RU116893U1 - Borehole device for measuring the optical properties of oil on the wellhead - Google Patents

Abstract

A downhole device for measuring the optical properties of oil at the wellhead, including a well flow line and containing an inlet and a discharge unit, an analog-to-digital converter, an electronic data storage and transmission unit, a thermostatting unit and a measuring photometric unit with a light source, a monochromator, a photometric sensor and a sample holder, characterized in that the measuring photometric unit contains a sample holder of variable cross-section with the possibility of its automatic change depending on the thickness of the layer of the oil under study, and the light source is made with the possibility of obtaining a light beam of a given wavelength and the possibility of examining oil in the required spectral range depending on its density in the visible, near infrared, and infrared zones in the field.

Description

The utility model relates to the oil industry and can be used in the operation of wells, namely when conducting studies of the physical properties of oil produced by optical methods in the field and can also be used to study the optical properties of any liquid media in other industries.

Prerequisites for creating a utility model.

Analysis of the current level of technology in this field showed the following.

Depending on the tasks performed, oil wells are equipped with intelligent systems for monitoring the hydrodynamic and geophysical characteristics of exploited reservoirs and monitoring equipment in real time to effectively manage field development. In this case, the wells are equipped with measuring instruments, transmitting devices, computing systems that are connected by an electronic database, and the design of which is determined by the purpose of an intelligent system, in particular, based on the determination of the optical properties of the produced oil, including high-viscosity oil and natural bitumen in field conditions.

A known method for optical research of wells containing equipment, including a sensor, a power supply unit and a ground recording device (Authors. St. USSR No. 192712, Cl. E21B 47/00 "Method for optical research of wells").

The disadvantage of this method is the impossibility of its application in the study of the properties of oil produced by optical methods, since the equipment is used in the study of the geological section of rocks that make up the well.

There is a method for studying well sections based on studying the intensity of radiation from a source. The downhole device includes a window, a modulator, an optical filter, an optical system, an infrared receiver and an electronic unit for transmitting a signal through a communication channel to a recording device (Aut. St. USSR No. 204958, class. E21B 47/00 “Method for studying sections wells ").

The disadvantage of this device is that it is used to study the walls of the well in order to obtain information about the section of the well, the device is not applicable to study the physical properties of the produced oil.

The purpose of the utility model is to obtain real-time reliable data on the properties of the oil produced for its study, and the ability to control changes in the properties of reservoirs and fluids based on the information obtained in the field.

This goal is achieved by using the inventive downhole device for measuring the optical properties of oil at the wellhead.

The downhole device for measuring the optical properties of oil at the wellhead is installed on the flow line of the well and contains a receiving and flow unit, an analog-to-digital converter, an electronic data storage and transmission unit, a temperature control unit and a measuring photometric unit with a light source, a monochromator, a photometric sensor and sample holder.

New is that the measuring photometric unit is equipped with a sample holder of variable cross-section with the possibility of automatically changing the cross-section depending on the thickness of the layer of the studied oil.

New is the fact that the light source is made with the possibility of obtaining a light beam of a given wavelength and the ability to study oil in the necessary spectral range depending on its density in the visible, near infrared, and infrared zones in field conditions.

The proposed technical solution is illustrated by the drawing.

Figure 1 presents a General view of a downhole device for measuring the optical properties of oil at the wellhead.

The circuit (figure 1) includes six main blocks. These are receiving 1, measuring photometric 2 and flow-out 3 blocks, analog-to-digital converter (ADC) 4, electronic data storage and transmission unit 5 and thermostatic control unit 6.

The measuring photometric unit 2 contains a light source 7, a monochromator 8, a sample holder 9 and a photometric sensor 10.

The downhole device for measuring the optical properties of oil at the wellhead also includes a flow line 11, and the flow unit 3 includes a tap for sampling 12 with a tap 13. A water absorber 14 is located in the receiving unit 1.

Downhole device for measuring the optical properties of oil at the wellhead works as follows.

The downhole device is installed at the wellhead (not indicated in FIG.).

According to the scheme in figure 1, the production from the well enters the receiving unit 1, passes through the water absorber 14 into the measuring photometric unit 2, where oil is studied and from there along the flow line 11 through the flow line 3 into the flow line of the well (not shown in Fig. )

The study of the optical properties of oil is preceded by thorough dehydration, since even a small amount of water can distort the measurement. For this purpose, water absorbers 14 are used, which can be stationary or removable devices in the form of hydrophobic membranes or water adsorbents.

Less than a gram of dehydrated oil is required to determine the light absorption coefficient (CSP). The measuring photometric unit 2 includes a light source 7, the light of which passes through a monochromator 8 to obtain a light beam of a given wavelength. The studied dehydrated oil enters the sample holder 9 of variable cross section. Monochromatic light passing through dehydrated oil is partially reflected and partially absorbed. The intensity of the transmitted light beam is measured by a photometric sensor 10. The spectrum of the used electromagnetic radiation is of fundamental importance (in laboratory conditions, solutions of oil in organic solvents are studied). Oils with a low density usually have lower light absorption coefficients and therefore they can be studied without dilution with organic solvents in the spectral range of 400-900 nm.

Oil with a high density and viscosity must be examined in the visible, near infrared and infrared. Optimal is the presence of a light source 7 in a wide range of electromagnetic radiation and an automated selection by the downhole device of the most suitable spectral range for the oil under study both in test and in operating mode. Of fundamental importance is the presence of a sample holder 9 of variable cross-section (for laboratory measurements, the cross-section corresponds to the width of the cell in which the solution is studied) since the thickness of the layer of the studied oil affects the accuracy of determining the optical properties. Optimal is the use of a downhole device with automatic detection and changing the cross section of the sample holder 9, to determine the light absorption coefficient of the studied oil.

Thermostatic control unit 6 is necessary to maintain a standard measurement temperature or determine the current temperature of the test oil in order to calculate corrections for the influence of temperature.

To control the measurements, a crane 13 is provided for periodic sampling of oil in order to conduct control laboratory studies of its optical properties in a test mode of operation of the equipment. The purpose of the ADC 4 is to translate the analogous results of measurements of the properties of the produced oil into digital form for long-term storage and transmission by wire or wireless methods to the electronic database for storing and transmitting data 5, which contains constantly updated information on the performance of wells and other indicators of field development.

The software of the borehole device for measuring the optical properties of oil at the wellhead provides the choice of the most optimal spectrum of electromagnetic radiation, automatic determination of the cross section of the sample holder of the most suitable diameter for determining the light absorption coefficient of the studied oil, and automated approximation of the measured properties of oil in the selected spectral range with the performance of the wells.

The proposed schematic diagram of a borehole device for measuring the optical properties of oil at the wellhead provides the ability to automatically record the optical parameters of the produced oil, including high viscosity oil and natural bitumen in a given wavelength range and automatically approximate these parameters with geological and field data to calculate reservoirs and reservoir properties or water cut products in the field.

The inventive utility model makes it possible to conduct better and more reliable studies in wells and across the entire productive horizon in the process of developing a field and, therefore, the possibility of exercising better control over field development.

Complementing existing intelligent systems, this downhole device can significantly improve management of an oil field’s development, including obtaining real-time information about reserves in real time, continuously monitoring, and monitoring changes in the properties of reservoirs and fluids during field development.

Claims (1)

A downhole device for measuring the optical properties of oil at the wellhead, including a flow line of a well and containing a receiving and flow unit, an analog-to-digital converter, an electronic data storage and transmission unit, a temperature control unit and a measuring photometric unit with a light source, a monochromator, a photometric sensor and sample holder, characterized in that the measuring photometric unit contains a sample holder of variable cross-section with the possibility of its automatic change depending on the thickness of the layer of the studied oil, and the light source is made with the possibility of obtaining a light beam of a given wavelength and the ability to study oil in the necessary spectral range depending on its density in the visible, near infrared, and infrared zones in the field.