CN210977452U

CN210977452U - Oil well working fluid level depth measuring system based on resistance measurement

Info

Publication number: CN210977452U
Application number: CN201921931527.0U
Authority: CN
Inventors: 刘尚伟; 欧阳晖; 柳明; 彭新; 方芸; 林莉; 雷阳; 张高明; 杜红彪; 许磊; 杨辉; 谢炜; 陈涛; 魏华; 罗伟; 耿攀; 徐正喜; 蔡凯; 吴浩伟; 李锐
Original assignee: Wuhan Haiwang Technologies Co ltd
Current assignee: Wuhan Haiwang Technologies Co ltd
Priority date: 2019-11-11
Filing date: 2019-11-11
Publication date: 2020-07-10
Anticipated expiration: 2029-11-11

Abstract

The utility model discloses an oil well working fluid level degree of depth measurement system based on resistance measurement, include: the oil well comprises a metal sleeve, an oil-submersible armored cable and an oil pipe, and well fluid is arranged between the metal sleeve and the oil pipe. The system aims at underground oil production equipment (an electric submersible centrifugal pump, a submersible linear motor reciprocating pump and the like) powered by a three-phase submersible armored cable, and utilizes the characteristic that the submersible cable armor and a metal sleeve are connected in series at a working fluid level through conductive well fluid to measure the resistance between the cable armor and the oil well sleeve at a well mouth and then convert the working fluid level depth of an oil well. Compared with the traditional sound wave measuring system, the system only needs to measure the resistance at the wellhead, has low equipment requirement and simple operation, and does not need to stop the oil well during detection.

Description

Oil well working fluid level depth measuring system based on resistance measurement

Technical Field

The utility model relates to an oil development technical field especially relates to an oil well working fluid level degree of depth measurement system.

Background

In oil production, in order to fully utilize the liquid production capacity of an oil well, the oil production rate of an oil pumping unit such as a head knocking machine and a centrifugal pump is generally matched with the liquid permeability of the oil well. However, in practical situations, even if the same well is used, the seepage rate of the well changes with the changes of the exploitation stage and the geological conditions, and under the condition that the oil extraction rate of the pumping unit is not changed, the change of the seepage rate of the well is reflected as the change of the working fluid level depth (the distance between the working fluid level of the well and the well mouth) of the well, the working fluid level depth is increased when the seepage rate of the well is reduced, and the working fluid level depth is reduced when the seepage rate of the well is increased. The change of the oil well seepage rate can be indirectly judged by regularly measuring the depth of the working fluid level of the oil well, so that a basis is provided for adjusting the oil extraction rate of the oil pumping unit, and the high yield of the oil well is realized.

The oil field currently adopts an echo method to measure the depth of the working fluid level. During measurement, sound waves are emitted underground by a sound bomb or other sound generating devices, the sound waves are reflected back to a wellhead after encountering the dynamic liquid level, the time difference between the emission and the reception of the sound waves is detected at the wellhead, and the distance obtained by multiplying the time difference by the sound velocity is twice the depth of the dynamic liquid level. The method is simple in principle, but actual acoustic echo is easily interfered by wax deposition on the wall of an oil well pipe and the like, measurement results are not easy to interpret, and meanwhile, in order to avoid interference of running noise of an oil extraction machine on acoustic waves, oil well stopping is often needed, and high yield of the oil well is not facilitated.

At present, most oil fields in China adopt the traditional oil beam type head-knocking machine for oil production, the head-knocking machine is mature in technology and simple in structure, but the problems of low efficiency, eccentric wear of pipe rods and the like exist. Under this background, such as latent oily linear electric motor reciprocating pump, novel rodless oil recovery equipment such as electronic latent oily linear electric motor reciprocating pump is promoted gradually and is tried on in the oil field, and this type rodless oil recovery comprises the converter that is located the well head, latent oily armoured cable and motor in the pit, and the converter is through latent oily armoured cable drive motor operation in the pit. The outer layer of the oil-submersible armored cable is wrapped by an anti-wear metal armor, the sleeve of the oil well is also made of a metal material, and the conductive characteristics of the two materials provide possibility for developing a targeted dynamic liquid level measuring system.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an oil well working fluid level degree of depth detecting system, this system are applicable to the underground oil production equipment that adopts the oily armoured cable power supply of diving. The system can calculate the working fluid level depth of the oil well only by measuring the resistance between the armor and the casing at the wellhead, so that the requirement on measuring equipment is low, the operation is simple, and the normal production of the oil well is not influenced.

The utility model provides an oil well working fluid level degree of depth measurement system based on resistance measurement, a serial communication port, include: the oil well comprises a metal casing, an oil-submersible armored cable and an oil pipe, well fluid is arranged between the metal casing and the oil pipe,

the voltage measuring device is connected in parallel at two ends of the direct current power supply,

the first end of the constant resistor is connected with the direct current power supply in series, and the second end of the constant resistor is connected with a first measuring terminal;

a first end of the ammeter is connected in series with the direct current power supply, and a second end of the ammeter is connected to a second measurement terminal;

the first measurement terminal is connected to an armor of the submersible armored cable;

the second measurement terminal is connected to the metal sleeve;

the oil well working fluid level depth measuring system determines the working fluid level depth of the oil well based on the output voltage and the current value, the armor resistance of the submersible armored cable in unit length and the resistance of the metal sleeve.

In a preferred implementation mode, the submersible armored cable comprises three single-core copper cables from inside to outside, lead covers respectively coated outside the three cables, glass fiber ribbons coated outside the lead covers, and an armor.

In another preferred implementation, the rated output voltage of the direct current power supply is 5V.

In another preferred implementation, the fixed resistor has a resistance of 1 Ω.

In another preferred implementation mode, the measurement range of the voltage measurement device is 0-10V, and the measurement precision grade is 0.1 grade.

In another preferred implementation mode, the measurement range of the voltage measurement device is 0-10A, and the measurement precision grade is 0.1 grade.

In another preferred implementation, the oil well working fluid level depth measurement system calculates the oil well working fluid level depth based on the following formula:

H＝R₁/R₀＝(V/I-R_i)/(R₀₁+R₀₂) Wherein V and I are respectively the readings of a voltmeter and an ammeter, R_iFor measuring constant resistance, R, in systems₀₁And R₀₂Are respectively a unitLength of armor resistance versus casing resistance.

The utility model has the advantages that: 1. the realization is simple; 2. the requirement on measuring equipment is low; 3. the normal production of the oil well is not affected.

Drawings

FIG. 1 is a schematic view of an oil well as measured in the present invention;

fig. 2 is a schematic circuit diagram of the measurement system of the present invention.

Reference numerals: 1-well wall 2-casing (metal material) 3-oil-submersible armored cable 4-oil pipe 5-well liquid 6-pump set

Detailed Description

Fig. 1 is a schematic diagram of an embodiment of the present invention for measuring well fluid level. The oil well comprises a metal casing 2, an oil-submersible armored cable 3 and an oil pipe 4, wherein well fluid 5 is arranged between the metal casing and the oil pipe. As can be seen from the figure, the periphery of the cylindrical oil well is supported by the casing pipe made of metal materials, and the casing pipe plays a role in supporting and reinforcing the well wall; the three-phase armored cable is led out from a control cabinet of a wellhead and then extends to the underground to drive the pump unit 6 to recover oil; the pump set is submerged by well liquid, so that good liquid feeding of the pump set is ensured; the pump set sends the oil out of the well mouth through the oil pipe; h is the depth of the working fluid level of the oil well to be measured.

FIG. 2 is a diagram of an equivalent electrical resistance circuit between the wellhead armored cable and the casing corresponding to FIG. 1. In the figure, a point A is a wellhead armor measuring point, and a point B is a wellhead casing measuring point; r₀₁And R₀₂The unit length of the armored cable resistance and the unit length of the sleeve resistance are respectively measured in advance, and H is the working fluid level depth of the oil well; r₀₁H and R₀₂H represents the sheath resistance and casing resistance from the wellhead to the working fluid level, respectively; rw is the well fluid resistance connecting the armor and the casing at the working fluid level.

The measuring system of the utility model comprises a voltage measuring device (such as a voltmeter), a current measuring device (an ammeter), a direct current power supply and a fixed value resistor Ri, wherein the voltage measuring device is connected in parallel at two ends of the direct current power supply, the first end of the fixed value resistor is connected with the direct current power supply in series, and the second end of the fixed value resistor is connected with a first measuring terminal; a first end of the ammeter is connected in series with the direct current power supply, and a second end of the ammeter is connected to a second measurement terminal; the first measurement terminal is connected to an armor of the submersible armored cable; the second measurement terminal is connected to the metal sleeve; the oil well working fluid level depth measuring system determines the working fluid level depth of the oil well based on the output voltage and the current value, the armor resistance of the submersible armored cable in unit length and the resistance of the metal sleeve.

As can be seen from fig. 2, the resistance obtained from the voltage vs. current meter:

V/I＝R_i+R₀₁*H+R₀₂*H+R_w＝R_i+(R₀₁+R₀₂)*H+R_w

in the above formula, V and I are respectively the readings of a voltmeter and an ammeter.

Resistance between armor and casing measured from the wellhead:

R₁＝V/I-R_i＝(R₀₁+R₀₂)*H+R_w。

because the well fluid generally has large water content and good conductivity, R is_wThe numerical value is far smaller than the sheath resistance and the sleeve resistance, and the numerical value can be ignored in practical calculation. Thus:

R₁＝R₀₁*H+R₀₂*H＝(R₀₁+R₀₂)*H

by combining the above formulas, the depth of the working fluid level of the oil well can be obtained as follows:

H＝R₁/R₀＝(V/I-R_i)/(R₀₁+R₀₂)

when the measuring system is used for measuring the depth of the working fluid level of an oil well, firstly, the armor and the oil well casing pipe with unit length are cut out on the ground, and the resistances at two ends of the armor and the cable are obtained by adopting a high-precision universal meter to measure, wherein the values are R respectively₀₁And R₀₂。

Two detection ends of the measuring device are respectively connected with an oil-submersible cable armor and a sleeve at a wellhead, and a voltmeter numerical value V and an ammeter numerical value I are read.

The working fluid level depth of the oil well to be measured is (V/I-R)_i)/(R₀₁+R₀₂)。

While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. An oil well working fluid level depth measurement system based on resistance measurement, comprising: the oil well comprises a metal casing, an oil-submersible armored cable and an oil pipe, well fluid is arranged between the metal casing and the oil pipe,

a first end of the current measuring device is connected in series with the direct current power supply, and a second end of the current measuring device is connected to a second measuring terminal;

the second measurement terminal is connected to the metal sleeve;

the current measuring device is used for measuring current in a loop, the voltage measuring device is used for measuring output voltage at two ends of the direct-current power supply, and the oil well working fluid level depth measuring system determines the oil well working fluid level depth based on the output voltage and the current value, the armor resistance of the submersible armored cable in unit length and the resistance of the metal sleeve.

2. The system for measuring the depth of the working fluid level of the oil well based on the resistance measurement as claimed in claim 1, wherein the submersible armored cable is respectively provided with the following components from inside to outside: three single-core copper cables, lead covers respectively coated outside the three single-core copper cables, glass fiber ribbons coated outside the lead covers and armor.

3. The system of claim 1, wherein the dc power supply has a rated output voltage of 5V.

4. The system of claim 1, wherein the fixed resistor has a resistance of 1 Ω.

5. The oil well working fluid level depth measuring system based on resistance measurement as claimed in claim 1, wherein the voltage measuring device has a measuring range of 0-10V and a measuring accuracy grade of 0.1.

6. The oil well working fluid level depth measuring system based on resistance measurement as claimed in claim 1, wherein the voltage measuring device has a measuring range of 0-10A and a measuring accuracy grade of 0.1.

7. The electrical resistance measurement based oil well working fluid level depth measurement system of claim 1, wherein the oil well working fluid level depth measurement system calculates the oil well working fluid level depth based on the following formula: h ═ R₁/R₀＝(V/I-R_i)/(R₀₁+R₀₂) Wherein V and I are respectively the readings of the voltage measuring device and the current measuring device in the measuring system, R_iFor measuring constant resistance, R, in systems₀₁And R₀₂Respectively an armor resistor and a sleeve resistor in unit length.