Disclosure of Invention
The application aims to solve the problems in the development of the ultra-deep fracture-cavity reservoir oil well, and provides an enhanced water injection oil extraction device and method for the ultra-deep fracture-cavity reservoir oil well, which can solve the problem that the traditional water injection mode is high in development cost.
The application relates to an enhanced water injection and oil extraction device for an ultra-deep fracture-cavity reservoir oil well, which comprises an oil pipe, a water injection and oil extraction conversion valve, a packer, an underground water injection pump and a sleeve; the casing is arranged in an oil well, the bottom end of the oil pipe is inserted into the casing, the top end of the oil pipe is communicated with external oil extraction equipment, an annulus is formed between the oil pipe and the casing, and the packer is arranged in the annulus and sleeved on the outer peripheral side of the oil pipe; the sleeve is communicated with the high-pressure water layer through a perforation, the pipe part of the oil pipe, which is opposite to the perforation, is an anti-erosion pipe part, the water injection and oil extraction conversion valve is arranged in the oil pipe, the water injection and oil extraction conversion valve controls the connection or disconnection between the interior of the oil pipe and the perforation, the water injection and oil extraction conversion valve is positioned above the high-pressure water layer, and the packer is positioned below the high-pressure water layer; and the oil pipe is also internally provided with a downhole water injection pump positioned below the water injection and oil extraction conversion valve.
The water injection and oil extraction conversion valve can comprise a water injection hole for communicating the inside and the outside of the oil pipe and a plugging mechanism for plugging the water injection hole; when the packer is set, the peripheral side surface of the packer is tightly attached to the inner wall surface of the sleeve; and an oil extraction pump is also arranged in the oil pipe, and the underground water injection pump and the oil extraction pump are arranged at intervals from top to bottom.
The application also relates to an enhanced water injection oil extraction method of the ultra-deep fracture-cavity reservoir oil well, which comprises the following steps,
step a, a well completion pipe string and a casing are put in;
b, keeping the packer in the casing, wherein the packer is positioned below the high-pressure water layer, then starting up the well completion pipe string, and after the process of starting up the well completion pipe string, communicating the high-pressure water layer with the casing at the corresponding position through a perforation;
c, discharging the oil pipe, enabling a water injection and oil extraction conversion valve of the oil pipe to be positioned above the packer, enabling the erosion-resistant pipe part to face the perforation, and enabling the water injection and oil extraction conversion valve to be communicated with the perforation;
d, setting the packer to enable the packer to be tightly attached to the sleeve to form sealing;
step e, closing the water injection oil extraction conversion valve, closing the communication between the oil pipe and the annulus at the moment, and starting oil extraction;
f, after the jet of the oil well is stopped, opening a water injection and oil extraction conversion valve to communicate the jet hole with the oil pipe, forming self-flowing water injection between the high-pressure water layer and the oil pipe, and then starting a downhole water injection pump to enhance water injection;
step g, observing the pressure of the well mouth, closing a water injection oil extraction conversion valve and a water injection pump in the well after determining that the pressure of the well mouth does not rise or the water absorption stops in the well, cutting off a channel between a high-pressure water layer and an oil pipe, and closing the well;
step h, when the pressure of the well head reaches a preset value, starting the oil extraction pump and starting oil extraction again;
and j, repeating the step f, the step g and the step h, and continuing the self-flow water injection and oil extraction work.
The reinforcing water injection oil recovery device of ultra-deep fracture-cavity type reservoir oil well of this application can utilize oil well self to bore the high-pressure water layer and the water injection pump in pit that meet as water injection power, makes the oil recovery need not to construct the water supply well, can also realize the reinforcing water injection, and save device cost and development investment have saved the energy consumption, have improved the benefit, and wholly reliable and stable. According to the enhanced water injection oil extraction method for the ultra-deep fracture-cave reservoir oil well, a closed-loop system for taking water, injecting water and extracting oil from the same well is realized through a proper underground tool, a construction process and a wellhead device by utilizing a high-pressure water layer and an underground water injection pump drilled in the oil well, the system is stable and reliable, huge water source well construction and water injection development bottom surface matching construction cost can be saved, development investment or cost is greatly saved, and economic benefits of carbonate reservoir development are improved.
Detailed Description
The present application is further described in conjunction with the following examples.
Example 1
One embodiment of the enhanced water injection oil extraction device for the ultra-deep fracture-cavity reservoir oil well, as shown in fig. 1, comprises an oil pipe 2, a packer 3 and a casing 1. In this embodiment, a casing 1 is arranged in the well, and the bottom end of a tubing 2 is inserted into the casing 1 and connected to a packer 3. When the packer 3 is set, the peripheral side surface of the packer 3 is tightly attached to the inner wall surface of the casing 1. An annular space 11 is formed between the oil pipe 2 and the casing 1, and the packer 3 is arranged in the annular space 11 and sleeved on the outer peripheral side of the oil pipe 2. The high-pressure water layer 4 is arranged outside the oil well, the casing 1 is communicated with the high-pressure water layer 4 through perforation holes, and the perforation holes 12 penetrate through the casing 1 and penetrate into rock layers in the high-pressure water layer 4. The pipe part of the oil pipe 2 facing the perforation 12 is an erosion resistant pipe part 21, the erosion resistant pipe part 21 may be an erosion resistant pipe part 21 on the entire circumference of the pipe section, or the pipe outer surface contacting the water flow from the perforation 12 may be an erosion resistant pipe part 21. The oil pipe 2 is also provided with a water injection and oil extraction conversion valve 20, the water injection and oil extraction conversion valve 20 is used for controlling the connection or disconnection between the interior of the oil pipe 2 and the perforation 12, the water injection and oil extraction conversion valve 20 is positioned above the high-pressure water layer 4 in the height direction, and the packer 3 is positioned below the high-pressure water layer 4 in the height direction. In an actual working condition, the water injection and oil extraction conversion valve is arranged at a position with the underground depth of about 1000m, the high-pressure water layer is arranged at a position with the underground depth of 3000m-3900m, and the packer is arranged at a position with the underground depth of up to an oil layer.
It should be noted that the water injection and oil recovery conversion valve 20 is arranged above the high-pressure water layer 4, and the distance between the two is relatively long, and as can be seen from the above practical working conditions, the height difference of at least 2000m exists, so that the design has two advantages. First, because there is a long distance between the water injection and oil extraction change-over valve 20 and the high-pressure water layer 4, the high-pressure water enters the annular space 11 after coming out from the high-pressure water layer 4, and then enters the oil pipe 2 through the water injection and oil extraction change-over valve 20 only after a long distance is needed, so that the water pressure is small, and the erosion of the whole equipment is weakened. Second, since the water injection/oil recovery conversion valve 20 is disposed at a position close to the wellhead, it is more convenient to connect and control an external control system.
And the oil pipe 2 is also internally provided with a downhole water injection pump 23 and an oil extraction pump 24 which are arranged at intervals from top to bottom in the height direction, the downhole water injection pump 23 is positioned below the water injection and oil extraction conversion valve 20, and the oil extraction pump 24 is positioned between the downhole water injection pump 23 and the packer 3. In utilizing natural energy, the downhole injection pump 23 may be activated to increase the injection rate to improve efficiency.
The water injection and oil extraction conversion valve 20 comprises a water injection hole which is communicated with the inside and the outside of the oil pipe 2 and a plugging mechanism which is used for plugging the water injection hole. It will be appreciated that the water injection and production diverter valve 20 has an inlet communicating with the annulus 11 and an outlet communicating with the interior of the tubing 2. Preferably, the water injection/oil recovery switching valve 20 may be an electric check valve. The plugging mechanism is controlled by the outside and can plug or conduct the water injection hole, so that when the oil well is in the jetting or oil extraction process, the plugging mechanism can plug the water injection hole to block the conduction between the annular space 11 and the oil pipe 2, namely the water injection and oil extraction conversion valve 20 is in a closed state; when water is injected into the oil layer, the plugging mechanism controls the water injection hole to conduct the annular space 11 and the oil pipe 2, and the self-flowing water injection of the high-pressure water layer 4 is realized, so that the pressure in the oil layer is supplemented and improved, and the oil extraction rate is improved. When the oil well needs the water injection, high pressure water layer 4 is through 12 water injection toward annular space 11 interior water injection of perforation, and pressure in the annular space can increase gradually, and when annular space pressure was greater than the pressure in the oil pipe, control shutoff mechanism opened the water injection hole, and the groundwater in with the annular space can flow to in the oil pipe 2 and flow to the oil reservoir by oneself under the effect of annular space pressure. When the oil well does not need water injection, the plugging mechanism is controlled to disconnect the water injection hole.
Because the water pressure of 4 departments of high pressure water layer is great to still can carry with grit, chemical corrosion material etc. by the water that high pressure water layer 4 came out, high pressure water impact ordinary oil pipe 2 can erode oil pipe 2, can lead to oil pipe 2 life-span to reduce, the problem of damage appears easily, even oil pipe 2 can take place to erode or the condition of breaking away. For this purpose, the outer wall of the oil pipe 2 at the high-pressure water layer, i.e. the erosion-resistant pipe section 21, can be subjected to an erosion-resistant treatment. The erosion-resistant treatment can be performed by a variety of methods such as thickening the wall thickness of the oil pipe, plating an erosion-resistant layer on the outer surface, and providing a reinforcing sleeve to enhance the resistance of the erosion-resistant pipe portion 21 against high-pressure water.
The reinforcing water injection oil extraction device of super deep fracture-cave type reservoir oil well of this embodiment novel structure is a complete sets of systematic, reliable and stable super deep fracture-cave type carbonate rock oil well water injection oil extraction device with one well, can utilize the high-pressure water layer that oil well self bore and meet as water injection power, makes the oil recovery need not to build the water source well, saves device cost and development investment, has saved the energy consumption, has improved the benefit.
The method for the enhanced water injection oil extraction device of the ultra-deep fracture-cavity reservoir oil well can comprise the following steps of:
firstly, a completion pipe string and a casing 1 are put in;
secondly, the packer 3 is left in the casing 1, the packer 3 is positioned below the high-pressure water layer 4, then the well completion pipe string is pulled up, and after the process of pulling up the well completion pipe string, the high-pressure water layer 4 and the casing 1 at the corresponding position are subjected to directional perforation to form a perforation 12;
thirdly, the oil pipe 2 is put down, the releasing of the oil pipe 2 is connected with the packer 3, the erosion-resistant pipe part 21 is opposite to the perforation hole 12, the water injection and oil extraction conversion valve 20 of the oil pipe 2 is positioned above the packer 3, and the water injection and oil extraction conversion valve 20 is communicated with the perforation hole 12;
fourthly, setting the packer 3 to enable the packer 3 to be tightly attached to the casing 1 to form sealing;
fifthly, closing the water injection and oil extraction conversion valve 20, closing the communication between the oil pipe 2 and the annulus 11, and starting an oil extraction pump 24 to extract oil from the oil layer;
sixthly, after the oil well stops spraying, the oil extraction pump 24 stops oil extraction, the water injection and oil extraction conversion valve 20 is opened to enable the perforation 12 to be communicated with the oil pipe 2, the gravity flow water injection is formed between the high-pressure water layer 4 and the oil pipe 2, and then the underground water injection pump 23 is started to start to enhance the velocity of the gravity flow water injection;
seventhly, observing the pressure of the well mouth, closing the water injection and oil extraction conversion valve 20 and the underground water injection pump 23 after determining that the pressure of the well mouth does not rise or the water absorption stops underground, cutting off a channel between the high-pressure water layer 4 and the oil pipe 2, and closing the well;
eighthly, when the pressure of the wellhead reaches a preset value, starting the oil extraction pump 24 and starting oil extraction again;
and step nine, repeating the step six, the step seven and the step eight, and starting the second round of artesian water injection and oil extraction work.
According to the enhanced water injection oil extraction method for the ultra-deep fracture-cavity reservoir oil well, a closed-loop system for water taking, water injection and oil extraction in the same well is realized by utilizing a high-pressure water layer drilled by the oil well and through a proper downhole tool, a construction process and a wellhead device, the system is stable and reliable, huge water source well construction and water injection development bottom surface matching construction cost can be saved, development investment or cost is greatly saved, and economic benefit of carbonate reservoir development is improved.
Example 2
In the second embodiment of the enhanced water injection and oil extraction device for an ultra-deep fracture-cavity reservoir oil well of the present application, referring to fig. 2, the main technical solution of this embodiment is the same as that of embodiment 1, and the features not explained in this embodiment adopt the explanations in embodiment 1, and are not described again here. This example differs from example 1 in that: in the present embodiment, the oil extraction pump 24 is not needed in the oil pipe 2, but only the downhole water injection pump 23 is provided, so that the oil extraction work can be performed in a blowout manner, and the downhole water injection pump 23 can still play a role in increasing the water injection effect.
Example 3
Referring to fig. 3, a third specific implementation of the enhanced water injection and oil extraction device for an ultra-deep fracture-cavity reservoir oil well in the present application is shown, and the main technical solution of this embodiment is the same as that of embodiment 1, and the features that are not explained in this embodiment are explained in embodiment 1, and are not described herein again. This example differs from example 1 in that: the oil extraction pump 24 and the downhole water injection pump 23 in the oil pipe 2 of the embodiment are both arranged above the high-pressure water layer 4, so that the control and installation of the oil extraction pump 24 and the downhole water injection pump 23 are more convenient. It should be noted that, in essence, the positions of the oil production pump 24 and the downhole water injection pump 23 may be selected according to actual requirements, and as long as the positions do not affect the downhole water injection and oil production operations in the oil pipe, the technical solution of the present application may be used.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the protection scope of the present application, and although the present application is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present application without departing from the spirit and scope of the technical solutions of the present application.