RU2267604C1 - Mine oil field development method - Google Patents

Abstract

FIELD: oil production industry, particularly to develop high-viscosity oil field.

SUBSTANCE: method involves injecting steam in surface injection wells and producing oil through underground wells provided with temperature control sensors located at well heads. Optical sensors recording temperature of produced oil are used as the temperature control sensors. Data received from sensors is transmitted through optical cable to computer, which processes the obtained data. The computer generates control command to surface injection well controllers, which inject steam or stop steam injection into corresponding injection wells to provide uniform oil reservoir heating and oil production intensification.

EFFECT: simplified regulation of oil to be produced, increased technological and economical efficiency of surface and underground development and increased safety of work performance in mine excavations.

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Description

The present invention relates to the oil industry and may find application in the development of high-viscosity oil fields.

A known method of producing highly viscous oil using heat. The method includes drilling in the center of an element for developing vertical injection wells along which horizontal production wells are located. Vertical production wells are drilled along the horizontal wellbore, of which some of the wells are located in the immediate vicinity of the horizontal wellbore, right up to the intersection with it. The remaining producing vertical wells are located at a distance of 3-20 m from their faces to the horizontal wellbore. Steam is injected into vertical injection wells and vertical production wells. At the same time, oil is taken from production wells. After steam breakthrough into vertical production wells, the injection is stopped, while continuing to take oil. Wells after the cessation of injection of steam into them and a decrease in pressure at the wellhead are also used for oil recovery. Through these wells, oil is flowing to the horizontal shafts. In the event of a decrease in temperature and flow rates in the wells, the next steam injection cycle is carried out. After stabilization of the temperature in the bottom-hole zone of production wells at a level of 60-80 ° C, the periodic injection of steam into the wells is stopped and subsequently they are used for oil extraction (RF Patent No. 2046934, CL E 21 B 43/24, publ. 10.27.95) .

The known method has a low oil recovery and development rate, and the application of the method is associated with the expensive drilling of many additional wells.

Closest to the proposed invention in technical essence is a method of mine development of a highly viscous oil field, including drilling injection and producing wells, drilling a well from the surface to the center of the block being developed, drilling into an underground gallery of a control well, its equipment with a temperature sensor to control the temperature in the gallery, injecting steam to injection wells from the surface before the sharp increase in temperature in the gallery, the cessation of steam injection, the extraction of oil from producing wells until the oil production rate of the wells reaches the minimum cost-effective level, repeating the steam injection and oil extraction cycles, when the temperature in the underground gallery rises to 90 ° С, water is pumped through the control well, while oil is taken through the remaining wells from the surface to the maximum permissible water cut (RF Patent No. 2143060, class E 21 B 43/24, op. 1999.12.20 - prototype).

The known method allows you to adjust the temperature in the underground gallery and prevent steam breakthroughs in existing mine workings. However, the method requires drilling additional wells. The method is complex, low-tech, leads to increased water cut of the produced oil. Temperature control is achieved in a complex and irrational way by flooding the mine.

The proposed invention solves the problem of simplifying the regulation of the temperature of the produced oil, increasing the technological and economic efficiency of thermal mine development using an underground-surface system, as well as the safety of mining operations.

The problem is solved in that in the method of mine development of a highly viscous oil field, including mining, drilling surface injection and underground production and steam distribution wells, equipping sensors for monitoring the temperature of underground wells, injecting steam into surface injection wells, stopping steam injection at higher temperatures and the selection of oil from underground wells, according to the invention, equipment with sensors for monitoring temperature is carried out at the mouths of underground wells, as sensors, optical sensors are used to record the temperature of the produced fluid, information from the sensors is transmitted via an optical cable to a computer in which the received information is processed, control commands are transmitted from the computer to control devices of surface injection wells that supply or interrupt steam supply to the corresponding injection wells wells to ensure uniform heating of the oil reservoir and intensification of oil production.

The features of the invention are:

1. mining;

2. Drilling of surface injection and underground production and steam distribution wells;

3. equipment with sensors for monitoring the temperature of underground wells;

4. steam injection into surface injection wells;

5. cessation of steam injection with increasing temperature;

6. selection of oil from underground wells;

7. equipment with sensors for monitoring temperature at the mouths of underground wells;

8. use as sensors optical sensors that record the temperature of the produced fluid;

9. transmitting information from sensors via optical cable to a computer;

10. processing the information received;

11. transfer of control commands from a computer to control devices of surface injection wells;

12. supply or interruption of steam supply to the respective injection wells to ensure uniform heating of the oil reservoir and intensification of oil production.

Signs 1-6 are common with the prototype, signs 7-12 are the essential distinguishing features of the invention.

SUMMARY OF THE INVENTION

During mine development of a highly viscous oil field, difficulties arise in aligning the temperature of the produced fluid (oil) at the mouths of different producing wells. Equalizing the temperature of the produced fluid in underground wells contributes to the uniform development of reserves. Regulation of the temperature of the produced fluid in underground wells by regulating the injection of steam through surface injection wells makes it possible to switch to an uninhabited technology for oil production, with the absence of maintenance personnel in the mines providing oil production. This allows you to increase the heating temperature of the reservoir and produced oil and thereby increase oil recovery and the rate of development of the field.

The proposed method solves the problem of simplifying the regulation of the temperature of the produced oil, increasing the technological and economic efficiency of the underground-surface thermal mine system, the safety of mining operations and the transition to uninhabited technology. The problem is solved as follows.

During the mine development of a highly viscous oil field, mining is carried out at the bottom of the reservoir or below it. Injection wells are drilled from the surface. Steam distribution wells are drilled into the bottomhole zones of surface injection wells from an underground gallery. Between the steam distribution wells from the mine workings are drilling production wells. Steam is pumped from the surface into injection wells and the formation is heated. In a mine, liquid is taken from underground wells and pumped through an oil pipeline to a surface or an underground central oil collection point. To measure the temperature of the produced fluid, the wellheads are equipped with sensors to monitor the temperature of the produced fluid. As sensors use optical sensors that record the temperature of the produced fluid. Information from the sensors is transmitted via an optical fiber cable to a computer located on the surface. The computer processes the received information. From the computer, control commands are transferred to control devices of surface injection wells, which supply or interrupt steam supply to the corresponding surface injection wells to ensure uniform heating of the oil reservoir and intensification of oil production.

The surface injection wells are tied with a control system that provides for connecting and disconnecting them from the injection system. Underground wells are tied with sensors to measure the temperature of the produced fluid. If the temperature of the produced fluid rises above the established well above the established limits, the surface injection wells having hydrodynamic connection with this underground well are disconnected from the coolant injection system. As a result, the temperature of the produced fluid in the underground well is normalized. In mining, only optical sensors are installed that record the temperature of the produced fluid. They do not require maintenance, and therefore, the operation of mining can be transferred to a closed (uninhabited) mode. The uninhabited operating regime of the mine workings, from which underground wells have been drilled, makes it possible to increase the temperature in them to 100 ° C, which leads to an increase in the average temperature of the formation and the rate of oil production. Sensors that record the temperature of the liquid are a mirror that is mounted on a bimetallic plate. The mirror and the bimetal plate are in a sealed enclosure. The sensor is attached to the mouth of an underground well. The produced fluid heats the surface of the well. Depending on the temperature, the bimetallic plate bends. A light signal is supplied to the mirror via an optical fiber cable, and the reflected signal is transmitted to a second optical fiber cable, through which it is transmitted to a digitizer connected to a computer located on the surface. The signal is digitized in accordance with the power of the reflected signal. The received information is displayed on a computer screen. Using the program, the work of surface injection wells is controlled. A variant is possible when the operation of the surface injection wells is controlled by the oil mine dispatcher. The use of optical sensors and fiber-optic communication provides complete fire safety in the mine workings when using these devices.

The claimed method provides automatic control of the coolant pumping into the oil reservoir depending on the temperature of the produced fluid in underground wells, the deserted operation of the mine workings from which underground wells are drilled, allows to increase the temperature in these workings to 100 ° C, which ensures an increase in the average temperature of the formation and, accordingly, the rate of oil recovery, increases the safety of work in oil mines.

The use of optical systems for recording temperature and transmitting information ensures complete fire safety when used in mine conditions, and they do not require any maintenance, which allows switching to closed operation of the developed sites.

Figure 1 shows the plot of the field being developed and the general scheme for controlling the operation of wells. Figure 2 (section aa) presents a diagram of the strapping system registration temperature of the produced fluid in underground wells. Figure 3 shows the principle device of the temperature sensor.

Temperature sensors 4 are installed at the mouths of underground production and steam distribution wells 3 at a site of a highly viscous oil or natural bitumen 1, equipped for thermal mine development using an underground-surface system, in the mine workings 2 at the mouths of underground production and steam distribution wells 4. A signal from a constant power source 5 optical fiber cable 6. In the temperature sensor 4, the light signal enters the mirror 7, which is mounted on a bimetallic plate 8. Depending on the surface temperature of the well zhiny which is determined by the temperature of the produced fluid, the bimetallic plate 8 is bent, so the reflected light signal entering the receiving optical fiber cable 9 has a varying power depending on the bending of the bimetallic plate 8.

On the optical fiber cable 9, the reflected signal is supplied to the digitizer 10, which translates the signal into a temperature value corresponding to its power. The digitized signal through the communication system 11 enters the computer 12, where the program performs its processing. Information on the temperature of the produced fluid in underground wells is displayed on the computer display 12.

After software processing of the input signal to the computer 12, a control command is issued via the communication channel 13 to the digitizer 10 and then through the communication channel 14 to devices (not shown in Fig.) That open or. closing of surface injection wells 15. Opening or closing of surface injection wells 15 may also be carried out by command of the oil mine dispatcher.

1-3, the arrows indicate the transmission directions of the optical signal.

Concrete example

A section of the Yaregskoye field of high viscosity oil is being developed with the following characteristics: depth - 200 m, initial reservoir temperature - 8 ° C, reservoir pressure - 0.1 MPa, reservoir thickness - 26 m, reservoir porosity - 26%, permeability - 3 μm ² , oil saturation - 87%, oil viscosity - 12000 MPa · s, oil density - 933 kg / m ³ .

At development site 1, surface injection wells 15 are drilled along the border with a pitch of 50 m and underground (production and steam distribution) wells 3. Steam distribution wells are drilled into the bottomhole zones of injection wells 15 from the underground gallery 2. Between the distribution wells from underground gallery 2, production wells are drilled. The distance between the faces of underground wells 3 is 25 m. Steam is pumped from the surface at a flow rate of 200 tons / day. into surface injection wells 15 and warm the formation. The produced liquid from underground wells 3 is discharged into an oil gathering groove constructed in a mine 2, which is transported by gravity to a local collection point, from where it is pumped through an oil pipeline to the surface or to an underground central oil collection point.

Temperature sensors 4 are installed at the mouths of underground wells 3. Temperature sensors 4 are supplied with a signal from a constant power light source 5 via an optical fiber cable 6. In a temperature sensor 4, a light signal enters a mirror 7, which is mounted on a bimetal plate 8. Depending on the temperature the surface of the well, which is determined by the temperature of the produced fluid, the bimetallic plate 8 is bent, so the reflected light signal incident on the receiving optical fiber 9 has a varying power depending on the bending of the bimetallic plate 8.

On the optical fiber cable 9, the reflected signal is supplied to the digitizer 10, which, depending on the power of the reflected signal, converts the signal to a temperature value corresponding to its power. The digitized signal through the communication system 11 enters the computer 12, where the program performs its processing. Information on the temperature of the produced fluid in underground wells is displayed on the computer display 12.

For each underground well, the oil geologist sets the temperature limits for the produced fluid, which are determined by the uniformity of the heating of the reservoir and the intensification of oil production in the area. Each surface injection well 15 has a hydrodynamic connection with a particular circle of underground wells. By changing the volumes of coolant injection through the surface injection wells 15, the oil layer is uniformly heated and oil production is intensified in the area.

After software processing the incoming signal to the computer, a control command is issued via communication channel 13 to digitizer 10 and then via communication channel 14 to devices (not shown in Fig.) That open or close surface injection wells 15. Opening or closing surface injection wells 15 can also performed at the command of the oil mine dispatcher.

The proposed method allows you to switch to a deserted mine oil production technology. When withdrawing maintenance personnel from mine 2, the temperature of the mine atmosphere in it can be increased to 100 ° C instead of 26 ° C when it is operated with maintenance personnel. This allows you to significantly increase the average temperature of the reservoir to 100 ° C or more, and accordingly increase the rate of oil recovery and increase the oil recovery factor (CIF) to 0.7% instead of 0.54 achieved at the Yaregskoye field. Compared with the prototype, the development time of a field site (to a recovery factor = 0.54) is reduced from 8 to 6 years. Due to the fiber optic technology, work safety is ensured. The cost of extracted oil is reduced by 8%.

Claims (1)

The method of mine development of a highly viscous oil field, including mining, drilling surface injection wells of underground production and steam distribution wells, equipping sensors for monitoring the temperature of underground wells, injecting steam into surface injection wells, stopping steam injection at elevated temperatures, and taking oil from underground wells, characterized in that the equipment with sensors for temperature control is carried out at the mouths of underground wells, as sensors and optical sensors are used to record the temperature of the produced fluid, information from the sensors is transmitted via an optical cable to a computer in which the received information is processed, control commands are transmitted from the computer to the control devices of surface injection wells, which supply or interrupt steam supply to the corresponding injection wells for ensuring uniform heating of the oil reservoir and intensification of oil production.

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