Well site calibration device of while-drilling neutron porosity logger and using method

Abstract

The invention discloses a well site calibration device of a while-drilling neutron porosity logger and a using method. A box body in the device is a hollow cuboid and used for containing water or organic glass, the end face of a bottom cover is arranged in an inwards-concave mode, the bottom cover is in lap joint with the outer diameter of the logger and covers a detection area, and the distance between the top of the logger and the upper surface of the water or the organic glass is greater than or equal to 25 cm; the logger is lapped in a groove in the upper surface of a first support, and second supports in front of and behind the box body are fixedly lapped on the outer diameter of the logger, so that the box body is horizontally arranged on the logger. When in use, the logger transmitsvalues to the box body to obtain a counting rate N<SS> with a short source distance and a counting rate N<LS> with a long source distance, then another group of data is obtained, and |N<SS>-N'<SS>| / N<SS> is less than 0.1 and |N<LS>-N'<LS>| / N<LS> is less than 0.1 by adjusting the target pressure step number, so that it is guaranteed that a circuit system and neutron yield of the logger in downholeoperation are stable and reliable, the stability of a measurement curve is improved, and the risk of tripping is reduced.

Description

technical field [0001] The invention belongs to the technical field of oil and gas drilling, in particular to a well site verification device and a using method of a neutron porosity logging tool while drilling. Background technique [0002] The neutron porosity logging tool while drilling is one of the radioactive tools while drilling, and its response mainly reflects the hydrogen content in rocks. The neutron porosity logging tool uses its own chemical neutron source and two detectors with long and short source distances to measure the attenuation rate of the epithermal neutron density that has not been captured by the formation along with the source distance, and convert the attenuation rate to Scaled porosity value. The tool is less affected by the borehole, and can obtain porosity parameters accurately and reliably. In the process of geological guidance drilling, it provides guarantee for the system to implement accurate guidance. The radioactive source used in the n...

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Problems solved by technology

[0004] When the neutron porosity logging tool is pulled to the well site and ready to go downhole, only the stability of the circuit system of the tool can be tested, and the radioactive working status cannot be detected at the well site

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