Foam flooding layered injection process device

Abstract

The utility model relates to a foam flooding layered injection process device which comprises an injection tubular column group, a liquid injection system and a gas injection system, wherein the liquid injection system and the gas injection system are respectively connected with injection tubular columns; the injection tubular column group is a concentric nested injection tubular column group, and at most three layers of concentric nested injection tubular column groups are nested; the depths of the injection pipe column are sequentially reduced from inside to outside; each injection pipe column is injected into each oil layer and is not in contact with other oil layers; the liquid injection system comprises liquid injection pipelines with the same number as the oil layers, and the gas injection system comprises gas injection pipelines with the same number as the oil layers. By means of the concentric nested injection pipe column set, the multi-branch liquid injection pipeline and the gas injection pipeline, layered injection of foam flooding is achieved. The device can realize layered injection operation of different gas foams such as air foam flooding, nitrogen foam flooding and carbon dioxide foam flooding, and has the advantages of simple and reasonable structure, high operation efficiency, strong operability, easiness in maintenance and the like.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of foam flooding improving oil recovery in the oilfield development process, especially relates to a foam flooding separate layer injection process device. BACKGROUND

[0002] In the process of stratum deposition and reservoir accumulation, multiple oil layers with different or obvious differences in physical properties such as porosity and permeability are usually formed, and in the development process, different development layer systems are formed by layer system division, and then corresponding well pattern is matched to select a suitable development mode for development.

[0003] Water injection development is a common and effective development technology in most domestic and foreign oilfields, which has many advantages such as low cost, small safety risk and good benefit. However, due to the heterogeneity of oil layer properties (both interlayer and intralayer), water channeling and water flooding problems are usually faced in the middle and late stages of water injection development, a large amount of injected water is produced from the oil well along the dominant channel, forming an invalid water cycle, resulting in low oil displacement efficiency and poor development effect. At this time, foam flooding can effectively plug the dominant seepage channel in the oil layer, expand the swept volume of the injected fluid, effectively reduce the water production of the oil well and improve the oil recovery, and play a role in improving the development effect. However, for multi-layer reservoirs, different injection parameters such as injection rate and injection pressure need to be designed for different oil layers during foam flooding to optimize economic benefits and development effect.

[0004] At present, the oilfields implementing foam flooding in China mainly include Zhongyuan oilfield, Baise oilfield, Daqing oilfield and Yanchang oilfield, and basically all are mixed injection and mixed production, and there is no related report on separate layer injection, and the separate layer injection technology needs to be improved. SUMMARY

[0005] The utility model aims at providing a foam flooding separate layer injection process device, and solves the problem of foam flooding separate layer injection of multi-layer heterogeneous reservoirs.

[0006] The technical scheme of the utility model is:

[0007] A foam flooding separate layer injection process device, comprising an injection pipe column group, a liquid injection system and a gas injection system connected with the injection pipe column respectively; the injection pipe column group is a concentric nested injection pipe column group, and the concentric nested injection pipe column group is nested at most three layers; the depth of the injection pipe column from inside to outside decreases in turn; each injection pipe column is injected into each oil layer and does not contact other oil layers; the liquid injection system contains liquid injection pipelines equal to the number of oil layers, and the gas injection system contains gas injection pipelines equal to the number of oil layers.

[0008] The oil sleeve annulus above each oil layer is provided with a packer; each injection pipe column corresponds to extend below the corresponding packer and simultaneously above the packer of the upper layer.

[0009] The first packer is arranged above the bottom oil layer, and the first injection pipe column is arranged in the innermost layer; the second packer is arranged above the top oil layer, and the second injection pipe column is arranged in the outermost layer; the first injection pipe column extends to below the first packer, and the second injection pipe column extends to between the first packer and the second packer; the injection liquid system comprises two injection liquid pipelines, and the injection gas system comprises two injection gas pipelines.

[0010] The intermediate oil layer can be arranged between the bottom oil layer and the top oil layer, the intermediate packer is arranged in the oil-casing annulus between the intermediate oil layer and the top oil layer, and the intermediate oil pipe is arranged between the first injection pipe column and the second injection pipe column; the intermediate oil pipe extends to between the first packer and the intermediate packer; the injection liquid system comprises three injection liquid pipelines, and the injection gas system comprises three injection gas pipelines.

[0011] The injection liquid system comprises a dosing device, a stirring tank, a lifting pump, a curing tank, a filtering device, a liquid storage tank, a water injection pump and a liquid distributor; the outlet end of the liquid distributor is connected to each injection liquid pipeline, and each injection liquid pipeline is connected to one injection pipe column; the liquid flow meter, the pressure gauge and the valve are arranged on each injection liquid pipeline.

[0012] The injection gas system comprises a gas distributor, the inlet end of the gas distributor is connected to the same gas source, and the outlet end of the gas distributor is connected to each injection gas pipeline; the gas flow meter, the pressure gauge and the valve are arranged on each injection gas pipeline.

[0013] The inner wall of the injection pipe column is coated with a coating layer for corrosion prevention.

[0014] The packer is a compression packer.

[0015] The lifting pump is a centrifugal pump, and the water injection pump is a reciprocating plunger pump.

[0016] The technical effect of the utility model lies in that:

[0017] The utility model discloses a concentric nested injection pipe column group, multiple branch injection liquid pipelines and injection gas pipelines, and realizes the layered injection of foam drive. The utility model can realize the layered injection operation of different gas foams such as air foam drive, nitrogen foam drive and carbon dioxide foam drive, and has the advantages of simple and reasonable structure, high operation efficiency, strong operability and easy maintenance. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is the structure schematic view of the foam drive layered injection process device when taking the two-layer oil layer as an example.

[0019] Reference: 1, liquid injection system; 2, first valve; 3, dosing device; 4, stirring tank; 5, lifting pump; 6, curing tank; 7, filtering device; 8, liquid storage tank; 9, water injection pump; 10, liquid preparation device; 11, liquid flow meter; 12, pressure gauge; 13, concentric nested injection string set; 14, gas flow meter; 15, gas preparation device; 16, gas injection system; 17, second valve; 18-1, first packer; 18-2, second packer; 19-1, bottom oil layer; 19-2, top oil layer; 20, liquid injection line; 21, gas injection line. DETAILED DESCRIPTION

[0020] Example 1

[0021] A foam flooding layer-by-layer injection process device, comprising an injection string set, a liquid injection system 1 and a gas injection system 16 connected to the injection string respectively; the injection string set is a concentric nested injection string set 13, and the concentric nested injection string set 13 is nested at most three layers; the depth of the injection string from inside to outside decreases in turn; each injection string is injected into each oil layer and does not contact other oil layers; the liquid injection system 1 contains liquid injection lines 20 equal to the number of oil layers, and the gas injection system 16 contains gas injection lines 21 equal to the number of oil layers. The specific implementation process of this embodiment is as follows:

[0022] Each injection string corresponds to an oil layer, and each injection string corresponds to a liquid injection line 20 and a gas injection line 21; the liquid injection system 1 sequentially passes through each liquid injection line 20 and the injection string to correspondingly inject the foam liquid into the oil layer, and the gas injection system 16 sequentially passes through each gas injection line 21 and the injection string to correspondingly inject the specific gas into the oil layer, and the foam liquid and the specific gas generate foam in the formation and drive oil.

[0023] Example 2

[0024] Based on example 1, it further comprises:

[0025] Each oil layer is provided with a packer above the oil jacket annulus; each injection string corresponds to extend below the corresponding packer and simultaneously above the packer of the upper layer; the packer separates each oil layer, so that the liquid and the specific gas in each injection string are only injected into the corresponding oil layer.

[0026] Example 3

[0027] Based on example 2, it further comprises:

[0028] When the oil layer is 2 layers, from bottom to top, the bottom layer oil layer and the top layer oil layer are sequentially arranged; the first packer 18-1 is arranged above the bottom layer oil layer 19-1, and the first injection pipe column is arranged in the innermost layer; the second packer 18-2 is arranged above the top layer oil layer 19-2, and the second injection pipe column is arranged in the outermost layer; the first injection pipe column extends below the first packer 18-1, and the second injection pipe column extends between the first packer 18-1 and the second packer 18-2; the injection liquid system 1 includes two injection liquid pipelines 20, and the injection gas system 16 includes two injection gas pipelines 21.

[0029] Embodiment 4

[0030] Based on the embodiment 3, further comprising:

[0031] When the oil layer is 3 layers, from bottom to top, the bottom layer oil layer 19-1, the middle layer oil layer and the top layer oil layer 19-2 are sequentially arranged; that is, the bottom layer oil layer 19-1 and the top layer oil layer 19-2 can further have the middle layer oil layer, the middle packer is arranged in the oil sleeve annulus between the middle layer oil layer and the top layer oil layer 19-2, and the middle oil pipe is arranged between the first injection pipe column and the second injection pipe column; the middle oil pipe extends between the first packer 18-1 and the middle packer; the injection liquid system 1 includes three injection liquid pipelines 20, and the injection gas system 16 includes three injection gas pipelines 21.

[0032] Embodiment 5

[0033] Based on the embodiment 4, further comprising:

[0034] The injection liquid system 1 includes the dosing device 3, the stirring tank 4, the lifting pump 5, the aging tank 6, the filtering device 7, the liquid storage tank 8, the water injection pump 9 and the liquid preparation device 10 which are sequentially connected; the outlet end of the liquid preparation device 10 is connected to each injection liquid pipeline 20, each injection liquid pipeline 20 is connected to one injection pipe column; the liquid flow meter 11, the pressure gauge 12 and the valve are arranged on each injection liquid pipeline 20. The injection gas system 16 includes the gas preparation device 15, the inlet end of the gas preparation device 15 is connected to the same gas source, and the outlet end of the gas preparation device 15 is connected to each injection gas pipeline 21; the gas flow meter 14, the pressure gauge 12 and the valve are arranged on each injection gas pipeline 21. The inner wall of the injection pipe column is coated with a coating for corrosion prevention. The packer is a compression packer. The lifting pump 5 is a centrifugal pump, and the water injection pump 9 is a reciprocating plunger pump.

[0035] The specific implementation process of the embodiment is as follows:

[0036] Taking the 2-layer oil layer as an example;

[0037] First, according to the design of the foam liquid concentration to be injected, the foam liquid is prepared in the stirring tank 4, and after stirring uniformly, it is pumped to the curing tank 6 for curing for 24 hours, and then the impurities and insoluble substances are filtered out through the filtering device 7 to reach the liquid storage tank 8. According to the design of the injection speed, the displacement of the injection pump 9 is adjusted, and then it enters the liquid preparation device 10 to prepare the liquid according to the demand of the oil layer, and then it is injected into the specified oil layer through each injection pipe column. During the injection process, the liquid flow meter 11 and the pressure gauge 12 measure the injection amount and injection pressure of the foam liquid respectively. After the foam liquid injection is completed, the valve (first valve 2) on the liquid injection pipeline 20 is closed, the valve (second valve 17) on the gas injection pipeline 21 is opened, the gas injection flow is adjusted through the gas preparation device 15, and then it is injected into the specified oil layer through each gas injection pipeline 21, and the flow is measured through the gas flow meter 14; and then the foam flooding under the target injection parameters is realized. It is particularly pointed out that usually multiple foam liquid slugs and gas slugs need to be injected in one project cycle, and the above steps can be repeated to achieve it.

Claims

1. A foam flooding and layering injection process device, comprising an injection string group, a liquid injection system (1) and a gas injection system (16) connected with the injection string respectively; characterized in that, The injection string group is a concentric nested injection string group (13), the concentric nested injection string group (13) is nested at most three layers; the depths of the injection strings from inside to outside are sequentially reduced; each injection string is injected into each oil layer and does not contact other oil layers; the injection liquid system (1) comprises injection liquid pipelines (20) equal in number to the oil layers, and the injection gas system (16) comprises injection gas pipelines (21) equal in number to the oil layers.

2. The apparatus of claim 1, wherein, Each oil jacket annulus above each oil layer is provided with a packer, the injection string located in the innermost layer extends below the corresponding packer, and the remaining injection strings extend below the corresponding packers and above the next packers at the same time.

3. The foam drive separate layer injection process apparatus of claim 2, wherein, A first packer (18-1) is provided above the bottom oil layer (19-1), and the injection string located in the innermost layer is a first injection string; a second packer (18-2) is provided above the top oil layer (19-2), and the injection string located in the outermost layer is a second injection string; the first injection string extends below the first packer (18-1), and the second injection string extends between the first packer (18-1) and the second packer (18-2); the injection liquid system (1) comprises two injection liquid pipelines (20), and the injection gas system (16) comprises two injection gas pipelines (21).

4. The apparatus of claim 3, wherein, The bottom oil layer (19-1) and the top oil layer (19-2) can also have an intermediate oil layer, an intermediate packer is provided in the oil jacket annulus between the intermediate oil layer and the top oil layer (19-2), and an intermediate tubing is provided between the first injection string and the second injection string; the intermediate tubing extends between the first packer (18-1) and the intermediate packer; the injection liquid system (1) comprises three injection liquid pipelines (20), and the injection gas system (16) comprises three injection gas pipelines (21).

5. The apparatus of claim 1, wherein, The injection liquid system (1) comprises a dosing device (3), a stirring tank (4), a lifting pump (5), a maturation tank (6), a filtering device (7), a liquid storage tank (8), a water injection pump (9), and a liquid dispenser (10) connected in sequence; the outlet end of the liquid dispenser (10) is connected to each injection liquid pipeline (20), each injection string is connected to an injection string; each injection liquid pipeline (20) is provided with a liquid flow meter (11), a pressure gauge (12), and a valve.

6. The apparatus of claim 1, wherein, The injection gas system (16) comprises a gas dispenser (15), the inlet end of the gas dispenser (15) is connected to the same gas source, and the outlet end of the gas dispenser (15) is connected to each injection gas pipeline (21); each injection gas pipeline (21) is provided with a gas flow meter (14), a pressure gauge (12), and a valve.

7. The apparatus of claim 1, wherein, The inner walls of the injection strings are coated with a coating for corrosion prevention.

8. The apparatus of claim 2, wherein, The packer is a compression packer.

9. The foam drive separate zone injection process apparatus of claim 5, wherein, The lifting pump (5) is a centrifugal pump, and the water injection pump (9) is a reciprocating plunger pump.

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