Device and method for qualitatively determining the stratified water absorption capacity of water injection wells

Abstract

The present invention discloses a device and method for qualitatively determining the stratified water absorption capacity of a water injection well. The device for qualitatively determining the stratified water absorption capacity of a water injection well comprises a packer and a water distributor installed on a downhole pipe column, wherein each layer of the water injection well corresponds to a packer and a water distributor, and the packer of each layer of the water injection well is located above the water distributor of its corresponding layer, and a water nozzle is installed on the water distributor, and the water nozzle is correspondingly provided with a front-of-the-nozzle pressure gauge and a rear-of-the-nozzle pressure gauge to record the front-of-the-nozzle pressure and the rear-of-the-nozzle pressure respectively. The device for qualitatively determining the stratified water absorption capacity of a water injection well proposed by the present invention can qualitatively determine the stratum water absorption capacity according to the front-of-the-nozzle pressure, the rear-of-the-nozzle pressure and the opening size of the water nozzle itself, and can quickly and simply determine the water absorption capacity of different strata, without having to lower the flow meter again for downhole testing, and the testing process is simple, easy to operate, and has low difficulty. In addition, the device for qualitatively determining the stratified water absorption capacity of a water injection well has the advantages of simple structure and easy implementation.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield water injection development, and in particular to a device and a method for qualitatively determining the stratified water absorption capacity of a water injection well. Background Art

[0002] In the process of oilfield water injection development, stratified water injection is the most important technical means for efficient and fine water injection. However, stratified water injection needs to be adjusted in time according to the geological conditions and the different water absorption capacity of each layer. The judgment of stratified water absorption capacity plays a vital role in the later adjustment.

[0003] At present, the conventional stratified water absorption capacity is mainly determined by testing the stratified water absorption index and measuring the stratified water absorption by a downhole flow meter. The process is complicated and the underground stratified water absorption test is difficult. Summary of the invention

[0004] The main purpose of the present invention is to provide a simple and easy-to-operate device and method for qualitatively determining the stratified water absorption capacity of a water injection well.

[0005] To achieve the above-mentioned purpose, the present invention provides a device for qualitatively determining the stratified water absorption capacity of a water injection well, comprising a packer and a water distributor installed on a downhole tubing, wherein each layer of the water injection well corresponds to a packer and a water distributor, the packer of each layer of the water injection well is located above the water distributor of its corresponding layer, a water nozzle is installed on the water distributor, and the water nozzle is correspondingly provided with a front-of-the-nozzle pressure gauge and a rear-of-the-nozzle pressure gauge to respectively record the front-of-the-nozzle pressure and the rear-of-the-nozzle pressure, and the stratum water absorption capacity is qualitatively determined according to the front-of-the-nozzle pressure, the rear-of-the-nozzle pressure and the opening size of the water nozzle itself.

[0006] Preferably, the device for qualitatively determining the stratified water absorption capacity of a water injection well further comprises a wire plug installed at the bottom end of the downhole tubular column.

[0007] Preferably, the device for qualitatively determining the stratified water absorption capacity of the water injection well also includes a controller electrically connected to the front-mouth pressure gauge and the rear-mouth pressure gauge.

[0008] Preferably, the packer corresponding to each layer of the water injection well is installed above the liquid level of its current layer.

[0009] Preferably, the front-mouth pressure gauge and the rear-mouth pressure gauge are sealed by a sealing packing.

[0010] Preferably, the opening of the water nozzle is adjustable.

[0011] The present invention further proposes a method for qualitatively determining the stratified water absorption capacity of a water injection well based on the above-mentioned device, comprising the following steps:

[0012] When injecting water into each layer of the water injection well, record the opening degree of each layer of the water nozzle, as well as the pressure before and after the nozzle displayed on the pressure gauge before and after the nozzle on the water nozzle;

[0013] The water absorption capacity of the current layer is determined by comparing the ratio of the pressure difference between the pressure in front of the mouth and the pressure behind the mouth to the opening of the water nozzle.

[0014] Preferably, the greater the ratio of the difference between the pressure in front of the mouth and the pressure behind the mouth to the opening of the water nozzle, the greater the water absorption capacity of the current layer.

[0015] The device for qualitatively determining the stratified water absorption capacity of a water injection well proposed by the present invention can qualitatively determine the stratified water absorption capacity according to the pressure before and after the nozzle and the opening size of the nozzle itself, so as to quickly and simply determine the water absorption capacity of different strata, without the need to lower the flow meter again for downhole testing, and the testing process is simple, easy to operate and has low difficulty. In addition, the device for qualitatively determining the stratified water absorption capacity of a water injection well has the advantages of simple structure and easy implementation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The present invention is a schematic structural diagram of a device for qualitatively determining the stratified water absorption capacity of a water injection well.

[0017] Figure 2 A schematic diagram of installation details of a water nozzle in a device for qualitatively determining the stratified water absorption capacity of a water injection well according to the present invention.

[0018] In the figure, 1-packer, 2-water distributor, 3-water nozzle, 4-pressure gauge in front of nozzle, 5-pressure gauge behind nozzle, 6-thread plug, 7-sealing packing, 8-pressure guide hole, 9-liquid outlet hole, 10-tail end liquid inlet hole, 11-outer cylinder, 12-center channel.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] It should be noted that in the description of the present invention, the terms "transverse", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0022] The invention provides a device for qualitatively determining the stratified water absorption capacity of a water injection well.

[0023] In this preferred embodiment, refer to Figure 1 , a device for qualitatively determining the stratified water absorption capacity of a water injection well, comprising a packer 1 and a water distributor 2 installed on a downhole pipe column, wherein each layer of the water injection well corresponds to a packer 1 and a water distributor 2 (two layers are arranged as an example in the figure), and the packer 1 of each layer of the water injection well is located above the water distributor 2 of its corresponding layer, and a water nozzle 3 is installed on the water distributor 2, and the water nozzle 3 is correspondingly provided with a front-mouth pressure gauge 4 and a rear-mouth pressure gauge 5 to record the front-mouth pressure and the rear-mouth pressure respectively. The opening of the water nozzle 3 is adjustable, and the opening size of the water nozzle 3 can be automatically recorded after the water nozzle 3 is actuated, and the stratum water absorption capacity is qualitatively determined according to the front-mouth and rear-mouth pressures and the opening size of the water nozzle itself.

[0024] Furthermore, the device for qualitatively determining the stratified water absorption capacity of a water injection well also includes a wire plug 6 installed at the bottom end of the downhole pipe string.

[0025] Furthermore, the device for qualitatively determining the water absorption capacity of the injection well layer also includes a controller electrically connected to the front-end pressure gauge 4 and the back-end pressure gauge 5. The controller records the front-end pressure and the back-end pressure of all water nozzles 3, so as to facilitate the calculation of the water absorption capacity of the current layer.

[0026] Furthermore, the packer 1 corresponding to each layer of the water injection well is installed above the liquid level of its current layer.

[0027] Reference Figure 2 The water nozzle 3 is installed inside the outer tube 11. The pressure gauge 4 before the nozzle and the pressure gauge 5 after the nozzle are sealed by a sealing packing 7.

[0028] The direction of water flow during the water injection process is: the pressure gauge 4 in front of the left nozzle - the central channel 12 - the tail end liquid inlet hole 10 - the water nozzle 3 - the liquid outlet hole 9.

[0029] The pressure collected by the pressure gauge 4 in front of the mouth is the water flow pressure in the central channel 12, while the pressure gauge 5 behind the mouth collects the pressure outside the outer tube 11 (the water flowing out of the liquid outlet 9 enters the pressure gauge 5 behind the mouth through the pressure guide hole 8). The pressure collected by the pressure gauge 4 in front of the mouth is the pressure at the front end of the water spout, and the pressure collected by the pressure gauge 5 behind the mouth is the pressure at the rear end of the water spout.

[0030] The following takes two layers as an example to explain the testing principle of this device in detail.

[0031] When water is injected into layer 1, the opening size of the water nozzle 3 is Ka, the front-mouth pressure gauge 4 records the front-mouth pressure A1 of the water nozzle 3 during water injection, and the back-mouth pressure gauge 5 records the back-mouth pressure A2 of the water nozzle 3. When water is injected into layer 2, the opening size of the water nozzle 3 installed at layer 2 is Kb, the corresponding front-mouth pressure gauge 4 records the front-mouth pressure B1 of the water nozzle 3 during water injection, and the back-mouth pressure gauge 5 records the back-mouth pressure B2 of the water nozzle 3.

[0032] By comparing (A1-A2) / Ka and (B1-B2) / Kb, the water absorption capacity of layer 1 and layer 2 can be qualitatively determined. When (A1-A2) / Ka>(B1-B2) / Kb, the water absorption capacity of layer 1 is greater than that of layer 2; when (A1-A2) / Ka<(B1-B2) / Kb, the water absorption capacity of layer 1 is less than that of layer 2.

[0033] The device for qualitatively determining the stratified water absorption capacity of a water injection well proposed by the present invention can qualitatively determine the stratified water absorption capacity according to the pressure before and after the nozzle and the opening size of the nozzle 3 itself, so that the water absorption capacity of different strata can be quickly and simply determined without the need to lower the flow meter again for downhole testing. The testing process is simple, easy to operate and has low difficulty. In addition, the device for qualitatively determining the stratified water absorption capacity of a water injection well has the advantages of simple structure and easy implementation.

[0034] The present invention further proposes a method for qualitatively determining the stratified water absorption capacity of a water injection well.

[0035] In this preferred embodiment, a method for qualitatively determining the stratified water absorption capacity of a water injection well based on the above-mentioned device comprises the following steps:

[0036] When injecting water into each layer of the water injection well, record the opening degree of each layer of the water nozzle 3, as well as the pressure before the nozzle and the pressure after the nozzle displayed on the pressure gauge 4 before the nozzle and the pressure gauge 5 after the nozzle on the water nozzle 3;

[0037] The water absorption capacity of the current layer is determined by comparing the ratio of the pressure difference between the pressure before the mouth and the pressure behind the mouth to the opening of the water nozzle 3.

[0038] The greater the ratio of the pressure difference between the pressure in front of the mouth and the pressure behind the mouth to the opening of the water nozzle 3, the greater the water absorption capacity of the current layer.

[0039] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A device for qualitatively determining the stratified water absorption capacity of a water injection well, characterized in that: It includes a packer and a water distributor installed on the downhole tubing, wherein each layer of the water injection well corresponds to a packer and a water distributor, the packer of each layer of the water injection well is located above the water distributor of its corresponding layer, a water nozzle is installed on the water distributor, the water nozzle is correspondingly provided with a front-of-the-nozzle pressure gauge and a rear-of-the-nozzle pressure gauge to record the pressure before the nozzle and the pressure after the nozzle respectively, and the water absorption capacity of the layer is qualitatively judged according to the pressure before the nozzle, the pressure after the nozzle and the opening size of the water nozzle itself; it also includes a wire plug installed at the bottom of the downhole tubing; the packer corresponding to each layer of the water injection well is installed above the liquid level of its current layer.

2. The device for qualitatively determining the stratified water absorption capacity of a water injection well according to claim 1, characterized in that: Also included is a controller electrically connected to the front-mouth pressure gauge and the back-mouth pressure gauge.

3. The device for qualitatively determining the stratified water absorption capacity of a water injection well according to claim 1, characterized in that: The front-mouth pressure gauge and the rear-mouth pressure gauge are sealed by a sealing packing.

4. The device for qualitatively determining the stratified water absorption capacity of a water injection well according to any one of claims 1 to 3, characterized in that: The opening degree of the water nozzle is adjustable.

5. A method for qualitatively determining the stratified water absorption capacity of a water injection well based on the device according to any one of claims 1 to 4, characterized in that: The following steps are involved: When injecting water into each layer of the water injection well, record the opening degree of each layer of the water nozzle, as well as the pressure before and after the nozzle displayed on the pressure gauge before and after the nozzle on the water nozzle; The water absorption capacity of the current layer is determined by comparing the ratio of the pressure difference between the pressure in front of the mouth and the pressure behind the mouth to the opening of the water nozzle.

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