RU2498059C1 - Method of oil lifting or thermal formation treatment and device for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: method includes pumping of working agent at high temperature and in vapour state through respective tubing to working chamber with cyclic product lifting through respective tubing and main injection valve to the ground level and extraction of product to working chamber through injection valve from downhole space with periodical injection of working agent through downhole space to formation with shutting off cyclic product uplifting and its extraction to working chamber. Injection of working agent is made to stratum with closing of tubing at the wellhead for lifted fluid passing through displacement chamber and auxiliary injection valve set to a bigger opening pressure than opening pressure of the main injection valve. Cyclic lifting of product from the stratum and its extraction to working chamber are made at continuous delivery of working agent to working chamber through choke that provides non-linear change and consumption limitation of working agent delivered to condensation chamber at hydraulic relay opening to ensure pressure drop in the chamber up to bottomhole pressure and receipt of product from the stratum through suction valve to the chamber.EFFECT: increasing efficiency of wells and equipment use during development of deposits of oil and natural bitumen with high viscosity by thermal treatment methods.2 cl, 1 dwg

Description

The group of inventions relates to the oil industry, in particular to technical means for heat treatment of the reservoir, as well as to methods and technical means for lifting products from wells with ultra-viscous oil and natural bitumen.

In particular, a pneumatic substitution air lift is known (A.S. No. 1242648, IPC F04F 1/08, publ. 07/07/86, Bull. No. 25), including a replacement chamber, water and air supply pipes, discharge and suction valves.

The method carried out by means of a water lift includes lowering the water inlet on the air inlet pipe into the well, lowering the water inlet in the air inlet pipe, supporting the bottom of the water inlet chamber, flushing the filter and the aquifer, raising the water inlet below the upper boundary of the aquifer with water being sucked into the well fluid chamber, air supply through the air supply pipe with the displacement of liquid from the chamber and lifting it to the surface through the water pipe, the release of compressed air from the air pipe with suction of the well fluid into the chamber, cyclic repetition of the cycles of displacement and injection of the well fluid.

The disadvantages of this device are the need for periodic movement of the device in the face to alternate the impact on the reservoir and displace fluid from the face, which requires additional tripping and depressurization of the wellhead, which can additionally lead to the exit of air from the high-pressure chamber in the well formed during the previous treatment of the formation, on the surface, and pose a threat to the safety of personnel and the safety of ground equipment, or to unplanned m downtime of the well and equipment in order to wait for the pressure drop in the well, as well as the inability to operate the device in a horizontal position. At the same time, to ensure operation in the automatic pumping mode, the water lift must be equipped with a special system of cyclic supply and release of compressed air, while the elastic properties of the air are not used to carry out the liquid pumping operation, the exhaust air is released into the atmosphere, which reduces the efficiency of the water lift.

The closest to the achieved result is the installation for lifting highly viscous liquids (AS No. 800418, IPC F04B 47/00, F04F 1/00, publ. 30.01.81 Bull. No. 4) mainly from a well containing a displacement chamber, pipe columns for the passage of the liquid to be lifted and the working agent to be supplied, as well as a suction and discharge valves installed in the respective cavities, the installation being provided with a housing, upper and lower seats installed at its ends, in the last of which there is a receiving valve, and a cross-flow coupling from passage channels installed in the upper saddle, with one channel of the coupling hydraulically in communication with the chamber, and the other with the discharge cavity and the pipe string for the passage of the lifted fluid.

The method implemented by the installation consists in alternating heat treatment of the bottom-hole formation zone with steam and pumping out products using a device containing a housing, receiving and discharge valves, a cross-flow coupling, an expulsion chamber, while the pre-filling of the displacement chamber with the pumped-out well product is carried out after the steam supply is stopped into the device due to its complete condensation, and the displacement of products with a fresh portion of steam when resuming its supply to the device.

A significant drawback of this closest analogue is that to switch the operating modes of the installation (alternating heat treatment of the bottom-hole formation zone with steam and pumping out the product) using the pump intake valve, it is necessary to raise or lower the steam supply column, which leads to a depressurization of the wellhead and high steam output pressure from the steam chamber formed in the well formation during the previous heat treatment to the surface, cooling the bottom-hole zone of the formation and, as shown by temporary experience poses a real threat to the safety of personnel and the safety of ground equipment and, as a result, often to the inability to use the unit for its intended purpose or unplanned downtime of the well and equipment to wait for a pressure drop in the well, as well as to the need for additional heat energy to heat the bottom hole formation zones to the initial temperature. The disadvantages of this analogue are the need (for organizing a continuous cyclic steam supply) to supply the device with an additional special system controlled by sensors that indicate the end of steam condensation in the displacement chamber and the fact that the elastic properties of the steam are not used to perform liquid pumping, which reduces the efficiency devices.

An object of the invention is to increase the efficiency of the use of wells and equipment when developing deposits of highly viscous oil and natural bitumen by thermal methods based on reducing operating costs by automating and expanding the functionality of the equipment with constant steam injection, increasing the operational reliability of downhole equipment as a result of refusal from an electromechanical drive, improving the safe working conditions at the installation by eliminating the need for depressurization ation wellhead, improvement conversion into useful work expended energy extraction oil by the most complete and rational use of energy supplied steam.

The stated technical problem is solved by a method for raising oil or thermal effects on the formation, including continuous and continuous during normal operation of the well in this way, the injection of the working agent in the vapor state through the corresponding pipe string into the working chamber with the selection of formation products into the working chamber through the suction valves from the bottom wells, alternating with the rise of formation products along the corresponding pipe string through the main pressure relief valve type day surface, or periodic injection of working fluid through the working chamber and the space in the downhole formation sampling to disconnect the working chamber and lifting the product reservoir to the surface.

What is new is that the injection of the working agent is carried out into the formation with overlapping at the wellhead of the pipe string for the passage of the liquid to be lifted through the working chamber and an additional discharge valve tuned to a setting pressure to open greater than a setting pressure to open the main discharge valve, and cyclic lifts formation production and its selection in the working chamber is carried out with a constant supply of the working agent in the displacement chamber through the throttle, providing non-linear change and ogre the decrease in the flow rate of the supplied working agent entering the condensation chamber when the pressure in the chamber drops as a result of the opening of the hydraulic relay to the pressure at the bottom of the well to ensure the formation production through the suction valve into the chamber.

The problem is solved by a device for lifting oil or heat exposure to a formation containing a displacement chamber, pipe strings for passing the liquid to be lifted and supplying a high-temperature working agent in a vapor state, as well as a receiving valve in communication with the downhole space and a pressure valve in communication with the pipe string for passage of the lifted fluid.

What is new is that the main discharge valve is set to the opening pressure, which is determined by the design pressure in the pipe string for supplying the high-temperature working agent minus the back pressure in the pipe string for the passage of the fluid to be raised, and the working chamber is equipped with an additional valve in communication with the downhole space and made with the ability to open at a pressure higher than the pressure setting of the opening of the main discharge valve, and a hydraulic relay communicated with intracranial with a living space and made with the possibility of opening when filling the working chamber with a working agent and closing when filling the working chamber with formation products, as well as a throttle connected to the pipe string for supplying the working agent and providing non-linear change and limitation of the flow rate of the supplied working agent entering the working chamber, when the pressure drops to the pressure at the bottom of the well when opening the hydraulic relay to ensure the flow of formation products through the inlet valve into the chamber with continuous giving the working agent in the same chamber, wherein the time delay switch intervals are determined: in the open position - working chamber filling time reservoir production, in the closed position - working chamber filling time agent.

The drawing shows a diagram of a device for lifting oil or thermal effects on the reservoir.

The device does not have moving parts and includes: a working chamber 1, a block of suction valves 2, a block of pressure valves 3. A pipe string for supplying a working agent in a vapor state is connected to the working chamber 1 — steam pipe 4 and a pipe string for passage of the fluid to be lifted — flow line 5, an additional valve 6 and a hydraulic relay 7. A high-temperature agent in a vapor state (for example: water vapor) enters the working chamber 1 through a steam line 4 through a quick-connect 8 and a throttle 9.

Additional valve 6 has a detachable connection for connecting a pipe of the required length to deliver steam to the desired location of the face (not shown in the drawing). When steam is delivered to the formation, the flow line 5 is closed on the day surface using a standard locking device.

To warm up the formation (not shown in the drawing), the flow line 5 is closed at the wellhead (not shown in the drawing), after which the steam is supplied through the steam line 4 through a quick-connect 8, throttle 9, chamber 1 and additional valve 6 to the downhole space (to the drawing) . not shown) and further into the reservoir.

To pump liquid from the bottom, the flow line 5 is opened, the additional valve 6 is automatically closed until the next injection of the working agent into the reservoir, since it is configured to open at a pressure higher than the opening pressure of the discharge valves 3. The steam is injected into the working chamber 1 through a steam line 4 through a quick disconnect connection 8, throttle 9, in this case three successive processes are cyclically performed: injection, absorption and heat recovery in the liquid.

The working agent entering the working chamber 1 exchanges heat with the liquid coming from the bottom to an equilibrium temperature, after which a vapor phase forms in the working chamber 1, and the pressure in the chamber rises to the discharge pressure, steam expanding to the pressure in the flow line 5 performs a useful job of pumping fluid through the discharge valves 3 into the flow line 5 due to the elastic properties of the steam. After pumping fluid from the working chamber 1, the hydraulic relay 7 switches to the normally open position and hydraulically communicates the working chamber 1 with the bottom of the well (not shown in the drawing), which leads to a sharp decrease in pressure in the chamber 1 and entails a non-linear change and restriction of steam flow through throttle 9. As a result of equalizing the pressure in the chamber 1 and at the bottom of the well, the check valve type 2 opens, the liquid phase of the production of the formation from the annulus under the action of gravitational forces and reservoir pressure enters the chamber 1 through the receiving valve 2 and relay 7. The throttle 9 is designed to nonlinearly change and limit the flow rate of the supplied working agent entering the condensation chamber 1 with a sharp decrease in pressure when opening the hydraulic relay 7, which does not allow compensating for the discharge in the chamber 1 with the discharge pressure steam, and contributes to its complete condensation as a result of heat and mass transfer with the reservoir fluid, which also contributes to a more intensive absorption of well products from the bottom and intensification of heat and assoobmena between steam and production wells. The exposure time of the relay 7 in the normally open position is determined by the volume of the working chamber 1 and the time of filling the chamber 1 with liquid. After completion of the process of heat and mass transfer between steam and liquid and simultaneous filling of chamber 1 with formation fluid to the level set when setting relay 7, relay 7 switches to the normally closed position, the pressure in chamber 1 increases non-linearly due to the appearance of the vapor phase of the working agent, and closes the receiving valve 2, the vapor pressure after the throttle 9 increases nonlinearly, the pressure in the chamber 1 reaches the discharge pressure and the products through the valves 3 and the flow line 5 rises to the surface. After completion of the pumping process and at the same time filling chamber 1 with a vaporous working agent to the level set during relay 7 setting, relay 7 switches to the normally open position. With further and uninterrupted supply of steam through the steam line to chamber 1, the installation will continue to work in an automatically continuing cyclic mode.

For additional injection of the working agent into the formation, the flow line 5 is closed at the mouth, after which the steam is supplied through the steam line 4 through a quick-connect 8, throttle 9, chamber 1 and additional valve 6 to the intra-borehole space and then to the formation. To resume the working cycle of raising the well’s production to the surface, just open the flow line 5. Any switching of the device’s operating modes occurs without depressurization of the wellhead.

Thus, the proposed method and device for lifting oil or thermal stimulation of the formation allows us to solve the technical problem of increasing the efficiency of the use of wells and equipment when developing deposits of high viscosity oil and natural bitumen by thermal methods.

Reducing operating costs is achieved by the ability to perform two functions with one device in an automatic mode, namely, steam injection into the formation and pumping of products to the surface, which eliminates the need for tripping operations to change operating modes and technological operations.

The reduction in operating costs is also achieved by increasing the operational reliability of downhole equipment, namely by increasing the duration of uptime due to the lack of design of the device:

- moving components and intense wear as a result of friction under conditions of increased solids content in the pumped liquid;

- submersible electric drive and electrical parts subject to overheating;

- a rod drive subject to loss of stability and a decrease in cyclic strength in a bent well profile;

- causes of equipment failures in the face of the possibility of formation of steam plugs at the bottom.

The reduction in operating costs is also achieved due to the rational use of the energy of the working agent, namely by eliminating the cases of forced ventilation of the well in the absence of tripping operations, and also mainly through the use of effective thermodynamic processes to convert external and latent heat of steam into useful work to raise well production on a day surface without a mechanical drive.

At the same time, labor costs for the repeated production of underground repairs, losses due to oil shortages caused by downtime for repairs and associated expenses for transportation and relocation of equipment for hoisting operations are excluded from the cost of operation, as a result, the useful yield of wells and equipment is improved, and safe working conditions are improved due to the lack of the possibility of uncontrolled release of steam.

The present invention improves the efficiency of the use of wells and equipment in the development of deposits of highly viscous oil and natural bitumen by thermal methods on the basis of reducing operating costs by automating continuous steam injection and expanding the functionality of the equipment, increasing the uptime of downhole equipment due to the rejection of the electromechanical drive, increasing the level safety work at the well by eliminating the need for depressurization of the mouth important, increasing the efficiency of the device by improving the conversion into useful work of energy spent on oil production through a more complete and efficient use of steam energy.

Claims (2)

1. A method of raising oil or heat exposure to a formation, including injecting a high-temperature working agent in a vapor state through an appropriate pipe string into a working chamber with cyclic lifting of the formation products through a corresponding pipe string through the main discharge valve to the surface and taking off the formation products into the working chamber through receiving valves from the downhole space, with periodic injection of the working agent through the downhole space into the reservoir with cyclic the production of the formation and its selection into the working chamber, characterized in that the injection of the working agent into the formation is performed with overlapping at the wellhead of the pipe string for the passage of the liquid to be raised through the working chamber and an additional pressure valve tuned to the setting pressure to open greater than the setting pressure to open the main discharge valve, and the cyclical lifting of the formation and its selection in the working chamber is carried out with a constant supply of the working agent in the displacement chamber through the core a wiper providing a nonlinear change and limiting the flow rate of the supplied working agent entering the condensation chamber when the hydraulic relay is opened to reduce the pressure in the chamber to the pressure at the bottom of the well and to ensure the formation production flows through the suction valve into the chamber. 2. A device for lifting oil or heat exposure to a formation containing a displacement chamber, pipe columns for the passage of the liquid to be raised and supplying a high-temperature working agent in a vapor state, as well as a receiving valve in communication with the downhole space and a main discharge valve in communication with the pipe string for the passage of the fluid to be lifted, characterized in that the main discharge valve is set to the opening pressure, which is determined by the design pressure in the pipe string to supply high the working agent minus the back pressure in the pipe string for the passage of the fluid to be lifted, and the working chamber is equipped with an additional valve in communication with the downhole space and configured to open at a pressure higher than the setting pressure to open the main discharge valve, and a hydraulic relay in communication with the downhole space and made with the possibility of opening when filling the working chamber with a working agent and closing when filling the working chamber with products th formation, as well as a throttle connected to the pipe string for supplying the working agent and providing non-linear change and limitation of the flow rate of the supplied working agent entering the condensation chamber when opening the hydraulic relay to ensure that the pressure in the chamber is reduced to the pressure at the bottom of the well and the production of the formation through the suction valve into the chamber with a continuous supply of the working agent into the chamber, and the relay holding time intervals are determined: in the open position, by the filling time of the working chamber They are the products of the reservoir, in the closed position - the time of filling the chamber with a working agent.

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