On-line measurement device of crude oil water content of wellhead

Abstract

An on-line measurement device of crude oil water content of a wellhead is applicable to on-line measurement of the wellhead crude oil water content of an oil field single well and mainly comprises a capacitance measurement front end and a data acquisition circuit, wherein the capacitance measurement front end is the most important link of the measurement device of the crude oil water content, and can convert the variation of the crude oil water content into a measurable capacitance signal; and the data acquisition circuit has two parts of a capacitance / voltage switching circuit and a voltage / current switching circuit which are designed based on a CAV444 chip and an AM462 chip respectively. The invention has the effects of realizing on-line precious measurement on the crude oil water content of the well head of an oil well, meeting the requirements on production dynamic analysis of the oil well and data transmission, having high measuring accuracy with the maximum relative difference within the range of + / -5%, conforming to the oil field anti-exposion requirement, and having small on-line measurement error and high reliability.

Description

technical field [0001] The invention relates to the technical field of oil recovery in oil fields, in particular to a detection device for extracted crude oil, which is an on-line measurement device for the water content of crude oil that can be applied to the wellhead of a single well in an oil field. Background technique [0002] Real-time measurement of crude oil water content is an important work in oil well production. The measurement object of water cut is divided into water-containing crude oil and dehydrated crude oil. Existing methods for measuring the water content of crude oil at the wellhead of oil wells are generally divided into two types, namely manual measurement and on-line measurement. At present, most of the water-bearing crude oil fields adopt the manual sampling measurement method. The manual sampling measurement method is divided into distillation method, electro-desorption method and Karl Fischer method according to the different means of oil-water s...

AI Technical Summary

Problems solved by technology

[0005] Disadvantages of the existing technology: the sampling time of the manual measurement method is long, it cannot be used for real-time measurement by the online measurement system, the sampling is random, and the human error is large, time-consuming and labor-intensive, and cannot meet the requirements of automatic management of oilfield production

[0006] However, the microwave and short wave methods of on-line measurement can not fully reflect the situation of mixed two-phase flow, so the measurement accuracy can meet the requirements under laboratory conditions, but cannot meet the accuracy requirements under specific field conditions.

Due to factors such as water-in-oil or oil-in-water, zero point drift is prone to occur, resulting in inaccurate measurement range and large nonlinear error

At the same time, due to the corrosion, scaling, waxing and other reasons of crude oil, the reliability of long-term operation of the instrument is poor

The traditional capacitance method is more accurate in measuring water cut, but the measuring range is small and the adjustability is poor, and it is only suitable for oil wells with water cut below 30%.

[0007] It can be seen that the lack of a low-cost, easy-to-install and high-precision measurement device suitable for oil well wellhead water cut measurement is the main obstacle to the development of oil well wellhead water cut on-line measurement technology at present.

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