A Downhole Auxiliary Measuring Device Based on Flexible Composite Materials

Abstract

The invention provides an auxiliary downhole measuring device based on a flexible composite material, which belongs to the technical field of neutron well logging, and is made of injection molding-grade reinforced nylon 6 material containing 5% to 15% alkali-free glass fiber, and includes closely connected conical Or an eccentric frustum-shaped upper body and a cylindrical lower body, the corresponding center or eccentricity of the upper body and the lower body is provided with a through hole with a diameter less than or equal to the diameter of the upper bottom surface of the upper body, which is used to place logging instruments; the side of the upper body is provided with There are fixed grooves for installing fixed logging instruments. The hydrogen content of the injection-molding grade reinforced nylon 6 material containing 5% to 15% alkali-free glass fiber used in the present invention is close to that of water, and there is no need to inject drilling fluid, which reduces the erosion of the well wall; the contained boron has a relatively high thermal neutron The high capture cross-section is beneficial for logging tools to detect thermal neutrons; the device has good heat resistance, strong corrosion resistance, and good flexibility, which can match different borehole diameter changes and adapt to complex downhole environments.

Description

A kind of downhole auxiliary measurement device based on flexible composite material technical field The invention belongs to the technical field of neutron logging, be specifically related to a kind of downhole auxiliary measurement based on flexible composite material device. Background technique [0002] Neutron porosity logging is a geophysical logging method that utilizes radioactive sources to explore formation porosity. by radiation The fast neutrons emitted from the source penetrate the drilling fluid, casing, cement and other components, and undergo a series of inelastic scattering, elastic and elastic scattering with the formation medium. Scattering and trapping reactions, based on the signal received by the detector, analyze the formation composition and properties. Due to the mass of hydrogen and neutrons The quantities are the closest, so hydrogen has the strongest moderating effect on neutrons and has the greatest impact on neutron logging. The rock sk...

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Problems solved by technology

However, the influence of the environmental parameters of the cased well on the instrument measurement response and the evaluation of the cement cement quality have greatly limited its practical application

Poor cement bonding, or excessive cement and casing thickness will greatly reduce the reliability of logging results

At the same time, downhole cement information such as cement density, cement thickness, and cement composition is usually unknown, and it is very difficult to obtain specific information about downhole cement. Therefore, there is a problem of insufficient research on cement cement quality evaluation technology

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