Annular experimental device for measuring dynamic sand-carrying capacity of fracturing fluid

Abstract

The utility model discloses an annular experimental device for measuring the dynamic sand-carrying capacity of fracturing fluid, which comprises a plurality of arc-shaped short pipes, the plurality of arc-shaped short pipes are spliced to form an annular channel, the annular channel is oppositely provided with a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are arranged on the outer walls of the arc-shaped short pipes. The liquid inlet is communicated with a sand-carrying liquid water tank through a water inlet pipe, the liquid outlet is communicated with a waste liquid recovery tank through a water outlet pipe, flow velocity detectors are arranged on the arc-shaped short pipes, and a shaftless pump propeller is arranged at the splicing position of the arc-shaped short pipes; and the plurality of shaftless pump propellers and the flow velocity detector are electrically connected with the control panel. The experimental device solves the problem that an existing experimental device for measuring the dynamic sand-carrying capacity of the fracturing fluid is low in experimental result accuracy.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and gas field development fracturing, and relates to an annular experimental device for measuring the dynamic sand carrying capacity of fracturing fluid. Background Art

[0002] With the development of large-scale volume fracturing technology, the significant increase in fracturing construction displacement has effectively improved the sand-carrying performance of the fracturing fluid, thereby greatly reducing the viscosity requirements of the fracturing fluid. The fracturing fluid can use slick water fracturing fluid with lower viscosity. It can be seen from indoor experiments and field applications that increasing the viscosity of the fracturing fluid can effectively improve the sand-carrying capacity of the fracturing fluid. At the same time, increasing the fracturing construction displacement (i.e., the flow rate of the sand-carrying fluid) can effectively improve the sand-carrying capacity of the fracturing fluid. However, the "SY / T 5107-2016 Water-Based Fracturing Fluid Performance Evaluation Method" currently used, the indoor experimental test items for evaluating the sand-carrying capacity of the fracturing fluid are all static performance tests, and it is impossible to associate the fracturing construction displacement (i.e., the flow rate of the sand-carrying fluid) with the sand-carrying capacity of the fracturing fluid, which is difficult to meet the requirements of the sand-carrying performance evaluation of large-volume fracturing fluids. Most of the existing technologies measure the static sand-carrying capacity of fracturing fluid. In terms of measuring the dynamic sand-carrying capacity of fracturing fluid, improvements are usually made on the basis of conventional rheometers. The sand-carrying fluid measurement containers used are all circular containers. The sand-carrying fluid has rotating vortices during the stirring process, resulting in inconsistent internal and external flow rates, affecting the accuracy of the measurement results. Utility Model Content

[0003] The utility model aims to provide an annular experimental device for measuring the dynamic sand carrying capacity of fracturing fluid, which solves the problem of low accuracy of experimental results in the existing experimental devices for the dynamic sand carrying capacity of fracturing fluid, and the measurement results are closer to the actual situation on site.

[0004] The technical scheme adopted by the utility model is an annular experimental device for measuring the dynamic sand carrying capacity of fracturing fluid, comprising a plurality of arc-shaped short tubes, the plurality of arc-shaped short tubes are spliced ​​to form an annular channel, a liquid inlet and a liquid outlet are relatively arranged in the annular channel, the liquid inlet and the liquid outlet are opened on the outer wall of the arc-shaped short tube, the liquid inlet is connected to the sand carrying liquid water tank through an inlet pipe, the liquid outlet is connected to the waste liquid recovery tank through an outlet pipe, a flow rate detector is arranged on the arc-shaped short tube, and a shaftless pump propeller is arranged at the splicing position of the plurality of arc-shaped short tubes; the shaftless pump propeller and the flow rate detector are both electrically connected to the control panel.

[0005] The utility model is also characterized in that:

[0006] The liquid inlet is located at the top end of the outer wall of the arc-shaped short tube, and the liquid outlet is located at the bottom end of the outer wall of the arc-shaped short tube.

[0007] A sealing baffle is arranged between the liquid inlet and the water inlet pipe, and a ball valve design is adopted for the liquid outlet.

[0008] A sand outlet is arranged near one side of the liquid outlet, and the sand outlet is integrally connected to a metering cylinder, and a pressure switch is arranged at the bottom of the metering cylinder.

[0009] A plurality of cushion blocks are arranged at the bottom of the arc-shaped short tube with the liquid inlet, and the plurality of cushion blocks make the annular channel have an inclination angle with the horizontal plane.

[0010] The flow velocity detector adopts a laser Doppler velocimeter.

[0011] Several arc-shaped short tubes are made of transparent material.

[0012] The utility model has the following beneficial effects: the utility model is an annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid, an annular liquid flow pipeline, and adopts a shaftless pump propeller as a liquid power device, which effectively solves the problem that conventional circular containers are difficult to simulate large-volume fracturing fluid sand carrying performance tests. By adding a liquid flow rate detector to detect the instantaneous flow rate of tracer particles in the sand-carrying fluid, the influence of the shear slip effect of the liquid on the accuracy of the suspended sand rheological curve is solved, and the sand settling metering cylinder is adopted to effectively improve the accuracy of the measurement results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model is a schematic diagram of the structure of an annular experimental device for measuring the dynamic sand carrying capacity of fracturing fluid.

[0014] In the figure, 1. arc-shaped short tube, 2. shaftless pump propeller, 3. liquid inlet, 4. flow rate detector, 5. liquid outlet, 6. metering cylinder, 7. waste liquid recovery tank, 8. control panel. DETAILED DESCRIPTION

[0015] The utility model is described in detail below with reference to the accompanying drawings and specific implementation modes.

[0016] The utility model is a ring-shaped experimental device for measuring the dynamic sand carrying capacity of fracturing fluid, and the structure is as follows Figure 1 As shown, it includes a plurality of arc-shaped short tubes 1, and the plurality of arc-shaped short tubes 1 are spliced ​​to form an annular channel. The annular channel is provided with a liquid inlet 3 and a liquid outlet 5 relatively, and the liquid inlet 3 and the liquid outlet 5 are opened on the outer wall of the arc-shaped short tube 1. The liquid inlet 3 is connected to the sand-carrying liquid water tank through an inlet pipe, and the liquid outlet 5 is connected to the waste liquid recovery tank 7 through an outlet pipe to discharge and recycle the waste liquid. A flow velocity detector 4 is arranged on the arc-shaped short tube 1, and a shaftless pump propeller 2 is arranged at the splicing position of the plurality of arc-shaped short tubes 1 to meet the requirements of a large sand-carrying liquid flow rate; the plurality of shaftless pump propellers 2 and the flow velocity detector 4 are electrically connected to a control panel 8, and the flow velocity detector 4 on the annular channel can effectively detect the instantaneous flow velocity of the sand-carrying liquid in the annular pipeline, and the control panel 8 is used to control the rotation speed of the shaftless pump propeller 2 and receive and process the speed data of the flow velocity detector 4.

[0017] The liquid inlet 3 is located at the top of the outer wall of the arc-shaped short tube 1, and the liquid outlet 5 is located at the bottom of the outer wall of the arc-shaped short tube 1. A sealing baffle is arranged between the liquid inlet 3 and the water inlet pipe. The liquid outlet 5 adopts a ball valve design and is sealed with the water outlet pipe to ensure that the liquid inlet and outlet do not leak during the implementation process and do not affect the normal flow of the sand-carrying liquid.

[0018] A sand outlet is arranged near one side of the liquid outlet 5, and the sand outlet is integrally connected to a metering cylinder 6. A pressure switch is provided at the bottom of the metering cylinder 6. The metering cylinder 6 is connected to the annular channel and is used to collect the settled sand in the annular channel and perform preliminary metering. The pressure switch is used to discharge the sand after completion.

[0019] A plurality of pads are arranged at the bottom of the arc-shaped short tube 1 with the liquid inlet 3, and the plurality of pads make the annular channel have an inclination with the horizontal plane, so as to facilitate the proppant (sand particles) settled in the annular channel pipeline to gather in the sand settling metering cylinder 6. Different pipeline inclination angles will affect the sand carrying performance of the fracturing fluid, and adjusting the inclination angle is helpful to simulate the complex environment of the flow of the sand carrying fluid on site.

[0020] The shaftless pump propeller 2 is used as a liquid acceleration device, and the number is not limited to one. Multiple shaftless pump propellers can be selected and combined in series to make the water flow entering the annular channel pre-swirl and become more uniform, thereby improving the propulsion efficiency. The shaftless pump propeller 2 eliminates the flow resistance of the rotating shaft to the liquid, and has no complicated transmission shaft system, while enhancing the sealing of the pipeline.

[0021] The flow rate detector 4 adopts a laser Doppler velocimeter, which is connected in series to the liquid flow pipeline. By adding tracer particles to the sand-carrying liquid, the laser Doppler velocimeter is used to monitor the instantaneous flow rate of the sand-carrying liquid in the annular pipeline.

[0022] The plurality of arc-shaped short tubes 1 are made of transparent material, and the annular channel is a transparent liquid flow pipeline. The length and radius of the pipeline can be freely combined according to actual conditions, the volume can be adjusted, and the liquid flow direction is not limited to clockwise flow.

[0023] The working principle of the annular experimental device for measuring the dynamic sand carrying capacity of the fracturing fluid of the utility model is that the flow rate detector 4 detects the instantaneous flow rate in the annular channel, which solves the influence of the shear slip effect of the liquid on the accuracy of the suspended sand rheological curve. The metering cylinder 6 is adopted to effectively improve the accuracy of the experimental results. The rotation speed of the shaftless pump propeller 2 is set and the real-time data signal transmission of the receiving flow rate detector 4 is transmitted through the control panel 8. The utility model can measure the sand carrying capacity (i.e., the maximum sand adding ratio) when the displacement and the viscosity of the fracturing fluid are fixed; measure the minimum fracturing fluid viscosity when the displacement and the sand adding ratio are fixed; and measure the minimum construction displacement when the viscosity of the fracturing fluid and the sand adding ratio are fixed.

[0024] Example 1

[0025] The annular experimental device for determining the dynamic sand-carrying capacity of the fracturing fluid of the utility model is used to determine the minimum sand-carrying fluid flow rate when the fracturing fluid has a fixed viscosity and a fixed sand addition ratio. The method is specifically implemented in the following steps:

[0026] Step 1: prepare a 10L volume of fracturing fluid, use a liquid viscometer to measure the viscosity of the prepared fracturing fluid, add a predetermined volume (0.1-10L) of proppant (quartz sand, ceramsite, resin-coated sand, etc.) to the fracturing fluid, and stir it thoroughly for more than 3 minutes until there is no proppant deposition at the bottom of the fracturing fluid, so as to form a uniformly mixed sand-carrying fluid;

[0027] At the same time, it can be calculated that:

[0028] The sand ratio of fracturing fluid (i.e. sand ratio) = added proppant volume / fracturing fluid volume × 100%

[0029] Step 2: Set different flow rate gradients (20, 19, 18, ..., 1 m / s), add the evenly mixed sand-carrying liquid into a 10L annular liquid flow pipeline (so that the pipeline is completely filled with the sand-carrying liquid), close the sealed liquid addition port, turn on the shaftless pump propeller, and make the sand-carrying liquid reach the highest flow rate gradient (5 m / s), and maintain this speed for a certain period of time until no proppant deposition occurs;

[0030] Step 3, observe the proppant sedimentation in the sand settling metering cylinder. If there is no proppant sedimentation, reduce the sand-carrying fluid flow rate to the next fluidity gradient and repeat step 2 until proppant sedimentation begins to appear in the sand settling metering cylinder. Finally, select the flow rate of this test result as the minimum sand-carrying fluid flow rate when the fracturing fluid and sand ratio is fixed.

[0031] Example 2

[0032] The annular experimental device for determining the dynamic sand carrying capacity of the fracturing fluid of the utility model is used to determine the minimum fracturing fluid viscosity when the sand carrying fluid flow rate and the sand adding ratio are fixed. The specific implementation is as follows:

[0033] Step 1: Prepare several portions of proppants of fixed volume (0.1-10L) and same specification, prepare 10L of fracturing fluids of different viscosity gradients (10, 20, 30, .... 100mPa·s), add 2L of proppants to each portion of fracturing fluid, stir thoroughly for more than 3 minutes, until no proppants are deposited at the bottom of the fracturing fluid, and form a uniformly mixed sand-carrying fluid;

[0034] At the same time, it can be calculated that:

[0035] The sand ratio of fracturing fluid (i.e. sand ratio) = added proppant volume / fracturing fluid volume × 100%

[0036] Step 2: Starting from the sand-carrying liquid with the highest viscosity, add 1 portion of the evenly mixed sand-carrying liquid into the annular liquid flow pipeline with a volume of 10L (so that the pipeline is completely filled with the sand-carrying liquid), and close the sealing liquid addition port;

[0037] Step 3: Turn on the shaftless pump propeller to make the sand-carrying fluid flow rate reach the set flow rate (1-20 m / s), maintain this speed for more than 3 minutes, and observe the proppant deposition in the sand settling metering cylinder. If there is no proppant deposition at the bottom of the sand settling metering cylinder, it proves that the fracturing fluid viscosity meets the requirements and can effectively suspend the proppant, and it is necessary to test a fracturing fluid with a lower viscosity;

[0038] Step 4, repeat steps 2-3 until proppant deposition occurs in the sand settling metering cylinder, and finally select the fracturing fluid viscosity of this test result as the minimum fracturing fluid viscosity when the sand-carrying fluid flow rate and the sand addition ratio are fixed.

[0039] Example 3

[0040] The annular experimental device for measuring the dynamic sand carrying capacity of the fracturing fluid of the utility model is used to measure the sand carrying capacity (i.e., the maximum sand adding ratio) at a fixed flow rate and fixed fracturing fluid viscosity, and is specifically implemented in the following steps:

[0041] Step 1, divide 10L of proppant of the same specification into multiple equal portions, prepare 10L volume of fracturing fluid, use a liquid viscometer to measure the viscosity of the prepared fracturing fluid, and then add all the fracturing fluid into a ring-shaped transparent container;

[0042] Step 2: Add 1 portion of proppant to the annular liquid flow pipeline filled with fracturing fluid, turn on the shaftless pump propeller, make the sand-carrying liquid flow rate reach the set speed (1-20 m / s), maintain the speed for more than 3 minutes, and observe the proppant deposition in the sand settling metering cylinder. If there is no proppant deposition at the bottom of the sand settling metering cylinder, it proves that the amount of sand added is small and the proppant can be effectively suspended, then the equipment needs to be stopped to further add 1 portion of proppant;

[0043] Step 3: Repeat step 2 until proppant deposition occurs in the sand measuring cylinder. Measure the volume of the remaining proppant and calculate:

[0044] Maximum sand addition ratio = (initial proppant volume - remaining proppant volume) / fracturing fluid volume × 100%

[0045] The utility model is an annular experimental device for measuring the dynamic sand carrying capacity of fracturing fluid. By adopting a shaftless pump propeller as a liquid power device of the annular channel, the sand carrying performance of large-displacement fracturing fluid can be accurately measured. By testing the sedimentation of proppant during the flow of fracturing fluid at different flow rates and viscosities, it is convenient and practical, comprehensively evaluates the sand carrying capacity of fracturing fluid, and screens out a suitable fracturing fluid system for oil and gas fracturing.

Claims

1. An annular experimental device for determining the dynamic sand carrying capacity of a fracturing fluid, characterized in that: The invention comprises a plurality of arc-shaped short tubes (1), wherein the plurality of arc-shaped short tubes (1) are spliced ​​to form an annular channel, wherein a liquid inlet (3) and a liquid outlet (5) are arranged opposite to each other in the annular channel, wherein the liquid inlet (3) and the liquid outlet (5) are opened on the outer wall of the arc-shaped short tube (1), the liquid inlet (3) is connected to a sand-carrying liquid water tank through an inlet pipe, and the liquid outlet (5) is connected to a waste liquid recovery tank (7) through an outlet pipe, a flow rate detector (4) is arranged on the arc-shaped short tube (1), and a shaftless pump propeller (2) is arranged at the splicing position of the plurality of arc-shaped short tubes (1); the plurality of shaftless pump propellers (2) and the flow rate detector (4) are electrically connected to a control panel (8).

2. The annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid according to claim 1, characterized in that: The liquid inlet (3) is located at the top end of the outer wall of the arc-shaped short tube (1), and the liquid outlet (5) is located at the bottom end of the outer wall of the arc-shaped short tube (1).

3. The annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid according to claim 2, characterized in that: A sealing baffle is provided between the liquid inlet (3) and the water inlet pipe, and the liquid outlet (5) adopts a ball valve design.

4. The annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid according to claim 1, characterized in that: A sand outlet is provided near one side of the liquid outlet (5), and the sand outlet is integrally connected to a metering cylinder (6). A pressure switch is provided at the bottom of the metering cylinder (6).

5. The annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid according to claim 1, characterized in that: A plurality of cushion blocks are arranged at the bottom of the arc-shaped short tube (1) having the liquid inlet (3), and the plurality of cushion blocks make the annular channel have an inclination angle with the horizontal plane.

6. The annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid according to claim 1, characterized in that: The flow velocity detector (4) adopts a laser Doppler velocimeter.

7. The annular experimental device for determining the dynamic sand carrying capacity of fracturing fluid according to claim 1, characterized in that: The plurality of arc-shaped short tubes (1) are made of transparent material.

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