RU2674046C1 - Complex device for surveying high-temperature wells - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to geophysical engineering, in particular for the oil and gas industry. Complex device for the study of high-temperature wells contains a main body with sensors of gamma-ray, coupler locator, pressure and temperature sensor placed sequentially from top to bottom with a working range up to +175 °C, as well as the lower body, connected to the main body by a high-temperature geophysical cable, with a temperature sensor located in it with a working range of up to +300 °C.

EFFECT: invention can be used to study oil and gas wells and allows to ensure the reliability of the measuring instruments of standard temperature performance in high-temperature wells, due to the possibility of controlling the temperature in the zone of location of devices with a sharp increase in temperature in the zone of injection of fuel and oxidizing composition into the reservoir.

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Description

The invention relates to geophysical engineering, in particular for the oil and gas industry, and can be used to study oil and gas wells.

When carrying out various types of thermal and thermogasochemical effects on the bottom-hole formation zone (hereinafter - PZP) and remote zones in order to increase oil recovery, of particular importance is the continuous measurement of the process physical parameters in the zone directly adjacent to the reaction zone and to the perforation holes of the casing string. The ranges of the measured parameters are as follows: pressure - up to 100 MPa; temperature - up to 300 ° С.

In addition to measuring pressure and temperature, to more accurately associate the instrument with a geological section, the gamma-ray exposure meter (scintillation detector) and magnetic coupling locator, which determines the location of the casing joint couplings, keyhole joints, or other possible ones, are also included in the downhole instrument sources of magnetic anomalies in the columns and the well.

A well-known integrated downhole tool containing gamma-ray sensors, couplings locator, pressure and temperature sensors located in its composite housing. The sensors are installed in the housing sequentially from top to bottom (Patent 2292571, publ. 2007).

This device is used to conduct geophysical studies in existing oil, gas and hydrothermal wells in order to optimize their operating modes, when constructing an inflow or absorption profile in wells in order to determine the flow rates of formations and interlayers and during repair and insulation works.

The disadvantage of this device is that the reliability of its operation is ensured under temperature conditions up to 150 ... 175 ° C.

At the same time, the need to measure high temperatures (up to 300 ° C and more) of the environment during the injection of fuel-oxidizing compositions (GOS) during thermal and thermochemical treatment of the bottom-hole formation zone necessitates the manufacture of a special device body to protect built-in sensors, wires, electronic circuit boards, etc. A typical solution for the implementation of such high-temperature devices is a Dewar vessel (thermostat). So, it is known a device for researching high-temperature wells, containing a Dewar vessel, which is a deep device with two cases placed one into the other, between which material with high heat-insulating properties is placed (Patent No. 2386809, publ. 2009).

In such devices, most sensors and electronic filling are placed in the inner case, only pressure and temperature receivers remain outside. The main disadvantages of these devices include the following:

1. A significant increase in the cost of the proposed solution (expertly up to 5 ... 8 times) in comparison with traditional options for descent devices.

2. The increase in size (diameter) and weight of the descent device due to increased metal consumption.

3. Increasing the complexity of maintenance and repair of the lander.

The problem to which the claimed invention is directed is to create an in-depth device that ensures the reliability of measuring instruments of standard temperature performance in high-temperature wells, by providing the ability to control the temperature in the area where these devices are located with a sharp increase in temperature in the injection zone of a fuel-oxidative composition (GOS) ) into the reservoir.

The problem is solved in that a comprehensive device for researching high-temperature wells, comprising a main body with gamma-ray logging sensors, coupler locator, pressure sensors and a temperature sensor with a working range up to + 175 ° C, is arranged in series with a lower case connected to the main body with a high-temperature geophysical cable with a temperature sensor located in it with an operating range up to + 300 ° С.

The implementation of a complex device with two components, including two housings connected by a high temperature cable, allows you to place standard temperature measuring instruments in a safe zone near the packer, and a remote temperature sensor directly in the zone of thermal or thermochemical impact on the formation, near the perforation holes of the casing.

The presence of a separate remote temperature sensor with an operating range of up to + 300 ° C allows you to record a temperature increase, including a sharp one, in the zone of GOS injection into the reservoir, and to take timely actions to reduce the temperature and prevent the downhole equipment from failing by pumping fresh water into perforation zone.

The invention is illustrated in the drawing, which shows a General view of an integrated device for the study of high-temperature wells.

The complex device for researching high-temperature wells contains a main (upper) body 2 mounted on a cable 1, with a gamma-ray sensor 3 (scintillation detector) placed therein, a coupler locator sensor 4, a pressure sensor 5 and a backup temperature sensor 6. The housing 2 is connected by a high-temperature geophysical cable 7 with the lower housing 8 of the device. A temperature sensor 9 (a platinum resistance thermometer) with an operating range of up to + 300 ° C, which is the main temperature sensor in this device, is installed in case 8.

The upper cable 1 is a geophysical single-core cable with a diameter of 5 6.35 mm. type KG1 × 0.75-30-200C or similar. The bottom cable 7 is preferably a three-core cable with a diameter of ∅4 mm. type MT 3 × 0.5-300 ° C or similar.

A set of basic measuring instruments, including sensors 3, 4, 5, 6, is built into the main (upper) case of the device, which during operation is located in the installation area of the packer (± 1 m.) - less heated space of the wellbore. Sensors 3, 4, 5, 6 are usually designed to operate in temperatures up to +175 (150) ° С and pressures up to 100 MPa.

The length of the cable 7, by means of which the lower case 8 of the device is connected to the upper case 2, is approximately 100 m, due to which the temperature sensor 9 is located in the zone of higher temperatures, near the perforation holes of the casing.

Before starting work on the injection into the well, for example, of combustible oxidizing compounds (GOS), the instrument assembly is lowered on the geophysical cable 1 into the tubing string to a predetermined depth so that the lower housing 8 is located in the area of the perforation holes of the casing string, and the upper case 2 is in the installation area of the packer. The operator, located in a specialized monitoring and control station (SKU), receives information about the temperature and pressure of the medium at the bottom.

After the start of GOS injection, the operator, using the built-in software, continuously records the temperature and pressure at the bottom in tabular and / or graphical form. When the temperature measured by the lower sensor 9 rises to + 100 ° С and above, the operator gives a command to stop the injection of GOS and the start of fresh water injection to cool the bottom.

Despite the fact that the sensor 9 is located approximately 100 m below the main sensors, exceeding the selected threshold temperature value (above 100 ° C) informs the operator about the rapid development of a chemical reaction with heat generation and the likelihood of a sharp increase in temperature in the area of the main body. To maintain the reliable operation of sensors 3, 4, 5, 6, temperature stabilization is required, for which the supply of GOS is stopped and water injection begins. When the temperature is equalized and stabilized at values below + 100 ° С, the GWK operator gives a command to stop the water injection and resume the GOS injection.

The descent and removal of this device from the well, even if there is pressure in the tubing string, can be performed using a special geophysical gateway, which is installed on the fountain.

Thus, the proposed two-component integrated device when performing thermogasochemical treatment of wells provides the following advantages:

1. The location of measuring instruments of standard temperature design in a safe zone near the packer and protecting them from failure in the event of a sharp increase in temperature in the zone of GOS injection into the reservoir.

2. The location in the most potentially heated zone of the bottom of the well of a separate remote temperature sensor with an operating range of up to + 300 ° C, which allows you to record a temperature increase, including a sharp one, and take steps to pump fresh water into the bottom to lower the temperature and prevent the exit of the downhole equipment out of order.

3. Does not require the use of expensive Dewar vessels (thermostats) to protect the instrument and electronic fillings from the effects of high temperatures, which reduces the cost, weight and size characteristics and simplifies maintenance.

Claims (1)

A comprehensive device for researching high-temperature wells, comprising a main body with gamma-ray logging sensors, coupler locator, pressure and temperature sensors with a working range of up to + 175 ° C, which is further characterized by a lower body connected to the main body with a high-temperature geophysical cable, with a temperature sensor placed in it with an operating range up to + 300 ° С.

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