Method and device for evaluating influence of different injected media on crude oil extraction effect and media

Abstract

The embodiment of the invention provides a method and device for evaluating the influence of different injected media on the crude oil extraction effect and media, and belongs to the field of unconventional oil reservoir extraction. The evaluation method is applied to a fracturing simulation system and comprises the steps that based on a fracturing fluid control system, a pre-constructed stratum model is fractured, so that cracks appear in the stratum model, and a first medium and a second medium are injected into a natural core column in the stratum model at different time periods through a displacement system, respectively obtaining the volume of crude oil extracted after the first medium and the second medium are injected; and evaluating the effects of injecting the first medium and the second medium to extract the crude oil according to the volumes of the two crude oil. In this way, after fracturing is completed, different media are injected into the pre-constructed stratum model, the volumes of the crude oil extracted after the media are injected are obtained, the effects of the different media on the extracted crude oil are evaluated, and then in later-stage extraction, the injected media can be further preferably selected according to the effects, and the crude oil yield and the extraction efficiency are improved.

Description

Technical Field

[0001] The invention relates to the technical field of unconventional oil reservoir exploitation, and in particular to an evaluation method, a device and a medium for evaluating the impact of different media injection on crude oil recovery effects. Background Art

[0002] With the increase in global demand for oil and gas resources, it is becoming increasingly difficult to increase reserves and production of conventional oil and gas resources, and they are gradually unable to meet the demand. Unconventional oil and gas with huge resource potential has received more and more attention. Although unconventional reservoirs are rich in resources, they also have the characteristics of poor physical properties, complex pore structure, low reservoir pressure coefficient, and low single well production capacity. Relying on conventional development methods, the crude oil production is very low or even zero. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a method, device and medium for evaluating the effect of injecting different media on crude oil recovery, so as to solve the technical problems existing in the above-mentioned prior art.

[0004] In order to achieve the above object, an embodiment of the present invention provides an evaluation method for the effect of injecting different media on crude oil recovery, which is applied to a fracturing simulation system. The fracturing simulation system includes a fracturing fluid control system, a displacement system and a liquid metering system. The analysis method includes:

[0005] Based on the fracturing fluid control system, fracturing is performed on a pre-constructed formation model so that cracks appear in the formation model, wherein the pre-constructed formation model is constructed based on the natural core column, the horizontal well and the three-layer cast formation;

[0006] Injecting a first medium into the formation model through the displacement system, and obtaining the volume of crude oil produced in the formation model after the first medium is injected based on the liquid metering system;

[0007] Injecting a second medium into the formation model through the displacement system, and obtaining the volume of crude oil produced in the formation model after the injection of the second medium based on the liquid metering system;

[0008] According to the volume of crude oil produced after the injection of the first medium and the volume of crude oil produced after the injection of the second medium, the effects of injecting the first medium and injecting the second medium to produce crude oil are evaluated.

[0009] Optionally, the fracturing simulation system further includes a microcomputer system, and the fracturing of the pre-built formation model based on the fracturing fluid control system includes:

[0010] The fracturing fluid control system is used to inject fracturing fluid into the horizontal well in the pre-constructed formation model. The microcomputer system is used to control the displacement of the fracturing fluid. When it is detected that the fracturing fluid overflows the formation model, the injection of the fracturing fluid is stopped.

[0011] Optionally, the evaluation method further includes:

[0012] Evaluate the crude oil recovery effect according to the injection method of the injection medium;

[0013] Acquiring, based on the liquid metering system, the volume of crude oil produced when the displacement system is displacing the formation model, and the volume of crude oil produced when the displacement system is performing huff and puff;

[0014] According to the volume of crude oil produced during the displacement and the volume of crude oil produced during the huff and puff, the effects of the displacement injection and the huff and puff injection on the produced crude oil are evaluated.

[0015] Optionally, the step of obtaining, based on the liquid metering system, the volume of crude oil produced when the displacement system is displaced by the formation model, and the volume of crude oil produced when the displacement system is performing huff and puff, comprises:

[0016] While starting the displacement system, the fracturing fluid system is closed, and the injection pressure is adjusted so that the internal pressure of the horizontal well reaches the pressure value required for displacement, and the volume of crude oil produced during displacement is obtained through the liquid metering system;

[0017] After the displacement system is opened for a period of time, the displacement system is closed for well blocking, and after counting the well blocking time, the volume of crude oil produced during the well blocking process is obtained through the liquid metering system.

[0018] Optionally, the evaluation method further includes:

[0019] Obtain the distribution of saturated crude oil in natural core columns after fracturing;

[0020] The natural core column is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection medium is displaced, and the crude oil production of pores of different sizes in the natural core column after the huff-and-puff process;

[0021] The first comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is displaced.

[0022] The second comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is subjected to a huff-and-puff process;

[0023] The effects of displacement injection and huff-and-puff injection on crude oil recovery are evaluated based on the first comparison result and the second comparison result.

[0024] Optionally, the method further includes:

[0025] After the medium displacement injection, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the displacement process;

[0026] After the medium is injected, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection process;

[0027] By comparing the crude oil production conditions of the natural core column pores of different sizes after displacement injection and the crude oil production conditions of the natural core column pores of different sizes after huff-and-puff injection, the crude oil recovery effects of displacement injection and huff-and-puff injection are evaluated.

[0028] Optionally, the construction of the pre-constructed formation model includes:

[0029] Placing the horizontal well and the natural core column in a mold, wherein the horizontal well is placed in the middle of the mold, and the natural core column is placed around the horizontal well at equal angles;

[0030] Actual rocks are selected as interlayers between the upper middle layer and the middle lower layer in the three-layer casting stratum, and the stratum model is obtained by casting in layers, wherein the stratum model has heterogeneity.

[0031] Optionally, before placing the natural core column in the mold, the evaluation method further comprises:

[0032] The natural core column is cleaned and dried, and then placed in a core holder. After adding confining pressure, the core is vacuumed and simulated oil is injected to make it saturated.

[0033] Optionally, before placing the horizontal well in the mold, the evaluation method further comprises:

[0034] Holes are drilled at equal distances along the axial direction of the horizontal well to simulate perforation holes for injecting the first medium or the second medium.

[0035] Accordingly, an embodiment of the present invention further provides an evaluation device for the effect of injecting different media on crude oil recovery, comprising:

[0036] A fracturing unit, used for fracturing a pre-constructed formation model based on the fracturing fluid control system, so that cracks appear in the formation model, wherein the pre-constructed formation model is constructed based on the natural core column, the horizontal well and the three-layer cast formation;

[0037] an acquisition unit, configured to inject a first medium into the formation model through the displacement system, and acquire the volume of crude oil produced in the formation model after the first medium is injected based on the liquid metering system; inject a second medium into the formation model through the displacement system, and acquire the volume of crude oil produced in the formation model after the second medium is injected based on the liquid metering system;

[0038] The evaluation unit is used to evaluate the effects of injecting the first medium and injecting the second medium to produce crude oil according to the volume of crude oil produced after injecting the first medium and the volume of crude oil produced after injecting the second medium.

[0039] Optionally, the fracturing unit is used for:

[0040] The fracturing fluid control system is used to inject fracturing fluid into the horizontal well in the pre-constructed formation model. The microcomputer system is used to control the displacement of the fracturing fluid. When it is detected that the fracturing fluid overflows the formation model, the injection of the fracturing fluid is stopped.

[0041] Optionally, the evaluation unit is further used for:

[0042] Evaluate the crude oil recovery effect according to the injection method of the injection medium;

[0043] Acquiring, based on the liquid metering system, the volume of crude oil produced when the displacement system is displacing the formation model, and the volume of crude oil produced when the displacement system is performing huff and puff;

[0044] According to the volume of crude oil produced during the displacement and the volume of crude oil produced during the huff and puff, the effects of the displacement injection and the huff and puff injection on the produced crude oil are evaluated.

[0045] Optionally, the evaluation unit is used to:

[0046] While starting the displacement system, the fracturing fluid system is closed, and the injection pressure is adjusted so that the internal pressure of the horizontal well reaches the pressure value required for displacement, and the volume of crude oil produced during displacement is obtained through the liquid metering system;

[0047] After the displacement system is opened for a period of time, the displacement system is closed for well blocking, and after counting the well blocking time, the volume of crude oil produced during the well blocking process is obtained through the liquid metering system.

[0048] Optionally, the evaluation unit is further used for:

[0049] Obtain the distribution of saturated crude oil in natural core columns after fracturing;

[0050] The natural core column is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection medium is displaced, and the crude oil production of pores of different sizes in the natural core column after the huff-and-puff process;

[0051] The first comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is displaced.

[0052] The second comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is subjected to a huff-and-puff process;

[0053] The effects of displacement injection and huff-and-puff injection on crude oil recovery are evaluated based on the first comparison result and the second comparison result.

[0054] Optionally, the acquisition unit is further used for:

[0055] After the medium displacement injection, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the displacement process;

[0056] After the medium is injected, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection process;

[0057] By comparing the crude oil production conditions of the natural core column pores of different sizes after displacement injection and the crude oil production conditions of the natural core column pores of different sizes after huff-and-puff injection, the crude oil recovery effects of displacement injection and huff-and-puff injection are evaluated.

[0058] Optionally, the fracturing unit is further used for:

[0059] The construction of the pre-built formation model includes:

[0060] Placing the horizontal well and the natural core column in a mold, wherein the horizontal well is placed in the middle of the mold, and the natural core column is placed around the horizontal well at equal angles;

[0061] Actual rocks are selected as interlayers between the upper middle layer and the middle lower layer in the three-layer casting stratum, and the stratum model is obtained by casting in layers, wherein the stratum model has heterogeneity.

[0062] Optionally, the fracturing unit is further used for:

[0063] The natural core column is cleaned and dried, and then placed in a core holder. After adding confining pressure, the core is vacuumed and simulated oil is injected to make it saturated.

[0064] Optionally, the fracturing unit is further used for:

[0065] Holes are drilled at equal distances along the axial direction of the horizontal well to simulate perforation holes for injecting the first medium or the second medium.

[0066] On the other hand, an embodiment of the present invention further provides a processor for running a program, wherein the program is used to execute the above-mentioned evaluation method when being run.

[0067] On the other hand, an embodiment of the present invention further provides a computer-readable medium having computer instructions stored thereon, wherein when the computer instructions are executed by a processor, the above-mentioned evaluation method is executed.

[0068] Through the above technical scheme, after fracturing is completed, different media are injected into the pre-constructed formation model to obtain the volumes of crude oil produced after the injection of each medium, and the effects of different media on the produced crude oil are evaluated. In the later production, the injection medium can be further optimized according to the effect to improve the crude oil production and production efficiency.

[0069] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0071] Figure 1 It is a flow chart of an implementation of a method for evaluating the effect of injecting different media on crude oil recovery provided by an embodiment of the present invention;

[0072] Figure 2 is a schematic diagram of a fracturing simulation system provided by an embodiment of the present invention;

[0073] Figure 3 is a schematic diagram of a pre-constructed formation model provided by an embodiment of the present invention;

[0074] Figure 4 It is a flow chart of an implementation of a method for evaluating the influence of different medium injection modes on crude oil recovery effect provided by an embodiment of the present invention;

[0075] Figure 5 It is another implementation flow chart of a method for evaluating the influence of different medium injection modes on crude oil recovery effect provided by an embodiment of the present invention;

[0076] Figure 6 An evaluation device for the effect of injecting different media on crude oil recovery provided by an embodiment of the present invention is a schematic diagram of the evaluation device.

[0077] Description of Reference Numerals

[0078] 11 horizontal well 12 natural core column

[0079] 13 Speed ​​sensor 14 Pressure sensor

[0080] 15 Casting sample 1 16 Casting sample 2 17 Casting sample 3

[0081] 2 Fracturing fluid control system 21 Fracturing fluid pipeline 22 Fracturing fluid one-way flow valve

[0082] 3Liquid metering system 31Mixed liquid pipeline

[0083] 4 displacement system 41 displacement pipeline 42 displacement one-way flow valve

[0084] 5 Confining pressure system 51 Confining pressure pipeline

[0085] 6 Microcomputer control system 61 Signal transmission line DETAILED DESCRIPTION

[0086] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0087] See also Figure 1 As shown in FIG. 1 , it is a flowchart of an implementation of an evaluation method for the effect of injecting different media on crude oil recovery provided by an embodiment of the present invention. The evaluation method is applied to a fracturing simulation system, wherein the schematic diagram of the fracturing simulation system is as shown in FIG. Figure 2 As shown, it includes a fracturing fluid control system 2, a liquid metering system 3 and a displacement system 4. The evaluation method implementation flow chart includes the following execution steps:

[0088] Step 100: Based on the fracturing fluid control system, a pre-constructed formation model is fractured to cause cracks to appear in the formation model.

[0089] The pre-constructed formation model is constructed based on the natural core column, horizontal well and three-layer cast formation.

[0090] In some embodiments, see Figure 2 As shown, the simulation system also includes a microcomputer system 23. In the step 100, the pre-built formation model is subjected to fracturing, and the following steps may be performed:

[0091] The fracturing fluid control system is used to inject fracturing fluid into the horizontal well in the pre-constructed formation model. The microcomputer system is used to control the displacement of the fracturing fluid. When it is detected that the fracturing fluid overflows the formation model, the injection of the fracturing fluid is stopped.

[0092] In some embodiments, the construction of the pre-constructed formation model comprises the following steps:

[0093] S1: placing the horizontal well and the natural core column in a mold, wherein the horizontal well is placed in the middle of the mold, and the natural core column is placed around the horizontal well at equal angles;

[0094] In some embodiments, before placing the natural core column into the three-dimensional model, the natural core column is first soaked in simulated oil to make the natural core column oil-saturated, and the pore structure and microscopic distribution of cracks of the natural core column before fracturing are obtained by CT scanning technology, and the distribution of crude oil is determined by the T2 spectrum of nuclear magnetic resonance.

[0095] S2: Select actual rocks as the interlayers between the upper middle layer and the middle lower layer in the three-layer casting stratum, and cast them in layers to obtain the stratum model, wherein the stratum model has heterogeneity.

[0096] In some embodiments, before executing step S1, the natural core column is cleaned and dried and then placed in a core holder, the core is vacuumed after adding confining pressure, and simulated oil is injected to make it saturated.

[0097] In some embodiments, before executing step S1, equidistant perforation is performed along the axial direction of the horizontal well to simulate perforation holes for injecting the first medium or the second medium.

[0098] In some embodiments, the pre-constructed formation model schematic diagram is constructed as follows Figure 3As shown, four sections of holes are drilled at equal distances along the axial direction of the horizontal well 11, and six holes are drilled at equal angles in each section, for a total of 24 holes, which are used to simulate perforation holes. The dimensions of the horizontal well 11 are an outer radius of 53.97 mm, an inner radius of 30.34 mm, and a length of 500 mm. The horizontal well 11 and the natural core column 12 are placed in the mold (50 mm above the bottom of the mold), and the placement positions are as follows: the horizontal well 11 is placed in the middle, and the natural core column 12 is divided into three pieces, which are placed at equal angles around the horizontal well at a distance of 100 mm. The dimensions of the natural core column 12 are an outer radius of 100 mm, an inner radius of 30 mm, and a height of 600 mm. Select the actual rock, and cut the actual rock into two pieces as the interlayer 16 by a saw blade cutter, with a size of 600 mm×600 mm×10 mm. A model was made by casting a 600mm×600mm×600mm cube sample 1 in layers. The model included a three-dimensional stratum (divided into three layers, 17, 18 and 19), a horizontal well 11, and a natural core column 12, all of which ran through the three-layer model. The permeability of the three-layer sample was made heterogeneous by configuring cement, so that the model simulation results were closer to the actual stratum conditions.

[0099] In some embodiments, the fracturing fluid control system 2 is connected to the liquid metering system 3 via the fracturing fluid pipeline 21 and the fracturing fluid one-way flow valve 22, the liquid metering system 3 is connected to the formation model via the mixed liquid pipeline, the displacement system 4 is connected to the microcomputer system 6 via the signal transmission line 61, and the displacement system 4 is connected to the natural core column via the displacement pipeline 41 and the one-way flow valve 42.

[0100] In some embodiments, see Figure 2 As shown, the fracturing simulation system also includes a confining pressure system 24, which connects the casting pattern 1 with the confining pressure system 5 and ensures the boundary sealing. The fracturing fluid control system 2 is connected, the fracturing source pipeline 25 is connected, the displacement is controlled by the microcomputer system 6, and the pressure-time curve is monitored in real time. When the fracturing fluid overflows from the edge of the casting pattern 1, the injection of the fracturing fluid is stopped through the control program.

[0101] In some embodiments, after fracturing is completed, it is in the depressurization and flowback stage. The pressure inside the horizontal well 11 is continuously monitored by the pressure sensor 14, and the internal pressure of the horizontal well is changed by the fracturing fluid control system 2 to set different flowback speeds. The speed sensor 13 is used for monitoring, and a functional relationship between the well pressure and the flowback speed is established to analyze the influence of the flowback speed on the crude oil recovery degree. CT scanning is used to monitor the influence of the speed change of the entire flowback process on the fracture distribution and pore characteristics. The signal is measured by the nuclear magnetic resonance T2 spectrum to calculate the changes in the seepage field and the crude oil saturation field after fracturing.

[0102] In the existing technology, hydraulic fracturing technology is mostly used to expand the contact area between the wellbore and the formation, form a fracture network with improved conductivity, and effectively increase the production of a single well. However, due to the influence of factors such as increased differential stress caused by hydraulic fracturing and reservoir heterogeneity defects, the reservoir rock body usually not only has tension-shear failure of small-scale cracks, but also has complex mechanical behaviors such as tension, shear, slip and dislocation of large-scale structural surfaces such as joints and faults. If natural fractures of different densities develop in the reservoir, there will be a problem of injection medium crossflow, and the oil well will quickly break through the injection medium in a short period of time, resulting in a rapid decline in production in a short period of time.

[0103] Step 101: injecting a first medium into the natural core column in the formation model through the displacement system, and obtaining the volume of crude oil produced in the formation model after the first medium is injected based on the liquid metering system.

[0104] Step 102: injecting a second medium into the natural core column in the formation model through the displacement system, and obtaining the volume of crude oil produced in the formation model after the second medium is injected based on the liquid metering system;

[0105] In some embodiments, the injected first medium and the injected second medium are different. The first medium and the injected second medium may be water and different gases, such as carbon dioxide.

[0106] Step 103: Evaluate the effects of injecting the first medium and injecting the second medium for producing crude oil according to the volume of crude oil produced after injecting the first medium and the volume of crude oil produced after injecting the second medium.

[0107] In some embodiments, in addition to evaluating the crude oil production volume in steps 100-103, the crude oil production effect can also be evaluated in the following second manner: evaluating the crude oil production effect according to the injection method of the injection medium, specifically including the following execution steps:

[0108] S200: Based on the liquid metering system, the volume of crude oil produced when the displacement system is displacing the formation model and the volume of crude oil produced when the displacement system is performing huff and puff are acquired.

[0109] In some implementations, when executing S200, the following steps may be performed:

[0110] While starting the displacement system, the fracturing fluid system is closed, and the injection pressure is adjusted so that the internal pressure of the horizontal well reaches the pressure value required for displacement, and the volume of crude oil produced during displacement is obtained through the liquid metering system;

[0111] After the displacement system is opened for a period of time, the displacement system is closed for well blocking, and after counting the well blocking time, the volume of crude oil produced during the well blocking process is obtained through the liquid metering system.

[0112] S201: Evaluate the effects of displacement injection and huff and puff injection on the crude oil produced according to the volume of crude oil produced during the displacement and the volume of crude oil produced during the huff and puff.

[0113] In some embodiments, see Figure 4 As shown, the crude oil recovery effect can also be evaluated according to the injection method of the injection medium, and the crude oil recovery effect can also be evaluated by the following steps:

[0114] S400: Obtain the distribution of saturated crude oil in the natural core column after fracturing.

[0115] S401: The natural core column is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection medium is displaced, and the crude oil production of pores of different sizes in the natural core column after the huff and puff process.

[0116] S402: Obtain a first comparison result by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is displaced.

[0117] S403: Obtain a second comparison result by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is subjected to a huff-and-puff process.

[0118] S404: Evaluate the effects of displacement injection and huff-and-puff injection on crude oil recovery based on the first comparison result and the second comparison result.

[0119] In some embodiments, see Figure 5 As shown, the crude oil recovery effect can be evaluated according to the injection method of the injection medium. The crude oil recovery effect can also be evaluated by the following steps:

[0120] S500: After the medium displacement injection, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production conditions of pores of different sizes in the natural core column after the displacement process.

[0121] S501: After the medium is injected, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection process.

[0122] Macroscopically, after large-scale fracturing, unconventional reservoirs form complex fracture networks. The original single medium reservoir becomes a dual medium reservoir with fractures and matrix coexisting, making it difficult to understand the distribution characteristics of the remaining oil. Microscopically, it is also difficult to directly observe and measure the characteristics of crude oil production in different pores. At present, the main methods for studying the distribution of remaining oil in pores are core thin section microscopic models, online CT scanning and nuclear magnetic resonance technology. The core thin section microscopic model is a one-dimensional simulation, and it is difficult to quantitatively characterize the remaining oil as a whole. Although online CT scanning can provide intuitive images of the remaining oil distribution, the accuracy of the scanning results is closely related to the image processing and resolution, and the subjective influence is serious, making it impossible to quantitatively analyze the changes in the oil phase in pore throats of different pore sizes. For this reason, the nuclear magnetic resonance method is used to analyze the microscopic characteristics of crude oil production and the distribution characteristics of remaining oil before and after real core fracturing.

[0123] S502: Evaluate the crude oil recovery effects of displacement injection and huff and puff injection by comparing the crude oil production conditions of the pores of different sizes of the natural core column after displacement injection and the crude oil production conditions of the pores of different sizes of the natural core column after huff and puff injection.

[0124] In some embodiments, a displacement scheme is performed by injecting different media using a displacement system, and the injection pressure is continuously modified based on the displacement system so that the horizontal well pressure reaches the pressure value required for displacement, the crude oil production volume is calculated, and the injection parameters are optimized; a throughput scheme is adopted, and the injection pressure is continuously modified based on the displacement system so that the horizontal well pressure reaches the pressure value required for displacement, the displacement system is closed, and after the well is blocked for a period of time, the displacement system is reopened to start production, and the throughput ends, and the produced crude oil volume is calculated in the same way, the injection parameters are optimized, the optimal blocking time is determined, the operation is repeated, the throughput times are counted, and the throughput cycle is optimized. Compare the produced crude oil volumes of displacement and throughput, adopt different injection media for operation, and evaluate the development effects of different injection methods with different injection media.

[0125] The two common injection methods for fracturing energy replenishment are displacement and throughput. If the displacement energy replenishment method is used, the injected medium will directly break through the production well along the fracture or high permeability channel, and the recovery rate is low; while the throughput energy replenishment method can effectively avoid the crossflow of the injected medium through the three stages of injection, well blocking and production, which can not only prolong the breakthrough time of the injected medium in the oil well, but also reasonably and effectively replenish the formation energy, with the advantages of strong pertinence, short cycle, quick effect and high recovery rate.

[0126] Accordingly, the present invention also provides an evaluation device for injecting different media to affect the crude oil recovery effect, and the schematic diagram of the evaluation device is shown in FIG. Figure 6 As shown, including:

[0127] A fracturing unit 600, configured to perform fracturing on a pre-constructed formation model based on the fracturing fluid control system, so that cracks appear in the formation model, wherein the pre-constructed formation model is constructed based on the natural core column, the horizontal well, and the three-layer cast formation;

[0128] The acquisition unit 601 is used to inject a first medium into the natural core column in the formation model through the displacement system, and acquire the volume of crude oil produced in the formation model after the first medium is injected based on the liquid metering system; inject a second medium into the natural core column in the formation model through the displacement system, and acquire the volume of crude oil produced in the formation model after the second medium is injected based on the liquid metering system;

[0129] The evaluation unit 602 is used to evaluate the effects of injecting the first medium and injecting the second medium to produce crude oil according to the volume of crude oil produced after injecting the first medium and the volume of crude oil produced after injecting the second medium.

[0130] In some embodiments, the fracturing unit 600 is used to:

[0131] The fracturing fluid control system is used to inject fracturing fluid into the horizontal well in the pre-constructed formation model. The microcomputer system is used to control the displacement of the fracturing fluid. When it is detected that the fracturing fluid overflows the formation model, the injection of the fracturing fluid is stopped.

[0132] In some implementations, the evaluation unit 602 is further configured to:

[0133] Evaluate the crude oil recovery effect according to the injection method of the injection medium;

[0134] Acquiring, based on the liquid metering system, the volume of crude oil produced when the displacement system is displacing the formation model, and the volume of crude oil produced when the displacement system is performing huff and puff;

[0135] According to the volume of crude oil produced during the displacement and the volume of crude oil produced during the huff and puff, the effects of the displacement injection and the huff and puff injection on the produced crude oil are evaluated.

[0136] In some embodiments, the evaluation unit 602 is used to:

[0137] While starting the displacement system, the fracturing fluid system is closed, and the injection pressure is adjusted so that the internal pressure of the horizontal well reaches the pressure value required for displacement, and the volume of crude oil produced during displacement is obtained through the liquid metering system;

[0138] After the displacement system is opened for a period of time, the displacement system is closed for well blocking, and after counting the well blocking time, the volume of crude oil produced during the well blocking process is obtained through the liquid metering system.

[0139] In some implementations, the evaluation unit 602 is further configured to:

[0140] Obtain the distribution of saturated crude oil in natural core columns after fracturing;

[0141] The natural core column is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection medium is displaced, and the crude oil production of pores of different sizes in the natural core column after the huff-and-puff process;

[0142] The first comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is displaced.

[0143] The second comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is subjected to a huff-and-puff process;

[0144] The effects of displacement injection and huff-and-puff injection on crude oil recovery are evaluated based on the first comparison result and the second comparison result.

[0145] In some implementations, the acquiring unit 601 is further configured to:

[0146] After the medium displacement injection, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the displacement process;

[0147] After the medium is injected, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection process;

[0148] By comparing the crude oil production conditions of the natural core column pores of different sizes after displacement injection and the crude oil production conditions of the natural core column pores of different sizes after huff-and-puff injection, the crude oil recovery effects of displacement injection and huff-and-puff injection are evaluated.

[0149] In some embodiments, the fracturing unit 600 is further used to:

[0150] The construction of the pre-built formation model includes:

[0151] Placing the horizontal well and the natural core column in a mold, wherein the horizontal well is placed in the middle of the mold, and the natural core column is placed around the horizontal well at equal angles;

[0152] Actual rocks are selected as interlayers between the upper middle layer and the middle lower layer in the three-layer casting stratum, and the stratum model is obtained by casting in layers, wherein the stratum model has heterogeneity.

[0153] In some embodiments, the fracturing unit 600 is further used to:

[0154] The natural core column is cleaned and dried, and then placed in a core holder. After adding confining pressure, the core is vacuumed and simulated oil is injected to make it saturated.

[0155] In some embodiments, the fracturing unit 600 is further used to:

[0156] Holes are drilled at equal distances along the axial direction of the horizontal well to simulate perforation holes for injecting the first medium or the second medium.

[0157] On the other hand, the present invention further provides a processor for running a program, wherein the program, when being run, is used to execute the evaluation method described in any one of the above embodiments.

[0158] On the other hand, the present invention further provides a computer-readable medium having computer instructions stored thereon, wherein when the computer instructions are executed by a processor, the evaluation method described in any one of the above embodiments is executed.

[0159] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0160] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0161] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0162] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0163] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0164] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0165] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0166] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0167] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for evaluating the effect of injecting different media on crude oil recovery, applied to a fracturing simulation system, characterized in that: The fracturing simulation system includes a fracturing fluid control system, a displacement system and a liquid metering system, and the analysis method includes: Based on the fracturing fluid control system, fracturing is performed on a pre-constructed formation model so that cracks appear in the formation model, wherein the pre-constructed formation model is constructed based on the natural core column, the horizontal well and the three-layer cast formation; Injecting a first medium into the natural core column in the formation model through the displacement system, and obtaining the volume of crude oil produced in the formation model after the first medium is injected based on the liquid metering system; Injecting a second medium into the natural core column in the formation model through the displacement system, and obtaining the volume of crude oil produced in the formation model after the injection of the second medium based on the liquid metering system; According to the volume of crude oil produced after the injection of the first medium and the volume of crude oil produced after the injection of the second medium, the effects of injecting the first medium and injecting the second medium to produce crude oil are evaluated.

2. The evaluation method according to claim 1, characterized in that: The fracturing simulation system further includes a microcomputer system, and the fracturing is performed on the pre-built formation model based on the fracturing fluid control system, including: The fracturing fluid control system is used to inject fracturing fluid into the horizontal well in the pre-constructed formation model. The microcomputer system is used to control the displacement of the fracturing fluid. When it is detected that the fracturing fluid overflows the formation model, the injection of the fracturing fluid is stopped.

3. The evaluation method according to claim 1, characterized in that: The evaluation method further comprises: Evaluate the crude oil recovery effect according to the injection method of the injection medium; Acquiring, based on the liquid metering system, the volume of crude oil produced when the displacement system is displacing the formation model, and the volume of crude oil produced when the displacement system is performing huff and puff; According to the volume of crude oil produced during the displacement and the volume of crude oil produced during the huff and puff, the effects of the displacement injection and the huff and puff injection on the produced crude oil are evaluated.

4. The evaluation method according to claim 3, characterized in that: The method of obtaining the volume of crude oil produced when the displacement system is used to displace the formation model based on the liquid metering system, and the volume of crude oil produced when the displacement system is used to perform huff and puff, comprises: While starting the displacement system, the fracturing fluid system is closed, and the injection pressure is adjusted so that the internal pressure of the horizontal well reaches the pressure value required for displacement, and the volume of crude oil produced during displacement is obtained through the liquid metering system; After the displacement system is opened for a period of time, the displacement system is closed for well blocking, and after counting the well blocking time, the volume of crude oil produced during the well blocking process is obtained through the liquid metering system.

5. The evaluation method according to claim 3, characterized in that: Also includes: Obtain the distribution of saturated crude oil in natural core columns after fracturing; The natural core column is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection medium is displaced, and the crude oil production of pores of different sizes in the natural core column after the huff-and-puff process; The first comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is displaced. The second comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is subjected to a huff-and-puff process; The effects of displacement injection and huff-and-puff injection on crude oil recovery are evaluated based on the first comparison result and the second comparison result.

6. The evaluation method according to claim 3, characterized in that: The method further comprises: After the medium displacement injection, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the displacement process; After the medium is injected, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection process; By comparing the crude oil production conditions of the natural core column pores of different sizes after displacement injection and the crude oil production conditions of the natural core column pores of different sizes after huff-and-puff injection, the crude oil recovery effects of displacement injection and huff-and-puff injection are evaluated.

7. The evaluation method according to claim 1, characterized in that: The construction of the pre-built formation model includes: Placing the horizontal well and the natural core column in a mold, wherein the horizontal well is placed in the middle of the mold, and the natural core column is placed around the horizontal well at equal angles; Actual rocks are selected as interlayers between the upper middle layer and the middle lower layer in the three-layer casting stratum, and the stratum model is obtained by casting in layers, wherein the stratum model has heterogeneity.

8. The evaluation method according to claim 7, characterized in that: Before placing the natural core column in the mold, the evaluation method further comprises: The natural core column is cleaned and dried, and then placed in a core holder. After adding confining pressure, the core is vacuumed and simulated oil is injected to make it saturated.

9. The evaluation method according to claim 7, characterized in that: Before placing the horizontal well in the mold, the evaluation method further comprises: Holes are drilled at equal distances along the axial direction of the horizontal well to simulate perforation holes for injecting the first medium or the second medium.

10. An evaluation device for the effect of injecting different media on crude oil recovery, characterized in that: include: A fracturing unit, used for fracturing a pre-constructed formation model based on the fracturing fluid control system, so that cracks appear in the formation model, wherein the pre-constructed formation model is constructed based on the natural core column, the horizontal well and the three-layer cast formation; an acquisition unit, configured to inject a first medium into the formation model through the displacement system, and acquire the volume of crude oil produced in the formation model after the first medium is injected based on the liquid metering system; inject a second medium into the formation model through the displacement system, and acquire the volume of crude oil produced in the formation model after the second medium is injected based on the liquid metering system; The evaluation unit is used to evaluate the effects of injecting the first medium and injecting the second medium to produce crude oil according to the volume of crude oil produced after injecting the first medium and the volume of crude oil produced after injecting the second medium.

11. The evaluation device according to claim 10, characterized in that The fracturing unit is used for: The fracturing fluid control system is used to inject fracturing fluid into the pre-built formation model, and the microcomputer system is used to control the displacement of the fracturing fluid. When it is detected that the fracturing fluid overflows the formation model, the injection of the fracturing fluid is stopped.

12. The evaluation device according to claim 10, characterized in that The evaluation unit is also used for: Evaluate the crude oil recovery effect according to the injection method of the injection medium; Acquiring, based on the liquid metering system, the volume of crude oil produced when the displacement system is displacing the formation model, and the volume of crude oil produced when the displacement system is performing huff and puff; According to the volume of crude oil produced during the displacement and the volume of crude oil produced during the huff and puff, the effects of the displacement injection and the huff and puff injection on the produced crude oil are evaluated.

13. The evaluation device according to claim 12, characterized in that: The evaluation unit is used to: While starting the displacement system, the fracturing fluid system is closed, and the injection pressure is adjusted so that the internal pressure of the horizontal well reaches the pressure value required for displacement, and the volume of crude oil produced during displacement is obtained through the liquid metering system; After the displacement system is opened for a period of time, the displacement system is closed for well blocking, and after counting the well blocking time, the volume of crude oil produced during the well blocking process is obtained through the liquid metering system.

14. The evaluation device according to claim 12, characterized in that: The evaluation unit is also used for: Obtain the distribution of saturated crude oil in natural core columns after fracturing; The natural core column is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection medium is displaced, and the crude oil production of pores of different sizes in the natural core column after the huff-and-puff process; The first comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is displaced. The second comparison result is obtained by comparing the distribution of saturated crude oil in the natural core column after fracturing and the crude oil utilization in pores of different sizes in the natural core column after the injection medium is subjected to a huff-and-puff process; The effects of displacement injection and huff-and-puff injection on crude oil recovery are evaluated based on the first comparison result and the second comparison result.

15. The evaluation device according to claim 11, characterized in that The acquisition unit is also used for: After the medium displacement injection, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the displacement process; After the medium is injected, the natural core is taken out from the fracturing simulation system, and T2 spectrum sampling and nuclear magnetic resonance are performed to obtain the crude oil production of pores of different sizes in the natural core column after the injection process; By comparing the crude oil production conditions of the natural core column pores of different sizes after displacement injection and the crude oil production conditions of the natural core column pores of different sizes after huff-and-puff injection, the crude oil recovery effects of displacement injection and huff-and-puff injection are evaluated.

16. The evaluation device according to claim 10, characterized in that The fracturing unit is also used for: The construction of the pre-built formation model includes: Placing the horizontal well and the natural core column in a mold, wherein the horizontal well is placed in the middle of the mold, and the natural core column is placed around the horizontal well at equal angles; Actual rocks are selected as interlayers between the upper middle layer and the middle lower layer in the three-layer casting stratum, and the stratum model is obtained by casting in layers, wherein the stratum model has heterogeneity.

17. The evaluation device according to claim 16, characterized in that The fracturing unit is also used for: The natural core column is cleaned and dried, and then placed in a core holder. After adding confining pressure, the core is vacuumed and simulated oil is injected to make it saturated.

18. The evaluation device according to claim 16, characterized in that The fracturing unit is also used for: Holes are drilled at equal distances along the axial direction of the horizontal well to simulate perforation holes for injecting the first medium or the second medium.

19. A processor, characterized in that: Used to run a program, wherein the program, when run, is used to execute the evaluation method according to any one of claims 1 to 9.

20. A computer readable medium, characterized in that Computer instructions are stored thereon, wherein when the computer instructions are executed by a processor, the evaluation method according to any one of claims 1 to 9 is executed.

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