CN103195408B - Oil/gas Well flow imaging measuring method - Google Patents

Abstract

The invention discloses a flow imaging measurement method for oil and gas wells, comprising: arranging a plurality of measuring electrode rings and shielding electrode rings on the oil well wall of the fluid to be measured at axial intervals; sequentially selecting an electrode in each measuring electrode ring as an excitation Electrode, excite the excitation electrode and the electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam-shaped electromagnetic field; sequentially select the electrodes in each measuring electrode ring that are separated from the excitation electrode by more than two as the receiving electrode to receive the response signal of the fluid medium; according to The response signals received by the electrodes in each measuring electrode ring are processed to generate flow parameters and images of the measured fluid section. The present invention is applicable to various situations of high and low water cut, can effectively overcome the "soft field" effect of general electrical measurement for multi-scanning measurement of multi-phase fluid flow cross-section, and can identify fluid medium with high resolution, and can detect multi-phase fluid in wells. The original flow interference is very small, and it has the advantages of strong real-time performance, no damage, low cost, and convenient application.

Description

Oil and gas well flow imaging measurement method

technical field

The patent of the invention belongs to the application of geophysical logging technology, and relates to an electromagnetic measurement method for dynamic monitoring of oil and gas well production and multiphase pipe flow imaging detection, specifically an imaging measurement method for oil and gas well flow.

Background technique

Oil and natural gas are stored in oil and gas layers thousands of meters deep underground, and are extracted through drilling. Oil and gas production well sections are generally provided with round steel casings or screens, and the angle is vertical, inclined or horizontal to the ground plane. Due to formation water or water injection development, the wellbore is often two-phase or three-phase flow of oil, gas and water. By using logging instruments to monitor the multiphase flow profile of the production well section, we can understand the production status of oil and gas layers, and take scientific and reasonable technical measures to ensure stable and high oil and gas production.

The distribution of multiphase fluids in oil and gas production wells is very complex, and the analysis of flow characteristics requires detailed information on each part of the flow section, which should be solved through nonlinear dynamic measurement research. The existing flow profile logging technology belongs to linear measurement, which collects the overall results of the medium within the detection range, and cannot provide accurate information on fluid distribution. New measurement methods and technologies are urgently needed. The oil and gas well flow imaging electromagnetic measurement method of the present invention can collect the information of the flow field in the well in a nonlinear scanning manner, reconstruct the flow image in real time through data processing, and accurately reflect the flow pattern and characteristics of the multiphase fluid in the oil and gas well.

Contents of the invention

An embodiment of the present invention provides a flow imaging measurement method for oil and gas wells, including:

A plurality of measuring electrode rings and shielding electrode rings are axially spaced on the oil well wall of the measured fluid;

Sequentially select an electrode in each measuring electrode ring as an excitation electrode, excite the excitation electrode and the electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam-shaped electromagnetic field;

Sequentially select the electrodes separated by more than two electrodes from the excitation electrode in each measuring electrode ring as receiving electrodes to receive the response signal of the fluid medium;

Flow parameters and images of the measured fluid section are generated after processing according to the response signals received by the electrodes in each measuring electrode ring.

Preferably, both the measuring electrode ring and the shielding electrode ring in the embodiment of the present invention have N electrodes arranged in a ring at equal intervals, where N>6.

Preferably, in the embodiment of the present invention, the electrodes in the measuring electrode ring are the same, and the electrodes in the shielding electrode ring are the same.

Preferably, the electrodes adjacent to the excitation electrodes up, down, left, and right in the embodiment of the present invention include: electrodes adjacent to the excitation electrodes in the measurement electrode ring where the excitation electrodes are located and electrodes adjacent to the excitation electrodes in the adjacent shielding electrode ring electrode.

In the embodiment of the present invention, exciting the excitation electrode and the electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam-shaped electromagnetic field includes:

Supply the excitation electrode, the electrode adjacent to the excitation electrode in the measurement electrode ring, and the electrode adjacent to the excitation electrode in the adjacent shielding electrode ring—an excitation signal with a constant current and a constant frequency, in the measured fluid A beam-shaped electromagnetic field is generated, and the frequency unit of the excitation signal is nMHz.

Preferably, in the embodiment of the present invention, the electrodes in each measuring electrode ring that are separated from the excitation electrode by more than two are sequentially selected as receiving electrodes, and receiving the response signal of the fluid medium includes:

Ground the four adjacent electrodes up, down, left, and right of the receiving electrode, that is, ground the electrodes adjacent to the receiving electrode in the measuring electrode ring and the shielding electrode ring.

The invention comprehensively utilizes the difference of dielectric properties and conductive properties of oil, gas and water to identify the fluid in the well. Sub-scanning measurement can effectively overcome the "soft field" effect of general electrical measurement, and identify the fluid medium with high resolution. In the method of the present invention, the electromagnetic array sensor is close to the well wall, without intruding into the fluid, and the original flow of the multiphase fluid in the well There are very few distractions. In addition, the method of the present invention belongs to functional imaging, and has the advantages of strong real-time performance, no damage, low cost, and convenient application.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the flowchart of the flow imaging measurement method for oil and gas wells of the present invention;

Fig. 2 is the vertical cross-sectional schematic view of the multi-layer annular electrode array structure adopted by the present invention

Fig. 3 is a schematic diagram of the longitudinal shielding of the detection electromagnetic field;

Fig. 4 is a schematic diagram of lateral focusing of the detection electromagnetic field;

Fig. 5 is a schematic diagram of the measurement mode of the multi-layer annular electrode array probe adopted in the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention provides a flow imaging measurement method for oil and gas wells, as shown in Figure 1, the method comprises:

Step S101, arranging a plurality of measuring electrode rings and shielding electrode rings at an axial interval on the oil well wall of the fluid to be measured;

Step S102, sequentially selecting an electrode in each measuring electrode ring as an excitation electrode, exciting the excitation electrode and electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam-shaped electromagnetic field;

Step S103, sequentially selecting the electrodes in each measuring electrode ring that are separated from the excitation electrodes by more than two distances as receiving electrodes to receive the response signal of the fluid medium;

Step S104, generating flow parameters and images of the measured fluid section after processing according to the response signals received by the electrodes in each measuring electrode ring.

Preferably, both the measuring electrode ring and the shielding electrode ring in the embodiment of the present invention have N electrodes arranged in a ring at equal intervals, preferably, N>6 in the present invention.

In the present invention, the electrodes adjacent to the excitation electrodes up, down, left, and right include: the electrodes adjacent to the excitation electrodes in the measurement electrode ring where the excitation electrodes are located, and the electrodes adjacent to the excitation electrodes in the adjacent shielding electrode ring.

In the embodiment of the present invention, exciting the excitation electrode and the electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam-shaped electromagnetic field includes:

Supply the excitation electrode, the electrode adjacent to the excitation electrode in the measuring electrode ring, and the electrode adjacent to the excitation electrode in the adjacent shielding electrode ring—an excitation signal with constant current and constant frequency to generate a beam-shaped electromagnetic field in the measured fluid , the frequency unit of the excitation signal is nMHz.

In the embodiment of the present invention, the electrodes in the measurement electrode rings that are more than two distances from the excitation electrodes are sequentially selected as the receiving electrodes, and receiving the response signal of the fluid medium includes: four electrodes that are adjacent to the upper, lower, left, and right sides of the receiving electrodes Grounding means grounding the electrode adjacent to the receiving electrode in the measuring electrode ring and in the shielding electrode ring.

The technical solution of the present invention will be further described in detail below in combination with specific implementation modes.

The purpose of the present invention is to provide a method for exciting a beam-like detection electromagnetic field in an oil and gas well, and scanning and measuring a cross-sectional image of a multiphase fluid flow.

The present invention is realized in the following manner:

The shielding electrode ring and the measuring electrode ring form a multi-layer annular electrode array. As shown in FIG. The number of electrodes is the same, and they are all composed of N identical electrodes arranged in a ring at equal intervals. In the embodiment of the present invention, N>6 in each electrode ring, too few electrodes will affect the measurement resolution, and too many electrodes may affect the measurement imaging real-time.

When exciting the electromagnetic field in the oil and gas well, put the electrode array close to the oil well wall and place it in the measured fluid, select any electrode in the measurement electrode ring and its adjacent 4 electrodes, and supply the constant current and constant frequency ( The excitation signal with the unit of nMHz) forms an electromagnetic field with a beam structure in the fluid in the well. As shown in Figure 3, it is a top view of a measuring electrode ring, wherein electrode 1 is used as an excitation electrode, and electrode 1, electrode 16 adjacent to electrode 1 and electrode 2 in the measuring electrode ring are given a constant current and a certain frequency. The excitation signal also gives an excitation signal to the electrode adjacent to the electrode 1 in the shielding electrode ring at the same time, which is not shown in the figure, forming a beam-shaped electromagnetic field. Figure 4 is a schematic diagram of the longitudinal shielding of the formed detection electromagnetic field, each electrode in the measuring electrode ring 401 is used as an excitation electrode, and 402 and 403 are shielding electrode rings adjacent to the electrode ring 401. Electrode 1 emits the same current, thereby suppressing the spread of the probe electromagnetic field in the radial direction. FIG. 5 is a schematic diagram of lateral focusing of the formed detection electromagnetic field. Electrodes 501, 502, and 503 are excitation electrodes. When electrode 505 is used as a receiving electrode, electrodes 504 and 506 are grounded.

When receiving useful signals in oil and gas wells, select the electrodes in the measuring electrode ring that are more than 2 away from the excitation electrodes, and ground the four adjacent electrodes up, down, left, and right. Also refer to Figure 3, select electrode 9 as the receiving electrode to receive useful signals. When signal, the electrode 10 and electrode 8 in the measuring electrode ring and the electrode adjacent to the electrode 9 in the adjacent shielding electrode ring are grounded, and the electrode 9 receives the response signal under the action of the fluid medium. The frequency of the excitation signal adopted by the present invention is nMHz, which can not only reflect the conductivity and dielectric properties of the fluid in the well at the same time, but also effectively avoid the influence of frequency dispersion caused by various reasons.

When scanning the measurement data, one electrode of the measuring electrode ring is sequentially selected for excitation, and the other N-5 electrodes are cyclically received, and each electrode in the measuring electrode ring is excited and cyclically received for N times. For the flow section, N×(N-5) independent measurement data can be collected. These measurement data respectively reflect the electrical parameters of the media in different parts of the measured flow section where the electrode ring is located, and can be processed to reconstruct the flow section image and determine the proportional velocity of each phase fluid. Similarly, the above operations are also performed on other measuring electrode rings in the measured fluid to obtain the image of the section where each electrode ring is located and the proportion of each phase fluid. Multi-scanning measurement of multi-phase fluid flow section can effectively overcome the "soft field" effect of general electrical measurement, and identify fluid media with high resolution

The invention provides a multi-phase fluid flow imaging measurement method in an oil and gas well, which comprises the construction of a multi-layer annular electrode array, beam detection electromagnetic field excitation, useful signal acceptance and data scanning measurement. The flow imaging electromagnetic measurement method for oil and gas wells of the present invention has three special advantages: one is to comprehensively utilize the difference in dielectric properties and conductivity properties of oil, gas and water to identify the fluid in the well, which is applicable to various situations of high and low water cut; By exciting the beam-shaped electromagnetic field in the well, and scanning and measuring the multiphase fluid flow section multiple times, it can effectively overcome the "soft field" effect of general electrical measurement and identify the fluid medium with high resolution; the third is that the electromagnetic array sensor is close to the well wall , there is no need to invade the fluid, and there is little interference with the original flow of the multiphase fluid in the well. In addition, this method belongs to functional imaging, which has the advantages of strong real-time performance, non-invasiveness, low cost, and convenient application.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

In the present invention, specific examples have been applied to explain the principles and implementation methods of the present invention, and the descriptions of the above examples are only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to this The idea of the invention will have changes in the specific implementation and scope of application. To sum up, the contents of this specification should not be construed as limiting the present invention.

Claims (7)

1. A flow imaging measurement method for oil and gas wells, characterized in that, the method comprises: A plurality of measuring electrode rings and shielding electrode rings are arranged on the oil well wall of the measured fluid at axial intervals; Sequentially select an electrode in each measuring electrode ring as an excitation electrode, excite the excitation electrode and the electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam-shaped electromagnetic field; Sequentially select electrodes in each measuring electrode ring that are separated from the excitation electrode by more than two electrodes as receiving electrodes to receive the response signal of the measured fluid; Flow parameters and images of the measured fluid section are generated after processing according to the response signals received by the electrodes in each measuring electrode ring. 2 . The method for measuring oil and gas well flow imaging according to claim 1 , wherein both the measuring electrode ring and the shielding electrode ring have N electrodes arranged in a ring at equal intervals, wherein N>6. 3 . The method for measuring oil and gas well flow imaging according to claim 2 , wherein the electrodes in the measuring electrode ring are the same, and the electrodes in the shielding electrode ring are the same. 4 . 4. The oil and gas well flow imaging measurement method according to claim 1, wherein the electrodes adjacent to the excitation electrode up, down, left, and right include: the electrodes adjacent to the excitation electrode in the measurement electrode ring where the excitation electrode is located electrode and the electrode adjacent to the excitation electrode in the adjacent shield electrode ring. 5. The oil and gas well flow imaging measurement method as claimed in claim 4, wherein said excitation of said excitation electrode and electrodes adjacent to the excitation electrode up, down, left, and right to generate a beam electromagnetic field comprises: Supply the excitation electrode, the electrode adjacent to the excitation electrode in the measurement electrode ring, and the electrode adjacent to the excitation electrode in the adjacent shielding electrode ring—an excitation signal with a constant current and a constant frequency, in the measured fluid Generates a beam-like electromagnetic field. 6. The oil and gas well flow imaging measurement method according to claim 1, characterized in that, the electrodes in each measuring electrode ring are sequentially selected as receiving electrodes separated by more than two electrodes from the excitation electrodes, and receive the measured electrodes. The response signal of the measured fluid includes: The four adjacent electrodes up, down, left, and right of the receiving electrode are grounded. 7. The oil and gas well flow imaging measurement method according to claim 4, wherein the grounding of the four electrodes adjacent to the upper, lower, left, and right sides of the receiving electrode comprises: The electrodes in the measuring electrode ring and in the shielding electrode ring adjacent to the receiving electrode are grounded.