Pressure measuring device and method for simulating overflow shut-in

Abstract

The invention provides a pressure measuring device and method for simulating overflow shut-in. The device comprises a sand filling model, a first liquid supply assembly, a simulation wellbore, a simulation drill string, a second liquid supply assembly, a blowout preventer, a choke manifold, a pressure detecting device and a processor. The sand-packed model can simulate a drilling reservoir and is provided with a plurality of pressurizing ports; the first liquid supply assembly is used for accommodating and pumping out simulated formation fluid; inserting the simulation shaft into a sand filling model; the simulation drill column is located in the simulation shaft; the second liquid supply assembly is used for accommodating and pumping out the simulated drilling fluid; the blowout preventer is arranged at the end, away from the sand filling model, of the simulation wellbore. The choke manifold is arranged between the simulation wellbore and the second liquid supply assembly; the pressure detection device is used for detecting the stress of the simulation wellbore in the well shut-in process in the overflow state; the processor is used for determining water hammer pressure and formation pressure according to the stress. Water hammer pressure and formation pressure can be obtained more accurately and quickly, and the well shut-in effect is improved.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas well blowout prevention, and in particular to a pressure measuring device and a pressure measuring method for simulating overflow well shut-in. Background Art

[0002] With the rapid development of human society's economy, production, and construction, the demand for oil and natural gas resources has also increased dramatically. Given that traditional fossil fuels remain the primary energy source, increasing the utilization rate of oil and gas resources is a key measure to address the energy shortage during social development. During oil development, overflows may occur due to the complexity of reservoirs. The most direct means of addressing overflows is to shut in the well. These are categorized as hard shut-ins and soft shut-ins. A hard shut-in involves directly closing the wellhead blowout preventer (BOP) with the surface choke manifold closed. A soft shut-in involves first closing the wellhead BOP and then the choke manifold with the surface choke manifold open. While a hard shut-in requires minimal movement and is quicker, the closure of the choke manifold suddenly interrupts the flow path, causing a sharp change in flow velocity. This leads to a rapid change in the kinetic energy of the fluid in the wellbore system, resulting in a "water hammer" effect and a sharp increase in pressure on the wellhead, casing, and formation. While soft shut-in can prevent excessive water hammer and ensure the safety of the wellhead and the pressure resistance of the casing, it also requires multiple shut-in actions and is slow. Therefore, selecting the appropriate shut-in method is crucial for improving oil resource utilization and ensuring the safety of the wellhead and the pressure resistance of the casing.

[0003] Due to the high cost of drilling, it is difficult to use field experiments to prove which shut-in method is more effective. Therefore, most of the overflow simulation test devices are used to simulate overflow. After the simulated overflow, the water hammer pressure is measured in the device, and the formation pressure is calculated based on the measured water hammer pressure. Then, based on the formation pressure, the optimal shut-in method is determined and the density of the well-killing fluid is converted to perform well shut-in and well-killing.

[0004] However, during actual drilling, especially under the complex conditions of high temperature and high pressure in deep wells (those deeper than 6,000 meters), the fluid flow within the wellbore is relatively complex. The wellbore in current overflow simulation experimental devices cannot effectively simulate the complex flow of actual fluids, resulting in deviations in water hammer pressure measurements, which in turn reduces the accuracy of formation pressure calculations, and thus reduces the accuracy of the optimal shut-in method and the determination of well-killing fluid density, ultimately leading to unsatisfactory shut-in and well-killing results in deep wells. Furthermore, calculating formation pressure based on measured water hammer pressure takes a considerable amount of time, reducing the efficiency of obtaining formation pressure and, consequently, well-killing efficiency in deep wells. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a pressure measuring device and a pressure measuring method for simulating overflow well shut-in, so as to improve the efficiency of obtaining formation pressure and improve the accuracy of determining the optimal well shut-in method.

[0006] To solve the above technical problems, the embodiments of the present application provide the following technical solutions: The first aspect of the present application provides a pressure measuring device for simulating overflow well shut-in, the device comprising: a sand filling model, a first liquid supply component, a simulated wellbore, a simulated drill string, a second liquid supply component, a blowout preventer, a choke manifold, a pressure detection device and a processor; wherein the sand filling model has a receiving space for containing sand and soil so that the sand filling model can simulate a drilling reservoir, and a plurality of boosting ports are provided on the sand filling model; the first liquid supply component is used to contain and pump out simulated formation fluid, and the first liquid supply component is connected to the plurality of boosting ports; the simulated wellbore is inserted into the sand filling model The simulated drill string is located in the simulated wellbore; the second fluid supply assembly is used to contain and pump out the simulated drilling fluid, and the second fluid supply assembly is connected to the simulated drill string; the blowout preventer is arranged at the end of the simulated wellbore away from the sand filling model; the throttle manifold is arranged between the simulated wellbore and the second fluid supply assembly; the pressure detection device is arranged on the wall of the simulated wellbore, and is used to detect the force applied to the simulated wellbore during the well shut-in process in the overflow state; the processor is connected to the pressure detection device, and is used to determine the water hammer pressure and formation pressure according to the force, and determine the optimal well shut-in method based on the water hammer pressure and formation pressure.

[0007] Compared to the prior art, the pressure measurement device for simulating overflow shut-in provided in the first aspect of this application, through a sand filling model, a simulated wellbore, a simulated drill string, a first fluid supply assembly, and a second fluid supply assembly, can more accurately simulate the overflow phenomenon affected by various factors such as formation fluid and drilling fluid during the drilling process. Simultaneously, in conjunction with a blowout preventer, a choke manifold, and a pressure detection device, it can directly obtain the water hammer pressure and formation pressure under the overflow shut-in state. The specific value of the formation pressure is no longer calculated based on the water hammer pressure, which can be obtained more quickly and accurately, and then the density of the well killing fluid can be converted efficiently and accurately, improving the efficiency and effectiveness of deep well killing. At the same time, the water hammer pressure and formation pressure are obtained in a more realistic simulation environment, and the accuracy of the water hammer pressure and formation pressure values ​​is higher. Based on the highly accurate water hammer pressure and formation pressure, the optimal shut-in method can be more accurately determined, improving the accuracy of the optimal shut-in method determination and enhancing the effectiveness of deep well shut-in. Furthermore, by simulating various downhole conditions in the pressure measurement device for simulating overflow shut-in, accurate and powerful data support can be provided for actual production.

[0008] In some modified embodiments of the first aspect of the present application, the pressure detection device includes: a plurality of stress strain gauges; wherein, the plurality of stress strain gauges are arranged outside the sand filling model along the axial direction of the simulated wellbore and are connected to the processor signal so that the processor determines the water hammer pressure of the simulated wellbore during the well shut-in process in the overflow state based on the detection results of the plurality of stress strain gauges.

[0009] Stress strain gauges are low-cost and provide precise measurements. They can ensure pressure measurement accuracy while reducing pressure measurement costs.

[0010] In some modified embodiments of the first aspect of the present application, the pressure detection device includes: multiple pressure sensors; wherein, the multiple pressure sensors are arranged in the sand filling model around the circumference of the simulated wellbore to determine the formation pressure of the simulated wellbore during the well shut-in process in the overflow state, and the multiple pressure sensors are connected to the processor signal so that the processor obtains the formation pressure.

[0011] Pressure sensors can accurately measure pressure under extrusion conditions. Using pressure sensors to measure formation pressure in sand filling models can improve the accuracy of formation pressure measurement.

[0012] In some modified embodiments of the first aspect of the present application, the device further includes: multiple cooling layers; wherein the multiple cooling layers are arranged along the axial direction of the simulated wellbore, and the cooling performance of the multiple cooling layers gradually increases in the direction away from the sand filling model.

[0013] The cooling layer can gradually reduce the temperature of the simulated wellbore from bottom to top, which can more accurately simulate the actual situation of the wellbore and thus improve the accuracy of pressure measurement.

[0014] In some modified embodiments of the first aspect of the present application, the device also includes: a heating layer; wherein the heating layer is arranged on the sand filling model and the first liquid supply component, the heating layer is connected to the processor signal, and the heating layer is used to heat the sand filling model and the first liquid supply component to the target temperature corresponding to the drilling reservoir according to the heating signal of the processor.

[0015] The heating layer can heat the simulated formation and formation fluid to a more realistic temperature, which can more accurately simulate the downhole drilling environment and thus improve the accuracy of pressure measurement.

[0016] In some modified implementations of the first aspect of the present application, multiple boost ports are evenly distributed on the bottom and side walls of the sand filling model; the first liquid supply assembly is used to determine a target boost port from the multiple boost ports based on the boost signal of the processor, and inject simulated formation fluid with a pressure greater than a preset pressure into the target boost port, and the pressure of the simulated formation fluid injected into the other boost ports among the multiple boost ports except the target boost port is equal to the preset pressure.

[0017] The multiple boosting ports evenly distributed in the sand filling model can simulate the flow of fluids in all directions within the drilling reservoir and the overflow state caused by local high pressure by injecting formation fluids of different pressures, thereby achieving accurate simulation of the overflow and realizing accurate measurement of the pressure under the accurately simulated overflow state, thereby improving the accuracy of the overflow shut-in pressure measurement.

[0018] In some modified embodiments of the first aspect of the present application, the first liquid supply assembly includes: a first tank body and a first booster pump; wherein, the first tank body is used to contain simulated formation fluid, the input end of the first booster pump is connected to the first tank body, and the output end of the first booster pump is connected to multiple boosting ports; the second liquid supply assembly includes: a second tank body and a second booster pump; wherein, the second tank body is used to contain simulated drilling fluid, the input end of the second booster pump is connected to the second tank body, and the output end of the second booster pump is connected to the simulated drill string.

[0019] The booster pump can accurately configure the injection pressure according to the requirements of different measurement scenarios, achieving convenient and accurate simulation of pressure measurement scenarios, thereby improving the accuracy of pressure measurement.

[0020] In some modified embodiments of the first aspect of the present application, the throttling manifold is a four-way manifold, the input end of the throttling manifold is connected to the end of the simulated wellbore away from the sand filling model, the first outlet of the throttling manifold opposite to the input end is connected to the second liquid supply assembly, the second outlet and the third outlet of the throttling manifold are used for spraying and draining, and control valves are provided on the input end, the first outlet, the second outlet and the third outlet of the throttling manifold.

[0021] By configuring a four-way choke manifold, not only can drilling fluid backflow be simulated, but also blowout and drainage can be achieved. By controlling the valve, multiple states can be simulated, thereby improving the accuracy of the current overflow state simulation, thereby improving the accuracy of pressure measurement and ultimately the accuracy of determining the optimal shut-in method.

[0022] In some modified embodiments of the first aspect of the present application, the device further includes: a backflush pipe; wherein the backflush pipe is arranged between the second liquid supply assembly and the simulated wellbore, for connecting the second liquid supply assembly and the simulated wellbore, and a control valve is provided on the backflush pipe.

[0023] The backflush pipe can be used to backflush the various pipelines of the device, thereby improving the convenience of device maintenance and cleaning.

[0024] The second aspect of the present application provides a pressure measurement method for simulating overflow well shut-in, which is applied to the device of the first aspect, and comprises: filling sand in a sand filling model based on actual drilling data, injecting simulated formation fluid into a first liquid supply component, and injecting simulated drilling fluid into a second liquid supply component; controlling the first liquid supply component to inject simulated formation fluid into the sand filling model, and when liquid is seen at the bottom of the simulated wellbore, controlling the second liquid supply component to inject simulated drilling fluid into the simulated drill string, and adjusting the injection pressure of the first liquid supply component and the second liquid supply component until the sand filling model is filled with sand. The pressure inside the well reaches the pressure of the drilling reservoir; the injection pressure of the first fluid supply assembly is adjusted so that the pressure difference between the injected simulated formation fluid and the injected simulated drilling fluid reaches the pressure difference at the bottom of the wellbore when the drilling reservoir overflows, so as to simulate overflow; a hard shut-in operation and a soft shut-in operation are performed respectively. The hard shut-in operation is to first close the blowout preventer and then close the choke manifold, and the soft shut-in operation is to first close the choke manifold and then close the blowout preventer, so that the optimal shut-in method is determined according to the water hammer pressure and formation pressure measured by the pressure detection device in the hard shut-in operation and the soft shut-in operation.

[0025] The pressure measurement method for simulating overflow and well shut-in provided in the second aspect of the present application has the same or similar beneficial effects as the pressure measurement device for simulating overflow and well shut-in provided in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and advantages of the exemplary embodiments of the present application will become readily understood by reading the detailed description below with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 Schematic diagram of the structure of the pressure measuring device for simulating overflow well shut-in in the embodiment of the present application Figure 1 ; Figure 2 Schematic diagram of the structure of the pressure measuring device for simulating overflow well shut-in in the embodiment of the present application Figure 2 ; Figure 3 Schematic diagram of the process of the pressure measurement method for simulating overflow well shut-in in the embodiment of the present application Figure 1 ; Figure 4 Schematic diagram of the process of the pressure measurement method for simulating overflow well shut-in in the embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0027] The following describes exemplary embodiments of the present application in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0028] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which this application belongs.

[0029] Currently, overflow simulation experimental devices are unable to accurately simulate the complex flow process of fluids within the wellbore, resulting in low accuracy in measuring water hammer pressure after overflow shut-in in deep wells, which in turn reduces the accuracy of determining the optimal shut-in method for deep wells. Furthermore, after obtaining the water hammer pressure after shut-in based on the overflow simulation device, calculating the formation pressure based on the water hammer pressure takes a considerable amount of time. Therefore, the efficiency of calculating formation pressure in deep wells is not high, which in turn reduces the efficiency of determining the density of the well-killing fluid, resulting in low efficiency in obtaining deep well kill results.

[0030] In view of this, the embodiments of the present application provide a pressure measuring device for simulating overflow well shut-in and a pressure measuring method for simulating overflow well shut-in. On the basis of the simulated wellbore, a sand filling model, a simulated drill string, a first liquid supply component, a second liquid supply component, a blowout preventer, a throttling manifold, a pressure detection device and a processor are added to simulate the real drilling scene to the maximum extent, and to more realistically simulate the overflow state and shut-in effect of the deep well under the simulated scene, thereby more accurately measuring the water hammer pressure during overflow well shut-in and directly measuring the formation pressure, thereby realizing accurate and efficient determination of the optimal shut-in method in the deep well.

[0031] It should be noted here that all components, data and related processing methods involved in this application are authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data comply with the relevant laws, regulations and standards of relevant countries and regions.

[0032] First, the pressure measuring device for simulating overflow well shut-in provided in the embodiment of the present application is described in detail.

[0033] Figure 1 The structure of the pressure measuring device for simulating overflow well shut-in in the embodiment of the present application is shown as follows: Figure 1 , see Figure 1 As shown, the device may include: a sand filling model 11, a first fluid supply assembly 12, a simulated wellbore 13, a simulated drill string 14, a second fluid supply assembly 15, a blowout preventer 16, a choke manifold 17, a pressure detection device 18 and a processor (not shown in the figure).

[0034] The sand filling model 11 has a receiving space for containing sand, soil, sand-soil and other structures so that the sand filling model 11 can simulate the drilling reservoir. A plurality of pressurizing ports 111 are provided on the sand filling model 11.

[0035] The sand-filled model 11 can be a container such as a cube or a sphere, as long as it can accommodate the simulated formation structure. The sand-filled model 11 can be made of, but is not limited to, steel or an alloy material with higher compressive strength, thereby ensuring that it can withstand the impact of high fluid pressure when combined with the pressurization port 111 and has high compressive strength.

[0036] Since the sand filling model 11 simulates a near-wellbore formation containing high-pressure formation fluid, in order to ensure that the simulation conditions are consistent with reality, the sand filling model 11 and the pipelines connected to it must ensure air tightness to prevent fluid from escaping from the gaps and causing the simulated high-pressure formation conditions to fail.

[0037] The structures contained in the sand filling model 11 can be configured and filled according to the composition of the stratum at the corresponding depth position.

[0038] The boost port 111 is a valve body structure that can be configured as, but is not limited to, a manually controlled one-way valve, enabling flexible manual control in conjunction with the experimental process. For example, to inject simulated formation fluid only into the bottom of the sandfill model 11, all boost ports 111 on the sidewalls of the sandfill model 11 are manually closed. Another example is to simulate high pressure in a specific area of ​​the sandfill model 11, and all boost ports 111 other than that area are manually closed. The number and location of the boost ports 111 can be set based on actual needs and are not limited here.

[0039] The first liquid supply assembly 12 is used to contain and pump out simulated formation fluid and is connected to the pressurization port 111 .

[0040] The simulated formation fluid in the first liquid supply assembly 12 is selected based on actual needs, namely, a specific formation environment prone to overflow. The characteristics of this formation environment are often constant, such as water, oil, natural gas, or a mixture of water, oil, and natural gas. Therefore, the formation fluid composition within a specific location and area is also essentially constant. Therefore, the composition of the extracted groundwater sample can be determined, and a liquid with the same composition can be prepared to serve as the simulated formation fluid in this embodiment.

[0041] The first liquid supply assembly 12 can, but is not limited to, a single liquid storage space. For example, formation fluid overflowing at 3,000 meters downhole may contain 70% water, 18% gas, 3% inorganic salt ions, and 7% condensate, while formation fluid overflowing at 5,000 meters downhole may contain 50% water, 29% gas, 5% inorganic salt ions, and 16% condensate. When simulating the overflow state of a formation 3,000 meters downhole, the simulated formation fluid is prepared according to a ratio of 70% water, 18% gas, 3% inorganic salt ions, and 7% condensate. When simulating the overflow state of a formation 5,000 meters downhole, the simulated formation fluid is prepared according to a ratio of 50% water, 29% gas, 5% inorganic salt ions, and 16% condensate. The prepared simulated formation fluid is placed in the first liquid supply assembly 12 for standby use.

[0042] The simulated wellbore 13 is inserted into the sand filling model 11. Specifically, the simulated wellbore 13 can be inserted into the sand filling model 11 according to the direction in which the actual wellbore is inserted into the formation. For example, the simulated wellbore 13 is inserted into the sand filling model 11 in a vertical direction.

[0043] The simulated drill string 14 is located in the simulated wellbore 13. Specifically, the simulated drill string 14 can be inserted into the simulated wellbore 13 according to the direction in which the actual drill string is inserted into the actual wellbore. For example, the simulated drill string 14 and the simulated wellbore 13 are coaxially arranged.

[0044] The simulated wellbore 13 and the simulated drill string 14 are both structures that are proportionally reduced based on the actual wellbore and drill string. For example, the wall of the actual wellbore is sandstone or carbonate rock, with a small amount of shale and mudstone. The wellbore has a stable wall and a layer of filter cake formed by drilling fluid on the wall. The wall of the entire wellbore has a certain degree of pressure resistance. Therefore, the simulated wellbore 13 can be made of a synthetic plastic material with a large thickness and a certain degree of pressure resistance, which can also improve the observability of the simulated wellbore 13. The simulated wellbore 13 can also be set to a transparent or translucent material to facilitate direct observation of the rising liquid level in the simulated wellbore 13 by the human eye when overflow occurs, ensuring an intuitive effect. Of course, even if the simulated wellbore 13 is not designed to be transparent or translucent, because it is made of a synthetic plastic material, the fluctuation of the internal liquid level can be seen under light to determine the starting time of overflow.

[0045] The length of the simulated wellbore 13 can be designed and adjusted according to actual needs, and the length of the simulated wellbore 13 can be set to be greater than 1.5 m, for example, 1.8 m, 2 m, etc.

[0046] The simulated wellbore 13 can be inserted into the sand-filled model 11 by simply inserting it so that the material in the sand-filled model 11 compresses the simulated wellbore 13 to maintain stability and prevent vibration and displacement. Alternatively, the simulated wellbore 13 can be inserted into the sand-filled model 11 and then fixed to the top surface of the sand-filled model 11 by bonding, welding, or other means to maintain stability and prevent vibration and displacement. The insertion depth of the simulated wellbore 13 can be designed and adjusted according to actual needs, as long as the bottom of the simulated wellbore 13 is spaced apart from the bottom of the sand-filled model 11.

[0047] When overflow occurs during the actual drilling process, there is not only drilling fluid in the wellbore, but also corresponding drilling tools, such as drill rods, drill bits and other drilling tool structures. These drilling tools also have a certain impact on the pressure of the wellbore. Therefore, a simulated drill string 14 is set in the simulated wellbore 13, which can truly simulate the process of drilling fluid entering the wellbore through the drill string, so as to achieve a more accurate simulation of the overflow state.

[0048] The second fluid supply assembly 15 is used to contain and pump out the simulated drilling fluid and is connected to the simulated drill string 14 .

[0049] The simulated drilling fluid in the second fluid supply assembly 15 is also selected to be the same as or have the same properties as the actual drilling fluid.

[0050] The blowout preventer 16 is disposed at one end of the simulated wellbore 13 away from the sand filling model 11 .

[0051] The throttling manifold 17 is disposed between the simulated wellbore 13 and the second liquid supply assembly 15 .

[0052] BOP 16 and choke manifold 17 are structures that are readily understood and utilized by those skilled in the art and will not be further described here. The simultaneous provision of BOP 16 and choke manifold 17 allows for adaptation to both hard and soft shut-in operations by adjusting the closing sequence of BOP 16 and choke manifold 17, thereby enhancing the device's applicability for both hard and soft shut-in research, broadening its scope of application, and ensuring data accuracy and the credibility of data evaluation.

[0053] The pressure detection device 18 is provided on the wall of the simulated wellbore 13 and is used to detect the force applied to the simulated wellbore 13 during the well shut-in process in the overflow state.

[0054] The pressure detection device 18 can be selected from devices having the same or similar measuring principles for detecting pressure according to the actual drilling conditions.

[0055] The processor is connected to the pressure detection device 18 and is used to determine the water hammer pressure and the formation pressure according to the force, and determine the optimal shut-in method based on the water hammer pressure and the formation pressure.

[0056] The processor can divide the pressure measured by the pressure detection device 18 into water hammer pressure and formation pressure, and then output corresponding pressure values, so that the optimal shut-in method can be manually selected from the hard shut-in and soft shut-in methods based on the water hammer pressure and formation pressure under hard shut-in and the water hammer pressure and formation pressure under soft shut-in. Alternatively, the processor can directly select the optimal shut-in method from the hard shut-in and soft shut-in methods based on the water hammer pressure and formation pressure under hard shut-in and soft shut-in according to a pre-configured optimal selection rule.

[0057] After the sand filling model 11, the first liquid supply assembly 12, the simulated wellbore 13, the simulated drill string 14, the second liquid supply assembly 15, the blowout preventer 16, the choke manifold 17, the pressure detection device 18 and the processor are assembled as required, a pressure measurement device simulating overflow well shut-in is obtained.

[0058] Because overflow tests are conducted under high pressure, the airtightness of the pressure measurement device used to simulate overflow and well shut-in must be verified before it is officially put into use. Only after passing the airtightness verification can the device be put into experimental use. This airtightness verification can be performed, but is not limited to, through infrared testing, flow testing, or pressure testing to determine the airtightness of the entire experimental device.

[0059] As can be seen from the above, the pressure measurement device for simulating overflow shut-in provided in the embodiment of the present application, through the sand filling model 11, simulated wellbore 13, simulated drill string 14, first liquid supply assembly 12, and second liquid supply assembly 15, can more accurately simulate the overflow phenomenon affected by various factors such as formation fluid and drilling fluid during the drilling process. At the same time, in conjunction with the blowout preventer 16, choke manifold 17, and pressure detection device 18, it can directly obtain the water hammer pressure and formation pressure under the overflow shut-in state. The specific value of the formation pressure is no longer calculated based on the water hammer pressure, and the formation pressure can be obtained more quickly and accurately, thereby efficiently and accurately converting the well killing fluid density, thereby improving the efficiency and effectiveness of deep well killing. At the same time, the water hammer pressure and formation pressure are obtained in a more realistic simulation environment, and the accuracy of the water hammer pressure and formation pressure values ​​is higher. Based on the highly accurate water hammer pressure and formation pressure, the optimal well shut-in method can be more accurately determined, improving the accuracy of the determination of the optimal well shut-in method and improving the deep well shut-in effect. In addition, by simulating various downhole conditions in the pressure measuring device 18 simulating overflow shut-in, accurate and powerful data support can be provided for actual production.

[0060] Further, as Figure 1 As a refinement and expansion of the device shown, an embodiment of the present application also provides a pressure measuring device for simulating overflow well shut-in.

[0061] Figure 2 The structure of the pressure measuring device for simulating overflow well shut-in in the embodiment of the present application is shown as follows: Figure 2 , see Figure 2 As shown, the device may include: a sand filling model 21, a first tank body 22, a first booster pump 23, a simulated wellbore 24, a simulated drill string 25, a second tank body 26, a second booster pump 27, a blowout preventer 28, a choke manifold 29, a processor (not shown in the figure), a stress strain gauge 210, a pressure sensor 211, a cooling layer 212, a heating layer 213 and a backflush pipe 214.

[0062] The sand-filled model 21 is provided with a plurality of pressurizing ports 111 , which are evenly distributed on the bottom wall and the side walls of the sand-filled model 21 .

[0063] The flow of simulated formation fluid into the simulated wellbore 24 during the overflow state is unidirectional. Fluid flow in actual formations involves both horizontal radial flow and upwelling from the wellbore bottom. Therefore, the top wall of the sandfill model 21 does not require the provision of pressurization ports 111. Instead, pressurization ports 111 are provided only on the sidewalls and bottom wall of the sandfill model 21. The distribution pattern and number of these ports can be adjusted based on actual needs and will not be elaborated upon here.

[0064] The distributed arrangement of multiple boost ports 111 enables the injection of corresponding simulated formation fluid into the sandfill model 21, while simultaneously boosting the pressure of the sandfill model 21 under the action of the first fluid supply assembly to simulate the high-pressure environment of the formation. The distributed arrangement of multiple boost ports 111 also enables the saturation of the sandfill model 21 with fluid from multiple directions, thereby preventing the formation of a single fluid flow channel between the simulated formation fluid injected through the boost ports 111 and the simulated wellbore 24. This not only increases the saturation within the sandfill model 21, but also prevents the formation of a single fluid flow channel within the sandfill model 21. Furthermore, corresponding experimental tests can be performed for high-pressure conditions. Specifically, when local high pressure in one or several directions needs to be simulated, it is only necessary to adjust the flow rate of the boost ports 111 in the corresponding directions, making the operation simple and quick.

[0065] Specifically, the first fluid supply assembly is configured to determine a target boost port from among the plurality of boost ports 111 based on the boost signal from the processor, and to inject simulated formation fluid at a pressure greater than a preset pressure into the target boost port. The pressure of the formation fluid injected into the remaining boost ports 111, excluding the target boost port, is equal to the preset pressure.

[0066] The first tank 22 and first booster pump 23 are the specific structures of the first fluid supply assembly. The first tank 22 is used to hold simulated formation fluid. The input end of the first booster pump 23 is connected to the first tank 22, and the output end of the first booster pump 23 is connected to the multiple boosting ports 111. By controlling the first booster pump 23, the simulated formation fluid in the first tank 22 can be injected into the sand pack model 21.

[0067] The operating parameters of the first boost pump 23 can be adjusted manually on the first boost pump 23 , or the first boost pump 23 can be connected to a processor so that the operating parameters of the first boost pump 23 can be adjusted through operations in the processor.

[0068] The second fluid supply assembly 15 includes a second tank 26 and a second booster pump 27. The second tank 26 is used to contain simulated drilling fluid. The input end of the second booster pump 27 is connected to the second tank 26, and the output end of the second booster pump 27 is connected to the simulated drill string 25. By controlling the second booster pump 27, the simulated drilling fluid in the second tank 26 can be injected into the simulated drill string 25.

[0069] The operating parameters of the second boost pump 27 can be adjusted manually on the second boost pump 27 , or the second boost pump 27 can be connected to a processor so that the operating parameters of the second boost pump 27 can be adjusted through operations in the processor.

[0070] The sizes and shapes of the first tank 22 and the second tank 26 can be designed according to actual needs and are not limited here. The first booster pump 23 and the second booster pump 27 can be of the same type or different types, as long as they can provide pressure and pump fluid in and out.

[0071] The simulated formation fluid in the first tank body 22 and the simulated drilling fluid in the second tank body 26 can not only be set to substances with the same composition as the actual ones, but also the simulated drilling fluid and the simulated formation fluid can be set to drilling fluid without solid phase or with low solid phase. Because overflow occurs in the wellbore in reality, most of the time after the formation fluid enters the wellbore, the physical conditions such as pressure change, the miscible or mixed gas in the formation fluid is separated, and the gas volume expands, causing the liquid level in the wellbore to rise rapidly until it overflows the wellhead. If the simulated formation fluid contains a lot of solid phase, the possibility of gas phase change is small. When overflow occurs, in order to achieve the upward overflow of the simulated formation fluid in the sand filling model 21, the only way is to increase the volume of liquid phase entering the simulated wellbore 24 per unit time by controlling the booster pump. At this time, the power consumption of the booster pump increases, affecting its service life, and then the drilling fluid without solid phase or with low solid phase can be used to protect the two booster pumps.

[0072] The stress strain gauge 210 and the pressure sensor 211 are specific structures of the pressure detection device.

[0073] A plurality of stress strain gauges 210 are arranged outside the sand filling model 21 along the axial direction of the simulated wellbore 24 and are connected to the processor signal so that the processor determines the water hammer pressure of the simulated wellbore 24 during the well shut-in process in the overflow state based on the detection results of the plurality of stress strain gauges 210.

[0074] In order to accurately obtain the water hammer pressure during the well shut-in process under overflow conditions, multiple stress strain gauges 210 need to be automatically detected in conjunction with a processor. The stress strain gauge 210 can be an element composed of a sensitive grid and other components for measuring strain. Based on the piezoresistive effect of semiconductors, when a conductor or semiconductor material undergoes mechanical deformation under the action of an external force, its resistance changes accordingly, and the magnitude of the applied force can be measured through the change in resistance. The processor is a programmable logic controller (PLC) capable of data transmission and reception, data processing, comparison, analysis, and program editing. The stress strain gauge 210 is set on the simulated wellbore 24. The stress strain gauge 210 is used to detect pressure at various locations on the simulated wellbore 24 during the well shut-in process under overflow conditions, and the processor automatically processes the data to obtain the water hammer pressure during the well shut-in process under overflow conditions.

[0075] Multiple pressure sensors 211 are arranged in the sand pack model 21 along the circumference of the simulated wellbore 24 to determine the formation pressure during the shut-in process of the simulated wellbore 24 in the overflow state. The multiple pressure sensors 211 are connected to the processor signal so that the processor can obtain the formation pressure.

[0076] To accurately calculate the actual formation pressure around the simulated wellbore 24, the number of pressure sensors 211 can be adjusted based on the actual measurement accuracy. Several pressure sensors 211 are placed around the circumference of the simulated wellbore 24 on the top wall of the sandfill model 21. This allows the pressure around the portion of the simulated wellbore 24 inserted into the sandfill model 21 to be detected, and the actual formation pressure can be calculated. This calculation method is readily understood and implemented by those skilled in the art and will not be elaborated upon here.

[0077] The choke manifold 29 can be a four-way manifold. The input end of the choke manifold 29 is connected to the end of the simulated wellbore 24 away from the sandfill model 21. The first outlet of the choke manifold 29, opposite the input end, is connected to the second fluid supply assembly. The second and third outlets of the choke manifold 29 are used for fluid discharge. Control valves are provided at the input end, first outlet, second outlet, and third outlet of the choke manifold 29.

[0078] To accommodate both hard and soft shut-in operations, the choke manifold 29 is configured as a four-way manifold. While the first outlet serves as a drain line to return fluid to the second tank 26 of the second liquid supply assembly, the upper and lower second and third outlets serve as blowdown lines to directly drain excess fluid that overflows during the shut-in process.

[0079] Manual control valves are provided on the first, second and third outlets of the throttling manifold 29 to open and close the corresponding outlets and even adjust the flow rate in accordance with different shut-in directions. This is easily understood by those skilled in the art and will not be elaborated here.

[0080] There can be multiple cooling layers 212 . The cooling layers 212 are spaced apart along the axial direction of the simulated wellbore 24 . The cooling performance of the cooling layers 212 gradually increases as they move away from the sand packing model 21 .

[0081] In actual formations, the temperature below the formation is typically higher. As the overflowing fluid flows upward through the wellbore, its temperature gradually decreases. Therefore, the temperature of the overflowing fluid in the wellbore gradually decreases from bottom to top. To improve the accuracy and realism of the simulation, several cooling layers 212 are provided axially along the outer wall of the simulated wellbore 24 to cool the simulated wellbore 24 and the simulated formation fluid flowing upward therein, thereby more realistically simulating the temperature changes in the wellbore during overflow during actual oil production.

[0082] Cooling layer 212 can be, but is not limited to, a water-cooled plate or a thermoelectric cooler (TEC) attached to the outer wall of simulated wellbore 24. Cooling layer 212 can be disposed around the circumference of simulated wellbore 24 at a certain height, or can be disposed on a portion of the circumferential surface.

[0083] If the cooling layer 212 is a water-cooled plate, several water-cooled plates can be connected in series, with cooling water flowing downward from the water-cooled plate at the top of the simulated well 24. This allows the cooling capacity of the water-cooled plate located above the simulated well 24 to be higher, while the cooling capacity of the water-cooled plates extending downward from the simulated well 24 gradually decreases. Alternatively, the cooling rate and capacity of the water-cooled plates can be adjusted by varying the temperature of the cold water. Furthermore, the cooling effect can be adjusted by adjusting the flow rate and velocity of the cold water within the plates.

[0084] When the cooling layer 212 is a semiconductor refrigerator, the cooling rate and cooling capacity can be adjusted directly by adjusting the power supply.

[0085] In order to achieve a situation where the simulated wellbore 24 is cooled from bottom to top, multiple cooling layers 212 can be evenly arranged along the axial direction of the simulated wellbore 24 .

[0086] The distance between adjacent cooling layers 212 can be designed and adjusted according to actual needs. For example, the distance is 5-10 cm. The specific distance can depend on the simulated length of the simulated wellbore 24, as long as the cooling effect can be guaranteed.

[0087] Because the simulated wellbore 24 is provided with not only a cooling layer 212 but also multiple stress and strain gauges 210 in the axial direction, to achieve a balance between pressure measurement accuracy and measurement cost, each stress and strain gauge 210 can be placed between two different adjacent cooling layers 212, that is, the stress and strain gauges 210 are spaced apart from the cooling layers 212. This allows the pressure of the simulated wellbore 24 to be measured at different temperatures, and avoids having multiple stress and strain gauges 210 measure the pressure at the same temperature.

[0088] Heating layer 213 is disposed above sand packing model 21 and first tank 22 of the first fluid supply assembly. Heating layer 213 is signal-connected to the processor. Heating layer 213 is configured to heat sand packing model 21 and first tank 22 of the first fluid supply assembly to a target temperature corresponding to the drilling reservoir based on heating signals from the processor.

[0089] The actual formation temperature is usually higher. To ensure accurate simulation, heating layers 213 are installed on the sides of the sand pack model 21 and on the first tank 22 of the first fluid supply assembly. The heating layers 213 heat the simulated formation fluid and the simulated formation to the target temperature corresponding to the drilling reservoir, achieving a more realistic simulation.

[0090] The heating layer 213 may be made of, but is not limited to, a conductive heating material. The size of the heating layer 213 can be designed and adjusted based on the actual dimensions of the sand-filled model 21 and the first tank 22. For example, if the side of the sand-filled model 21 measures 220 cm by 220 cm, sixteen conductive heating sheets measuring 20 cm by 10 cm can be used, attached in series to the sidewalls of the sand-filled model 21 in four rows and four columns.

[0091] The backflush pipe 214 is provided between the second booster pump 27 in the second liquid supply assembly and the simulated wellbore 24, and is used to connect the second booster pump 27 in the second liquid supply assembly and the simulated wellbore 24. A control valve is provided on the backflush pipe 214.

[0092] Under normal circumstances, drilling fluid typically enters the wellbore through the drill string and then flows back through the annulus. In some special cases, drilling fluid needs to be injected from the annulus. Therefore, a corresponding backflush pipe 214 can also be provided on the simulated wellbore 24. Through the backflush pipe 214, simulated drilling fluid can be injected from the annulus into the simulated wellbore 24, improving the realism of the simulation.

[0093] By manually or automatically controlling the opening and closing of the control valve in the backflush pipe 214 , simulation of various states can be achieved.

[0094] The simulated wellbore 24, the simulated drill string 25 and the blowout preventer 28 are the same as those in the above embodiment. Figure 1 The structures and functions of the simulated wellbore 13, simulated drill string 14 and blowout preventer 16 are the same and will not be described in detail here.

[0095] After the above-mentioned pressure measuring device for simulating overflow well shut-in is installed and the air tightness is confirmed to be correct, the pressure measuring device for simulating overflow well shut-in can be used to measure the water hammer pressure and formation pressure when shutting in different ways under various overflow conditions.

[0096] Next, the pressure measurement method for simulating overflow well shut-in provided in the embodiments of the present application is described in detail.

[0097] Figure 3 Schematic diagram of the process of the pressure measurement method for simulating overflow well shut-in in the embodiment of the present application Figure 1 , see Figure 3 As shown, the method may include: S31: filling the sand filling model with sand based on actual drilling data, injecting simulated formation fluid into the first fluid supply assembly, and injecting simulated drilling fluid into the second fluid supply assembly.

[0098] Actual drilling data may refer to various data involved in actual drilling, such as the structure and composition of the formation being drilled, the actual density of the drilling fluid used, the dimensions and material of the wellbore used, etc. The specific content of the actual drilling data is not limited here, as long as it can enable the pressure measurement device used to simulate overflow shut-in to restore the actual overflow state.

[0099] The sand filling model's containment space is filled with sand of the same or similar composition to the actual formation being drilled. The first fluid supply assembly is filled with simulated formation fluid of the same or similar properties to the actual formation fluid. The second fluid supply assembly is filled with simulated drilling fluid of the same or similar properties to the actual drilling fluid. At this point, preparations for the drilling simulation are complete.

[0100] S32: Control the first fluid supply assembly to inject simulated formation fluid into the sand filling model. When liquid is seen at the bottom of the simulated wellbore, control the second fluid supply assembly to inject simulated drilling fluid into the simulated drill string, and adjust the injection pressure of the first fluid supply assembly and the second fluid supply assembly until the pressure in the sand filling model reaches the pressure of the drilling reservoir.

[0101] The first fluid supply assembly injects simulated formation fluid into the sandfill model. When liquid is visible at the bottom of the simulated wellbore, formation fluid seepage has been simulated. Simulated drilling fluid is then injected into the simulated wellbore via the second fluid supply assembly. The pumping pressures of the simulated formation fluid and drilling fluid are adjusted until the pressure within the sandfill model reaches that of the drilled reservoir. This further simulates the formation conditions before overflow. Furthermore, the sandfill model is saturated with simulated formation fluid, preventing premature entry of simulated drilling fluid into the sandfill model and affecting the simulated formation fluid composition. This state indicates that the simulated formation fluid and simulated drilling fluid in the sandfill model are in relative equilibrium.

[0102] The determination of whether liquid is present at the bottom of the simulated wellbore can be based on visual observation or pressure sensor detection data. Both of these determination methods are known and used by those skilled in the art and will not be described in detail here.

[0103] S33: adjusting the injection pressure of the first fluid supply assembly so that the pressure difference between the injected simulated formation fluid and the injected simulated drilling fluid reaches the pressure difference at the bottom of the wellbore when the drilling reservoir overflows, so as to simulate overflow.

[0104] At this point, the actual overflow simulation begins. The pressure in the first fluid supply assembly is continuously increased until the simulated formation fluid pressure within the sand pack exceeds the drilling fluid pressure. Overflow is achieved when the pressure difference between the two reaches the pressure difference at the bottom of the wellbore corresponding to the overflow of the formation fluid. This pressure difference is readily understood and comprehensible by those skilled in the art.

[0105] The simulation process can simulate different sources of overflow pressure by adjusting different boosting ports in the sand filling model according to actual needs, so that the overflow pressure source has a clear directionality, thereby being able to study the impact of overflow pressure sources in different directions on the pressure in the wellbore.

[0106] S34: performing a hard shut-in operation and a soft shut-in operation respectively. The hard shut-in operation is to first close the blowout preventer and then close the choke manifold, while the soft shut-in operation is to first close the choke manifold and then close the blowout preventer. In this way, the optimal shut-in method is determined according to the water hammer pressure and formation pressure measured by the pressure detection device during the hard shut-in operation and the soft shut-in operation.

[0107] During a hard shut-in, the pressure sensing device measures the pressure at each location within the simulated wellbore, which the processor then uses to calculate the water hammer pressure and formation pressure associated with the hard shut-in. During a soft shut-in, the pressure sensing device measures the pressure at each location within the simulated wellbore, which the processor then uses to calculate the water hammer pressure and formation pressure associated with the soft shut-in. By comparing the water hammer pressure and formation pressure during the hard and soft shut-ins, the optimal shut-in method can be selected.

[0108] Because part of the pressure detection device is located outside the simulated sand filling model in the wellbore, this part of the pressure detection device can measure the wellbore pressure during the overflow operation, thereby converting the water hammer pressure through the processor. Another part of the pressure detection device is located inside the simulated sand filling model in the wellbore, and this part of the pressure detection device can measure the formation pressure during the overflow operation, thereby deriving or converting the formation pressure that meets actual needs through the processor. Compared with calculating one force based on another, this conversion process is simpler and more efficient, thereby improving the efficiency of obtaining formation pressure.

[0109] Before, during, and after hard and soft shut-in operations, pressure can be measured using a pressure detection device to provide more realistic, accurate, and comprehensive data support for subsequent analysis and calculations.

[0110] Before performing hard or soft shut-in operations, measure water hammer pressure and formation pressure using pressure monitoring devices and processing. When water hammer pressure exceeds formation pressure, there may be a risk of a kick or blowout, requiring rapid wellhead control, and a hard shut-in is preferred. When water hammer pressure is equal to or lower than formation pressure, the wellbore is in equilibrium and the risk is low. A soft shut-in can be selected to gradually control wellhead pressure. When water hammer pressure is less than formation pressure, formation fluid intrusion into the wellbore is possible, requiring a shut-in method based on the invasion rate and pressure changes. If pressure rises rapidly, a hard shut-in is selected. If pressure changes slowly, a soft shut-in is selected.

[0111] At this point, it can be considered that the optimal shut-in method has been selected. Of course, the optimal shut-in method selected at this time can also be further verified to more accurately determine the optimal shut-in method.

[0112] After selecting a hard or soft shut-in, during the hard or soft shut-in operation, the water hammer pressure and formation pressure are measured using the pressure detection device and processor. If the relationship between the water hammer pressure and formation pressure is the same as previously determined, hard or soft shut-in is preliminarily determined to be the optimal shut-in method. If the relationship between the water hammer pressure and formation pressure is different from the previously determined relationship, the device is restored to the overflow state based on the current relationship between the water hammer pressure and formation pressure, and a soft or hard shut-in is performed again. If the current relationship between the water hammer pressure and formation pressure is the same as previously determined, soft or hard shut-in is preliminarily determined to be the optimal shut-in method.

[0113] After performing a hard or soft shut-in, the water hammer pressure and formation pressure are obtained through the pressure detection device and processor. If the relationship between the water hammer pressure and the formation pressure is the same as the previously determined relationship, then the hard or soft shut-in is preliminarily determined to be the final optimal shut-in method. If the relationship between the water hammer pressure and the formation pressure is different from the previously determined relationship, then based on the current relationship between the water hammer pressure and the formation pressure, the device is restored to the overflow state and a soft or hard shut-in is performed again. After the shut-in operation, the current relationship between the water hammer pressure and the formation pressure is obtained through the pressure detection device and processor, and it is determined whether it matches the previously measured relationship between the water hammer pressure and the formation pressure. If so, then the soft or hard shut-in is finally determined to be the optimal shut-in method. If not, then the hard or soft shut-in is finally determined to be the optimal shut-in method.

[0114] Furthermore, as a response to the above Figure 3 As a refinement and extension of the method shown, an embodiment of the present application also provides a pressure measurement method for simulating overflow well shut-in.

[0115] Figure 4 Schematic diagram of the process of the pressure measurement method for simulating overflow well shut-in in the embodiment of the present application Figure 2 , see Figure 4 As shown, the method may include: S41: Based on actual drilling data, the control valves on the input end, the first outlet, the second outlet, and the third outlet of the choke manifold are switched on and off, and the control valve on the backflush pipe is switched on and off.

[0116] The actual drilling data may also include the components used in the actual drilling process and their specific parameters, such as: what type of choke manifold is used, the switch status of each control valve in the choke manifold, whether a backflush pipe is used, etc.

[0117] When it is necessary to perform pressure measurement for a certain overflow factor, the pressure measurement device for simulating overflow and well shut-in can be adjusted based on the overflow factor and actual drilling data.

[0118] S42: Based on actual drilling data, sand is filled in the sand filling model, simulated formation fluid is injected into the first fluid supply component, simulated drilling fluid is injected into the second fluid supply component, and the sand filling model and the first fluid supply component are adjusted to the target temperature corresponding to the drilling reservoir by controlling the heating layer through the processor.

[0119] In order to be more consistent with the actual overflow scenario, it is also necessary to heat the simulated formation fluid injected into the first fluid supply assembly and the sand contained in the sand filling model so that the simulated formation fluid and sand reach the actual formation temperature, that is, the target temperature.

[0120] When adjusting the temperature of a sand-filled model, the model can be kept at the target temperature for a period of time, for example, 10-24 hours, to achieve uniform temperature throughout the model. The specific holding time depends on the sand-filled model's insulation performance and is not a limitation here. The better the sand-filled model's insulation performance, the shorter the holding time. The worse the sand-filled model's insulation performance, the longer the holding time.

[0121] To avoid energy loss, the first fluid supply assembly can be insulated after the sandfill model is insulated. Especially when the target temperature exceeds 100°C and the temperature difference between the sandfill model and the first fluid supply assembly is small, the following steps can be used: First, insulate the sandfill model. When the sandfill model reaches the target temperature, heat the first fluid supply assembly to 80-95°C. Then, control the injection of simulated formation fluid from the first fluid supply assembly into the sandfill model. Continue to insulate the sandfill model for a period of time.

[0122] In the process of determining whether the temperature of the sand-filled model has reached the target temperature, the temperature at any point of the sand-filled model can be detected by a thermometer or temperature detector (e.g., a temperature gun) or a temperature sensor. As long as the temperature difference from the target temperature does not exceed 2°C, it can be considered that the target temperature has been reached, i.e., the insulation is successful.

[0123] S43: Control the first fluid supply assembly to inject simulated formation fluid into the sand filling model. When liquid is seen at the bottom of the simulated wellbore, control the second fluid supply assembly to inject simulated drilling fluid into the simulated drill string, and adjust the injection pressures of the first fluid supply assembly and the second fluid supply assembly until the pressure in the sand filling model reaches the pressure of the drilling reservoir.

[0124] When the simulated formation fluid in the first fluid supply assembly is injected into the simulated formation, it can pass through each pressurization port evenly to achieve uniform injection of the simulated formation fluid, thereby improving the authenticity of the simulated formation environment.

[0125] After the simulated drilling fluid is injected into the simulated wellbore, the simulated drilling fluid and the simulated formation fluid mix and flow in the simulated wellbore. The cooling layer can reduce the temperature of the simulated drilling fluid and the simulated formation fluid in the wellbore from bottom to top, so as to more realistically simulate the formation and drilling environment.

[0126] S44: adjusting the injection pressure of the first fluid supply assembly to different pressurization ports so that the pressure difference between the injected simulated formation fluid and the injected simulated drilling fluid reaches the pressure difference at the bottom of the wellbore when the drilling reservoir overflows, thereby simulating overflow.

[0127] At this time, when injecting simulated formation fluid into the boost port, you can select the corresponding boost port to inject the simulated formation fluid of the corresponding flow rate according to different experimental requirements to simulate the overflow situation under the influence of different overflow positions. For example: if the experiment needs to simulate downhole overflow, you can inject a larger flow rate of simulated formation fluid into the boost port at the bottom of the sandfill model, and a smaller flow rate of simulated formation fluid into the boost port on the side wall of the sandfill model. The specific flow rate of each boost port for injecting simulated formation fluid can be determined according to actual conditions and is not limited here.

[0128] S45: performing a hard shut-in operation and a soft shut-in operation respectively. The hard shut-in operation is to first close the blowout preventer and then close the choke manifold, while the soft shut-in operation is to first close the choke manifold and then close the blowout preventer. In this way, the optimal shut-in method is determined according to the water hammer pressure and formation pressure measured by the pressure detection device in the hard shut-in operation and the soft shut-in operation.

[0129] The specific implementation of step S45 and the specific implementation of step S34 in the aforementioned embodiment can be found in the relevant descriptions in the aforementioned embodiment, and will not be repeated here.

[0130] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A pressure measuring device for simulating overflow well shut-in, characterized in that: The device comprises: a sand filling model, a first fluid supply component, a simulated wellbore, a simulated drill string, a second fluid supply component, a blowout preventer, a choke manifold, a pressure detection device and a processor; wherein, The sand filling model has a receiving space for containing sand and soil so that the sand filling model can simulate a drilling reservoir, and a plurality of pressurizing ports are provided on the sand filling model; The first liquid supply assembly is used to contain and pump out simulated formation fluid, and the first liquid supply assembly is connected to the multiple pressurization ports; The simulated wellbore is inserted into the sand packing model; The simulated drill string is located in the simulated wellbore; The second fluid supply assembly is used to contain and pump out simulated drilling fluid, and the second fluid supply assembly is connected to the simulated drill string; The blowout preventer is arranged at one end of the simulated wellbore away from the sand filling model; The throttling manifold is arranged between the simulated wellbore and the second liquid supply assembly; The pressure detection device is arranged on the wall of the simulated wellbore and is used to detect the force applied to the simulated wellbore during the well shut-in process in the overflow state; The processor is in communication with the pressure detection device, and is configured to determine the water hammer pressure and the formation pressure according to the force, and determine an optimal shut-in method based on the water hammer pressure and the formation pressure.

2. The device according to claim 1, characterized in that The pressure detection device includes: a plurality of stress strain gauges; wherein, The plurality of stress strain gauges are arranged outside the sand filling model along the axial direction of the simulated wellbore and are connected to the processor signal so that the processor determines the water hammer pressure of the simulated wellbore during the well shut-in process in the overflow state based on the detection results of the plurality of stress strain gauges.

3. The device according to claim 1, characterized in that The pressure detection device includes: a plurality of pressure sensors; wherein, The plurality of pressure sensors are arranged in the sand filling model along the circumference of the simulated wellbore to determine the formation pressure of the simulated wellbore during the shut-in process in the overflow state. The plurality of pressure sensors are connected to the processor signal so that the processor obtains the formation pressure.

4. The device according to any one of claims 1 to 3, characterized in that The device further comprises: a plurality of cooling layers; wherein, The plurality of cooling layers are arranged along the axial direction of the simulated wellbore, and the cooling performance of the plurality of cooling layers gradually increases in a direction away from the sand filling model.

5. The device according to any one of claims 1 to 3, characterized in that The device further comprises: a heating layer; wherein, The heating layer is arranged on the sand filling model and the first liquid supply component, and the heating layer is connected to the processor signal. The heating layer is used to heat the sand filling model and the first liquid supply component to the target temperature corresponding to the drilling reservoir according to the heating signal of the processor.

6. The device according to any one of claims 1 to 3, characterized in that The plurality of pressurizing ports are evenly distributed on the bottom and side walls of the sand-filled model; The first liquid supply component is used to determine a target boost port from the multiple boost ports according to the boost signal of the processor, and inject simulated formation fluid with a pressure greater than a preset pressure into the target boost port. The pressure of the simulated formation fluid injected into the other boost ports among the multiple boost ports except the target boost port is equal to the preset pressure.

7. The device according to any one of claims 1 to 3, characterized in that The first fluid supply assembly includes: a first tank and a first booster pump; wherein the first tank is used to contain the simulated formation fluid, the input end of the first booster pump is connected to the first tank, and the output end of the first booster pump is connected to the multiple boosting ports; The second fluid supply assembly includes: a second tank body and a second booster pump; wherein, the second tank body is used to contain the simulated drilling fluid, the input end of the second booster pump is connected to the second tank body, and the output end of the second booster pump is connected to the simulated drill string.

8. The device according to any one of claims 1 to 3, characterized in that The throttle manifold is a four-way manifold, the input end of the throttle manifold is connected to the end of the simulated wellbore away from the sand filling model, the first outlet of the throttle manifold opposite to the input end is connected to the second liquid supply assembly, the second outlet and the third outlet of the throttle manifold are both used for spraying and draining liquid, and control valves are provided on the input end, the first outlet, the second outlet and the third outlet of the throttle manifold.

9. The device according to any one of claims 1 to 3, characterized in that The device further comprises: a recoil pipe; wherein, The backflush pipe is arranged between the second liquid supply component and the simulated wellbore, and is used to connect the second liquid supply component and the simulated wellbore. A control valve is provided on the backflush pipe.

10. A pressure measurement method for simulating overflow well shut-in, characterized in that: The method is applied to the device according to any one of claims 1 to 9, and the method comprises: Filling the sand filling model with sand based on actual drilling data, injecting simulated formation fluid into the first fluid supply assembly, and injecting simulated drilling fluid into the second fluid supply assembly; controlling the first fluid supply assembly to inject the simulated formation fluid into the sand packing model; when liquid is seen at the bottom of the simulated wellbore, controlling the second fluid supply assembly to inject the simulated drilling fluid into the simulated drill string; and adjusting the injection pressures of the first fluid supply assembly and the second fluid supply assembly until the pressure in the sand packing model reaches the pressure of the drilling reservoir; Adjusting the injection pressure of the first fluid supply assembly so that the pressure difference between the injected simulated formation fluid and the injected simulated drilling fluid reaches the pressure difference at the bottom of the wellbore when the drilling reservoir overflows, thereby simulating overflow; A hard shut-in operation and a soft shut-in operation are performed respectively. The hard shut-in operation is to first close the blowout preventer and then close the choke manifold. The soft shut-in operation is to first close the choke manifold and then close the blowout preventer. In this way, the optimal shut-in mode is determined according to the water hammer pressure and formation pressure measured by the pressure detection device in the hard shut-in operation and the soft shut-in operation.

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