Gamma energy spectrum-based method for identifying clay shale reservoir and uranium ore occurrence on spot

Abstract

The invention relates to a gamma energy spectrum-based method for identifying clay shale reservoir and uranium ore occurrence on the spot, which comprises the following steps that: rock debris in corresponding depth of drilling fluid is continuously sampled or a core acquired through the core drilling is sampled according to corresponding depths; the rock debris sample or the core sample is placed into a matched lead tank, and a gamma energy spectrum probe is used for measuring the rock debris sample or the core sample inside the lead tank; then counting rates and activity of uranium (U), radium (Ra), thorium (Th) and kalium (K) and a total gamma value are acquired according to the measurement result, so that the real content of U(Ra), Th and K in the rock can be calculated; and finally, a variation curve of the contents of U(Ra), Th and K is drawn according to the calculation results, and the clay shale reservoir and the uranium ore occurrence are identified according to variation characteristics of the curve. Gamma energy spectrum measurement and analysis on rock debris or the core which are acquired from the drilling are directly performed, so that the clay shale reservoir and the uranium ore occurrence can be rapidly identified and evaluated. The method is an economical and efficient method. The gamma energy spectrum measurement is performed on the drilling site, so that influence of an external environment on the rock sample can be avoided, and the accuracy of the measurement result can be guaranteed.

Description

technical field [0001] The invention relates to a method for on-site identification of mud shale reservoirs and uranium deposits based on gamma energy spectrum. Background technique [0002] Natural gamma rays in formation rocks are mainly produced by 238 U Department of Radiology, 232 Th radiology and 40 produced by K. 238 U Department, 232 The energy and intensity of gamma rays emitted by each nuclide in the Th system are different, and some nuclides also emit gamma rays with multiple energies, so the energy distribution of gamma rays is complex. 40 K is a monoenergetic gamma-ray-emitting nuclide, the only gamma-ray energy it emits is 1.46 MeV. According to U-series decay table, Th-series decay table and 40 The data provided by the K single-energy ray source can be programmed with Matlab to make their energy spectra respectively, as shown in Fig. 1, Fig. 2 and Fig. 3 respectively. 238 U Department, 232 Th line and 40 K gamma line. The above three figures show the...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to use economical and effective technical means to solve the problem of rapid identification and evaluation of mud shale reservoirs and uranium deposits at the drilling site, and provide timely and reliable basis for the next step of construction decision-making

Images