Method for determining content of uranium and organic carbon in uranium-rich hydrocarbon-source rocks

Abstract

A method for determining content of uranium and organic carbon in uranium-rich hydrocarbon-source rocks comprises steps as follows: firstly, hydrocarbon-source rock core samples obtained through multi-hole drilling coring is acquired in a certain area, a radioactive uranium content value and an organic carbon content value of each hydrocarbon-source rock core are measured through an experiment, logging values of a natural gamma curve and a natural gamma-spectrum curve in logging curves, as well as resistivity, compensating sonic differential time and compensating density of the depth position of each rock core are acquired, a corresponding relation between the uranium content and the natural gamma curve as well as the natural gamma-spectrum curve is established and fitted to form a function, the corresponding relation between the organic carbon content values and related logging curve values is established and fitted to form a function, and the uranium content in each depth position and the hydrocarbon-source rock organic carbon content in each depth position in a well are determined according to the fitted function. Response of the uranium-rich hydrocarbon-source rocks in logging information is sufficiently considered, various logging information is comprehensively utilized to quantify and determine the content of uranium and organic carbon in the uranium-rich hydrocarbon-source rocks, and an obtained result is more accurate.

Description

technical field [0001] The invention relates to the technical field of evaluation of uranium-rich source rocks, in particular to a method for determining uranium content and organic carbon content of uranium-rich source rocks. Background technique [0002] Source rocks are the material basis for oil and gas accumulation. Without source rocks, there will be no oil and gas generation. Therefore, it is of great significance to evaluate source rocks, especially uranium-rich source rocks, in oil and gas exploration. [0003] Organic carbon (TOC) content is an important index for evaluating the quality of source rocks, and plays a very important role in estimating the scale of oil and gas resources in sedimentary basins and in oil exploration. At the same time, research in recent years has shown that the enrichment of uranium in source rocks It is usually closely related to the enrichment of organic carbon content (TOC), and has an important stimulating effect on the maturation of...

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Problems solved by technology

[0007] The above-mentioned ΔlgR method is a theoretical-empirical formula proposed in the early research on hydrocarbon generation of source rocks, and it is mainly applicable when the kerogen maturity of source rocks is in immature-high maturity stage; - When the stage of maturity is too high, there are some errors in the calculation results of the ΔlgR method. In addition, because the abundance of organic matter is closely related to the uranium content in general, the application of the radioactivity curve is not considered in the ΔlgR method. It is also one of its shortcomings

[0008] At present, when the existing methods for determining the organic carbon content of source rocks determine the organic carbon content, the results of the obtained organic carbon content are often inaccurate, and at the same time, the determination of the uranium content of the uranium-rich source rocks is not considered.

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