Device and method for statically dispersing dry polymer powder for oil displacement

Abstract

The invention relates to a device and a method for statically dispersing dry polymer powder for oil displacement, and belongs to the technical field of chemical flooding injection allocation. Comprising a shell and a plurality of rows of turbulent flow columns, the turbulent flow columns are evenly distributed at equal intervals, the two ends of each turbulent flow column are fixed to the inner wall of the shell, the upstream faces of the turbulent flow columns are perpendicular to the flowing direction of polymer dry powder, and turbulent flow can be generated when water flow carries the polymer dry powder to pass through the turbulent flow columns. The turbulence intensity calculation method comprises the following steps: assuming the size and the number of any even-number-row turbulence columns; calculating a Reynolds number Re; when Re is larger than or equal to 4000, the turbulence intensity I is calculated according to Re, and I = 0.16 * Re-0.125; and when I is greater than or equal to 10%, ending calculation to obtain the size and the number of even rows of turbulent columns. According to the polymer dry powder dispersing device, the turbulent flow columns are arranged in the shell at intervals, polymer dry powder is dispersed when water flows through the turbulent flow columns, the effect of completely dispersing the polymer dry powder is achieved, and meanwhile the effects of reducing energy consumption and reducing unnecessary cost are achieved.

Description

Technical Field

[0001] The present invention relates to a static dispersion device and method for polymer dry powder used in oil displacement, belonging to the technical field of chemical flooding injection allocation. Background Art

[0002] The polymer-surfactant binary oil displacement technology (hereinafter referred to as binary flooding) is of great significance for old oilfields to transform the development mode, improve the recovery factor, alleviate the trend of production decline, and improve economic benefits.

[0003] The daily oil production in the industrial test of binary flooding increased by 5 times compared with that before the conversion of flooding. Based on the good results obtained in the industrial test of binary flooding, the oilfield has continuously carried out the promotion work of the surface engineering of binary flooding.

[0004] Patent Application No. CN2013201052042 discloses a profile control and flooding integration device, and the specific process flow is as follows: The purified sewage from the injection water pipeline near the injection allocation station passes through a cut-off valve and a regulating valve, and then enters the mixing tank through a jet injector. At the same time, polyacrylamide is also sucked into the mixing tank under the negative pressure of the jet injector after being weighed by weight. Water and polyacrylamide are stirred and dispersed in the mixing tank by a stirrer, and then undergo stirring and aging. The polymer target liquid after good aging flows by gravity to the polymer injection pump, and is pressurized and metered by the polymer injection pump and then transported to the wellhead for injection underground.

[0005] The dispersion effect of polymer dry powder in water directly affects the aging effect of the polymer and the viscosity of the target liquid. If the polymer dry powder is not completely dispersed in water, fish eyes and sticky masses will be generated during the aging process, which will directly affect the development effect after injection into the formation.

[0006] At present, the existing technology uses a stirrer to stir and disperse the polymer dry powder. There are hydraulic dead corners during the stirring process, and the polymer dry powder cannot be completely dispersed. At the same time, power consumption is required during the stirring process. Calculated according to the average daily injection of 60 m 3 injected liquid, the profile control and flooding integration device needs to prepare the target liquid 6 times, which will consume a large amount of energy and also result in a significant increase in redundant costs. Summary of the Invention

[0007] The present invention discloses a static dispersion device and method for polymer dry powder used in oil displacement, aiming to solve the problems that there are hydraulic dead corners when using a stirrer to disperse the polymer dry powder, and complete dispersion cannot be achieved, and at the same time solve the problems of energy consumption required for stirring dispersion and cost increase.

[0008] The technical solution adopted by the present invention is a static dispersion device for polymer dry powder used in oil displacement, which includes a housing and several rows of turbulence columns. The several rows of turbulence columns are evenly distributed at equal intervals, and both ends of the turbulence columns are fixed on the inner wall of the housing. The water-facing surface of the turbulence column is perpendicular to the flowing direction of the polymer dry powder. When water flow carries the polymer dry powder through the turbulence column, turbulence will be generated.

[0009] Further, any three turbulence columns in the adjacent rows and with the closest distance are arranged in a staggered shape like a pin.

[0010] Further, the number of turbulence columns in the odd rows is n + 1, and the number of turbulence columns in the even rows is n.

[0011] Further, the housing is installed on the pipeline between the jet suction device and the mixing tank.

[0012] Further, the diameter of the pipeline is the inscribed circle of the housing.

[0013] Further, the housing is a cuboid.

[0014] Further, the materials of the housing and the turbulence columns are carbon steel.

[0015] The present invention also provides a method for calculating the turbulence intensity of the static dispersion device for polymer dry powder used in oil displacement. The specific steps are as follows:

[0016] Step 1, perform calculations using the iterative method. First, assume the size and number of any even-row turbulence columns.

[0017] Step 2, according to the equivalent pipe diameter d 1 、equivalent flow velocity v 1 、fluid density ρ, fluid dynamic viscosity μ, calculate the Reynolds number Re, Re = ρv 1 d 1 / μ;

[0018] Among them, d 1 = 2×[(S 1 -S 2 ) / 3.14] 0.5 , with the unit of m 2 ; v 1 = Q / (S 1 -S 2 ), with the unit of m / s, Q is the flow rate; fluid density ρ, with the unit of kg / m 3 ; fluid dynamic viscosity μ, with the unit of Pa.s; where S 1 -the cross-sectional area of the housing perpendicular to the flowing direction, S 2 -the cross-sectional area of a certain even-row turbulence column perpendicular to the flowing direction; (S 1 -S 2) is the area difference between the housing of any even row and the turbulent column;

[0019] Step 3: Compare the calculated Reynolds number Re. When Re < 4000, return to Step 1, adjust the size or quantity of the turbulent column, and recalculate Re. When Re ≥ 4000, proceed to the next calculation;

[0020] Step 4: Calculate the turbulence intensity I according to Re, I = 0.16 × Re -0.125 ;

[0021] Step 5: Check the turbulence intensity. I < 1% is called low turbulence intensity, and greater than 10% is called high turbulence intensity; when I < 10%, return to Step 1, adjust the size or quantity of the turbulent column, and recalculate I. When I ≥ 10%, the calculation ends.

[0022] The present invention discloses a polymer dry powder static dispersion device and method for oil displacement. The beneficial effect is that by arranging a number of turbulent columns at intervals in the housing, when water flows through, the polymer dry powder is dispersed by the high-turbulence-intensity fluid, achieving the effect of completely dispersing the polymer dry powder, and at the same time achieving the effects of reducing energy consumption and unnecessary costs, and assisting in oilfield development. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 Shown is a schematic cross-sectional view of the structure of the present invention parallel to the flow direction;

[0025] Figure 2 Shown is a schematic diagram of the turbulence simulation of the present invention.

[0026] Explanation of the numbers in the figure: 1. Housing; 2. Turbulent column.

[0027] Specific implementation method

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0029] To further understand the content of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0030] Embodiment 1:

[0031] As Figures 1-2 shown, this embodiment provides a static dispersion device for polymer dry powder used in enhanced oil recovery, including a housing 1 and several rows of turbulence columns 2. The housing 1 is a cuboid, and both ends of the turbulence columns 2 are fixed on the inner walls of the upper and lower surfaces of the housing 1. The number of turbulence columns 2 in the odd rows is n + 1, and the number of turbulence columns 2 in the even rows is n. Any three adjacent and closest turbulence columns 2 in adjacent rows are arranged in a staggered shape like a pin. The housing 1 is installed on the pipeline between the jet suction device and the mixing tank. The pipeline diameter is the inscribed circle of the housing 1. The cross-sections at both ends of the turbulence column 2 are square. The water-facing surface of the turbulence column 2 is perpendicular to the flow direction of the polymer dry powder, and turbulence will be generated when the water flow carries the polymer dry powder through the turbulence column 2.

[0032] The present invention also provides a method for calculating the turbulence intensity of a static dispersion device for polymer dry powder used in enhanced oil recovery, and the specific steps are as follows:

[0033] Step 1, calculate using the iterative method. First, assume the size and number of any even-row turbulence columns 2;

[0034] Step 2, according to the equivalent pipe diameter d 1 , equivalent flow velocity v 1 , fluid density ρ, and fluid dynamic viscosity μ, calculate the Reynolds number Re, Re = ρv 1 d 1 / μ;

[0035] Among them, d 1 = 2 × [(S 1 - S 2 ) / 3.14] 0.5 , with the unit of m 2 ; v 1 = Q / (S 1 - S 2 ), with the unit of m / s, Q is the flow rate; fluid density ρ, with the unit of kg / m3 ; the hydrodynamic viscosity μ, in the unit of Pa·s; where S 1 - the cross-sectional area of the housing perpendicular to the flow direction, S 2 - the cross-sectional area of a certain even row of turbulent columns perpendicular to the flow direction; (S 1 - S 2 ) is the area difference between the housing and the turbulent column of any even row;

[0036] Step 3: Compare the calculated Reynolds number Re. When Re < 4000, return to Step 1, increase the size or quantity of the turbulent columns 2, recalculate Re, and when Re ≥ 4000, proceed to the next calculation;

[0037] Step 4: Calculate the turbulence intensity I based on Re, I = 0.16 × Re -0.125 ;

[0038] Step 5: Check the turbulence intensity. I < 1% is called low turbulence intensity, and greater than 10% is called high turbulence intensity; when I < 10%, return to Step 1, adjust the size or quantity of the turbulent columns 2, recalculate I, and when I ≥ 10%, the calculation ends.

[0039] According to the above method for calculating the turbulence intensity, iterate repeatedly to obtain the corresponding number of turbulent columns 2 with specific sizes to be set in the dispersion device. For example, if n = 2, then there are 2 even-row turbulent columns 2, and 3 odd-row turbulent columns 2.

[0040] Turbulence mixing principle: Turbulence is a flow state of a fluid. When the flow velocity is very small, the fluid flows in layers without mixing, which is called laminar flow; gradually increasing the flow velocity, the streamlines of the fluid begin to show wavy swings, and the frequency and amplitude of the swings increase with the increase of the flow velocity. This flow condition is called transitional flow; when the flow velocity increases to a very large value, the streamlines are no longer clearly distinguishable, there are many small vortices in the flow field, and there is not only sliding but also mixing between adjacent flow layers, forming turbulence. The basic characteristic of turbulence is the randomness of the movement of fluid microgroups. Turbulent microgroups not only have longitudinal and transverse pulsations but also have reverse movements relative to the total movement of the fluid. Therefore, the trajectories of fluid microgroups are extremely disordered and change rapidly with time. The velocity of the fluid flowing through a fixed point changes irregularly with time, and various parts are vigorously mixed.

[0041] In the present invention, a plurality of turbulent columns 2 are arranged at intervals in the housing 1. By utilizing the intense mixing effect of turbulence, when water flows through, the polymer dry powder is completely dispersed by the fluid with high turbulence intensity, solving the problems that there are hydraulic dead corners when using a stirrer to disperse the polymer dry powder and it is impossible to achieve complete dispersion, and at the same time solving the problems of energy consumption and cost increase required for stirrer dispersion.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A static dispersion device for polymer dry powder used in enhanced oil recovery, characterized in that, it includes a housing (1) and several rows of turbulent columns (2). The several rows of turbulent columns (2) are evenly distributed at equal intervals, and both ends of the turbulent columns (2) are fixed on the inner wall of the housing (1). The water-facing surface of the turbulent columns (2) is perpendicular to the flow direction of the polymer dry powder. When the water flow carries the polymer dry powder through the turbulent columns (2), turbulence will be generated.

2. The static dispersion device for polymer dry powder used in enhanced oil recovery according to claim 1, characterized in that, any three adjacent and closest turbulent columns (2) in adjacent rows are arranged in a staggered shape like a pin.

3. The static dispersion device for polymer dry powder used in enhanced oil recovery according to claim 2, characterized in that, the number of turbulent columns (2) in odd rows is n + 1, and the number of turbulent columns (2) in even rows is n.

4. The static dispersion device for polymer dry powder used in enhanced oil recovery according to claim 1, characterized in that, the housing (1) is installed on the pipeline between the jet suction device and the mixing tank.

5. The static dispersion device for polymer dry powder used in enhanced oil recovery according to claim 4, characterized in that, the pipeline diameter is the inscribed circle of the housing (1).

6. The static dispersion device for polymer dry powder used in enhanced oil recovery according to claim 5, characterized in that, the housing (1) is a cuboid.

7. The static dispersion device for polymer dry powder used in enhanced oil recovery according to claim 1, characterized in that, the materials of the housing (1) and the turbulent columns (2) are carbon steel.

8. A calculation method for the turbulence intensity of a static dispersion device for polymer dry powder used in enhanced oil recovery, characterized in that, the specific steps are as follows: Step 1, use the iterative method for calculation. First, assume the size and number of any even-row turbulent columns (2); Step 2: According to the equivalent pipe diameter d 1 , equivalent flow velocity v 1 , fluid density ρ, and fluid dynamic viscosity μ, calculate the Reynolds number Re, where Re = ρvd 1 / μ; 1 / μ; where d 1 = 2 × [(S 1 - S 2 ) / 3.14] 0.5 , with the unit of m 2 ; v 1 = Q / (S 1 - S 2 ), with the unit of m / s, where Q is the flow rate; the fluid density ρ, with the unit of kg / m 3 ; the fluid dynamic viscosity μ, with the unit of Pa·s; where S 1 – the cross-sectional area of the shell perpendicular to the flow direction, S 2 – the cross-sectional area of a certain even row of turbulent columns perpendicular to the flow direction; (S 1 - S 2 ) is the area difference between the shell and the turbulent columns of any even row; Step 3, compare the calculated Reynolds number Re. When Re < 4000, return to Step 1, increase the size or number of the turbulent columns (2), and recalculate Re. When Re ≥ 4000, proceed to the next calculation; Step 4: Calculate the turbulence intensity I according to Re, where I = 0.16 × Re -0.125 ; Step 5, check the turbulence intensity. I < 1% is called low turbulence intensity, and greater than 10% is called high turbulence intensity; when I < 10%, return to Step 1, adjust the size or number of the turbulent columns (2), and recalculate I. When I ≥ 10%, the calculation ends, and the size and number of the even-row turbulent columns (2) are obtained.

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