公开(公告)号：US11313223B2

公开(公告)日：2022-04-26

申请号：US16470539

申请日：2018-12-10

Applicant: PETROCHINA COMPANY LIMITED

Inventor： Hongliang Wu ,  Ning Li ,  Zhou Feng ,  Changlin Lan ,  Tao Lv ,  Kewen Wang ,  Qingfu Feng

IPC: G01V5/12 ,  E21B49/00 ,  G01V5/10

Abstract: A gamma ray spectrum unfolding method for elemental capture spectroscopy logging and a device therefor including the steps of first preprocessing the data obtained from an elemental capture spectrometry instrument; constructing a primary element group and an auxiliary element group according to the degree of interactions among the elements via theoretical analysis and numerical calculation of spectrum profiles, characteristic peak channels, and backgrounds of different elements; unfolding by using the least square method based on the construction of the primary element group and the auxiliary element group; and finally reconstructing the spectrum based on theory according to the yield of each element obtained by unfolding with the least square method, and comparing the measured gamma ray spectrum with the reconstructed gamma ray spectrum for error control, thereby improving the spectrum unfolding precision.

公开(公告)号：US10401311B2

公开(公告)日：2019-09-03

申请号：US15888809

申请日：2018-02-05

Applicant: PetroChina Company Limited

Inventor： Hongliang Wu ,  Ning Li ,  Changlin Lan ,  Zhou Feng ,  Qingfu Feng ,  Kewen Wang

IPC: G01N23/222 ,  G01N23/2204 ,  G01V5/10

Abstract: The present invention provides a method and a device for measuring a formation elemental capture gamma ray spectrum, pertaining to the field of oil-gas exploration and well logging technologies. The method comprises: performing moderation on neutrons emitted from a neutron source according to a neutron capture cross section of a test sample; and adjusting a relative location of the test sample with respect to the neutron source, so that a standard capture gamma ray spectrum of the test sample is measured and obtained at a location where a thermal neutron flux reacting with atomic nucleuses of the test sample reaches a first predetermined value. The present invention performs moderation on a neutron source according to neutron capture cross sections of different test samples to measure and obtain elemental capture gamma ray spectra of the test samples, thereby obtaining various formation elemental capture gamma ray spectra with higher accuracy.

公开(公告)号：US20180172608A1

公开(公告)日：2018-06-21

申请号：US15888809

申请日：2018-02-05

Applicant: PetroChina Company Limited

Inventor： Hongliang WU ,  Ning Li ,  Changlin Lan ,  Zhou Feng ,  Qingfu Feng ,  Kewen Wang

IPC: G01N23/222 ,  G01N23/2204

CPC classification number: G01N23/222 ,  G01N23/2204 ,  G01V5/101

Abstract: The present invention provides a method and a device for measuring a formation elemental capture gamma ray spectrum, pertaining to the field of oil-gas exploration and well logging technologies. The method comprises: performing moderation on neutrons emitted from a neutron source according to a neutron capture cross section of a test sample; and adjusting a relative location of the test sample with respect to the neutron source, so that a standard capture gamma ray spectrum of the test sample is measured and obtained at a location where a thermal neutron flux reacting with atomic nucleuses of the test sample reaches a first predetermined value. The present invention performs moderation on a neutron source according to neutron capture cross sections of different test samples to measure and obtain elemental capture gamma ray spectra of the test samples, thereby obtaining various formation elemental capture gamma ray spectra with higher accuracy.