Measuring device for core displacement produced liquid of tight oil reservoir
By designing a core displacement and production liquid measurement device for the dense reservoir, using transparent plastic coils and angle dials, high-precision fluid metering is achieved, solving the problem of insufficient metrological accuracy or high cost in the prior art, and is suitable for dense core chamber internal displacement experiments.
Patent Information
- Application Number
- CN202510471770.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-07-11
AI Technical Summary
In the prior art, the measurement method is insufficient in the process of dense core displacement or high cost, which cannot meet the needs of dense reservoir development.
A compact reservoir core displacement and production liquid measurement device is designed, including transparent plastic coils, glass shells, rotary positioning pointers and angle dials. High-precision measurement is achieved through the calculation formula V=f(x,θ), and the measurement accuracy is up to 0.005ml.
It provides an inexpensive and high-precision metering device suitable for indoor displacement experiments of dense core chambers, reduces crude oil adhesion and wall hanging, improves metrology accuracy, and is suitable for volume measurement of liquids and gases.
Smart Images
Figure CN120294298A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a high-precision fluid metering device used in the core displacement process in oil and gas engineering, and specifically to a measuring device for the produced fluid of core displacement in tight oil reservoirs. Background Art
[0002] In newly discovered oil reservoirs, the proportion of unconventional reservoirs is rising rapidly. As the main type of unconventional oil and gas resources, tight oil and gas are the key areas of current oil and gas exploration and development.
[0003] Currently, the development of tight oil reservoirs in China urgently needs to accelerate the theoretical research process to guide mineral production practices. Tight reservoirs generally have the characteristics of low matrix permeability, complex pore structures, and strong heterogeneity. The core displacement experiment period in tight cores is long, the produced fluid volume per unit time is low, and the accuracy requirements for the metering means of produced fluids are high. How to accurately measure the produced fluids in tight core displacement experiments under indoor experimental conditions is one of the key problems that must be solved in the research of tight oil development.
[0004] The main problems existing in the existing metering means are: (1) The accuracy of conventional and inexpensive metering means such as test tubes / measuring cylinders is insufficient; (2) High-precision metering means, such as means of setting up high-speed cameras for real-time monitoring, are costly and cannot be widely promoted. Summary of the Invention
[0005] The purpose of the present invention is to provide a measuring device for the produced fluid of core displacement in tight oil reservoirs, which is used to solve the problems of insufficient accuracy or high cost of the calculation means used in the process of tight core displacement in the prior art.
[0006] The technical solution adopted by the present invention to solve its technical problems is: This measuring device for the produced fluid of core displacement in tight oil reservoirs includes a transparent plastic coiled pipe, a glass outer shell, a rotating positioning pointer, an angle scale, a positioned colored liquid slug, a terminal fluid collection container, and a support base. The glass outer shell is horizontally fixed on the support base. The transparent plastic coiled pipe is arranged in the glass outer shell. The glass outer shell is composed of a glass upper outer shell and a glass lower outer shell fixed together by screws. The rotating positioning pointer and the angle scale are centrally arranged on the upper surface of the glass upper outer shell. The transparent plastic coiled pipe forms an annular coiled pipe belt. The projection of the angle scale is located within the hollow circle surrounded by the transparent plastic coiled pipe. The inlet of the transparent plastic coiled pipe is located on the outer circle. The inlet pipe is provided with a quick connector at the inlet end, and a colored liquid slug is arranged in the inlet pipe. The outlet of the transparent plastic coiled pipe is located on the inner circle, and the outlet pipe is connected to the terminal fluid collection container;
[0007] The rotating positioning pointer cooperates with the angle scale. Each small grid of the angle scale is 1°, and each large grid is 5°. Read the number of turns and the angle where the liquid column enters the transparent plastic coil pipe, and calculate the volume of the produced liquid through the calculation formula V = f(x,θ). The measurement accuracy reaches 0.005 ml. In the formula, x is the number of turns where the liquid column enters the transparent plastic coil pipe, θ is the angle, and V is the volume of the produced liquid.
[0008] In the above solution, the specific calculation process of the volume of the produced liquid is as follows:
[0009] The length of the inlet pipe is 100 mm, and the fluid volume V1 of the inlet pipe is 0.31 cm 3 , The center line of the transparent plastic coil pipe is a logarithmic spiral line with an outer diameter of 200 mm, an inner diameter of 100 mm, 10 turns, and a pitch of 5 mm. Approximate the logarithmic spiral line as a circle.
[0010] Spiral direction from inlet to outlet: The top diameter of the first turn of the outermost circle is 200 mm, the bottom diameter is 190 mm, the top diameter of the second turn is 190 mm, the bottom diameter is 180 mm, and so on. The top diameter of the tenth turn of the innermost circle is 110 mm, and the bottom diameter is 100 mm. Calculate their equivalent diameters:
[0011]
[0012] The equivalent diameter and the number of turns conform to a linear function relationship, and the relationship formula is as shown in Equation 1-2:
[0013] D = -10.01x + 204.88(1-2)
[0014] Then the length of each turn of the transparent plastic coil pipe is calculated by formula 1-3:
[0015] L = πD = π(-10.01x + 204.88)(1-3)
[0016] The volume of the fluid in the Xth turn of the transparent plastic coil pipe is calculated by Equation 1-4:
[0017]
[0018] The Xth turn of the transparent plastic coil pipe is evenly divided into 360 parts by the angle scale, then the volume corresponding to the angle θ is:
[0019]
[0020] The fluid volume at any position of the transparent plastic coil pipe is:
[0021]
[0022] Then the method for displacing and producing the liquid volume is as follows:
[0023]
[0024] In the formula: D is the equivalent diameter in mm, D1 is the top diameter of the helix in mm, D2 is the bottom diameter of the helix in mm, L is the length of each turn of the transparent plastic coiled tube in mm, V x is the volume of the fluid in the X-th turn of the transparent plastic coiled tube in cm 3 , d is the diameter of the transparent plastic coiled tube in mm, V θ is the volume of the fluid corresponding to the θ angle in cm 3 , V2 is the volume of the fluid at any position of the transparent plastic coiled tube in cm 3 .
[0025] In the above solution, the glass shell is a borosilicate glass shell, and the transparent plastic coiled tube is a PE polyethylene transparent plastic coiled tube. The PE polyethylene transparent plastic coiled tube is an elastic hose with an inner diameter of 2 mm and a wall thickness of 1 mm.
[0026] In the above solution, the lower glass shell is connected to the support base. One end of the rotary positioning pointer is fixed in the center of the upper glass shell by a stainless steel rivet. The inner circle of the upper glass shell is engraved with angles, and the upper surface has grooves. The upper surface of the upper shell is connected to the rotary positioning pointer and the angle scale by rivets. And a through hole with a diameter of 5 mm is left at the intersection of the polar axis of the scale and the innermost circle of the coiled tube. The lower surface has grooves. The upper glass shell and the lower glass shell are connected by rivets; the terminal fluid collection vessel is a gas collection bottle or a liquid collection bottle.
[0027] In the above solution, the liquid collection bottle is an open bottle filled with clear water, and the outlet pipe of the transparent plastic coiled tube is inserted into the bottom of the clear water; the gas collection bottle is provided with a sealed rubber stopper at the bottle mouth, and there are two through holes in the sealed rubber stopper. The bottle is filled with clear water. The transparent plastic coiled tube is short and located above the liquid surface, and the outlet pipe of the collection bottle is long and located at the bottom of the bottle.
[0028] In the above solution, the positioning colored liquid slug is used to measure gas and plays a positioning role when the measured fluid is gas. When the measured fluid is liquid, the position of the liquid column of the liquid is used as the standard.
[0029] In the above solution, the measuring device for the produced fluid of the tight reservoir core displacement is used during the displacement of the reservoir core, and is used in cooperation with an ISCO pump, an intermediate container, a core inlet pressure gauge, a core outlet pressure gauge, a core holder, and a constant temperature box. It is connected to the outlet end of the core holder through a quick connector at the inlet end. The ISCO pump is connected to the intermediate container, and the intermediate container is connected to the inlet end of the core holder. The transparent plastic coiled tube serves as the passage of the fluid, and the position of the fluid liquid level can be directly observed to achieve accurate measurement of the fluid.
[0030] Beneficial effects:
[0031] 1. In the high-precision coiled tube metering device described in the present invention, by reading the position pointer of the liquid level and the indication of the angle scale, and substituting into the formula V = f(x,θ), the volume of the liquid column can be accurately calculated, and the measurement accuracy can reach 0.005 ml. It is a relatively inexpensive high-precision metering device used to solve the problem of high-precision metering of the produced fluid in the current indoor displacement experiment of tight cores.
[0032] 2. The materials used for each component in the present invention are all common materials in the laboratory, with mature technology and low price. The structure is simple, firm and durable, which is conducive to the wide promotion of the device.
[0033] 3. The high-precision coiled tube metering device described in the present invention has a wide range of applications. It can not only be used to measure the volume of liquid, but also be used to measure the volume of the produced gas in the gas drive experiment.
[0034] 4. When the high-precision coiled tube metering device described in the present invention is in use, the produced fluid is always in a moving state in the coiled tube, which can effectively reduce the adhesion and wall hanging of crude oil, thereby improving the measurement accuracy. The upper and lower shells of the device are connected by rivets and are detachable. When the PE plastic coiled tube is damaged after long-term use, it can be replaced at any time. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 is a schematic structural diagram of the overall displacement device when the present invention is applied to reservoir core displacement.
[0036] Figure 2 is a top view of the present invention.
[0037] Figure 3 is a schematic diagram of the rotating positioning pointer and the angle scale.
[0038] In the figure: 1 ISCO pump, 2 metal valve, 3 intermediate container, 4-1 inlet pressure gauge, 4-2 outlet pressure gauge, 5 core holder, 6-1 quick connector, 6-2 positioning colored liquid slug, 6-3 transparent plastic coiled tube, 6-4 rotating positioning pointer, 6-5 angle scale, 6-6 glass lower shell, 6-7 glass upper shell, 6-8 support base, 6-9 liquid collection bottle, 6-10 gas collection bottle, 7 constant temperature box. DETAILED DESCRIPTION OF THE INVENTION
[0039] The following further describes the present invention with reference to the drawings:
[0040] Refer to Figures 1 - 3, This measuring device for the produced fluid in core displacement of tight reservoirs consists of a quick connector 6-1 at the inlet end, a positioned colored liquid slug 6-2, a PE polyethylene transparent plastic coiled pipe 6-3, a rotating positioning pointer 6-4, an angle scale 6-5, a lower outer shell 6-6 made of high borosilicate glass, an upper outer shell 6-7 made of high borosilicate glass, a support base 6-8, a terminal liquid collection bottle 6-9, and a terminal gas collection bottle 6-10. The usage scenario of the present invention is core displacement experiments, and it is connected to the outlet end of the core holder through the quick connector at the inlet end. The PE polyethylene transparent plastic coiled pipe can visually observe the position of the fluid liquid level and, in cooperation with the rotating pointer protractor, achieve precise measurement of the fluid. The upper and lower outer shells made of high borosilicate glass have a protective and limiting effect on the PE polyethylene transparent plastic coiled pipe, and the lower outer shell is connected to the support base. The rotating pointer and the angle scale are fixed at the center of the upper outer shell made of high borosilicate glass by stainless steel rivets, and a fluid collection vessel is provided at the end of the device. The present invention realizes precise measurement of the fluid during the core displacement experiment of the reservoir with low cost.
[0041] The PE polyethylene transparent plastic coiled pipe 6-3 is an elastic PE polyethylene transparent plastic hose with an inner diameter of 2 mm and a wall thickness of 1 mm, and its softening point is 135 °C, which can ensure no deformation under most core displacement experiment scenarios.
[0042] The high borosilicate glass outer shell is composed of a lower glass outer shell 6-6 and an upper glass outer shell 6-7. The lower surface of the lower glass outer shell 6-6 is connected to the support base 6-8, and the upper surface has a groove, which has the function of protecting and positioning the PE polyethylene transparent plastic coiled pipe; the upper surface of the upper glass outer shell 6-7 is connected to the rotating positioning pointer and the angle scale by rivets, and a through hole with a diameter of 5 mm is left at the intersection of the polar axis of the scale and the innermost circle of the coiled pipe, and the lower surface has a groove, the function of which is to protect and position the PE polyethylene transparent plastic coiled pipe. The upper and lower outer shells of the high borosilicate glass outer shell are connected by rivets.
[0043] The rotating positioning pointer 6-4 cooperates with the angle scale 6-5. The rotating positioning pointer has scales, which respectively point to the 1st to 10th circles of the coiled pipe from the outside to the inside. Each small grid of the angle scale is 1 °, and each large grid is 5 °. Read the number of circles and the angle where the liquid column enters the coiled pipe, and substitute them into the calculation formula V = f(x, θ) to obtain the volume of the liquid column, and the measurement accuracy can reach 0.005 ml.
[0044] The end fluid collection vessel can select liquid collection bottles 6-9 and gas collection bottles 6-10 according to the measured fluid. The liquid collection bottle is an open bottle filled with clear water, and the end of the PE plastic pipe is kept at the bottom of the clear water to avoid errors caused by the volatilization of the liquid in the coiled pipe. The gas collection bottle is provided with a sealing rubber stopper at the bottle mouth, and there are two through holes for the inlet and outlet thin pipes on the rubber stopper. The bottle is filled with clear water. The inlet pipe is short and located above the liquid level, and the outlet pipe is long and located at the bottom of the bottle. The colored liquid slug (for measuring gas) in the positioning device described in the solution only plays a positioning role when the measured fluid is gas. When the measured fluid is liquid, the position of the liquid column of the liquid is taken as the standard.
[0045] Refer to Figure 1 , the present invention is used in combination with an ISCO pump 1, 6 metal valves 2, an intermediate container 3, an inlet pressure gauge 4-1 and an outlet pressure gauge 4-2, a core holder 5 and a constant temperature box 7 in the reservoir core displacement experiment. The intermediate container 3, the inlet pressure gauge 4-1, the outlet pressure gauge 4-2, the core holder 5 and the measuring device for the produced fluid from the tight oil reservoir core displacement are arranged in the constant temperature box. It is connected to the outlet end of the core holder through a quick connector at the inlet end. The PE polyethylene transparent plastic coiled pipe serves as the fluid passage, and the fluid liquid level position can be visually observed, and it is combined with a rotating pointer protractor to achieve precise measurement of the fluid. The upper and lower outer shells of high borosilicate glass have a protective and limiting effect on the PE polyethylene transparent plastic coiled pipe, and the lower outer shell is connected to the support base. One end of the rotating pointer is fixed in the center of the upper outer shell of high borosilicate glass through a stainless steel rivet. The inner circle of the upper outer shell of high borosilicate glass is engraved with angles. The end fluid collection vessel of the device can be divided into a gas collection bottle and a liquid collection bottle according to the measured fluid.
[0046] In the solution of the present invention, there is a straight pipe section at the inlet end of the coiled pipe with a length of 100 mm, and the fluid volume V1 of this part is 0.31 cm 3 , the center line of the coiled pipe is a logarithmic spiral line with an outer diameter of 200 mm, an inner diameter of 100 mm, 10 turns, and a pitch of 5 mm. Since it is relatively complex to directly calculate the perimeter and area of the logarithmic spiral line, its "equivalent diameter" is calculated here. The logarithmic spiral line is approximated as a circle to simplify the calculation process.
[0047] The top diameter of the outermost circle (the 1st circle) of the spiral line is 200 mm, the bottom diameter is 190 mm, the top diameter of the 2nd circle is 190 mm, the bottom diameter is 180 mm, and so on. The top diameter of the innermost circle (the 10th circle) is 110 mm, and the bottom diameter is 100 mm. According to formula 1-1, their equivalent diameters are calculated, and the results are shown in Table 1-1.
[0048]
[0049] Table 1-1 Equivalent diameter table of the spiral line center line
[0050]
[0051] In Table 1-1, the equivalent diameter and the number of turns conform to a linear function relationship, and the relationship formula is as shown in Equation 1-2.
[0052] D = -10.01x + 204.88 (1-2)
[0053] Then the length of each coil of the coiled tube can be calculated by Formula 1-3.
[0054] L = πD = π(-10.01x + 204.88) (1-3)
[0055] The volume of the fluid in the Xth coil of the coiled tube can be calculated by Equation 1-4.
[0056]
[0057] The Xth coil of the coiled tube is evenly divided into 360 parts by the angle scale, then the volume corresponding to the angle θ is
[0058]
[0059] The volume of the fluid at any position of the coiled tube flow metering device is
[0060]
[0061] Then the method for measuring the volume of the produced fluid in the displacement experiment by using the device described in the invention is as follows:
[0062]
[0063] Where: D—the equivalent diameter (mm), D1—the top diameter of the spiral line (mm), D2—the bottom diameter of the spiral line (mm), x—the number of turns of the coiled tube, L—the length of each coil of the tube (mm), V x —the volume of the fluid in the Xth coil of the coiled tube (cm 3 ), d—the diameter of the coiled tube (mm), θ—the angle (°), V θ —the volume of the fluid corresponding to the θ angle (cm 3 ), V2—the volume of the fluid at any position of the coiled tube (cm 3 ), V—the volume of the produced fluid (cm 3 )
[0064] Use the device described in the present invention to carry out the experiment, and the steps are as follows:
[0065] (1) Clean the intermediate container, core holder and other instrument equipment, and prepare a 25-mm standard plug dense core sample by wire cutting.
[0066] (2) Wash, dry, evacuate, saturate with simulated formation water and weigh the core.
[0067] (3) Saturate the core with simulated oil, let it stand for aging, and weigh it.
[0068] (4) Place the aged tight core in the core holder 5, and prepare the displacement fluid in the intermediate container 3.
[0069] (5) Turn on the thermostat 7. After the temperature of the whole system stabilizes, turn on the inlet valve, outlet valve of the intermediate container and the two valves in front of the inlet of the core holder 5 in sequence.
[0070] (6) Use the ISCO pump 1 to apply pressure to the fluid in the intermediate container 3. After the pressure stabilizes, turn on the two valves behind the outlet of the core holder 5 and start the displacement.
[0071] (7) After displacing for a fixed time, observe the position of the liquid column in the coil metering device. Move the rotating positioning pointer so that the left edge of the pointer is flush with the top surface of the liquid column. Read the number of turns scale of the rotating positioning pointer and the angle shown on the angle scale disk, and substitute them into the formula V = f(x,θ) to obtain the liquid volume.
[0072] (8) Calculate the oil slug volume and the displacement medium volume at this moment according to the operation in step (7) respectively, and record them.
[0073] (9) Repeat steps (7) and (8) until the displacement experiment ends, clean the instrument and equipment, and analyze the experimental data.
Claims
1. A measuring device for the produced fluid in core displacement of a tight reservoir, characterized in that: This measuring device for the produced fluid of core displacement in tight reservoirs includes a transparent plastic coiled pipe, a glass housing, a rotating positioning pointer, an angle scale, a positioned colored liquid slug, a terminal fluid collection vessel, and a support base. The glass housing is horizontally fixed on the support base. The transparent plastic coiled pipe is arranged in the glass housing. The glass housing is composed of an upper glass housing and a lower glass housing fixed together by screws. The rotating positioning pointer and the angle scale are centrally arranged on the upper surface of the upper glass housing. The transparent plastic coiled pipe forms an annular coiled pipe belt. The projection of the angle scale is located within the hollow circle enclosed by the transparent plastic coiled pipe. The inlet of the transparent plastic coiled pipe is located on the outer circle, and a quick connector for the inlet end is arranged on the inlet pipe. A colored liquid slug is arranged in the inlet pipe. The outlet of the transparent plastic coiled pipe is located on the inner circle, and the outlet pipe is connected to the terminal fluid collection vessel; The rotating positioning pointer cooperates with the angle scale. Each small grid of the angle scale is 1°, and each large grid is 5°. Read the number of circles and the angle where the liquid column enters the transparent plastic coiled pipe, and calculate the volume of the produced fluid through the calculation formula V = f(x,θ). The measurement accuracy reaches 0.005 ml. In the formula, x is the number of circles where the liquid column enters the transparent plastic coiled pipe, θ is the angle, and V is the volume of the produced fluid.
2. The temporary plugging agent strength evaluation device according to claim 1, characterized in that: The specific calculation process of the volume of the produced fluid is as follows: The length of the inlet pipe is 100 mm, and the fluid volume V1 in the inlet pipe is 0.31 cm 3 , the center line of the transparent plastic coiled pipe is a logarithmic spiral with an outer diameter of 200 mm, an inner diameter of 100 mm, 10 turns, and a pitch of 5 mm. The logarithmic spiral is approximated as a circle, Spiral direction from the inlet to the outlet: The top diameter of the first circle of the outermost circle is 200 mm, and the bottom diameter is 190 mm. The top diameter of the second circle is 190 mm, and the bottom diameter is 180 mm. And so on. The top diameter of the tenth circle of the innermost circle is 110 mm, and the bottom diameter is 100 mm. Calculate their equivalent diameters: The equivalent diameter and the number of circles conform to a linear function relationship, and the relationship formula is as shown in formula 1-2: D = -10.01x + 204.88 (1-2) Then the length of each circle of the transparent plastic coiled pipe is calculated through formula 1-3: L = πD = π(-10.01x + 204.88) (1-3) The volume of the fluid in the Xth circle of the transparent plastic coiled pipe is calculated through formula 1-4: The Xth circle of the transparent plastic coiled pipe is evenly divided into 360 parts by the angle scale. Then the volume of the fluid corresponding to the angle θ is: The volume of the fluid at any position of the transparent plastic coiled pipe is: Then the method for the volume of the displacement produced fluid is as follows: Where: D is the equivalent diameter in mm, D1 is the top diameter of the helix in mm, D2 is the bottom diameter of the helix in mm, L is the length of each turn of the transparent plastic coil tube in mm, V x is the volume of the fluid in the X-th turn of the transparent plastic coil tube in cm 3 , d is the diameter of the transparent plastic coil tube in mm, V θ is the volume of the fluid corresponding to the θ angle in cm 3 , V2 is the volume of the fluid at any position of the transparent plastic coil tube in cm 3 .
3. The temporary plugging agent strength evaluation device according to claim 2, wherein: The glass housing is a high borosilicate glass housing, and the transparent plastic coiled pipe is a PE polyethylene transparent plastic coiled pipe. The PE polyethylene transparent plastic coiled pipe is an elastic hose with an inner diameter of 2 mm and a wall thickness of 1 mm.
4. The temporary plugging agent strength evaluation device according to claim 3, wherein: The lower glass housing is connected to the support base. One end of the rotating positioning pointer is fixed in the center of the upper glass housing by a stainless steel rivet. The inner circle of the upper glass housing is engraved with angles, and the upper surface has grooves. The upper surface of the upper housing is connected to the rotating positioning pointer and the angle scale by rivets, and there is a through hole with a diameter of 5 mm at the intersection of the polar axis of the scale and the innermost circle of the coiled pipe. The lower surface has grooves. The upper glass housing and the lower glass housing are connected by rivets; The terminal fluid collection vessel is a gas collection bottle or a liquid collection bottle.
5. The temporary plugging agent strength evaluation device according to claim 4, characterized in that: The liquid collection bottle is an open bottle filled with clear water, and the outlet pipe of the transparent plastic coiled pipe is inserted into the bottom of the clear water; the gas collection bottle has a sealed rubber stopper at its mouth, with two through holes on the sealed rubber stopper, the bottle is filled with clear water, the transparent plastic coiled pipe is short and located above the liquid level, and the outlet pipe of the collection bottle is long and located at the bottom of the bottle.
6. The temporary plugging agent strength evaluation device according to claim 5, wherein: The positioned colored liquid slug is used to measure gas, plays a positioning role when the measured fluid is gas, and when the measured fluid is liquid, the position of the liquid column of the liquid is taken as the standard.
7. The temporary plugging agent strength evaluation device according to claim 6, characterized in that: The measuring device for the produced fluid from core displacement in tight reservoirs is used during reservoir core displacement, in cooperation with an ISCO pump, an intermediate container, a core inlet pressure gauge, a core outlet pressure gauge, a core holder, and a constant temperature box. It is connected to the outlet end of the core holder through a quick connector at the inlet end. The ISCO pump is connected to the intermediate container, and the intermediate container is connected to the inlet end of the core holder. The transparent plastic coiled pipe serves as the fluid passage, visually observing the fluid liquid level position to achieve accurate measurement of the fluid.