invention relates to the technical field of petroleum geological exploration, in particular to a method and a device for identifying a stratum lithology interface. Background With the deep development of petroleum exploration, the exploration from a constructed oil reservoir to a lithology trap oil reservoir is not only required to be fine-structured, but also is required to be predicted, logging data are uneven for an old oil region, and geophysical prospecting work is limited. The sand shale speed superposition of the objective interval of the special research area is difficult to accurately predict the lithology boundary by seismic wave impedance inversion. The existing method is mainly a lithologic boundary recognition method based on well-seismic combination. However, for limited resolution and multiple effects of deep and ultra-deep seismic data, depth resolution is not high, resulting in low prediction accuracy, which has been a problem. Disclosure of Invention In view of the foregoing, the present invention has been made to provide a method and apparatus for identifying a lithology interface of a formation that overcomes or at least partially solves the foregoing problems. In a first aspect, an embodiment of the present invention provides a method for identifying a lithology interface of a stratum, including: acquiring a crustal electric field lithology test CYT curve obtained by measuring an underground target by using an electric field lithology detector; performing interface processing calculation on the CYT curve to obtain a lithology interface curve; and identifying stratum parts larger than the cut-off value in the lithology interface curve as lithology interfaces according to the preset cut-off value. In one embodiment, performing an interface processing calculation on the CYT curve to obtain a lithology interface curve, including: For each sampling point of the CYT curve measured by the electric field lithology detector, sequentially calculating the ratio of the CYT value of each sampling point to the CYT value of the last sampling point according to the sequence from the ground to the underground to obtain the value of each point on the lithology interface curve; and generating the lithology interface curve according to the values of all points on the lithology interface curve. In one embodiment, the interface processing calculation formula includes: wherein i represents the number of sampling points measured by the instrument, the value of i is from 1 to N, the measurement is started from the ground, i represents the ith sampling point, and i+1 represents the (i+1) th sampling point. CYT (i) represents the CYT curve value corresponding to the ith sampling point, and ith (i) is the ith point on the lithology interface curve. In one embodiment, identifying, as a lithology interface, a stratum portion of the lithology interface curve corresponding to a value greater than a predetermined cutoff value, includes: comparing each point value on the lithology interface curve with the preset cut-off value; uniformly correcting the value of the lithology interface curve larger than the cutoff value to be a first preset value; the first preset value is used for representing that the stratum where the point is located is a lithology interface, and the depth corresponding to the point is the depth of the lithology interface. In one embodiment, the method for identifying a lithology interface of a stratum further includes: uniformly correcting the value of the lithology interface curve smaller than or equal to the cutoff value to a second preset value, wherein the second preset value is unequal to the first preset value; the second preset value is used for representing that the stratum where the point is located is a non-lithology interface, and the depth corresponding to the point is the depth of the non-lithology interface. In one embodiment, the cutoff value ranges from 2.5 to 10. In a second aspect, an embodiment of the present invention provides a device for identifying a lithology interface of a stratum, including: The CYT curve acquisition module is used for acquiring a crustal electric field lithology test CYT curve obtained by measuring an underground target by using an electric field lithology detector; The data processing module is used for performing interface processing calculation on the obtained CYT curve to obtain a lithology interface curve; And the identification module is used for identifying stratum parts which are larger than the cut-off value and correspond to the cut-off value in the lithology interface curve as lithology interfaces according to the preset cut-off value. In a third aspect, an embodiment of the present invention provides a server, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, where the processor implements a method