CN109696282B

CN109696282B - Acoustic emission detection device for deepwater process facilities

Info

Publication number: CN109696282B
Application number: CN201910059740.5A
Authority: CN
Inventors: 刘书杰; 李强; 文敏; 谢仁军; 武治强; 徐长航; 王召龙; 杜莎莎; 张源
Original assignee: China University of Petroleum East China; China National Offshore Oil Corp CNOOC; CNOOC China Ltd
Current assignee: China University of Petroleum East China; China National Offshore Oil Corp CNOOC; CNOOC China Ltd
Priority date: 2019-01-22
Filing date: 2019-01-22
Publication date: 2021-08-20
Anticipated expiration: 2039-01-22
Also published as: CN109696282A

Abstract

The invention belongs to the field of deepwater leak detection, and in particular relates to an acoustic emission detection device for deepwater process facility leakage, comprising an external pressure resistance device, an internal acoustic emission detection system and a deepwater process facility leak detection method. The anti-compression device includes: a cylinder body, a spherical cap-shaped head, a flat-covered head and a fixing device, the spherical cap-shaped head is provided with a watertight connector to realize power supply and signal transmission, and the welding ring is convenient for fixing and handling; The flat cover head ensures good signal transmission; the adjustable clamp structure is designed to match and fix process facilities of different shapes and sizes; the acoustic emission detection system includes: an acoustic emission sensor, a signal transmission cable, and a signal processor. The anti-compression device of the invention has the functions of anti-pressure and waterproof, good signal transmission, reasonable design, collects the signal through the acoustic emission sensor, transmits the signal to the signal processor, and combines the characteristics of the deep-water process facility leakage acoustic emission signal in the frequency domain. Deepwater process facility leak detection.

Description

Acoustic emission detection device for deepwater process facilities

Technical Field

The invention belongs to a deepwater leakage detection device, and particularly relates to a design of a deepwater process facility acoustic emission detection device.

Background

In recent years, driven by the need of energy sources, oil and gas exploitation gradually shifts from land to sea, and the exploitation amount of marine oil and gas is gradually increased. The deep water oil and gas exploitation process facility is a main component of an offshore oil and gas field development and production system. Ensuring the normal operation of deepwater process facilities is the key to ensuring the exploitation of ocean oil and gas.

However, the environment on the sea bottom is more complex than that on the land, resulting in that the deepwater process facility is in a dynamically changing engineering geological environment for a long time, and the outside is more susceptible to damage and interference by various factors. Under the influence of physical, chemical and mechanical factors, the deep water process facility has different degrees of corrosion, damage, deformation, scouring, deviation, suspension span and other defects, which cause damage accumulation, leakage, perforation, fracture and fracture in serious conditions and cause oil spill accidents. In 1998-2012, in the marine production accidents reported by the domestic public development tables and the marine production tables, only the leakage accidents of the marine pipelines are 19 times, wherein 10 times occur in the Bohai sea area, 6 times occur in the yellow sea area, and 3 times occur in the east sea area; the leakage of natural gas is 4, and the leakage of oil is 15. Therefore, the leakage probability of the deepwater process facility is extremely high. In addition, deepwater process facilities have large investment and high risk, once an oil leakage accident occurs, not only normal exploitation of oil and gas is influenced, production loss is caused, but also severe pollution is caused to the marine environment, certain impact is brought to the local environment, once an ignition source is ignited, a fire explosion accident occurs, direct accident damage is caused, and the consequence is not imaginable.

Therefore, the leakage of the deepwater process facilities becomes a prominent problem restricting the industrialized development process of China, and the accurate detection of the leakage of the deepwater process facilities is more and more important. However, the leakage of the deepwater process facility has the characteristics of invisibility, wide nodes, complex form, difficult detection, easy signal interference by environment and the like, and most of detection methods for onshore leakage are not suitable for the deepwater process facility, so that the realization of early real-time, online and comprehensive monitoring of leakage of the deepwater process facility becomes a big problem, and no major breakthrough is made at home and abroad.

Stress wave detection is one of effective means for leakage detection, also called acoustic emission detection, and has good applicability to the fluid leakage problem in theory. The method can excite stress waves when the fluid leaks, the stress waves are transmitted through the wall surface of the process facility and the fluid, the high-frequency weak stress wave signals can be collected by using the acoustic emission sensor arranged outside the equipment, and then the leakage rule of the process facility is explored by using the signals. The technology can provide a reliable and practical tool means for fluid leakage detection in engineering. However, how to ensure the sound emission detection device to work in a healthy state in a deep sea environment and to be fixedly installed is a difficult point.

Disclosure of Invention

Aiming at the complex characteristics of the seabed environment, the acoustic emission detection device for the deepwater process facility is designed in order to realize that the acoustic emission detection device has a stable and good signal transmission function under the deepwater environment.

In order to achieve the purpose, the design scheme adopted by the invention is as follows:

the device comprises an external compression-resistant device and an internal acoustic emission detection system, wherein the compression-resistant device comprises: (1) a cylindrical pressure-resistant cylinder; (2) the upper part adopts a spherical cap-shaped end socket, and is provided with a watertight connector clip which can be connected with an external cable, thereby realizing power supply and signal transmission; (3) the hanging rings are welded on the two sides of the spherical end socket flange, so that the device is fixed and convenient to transport; (4) the lower part of the device adopts a flat cover end socket, and selects 45 # steel with higher strength in common waveguide materials, so that the signal attenuation of stress waves is reduced as much as possible on the premise of ensuring the pressure-bearing performance; (5) the bottom part is fixed with a measured process facility by using an adjustable hoop structure, and the adjustable hoop structure can be matched with process facilities with various shapes and sizes, such as pipelines, Christmas trees and the like; the cylinder body and the spherical head are made of aluminum alloy 7050 materials with higher strength, the head and the cylinder body are fastened and connected by flanges, and an O-shaped sealing ring with strong sealing performance is used for sealing; the internal acoustic emission detection system portion includes an acoustic emission sensor, a signal transmission cable, and a signal processor.

Aiming at the complex seabed environment, the invention has the following beneficial effects:

(1) in consideration of the problems of hydrostatic pressure and corrosion under deep sea environmental conditions, the design adopts metal with high specific strength and high specific rigidity.

(2) The structure is simple, the disassembly is convenient, the end socket and the barrel body can be communicated with the outside as required, and the installation and the maintenance of internal parts are convenient.

(3) The seal head and the cylinder body are sealed by the O-shaped ring, and the radial seal and the axial seal are combined, so that the structure is simple, and the seal is reliable.

(4) The mounting and fixing device can realize the matching of process facilities with various shapes and sizes, and has wider application range.

(5) The external pressure-resistant device can ensure that the internal acoustic emission detection system can normally operate in a deep sea environment, and realizes leakage detection of process facilities.

Drawings

The invention will be described in detail with reference to the following drawings

Fig. 1 is a plan view of an acoustic emission testing device for a deepwater process installation.

Fig. 2 is a perspective view of an acoustic emission detection device of a deepwater process facility.

Fig. 3 is a perspective view of the shaft core.

Fig. 4 is an example of a leakage free spectrum map.

Fig. 5 is an example of a leakage spectrum map.

Detailed Description

As shown in figure 1, the device comprises a spherical head 1, a lifting ring 2, a cylinder 3, an O-shaped ring 4, a flat cover head 5, a hoop structure 6, an acoustic emission sensor 7, a signal processor 8 and a power supply 9.

The device is characterized in that the external spherical head 1 and the cylinder 3 and the flat head 5 and the cylinder 3 are tightly connected by flanges, the spherical head 1 and the cylinder 3 are radially sealed by double sealing rings, the flat head 5 and the cylinder 3 are combined by double sealing rings, and the radial sealing and the axial sealing are combined, so that the sealing mode is simple and reliable; the spherical head 1 and the cylinder 3 are made of aluminum alloy 7050 materials with higher strength, lighter weight and high cost performance, so that the volume, the weight and the cost are reduced; the flat cover end socket 5 adopts 45 steel with good wave guiding performance and higher strength, thereby reducing the transmission loss of stress waves and realizing accurate judgment of leakage; the lifting rings 2 are welded on two sides of the spherical head flange, so that the whole device is convenient to carry on one hand, and the device is assisted to be fixed on the other hand; the band structure 6 is designed in a minor arc shape, as shown in fig. 1 and 2, with one end connected by a pin and around which the band can rotate, accommodating a variety of configurations and sizes of process facility sizes, and the other end using a core as shown in fig. 3, which is formed by welding two bolts to the pin.

An Acoustic emission sensor 7 and a signal processor 8 in the device are main elements of an Acoustic emission leakage detection system, the Acoustic emission sensor 7 uses an integrated sensor of Physical Acoustic Corp (PAC) company, and the integrated acquisition, 40dB preamplifier and a filter are integrated; AEwin software is arranged in the signal processor 8, and real-time storage, waveform processing and display of signals are achieved.

The specific detection method comprises the following steps: an acoustic emission signal generated when the deepwater process facility normally operates and leaks is transmitted to an acoustic emission sensor 7 through a bottom flat cover end socket 5, the acoustic emission sensor 7 collects, amplifies and converts the acoustic emission signal and then transmits the signal to a signal processor 8, the signal processor 8 processes and displays the signal, the process facility to be detected is judged to be in a normal operation state according to the characteristic that no obvious wave peak exists in a frequency spectrogram of figure 4, and the process facility to be detected is judged to leak through the characteristic that an obvious frequency peak exists in 50-400KHz of the frequency spectrogram of figure 5.

Claims

1. a deep-water process facility leakage acoustic emission detection device, comprising an external pressure-resistant device and an internal acoustic emission detection system is characterized in that:

The compression resistance device includes a spherical cap, a cylinder, an O-ring, an easy-to-wave flat cover and a clamp structure;

Flanges are used between the spherical cap and the cylinder and between the flat cap and the cylinder; double sealing rings are used between the spherical cap and the cylinder Radial sealing, a double sealing ring combining radial sealing and axial sealing is used between the flat cover head and the cylinder body; the clamp structure is in the shape of an inferior arc, and the first end is connected by a pin, The band is rotatable around this end, and the clamp structure mounts the compression device to the process facility under test;

The internal acoustic emission detection system includes an acoustic emission sensor, a signal transmission cable, and a signal processor;

The acoustic emission sensor and the signal processor are installed in the pressure-resistant device, and the acoustic emission sensor is close to the flat cover head;

The acoustic emission sensor transmits the acoustic emission signal to the signal processor through the signal transmission cable, and the signal processor determines the leakage state of the process facility through the collected signal.