Controlled source integrated nuclear logging instrument and logging method

Abstract

The invention discloses a controlled source integrated nuclear logging instrument and a logging method. The controlled source integrated nuclear logging instrument comprises a neutron generator, a near-thermal neutron detector, an ultra-thermal neutron detector, a near-gamma detector, a far-gamma detector and a far-thermal neutron detector which are sequentially arranged from one end to the otherend, wherein the near-thermal neutron detector and the ultra-thermal neutron detector are arranged side by side, and the far-gamma detector and the far-thermal neutron detector are arranged side by side; and the distance between the near-thermal neutron detector and the neutron generator as well as the distance between the ultra-thermal neutron detector and the neutron generator is 30+ / -3 cm, thedistance between the near-gamma detector and the neutron generator is 45+ / -3 cm, and the distance between the far-gamma detector and the neutron generator as well as the distance between the far-thermal neutron detector and the neutron generator are 75+ / -3 cm. The yield of all elements in a formation, the formation porosity and the formation density value can be calculated simultaneously, multipledownhole measurement is avoided, and the measurement efficiency is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of well logging, and relates to a controllable source integrated nuclear well logging tool and a well logging method. Background technique [0002] Petroleum exploration well logging includes technologies and equipment such as electrical logging, acoustic logging, nuclear logging, and nuclear magnetic logging. Nuclear logging mainly includes logging technologies such as natural gamma ray, density, neutron porosity, and formation elements. Instruments and equipment, traditional density logging uses cesium-137 source, neutron logging and formation element logging use americium beryllium neutron source, the use, transportation and storage of chemical sources are a great challenge to safety and environmental protection, and , Density, neutron, and formation element logging are all separate instruments, which need to be measured in the well separately, or combined logging, and the efficiency of logging operations...

AI Technical Summary

Problems solved by technology

[0002] Petroleum exploration well logging includes technologies and equipment such as electrical logging, acoustic logging, nuclear logging, and nuclear magnetic logging. Nuclear logging mainly includes logging technologies such as natural gamma ray, density, neutron porosity, and formation elements. Instruments and equipment, traditional density logging uses cesium-137 source, neutron logging and formation element logging use americium beryllium neutron source, the use, transportation and storage of chemical sources are a great challenge to safety and environmental protection, and , the logging of density, neutron and formation elements are all separate instruments, which need to be measured in the well separately, or combined logging, and the efficiency of logging operation is low

In recent years, neutron porosity and formation element logging have also been carried out using controllable neutron sources, but they are all separate instruments and equipment. If multiple detectors are directly stacked, the problem of mutual influence between detectors needs to be solved to ensure the detection precision

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