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CN-121995517-A - Quantitative prediction method for organic carbon content of lake-phase hydrocarbon source rock

CN121995517ACN 121995517 ACN121995517 ACN 121995517ACN-121995517-A

Abstract

The invention discloses a quantitative prediction method for organic carbon content of a lake-phase hydrocarbon source rock, which comprises the steps of 1) establishing a corresponding table of measured single-well rock core or rock debris sample organic carbon content test data and logging data, 2) carrying out multiple linear regression, calculating TOC values by using logging data, 3) calculating organic carbon content values of single-well longitudinal uniform nodes, 4) establishing single-well longitudinal distribution acoustic impedance values, 5) carrying out well shock calibration by using JASON software to obtain optimized wavelet inversion seismic wave impedance, and 6) calculating the organic carbon content of a section and a space node. Quantitatively predicting the organic carbon content distribution of the hydrocarbon source rock on different scales such as a section, a plane, a space and the like, and further analyzing the thickness distribution range of organic matters with different abundance content levels.

Inventors

  • JIANG LONGYAN
  • QUAN XIAOYUAN
  • HUANG ZHONGQUN
  • QI RONG
  • SHAO LONGKAN
  • YIN CHAO

Assignees

  • 中国石油化工股份有限公司
  • 中国石油化工股份有限公司华北油气分公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (7)

  1. 1. A quantitative prediction method for organic carbon content of a lake-phase hydrocarbon source rock is characterized by comprising the following steps: 1) Establishing a table corresponding to the measured organic carbon content test data and logging data of the single well core or the rock debris sample; 2) Developing multiple linear regression, and calculating TOC value by using logging data; 3) Calculating the organic carbon content value of a single well longitudinal uniform node; 4) Establishing a single well longitudinal distribution acoustic impedance value; 5) Performing well earthquake calibration by using JASON software to obtain optimized wavelet inversion earthquake wave impedance; 6) And calculating the organic carbon content of the section and the space node.
  2. 2. The quantitative prediction method of organic carbon content in lake-phase hydrocarbon source rock according to claim 1, wherein in the step 1), correlation analysis is performed by using measured data of organic carbon content of samples and single logging data, preferably logging data with good correlation is obtained, and sample data is established for forming a fitting relation.
  3. 3. The quantitative prediction method of organic carbon content of lake-phase hydrocarbon source rock according to claim 2, wherein in the step 2), according to a least square fitting principle, multiple linear regression is performed by taking sample organic carbon content toc as a dependent variable and optimal logging data as independent variables, so as to obtain the optimal fitting effect, wherein the fitting formula is as follows: TOC=a 1 *lg(LLS)+b 1 *AC+c 1 *DEN+d 1 (1) Wherein LLS is resistivity logging data, AC is sonic time difference logging data, DEN is density logging data, and a 1 、b 1 、c 1 、d 1 is fitting coefficient of each variable.
  4. 4. The method for quantitatively predicting the organic carbon content of the lake-phase hydrocarbon source rock according to claim 3, wherein in the step 3), the organic carbon content value of each node in the longitudinal direction of the single well is calculated according to the resistivity, the sonic wave time difference and the density parameter of the single well by using a fitting formula (1).
  5. 5. The method for quantitatively predicting the organic carbon content of the lake-phase hydrocarbon source rock according to claim 4, wherein in the step 4), the acoustic impedance value of the single well is calculated by using acoustic time difference and density value logging data of the constraint single well through a formula (2), and the correlation analysis is carried out on the acoustic impedance value and the organic carbon content value calculated by fitting the single well through a formula (3); the formula (2) is as follows: WELL AI =DEN/AC (2) Wherein WELL AI is single WELL acoustic impedance, DEN is density logging, and AC is acoustic time difference; equation (3) is as follows: TOC= a 2 *WELL AI +b 2 (3) Wherein TOC is the organic carbon content value of a single well, and a 2 、b 2 is the coefficient.
  6. 6. The quantitative prediction method of organic carbon content of lake-phase hydrocarbon source rock according to claim 5, wherein in the step 5), according to the seismic data and geological interpretation result data of the earthquake, the acoustic impedance of the constraint single well and the well bypass seismic data are subjected to correlation fitting, the sparse pulse inversion module in the JASON software is utilized to predict the seismic wave impedance, and the correlation of the acoustic impedance of the single well and the seismic wave impedance is obtained by repeatedly adjusting the correspondence of the single well and the layering and phase parameters of the earthquake, and the wave impedance of the seismic section and the spatial node is calculated by inversion, wherein the formula describing the good correlation is as follows: WELL AI ＝a 3 *SEIS AI +b 3 (4) Wherein WELL AI is single WELL acoustic impedance, SEIS AI is inverted seismic wave impedance, and a 3 、b 3 is coefficient.
  7. 7. The method for quantitatively predicting the organic carbon content of the lake-phase hydrocarbon source rock according to claim 6, wherein in the step 6), the formula (5) for calculating the organic carbon content by using the inverted seismic wave impedance data is obtained by the obtained formulas (3) and (4): TOC= A*SEIS AI +B (5) TOC is organic carbon content, SEIS AI is earthquake inversion wave impedance, and coefficient A=a 2 *a 3 ;B＝a 2 *b 3 +b 2 ; The cross-section TOC (x, y) and the spatial TOC (x, y, z) are calculated.

Description

Quantitative prediction method for organic carbon content of lake-phase hydrocarbon source rock Technical Field The invention relates to the technical field of oil and gas field exploration and development, in particular to a quantitative prediction method for organic carbon content of a lake-phase hydrocarbon source rock. Background In shale evaluation, organic carbon content is an important parameter. The acquisition of the parameter generally needs to be obtained through sampling and experiments, the data points are limited, the investment is high, and the limitation exists on regional geological evaluation. If the quantitative prediction can be performed by using logging data or seismic data with abundant data, the area range of shale research can be effectively enlarged, and the research precision and depth can be improved. The present application publication number CN106568918B discloses a method for predicting TOC of organic carbon content of shale, which comprises the steps of carrying out physical test analysis on shale rock samples to obtain rock parameters of the shale rock samples, obtaining mathematical relations between TOC of the rock samples and each logging parameter in a plurality of logging parameters based on the rock parameters, calculating similarity between TOC and the logging parameters, selecting the logging parameter with the maximum similarity value as a prediction parameter, and predicting TOC of the shale based on the value of the prediction parameter and the mathematical relations between TOC and the prediction parameter. This prediction method does not take into account the prediction of the mudstone rock sample. In the oil exploration and development document in 2007 01, in the oil exploration and development document in Bohai Bay basin oil-rich pit as an example, the seismic and logging information is used for predicting and evaluating the hydrocarbon source rock, and the logging information such as acoustic time difference, resistivity, density and the like is used for calculating the organic matter abundance of the hydrocarbon source rock. The TOC value calculated by using the logging data is very close to the actual measurement value of the core sample, so that the spatial distribution of the source rock can be determined and the quality of the source rock can be evaluated by using the seismic data and the logging information. However, in the aspect of logging, the method utilizes the acoustic logging curve and the resistivity logging curve to carry out overlapping calculation, and too many human interference factors exist in the overlapping process, and in the aspect of utilizing the seismic data, only the reflection characteristics of the earthquake are utilized, and only the qualitative analysis stage of the seismic attribute characteristics is remained, so that the method is unfavorable for reasonably and accurately carrying out the evaluation of the oil and gas bearing basin resources. In summary, although research on quantitative prediction of shale organic carbon is more and more paid attention to, and various quantitative prediction methods of organic carbon exist, the current methods are basically focused on single-point data such as logging data, and the application of the single-point data in combination with seismic data is not performed. Disclosure of Invention The invention aims to provide a quantitative prediction method for organic carbon content of a lake-phase hydrocarbon source rock, which is used for quantitatively predicting the organic carbon content distribution of the hydrocarbon source rock on different scales of a section, a plane, a space and the like, so as to analyze the thickness distribution range of organic matters with different abundance content levels and perform quantitative geological evaluation. The invention discloses a quantitative prediction method for organic carbon content of a lake-phase hydrocarbon source rock, which comprises the following steps: 1) Establishing a table corresponding to the measured organic carbon content test data and logging data of the single well core or the rock debris sample; 2) Developing multiple linear regression, and calculating TOC value by using logging data; 3) Calculating the organic carbon content value of a single well longitudinal uniform node; 4) Establishing a single well longitudinal distribution acoustic impedance value; 5) Performing well earthquake calibration by using JASON software to obtain optimized wavelet inversion earthquake wave impedance; 6) And calculating the organic carbon content of the section and the space node. In step 1), correlation analysis is performed by using measured data of the organic carbon content of the sample and single logging data, such as resistivity, natural gamma, acoustic time difference, density, and the like, preferably logging data with good correlation, and sample data is established for forming a fitting relation. If the natural log values are to b