Physical simulation experiment method and device for coping with inter-well interference technology
By simulating the fracturing process of the parent well and child well on the core sample, the existing technology cannot meet the indoor test simulation problem of the parent well pre-pressurization to cope with inter-well interference, effective physical simulation of inter-well interference is achieved, and development parameters and technical support are optimized.
Patent Information
- Application Number
- CN202311419375.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-30
- Publication Date
- 2025-05-02
AI Technical Summary
The prior art cannot meet the indoor test simulation of pre-pressurization of the parent well to deal with inter-well interference, and lacks effective physical simulation experimental methods and devices.
By drilling the wellbore on the core sample, applying triaxial stress and pumping fracturing fluid, the fracturing process of the parent and child wells is simulated, the fracturing curves and cracks are recorded, and the packaging treatment and three-dimensional imaging technology are optimized to achieve physical simulation of inter-well interference.
It provides effective physical simulation experimental methods and devices, which can simulate inter-well interference in indoor experiments, optimize encrypted wells and three-dimensional development parameters, provide support for the pre-pressurization technology of parent wells, and explore the laws of inter-well interference and crack growth and expansion.
Smart Images
Figure CN119914231A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oilfield development, and is a physical simulation experiment method and device for coping with well-to-well interference technology. Background Art
[0002] With the increase in the intensive drilling of unconventional oil and gas reservoirs, fracture interference interactions (FDI) between wells, also known as frac hits or FDIs, have received increasing attention. Several studies have analyzed the impact of FDI on the production of parent and daughter wells in various unconventional oil and gas reservoirs. Studies have shown that depleted parent wells almost always have a negative impact on daughter wells. Although the impact of FDI on the parent well can be negative or positive, negative impacts are more common.
[0003] In order to deal with this kind of well-to-well interference during fracturing, some mitigation strategies have been proposed, including plugging adjacent low-yield wells, shutting down adjacent wells, using water pre-pressurization in the parent well to balance the downhole stress field with a large flow rate, repeated fracturing (Joslin et al., 2020), adjusting the completion design of the sub-well (Brady et al., 2022), and optimizing the sub-well development plan. Among the above processes and methods, water preloading in the parent well is considered to be an effective technology that can re-pressurize the parent well and establish a stress barrier to protect the parent well and promote symmetrical fracture growth in the sub-well. However, all current research methods are limited to numerical simulation and field tests, and there is no experimental method research and evaluation for indoor test simulation. Summary of the invention
[0004] The present invention provides a physical simulation experimental method and device for coping with well-to-well interference technology, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem that the prior art cannot meet the indoor test simulation of pre-pressurization of the parent well to cope with well-to-well interference.
[0005] One of the technical solutions of the present invention is achieved by the following measures: A physical simulation experimental method for coping with well-to-well interference technology is carried out according to the following steps: The first step is to drill a first borehole on the top surface of the core sample, and place a first wellbore in the first borehole as a simulated mother well, place the core sample in a triaxial fracturing device, apply triaxial stress to the core sample, and pump fracturing fluid into the first wellbore to break the core sample to generate cracks, complete the first fracturing, and record the first fracturing curve of the simulated mother well; The second step is to perform three-dimensional imaging on the core sample after the first fracturing and to reconstruct the fracture network of the core sample in three dimensions; The third step is to pack the core sample after the first fracturing. According to the three-dimensional imaging results, a second borehole is drilled at the top of the packed core sample without cracks, and a second wellbore is installed as a simulated sub-well. The fourth step is to place the core sample processed in the third step into a triaxial fracturing device, pump fracturing fluid into the first wellbore for pre-pressurization, and then pump fracturing fluid into the second wellbore to complete the second fracturing, and record the second fracturing curve of the simulated mother well and the fracturing curve of the simulated child well; The fifth step is to detect the core samples after the second fracturing to obtain the crack conditions of the core samples.
[0006] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: In the first step above, the core sample is in the shape of a cuboid, with a length, width and height of 20 cm to 45 cm respectively.
[0007] In the first step, the distance between the center of the first borehole and the center of the top surface of the core sample is 10 cm to 20 cm.
[0008] In the third step above, the specific operation of the wrapping treatment is: wrap the core sample of the first fracturing with a membrane cloth, then place the core sample in a mold, and seal the core sample with a sealant that can withstand pressure and has deformable properties. After the core sample is sealed, place it naturally in the mold to dry and demold it.
[0009] The sealant is epoxy resin, and the thickness of the sealant after drying is 1 cm to 2 cm.
[0010] In the second step, the specific operation of three-dimensional imaging is: using CT scanning or using nuclear magnetic resonance technology to reconstruct the three-dimensional fractures while retaining the fracturing fluid in the core sample.
[0011] The specific operation of the fifth step is: use a microseismic detection device to detect the core sample after the second fracturing, obtain the crack generation or crack expansion of the core sample, and perform three-dimensional imaging of the core sample after the second fracturing to reconstruct the crack morphology in three dimensions.
[0012] The second technical solution of the present invention is achieved through the following measures: a device for implementing a physical simulation experimental method for coping with inter-well interference technology, including a computer, a core sample, a first fracturing fluid pump, a second fracturing fluid pump and a triaxial fracturing device, the core sample is placed in the triaxial fracturing device, the top surface of the core sample is installed with a first wellbore and a second wellbore, the outlet of the first fracturing fluid pump is fixedly connected to the inlet of the first wellbore by a first fracturing fluid pipeline, a first pressure sensor is fixedly installed on the first fracturing fluid pipeline, the outlet of the second fracturing fluid pump is fixedly connected to the inlet of the second wellbore by a second fracturing fluid pipeline, a second pressure sensor is fixedly installed on the second fracturing fluid pipeline, and the first pressure sensor and the second pressure sensor are both communicatively connected to the computer.
[0013] The present invention uses a physical simulation method to address fracturing interference in parent-child wells or adjacent wells, provides effective physical simulation for using parent well pre-pressurization to deal with well-to-well interference, optimizes infill well and integrated three-dimensional development parameters, and provides indoor test support for parent well pre-pressurization technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Attached Figure 1 This is a schematic diagram of the process flow of Example 8 of the present invention.
[0015] Attached Figure 1 The codes in are: 1 is a computer, 2 is a core sample, 3 is a first fracturing fluid pump, 4 is a second fracturing fluid pump, 5 is a first wellbore, 6 is a second wellbore, 7 is a first fracturing fluid pipeline, 8 is a first pressure sensor, 9 is a second fracturing fluid pipeline, and 10 is a second pressure sensor.
[0016] Attached Figure 2 Schematic diagram of secondary packaging treatment of core samples. Figure 2 The codes in the figure are: A is sealant, B is core sample, C is cracks produced by the first fracturing of the core sample, and D is the first wellbore.
[0017] Attached Figure 3 This is the fracturing curve of the simulated parent well in Example 9 of the present invention.
[0018] Attached Figure 4 This is the fracturing curve of the simulated sub-well in Example 9 of the present invention.
[0019] Attached Figure 5 This is a schematic diagram of simulating a hydraulic fracture in a parent well in Example 9 of the present invention.
[0020] Attached Figure 6 Schematic diagram of fractures in a child well after pre-pressurization of the parent well in Example 9 of the present invention. DETAILED DESCRIPTION
[0021] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art.
[0022] In the present invention, unless otherwise specified, the equipment and devices used are all the equipment and devices known and used in the art.
[0023] The present invention will be further described below in conjunction with embodiments: Example 1: Figure 1 As shown, the physical simulation experimental method for coping with well-to-well interference technology is carried out in the following steps: In the first step, a first borehole is drilled on the top surface of the core sample 2, and a first wellbore 5 is placed in the first borehole as a simulated mother well, the core sample 2 is placed in a triaxial fracturing device, triaxial stress is applied to the core sample 2, and fracturing fluid is pumped into the first wellbore 5 to break the core sample 2 and generate cracks, completing the first fracturing, and recording the first fracturing curve of the simulated mother well; The second step is to perform three-dimensional imaging on the core sample 2 after the first fracturing, and three-dimensionally reconstruct the fracture network of the core sample 2; The third step is to perform a packing treatment on the core sample 2 after the first fracturing. According to the three-dimensional imaging result, a second borehole is drilled at a position without cracks on the top surface of the packed core sample 2, and a second wellbore 6 is installed as a simulated sub-well. The fourth step is to place the core sample 2 processed in the third step into a triaxial fracturing device, pump the fracturing fluid into the first wellbore 5 for pre-pressurization, and then pump the fracturing fluid into the second wellbore 6 to complete the second fracturing, and record the second fracturing curve of the simulated mother well and the fracturing curve of the simulated child well; The fifth step is to detect the core sample 2 after the second fracturing to obtain the crack conditions of the core sample 2.
[0024] Example 2: Figure 1 As shown, as an optimization of the above embodiment, in the first step, the core sample 2 is in the shape of a cuboid, with a length, width, and height of 20 cm to 45 cm respectively. Specifically, the size of the core sample 2 can be selected as 30 cm long*30 cm wide*30 cm high or 40 cm long*30 cm wide*30 cm high.
[0025] Example 3: Figure 1 As shown, as an optimization of the above embodiment, in the first step, the distance between the center of the first borehole and the center of the top surface of the core sample 2 is 10 cm to 20 cm.
[0026] Example 4: Figure 1 As shown, as an optimization of the above embodiment, in the third step, the specific operation of the wrapping treatment is: wrap the core sample 2 of the first fracturing with a membrane cloth, then place the core sample 2 in a mold, and seal the core sample 2 with a sealant that can withstand pressure and has deformable properties. After the core sample 2 is sealed, it is naturally placed in the mold to dry and demold. In the present invention, the membrane cloth can be a tape or a plastic wrap. The first wellbore 5 cannot be sealed during the wrapping treatment. Using a sealant to seal the core sample 2 can ensure that the pressure is not removed from the cracks when the simulated mother well is pre-pressurized.
[0027] Example 5: Figure 1 As shown, as an optimization of the above embodiment, the sealant is epoxy resin, and the thickness of the sealant after drying is 1 cm to 2 cm.
[0028] Example 6: Figure 1As shown, as an optimization of the above embodiment, in the second step, the specific operation of three-dimensional imaging is: using CT scanning or using nuclear magnetic resonance technology to perform three-dimensional reconstruction of the fracture while retaining the fracturing fluid in the core sample 2. In addition, the core sample 2 used in the experiment can also be destroyed along the crack initiation crack, and then the traditional imaging method (such as an ordinary camera) needs to be used to take multiple shots to obtain images from different perspectives during three-dimensional reconstruction, and then use the parallax information therein to obtain depth information through feature extraction, feature matching and other methods to achieve three-dimensional reconstruction. This method often requires sacrificing acquisition time or using multiple cameras to collect simultaneously. Alternatively, it is also a feasible means to use RGBD cameras, structured light, lasers and other methods to obtain depth information combined with two-dimensional images for three-dimensional reconstruction. Using CT nuclear magnetic resonance technology to perform three-dimensional reconstruction of fractures will not damage the core sample 2.
[0029] Example 7: Figure 1 As shown, the specific operation of the fifth step is: use a microseismic detection device to detect the core sample 2 after the second fracturing, obtain the crack generation or crack extension of the core sample 2, and perform three-dimensional imaging of the core sample 2 after the second fracturing to reconstruct the crack morphology in three dimensions.
[0030] Example 8: Figure 1 As shown, the device for implementing the physical simulation experimental method for coping with the technology of inter-well interference includes a computer 1, a core sample 2, a first fracturing fluid pump 3, a second fracturing fluid pump 4 and a triaxial fracturing device, the core sample 2 is placed in the triaxial fracturing device, the top surface of the core sample 2 is installed with a first wellbore 5 and a second wellbore 6, the outlet of the first fracturing fluid pump 3 and the inlet of the first wellbore 5 are fixedly connected with a first fracturing fluid pipeline 7, the first fracturing fluid pipeline 7 is fixedly installed with a first pressure sensor 8, the outlet of the second fracturing fluid pump 4 and the inlet of the second wellbore 6 are fixedly connected with a second fracturing fluid pipeline 9, the second fracturing fluid pipeline 9 is fixedly installed with a second pressure sensor 10, and the first pressure sensor 8 and the second pressure sensor 10 are both communicatively connected with the computer 1. Figure 1 The blue arrow in the middle shows the triaxial pressure provided by the triaxial fracturing device.
[0031] As required, valves, thermometers, flow meters, etc. that enable normal operation of the device are fixedly installed on each pipeline of the device for implementing the physical simulation experimental method for coping with well-to-well interference technology.
[0032] Example 9: The physical simulation experimental method for coping with well-to-well interference technology is carried out according to the following steps: In the first step, the outcrop core collected from the site or the target reservoir is made into a core sample 2 with a length of 40 cm, a width of 30 cm, and a height of 30 cm. A hole with a diameter of 2 cm is drilled in the upper right corner of the top surface of the core sample 2. The center of the hole is 7 cm away from the length and width of the core sample 2, and the first wellbore 5 (simulating the mother well) is installed in the borehole. The core sample 2 is placed on the triaxial fracturing device, and triaxial stress is applied to the core sample 2. The experimental parameters are set according to the parameters of the target reservoir. The first fracturing fluid pump 3 injects the fracturing fluid (viscosity of 20 mPa·s) into the first wellbore 5 (simulating the mother well) at a flow rate of 20 ml / min, performs the first fracturing on the core sample 2, and records the first fracturing curve of the simulated mother well (see Figure 3 The red curve on the left in the middle) gives a burst pressure of 22.7 MPa.
[0033] In the second step, a CT scan was performed on the core sample 2 after the first fracturing (see Figure 5 ).
[0034] Step 3: Wrap the core sample 2 with plastic wrap and then seal it with 2 cm thick epoxy resin (see Figure 2 ), according to the three-dimensional imaging results in the second step, a second borehole with a diameter of 2 cm is drilled at a crack-free position on the top surface of the core sample 2 after packaging, and a second wellbore 6 (simulated sub-well) is installed.
[0035] In the fourth step, the core sample 2 processed in the third step is placed in a triaxial fracturing device, and triaxial stresses are applied as σ v =27MPa,σ H =11MPa,σ h =7MPa. Seal the first wellbore 5, and inject fracturing fluid with a pressure of 2MPa into the second wellbore 6. The purpose is to check the tightness of the core sample 2 after the packing treatment. When the tightness is intact, inject clean water into the first wellbore 5 to reach a pressure of 11MPa and maintain it. Inject fracturing fluid (viscosity of 20mPa·s) into the second wellbore 6 at a flow rate of 20ml / min, perform a second fracturing on the rock sample, and record the second fracturing curve of the simulated mother well (see Figure 3 The red curve on the right in the middle) and the fracturing curve of the simulated sub-well (see Figure 4 ); the second bursting pressure is 22.89MPa.
[0036] The fifth step is to use the acoustic emission data acquisition system (i.e., microseismic detection device, DS5-32B of Beijing Ruandao Company) to detect the core sample 2 after the second fracturing to obtain the crack situation of the core sample 2. Through the screening and analysis of the microseismic experiment, it is proved that new cracks have been generated, rather than just the old cracks that were previously connected. The 10 probes equipped with the acoustic emission data acquisition system are distributed on the three surfaces of the core sample 2, and are adsorbed and bonded to the rock surface using magnets and high-strength glue, which can perform three-dimensional stereoscopic monitoring of the acoustic emission signals inside the core sample 2 during the test.
[0037] According to the fracturing curve, it can be concluded that after the pre-pressurization of the mother well, the force field in the sample is reconstructed, and the fracture pressure after pre-pressurization is greater than the first fracturing. The fracture network in the sample is reconstructed in three dimensions, and the following rules are found: after the pre-pressurization of the mother well, the fracture formation is more complex, and it is easy to connect the natural fractures formed before. After pre-pressurization in the mother well, the fracture initiation pressure of the child well will be higher than the previous fracture initiation pressure of the mother well. When the main fractures of the two wells are connected, the pressures are close.
[0038] To sum up, the physical simulation experimental method and device for coping with well-to-well interference technology of the present invention can effectively provide effective physical simulation for using parent well pre-pressurization to cope with well-to-well interference from the physical simulation level, optimize the development parameters of infill wells and integrated three-dimensional development, and provide indoor test support for parent well pre-pressurization technology, and provide experimental support for adjusting the completion design of sub-wells or wells with close distances and pressure interference in three-dimensional development, optimizing development plans, and exploring the laws of well-to-well interference between parent and child wells or adjacent wells and the laws of fracture growth and expansion, filling the gap in the study of well-to-well interference between parent and child wells or adjacent wells at the physical simulation level.
[0039] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.
Claims
1. A physical simulation experimental method for coping with well-to-well interference technology, characterized in that Follow these steps: The first step is to drill a first borehole on the top surface of the core sample, and place a first wellbore in the first borehole as a simulated mother well, place the core sample in a triaxial fracturing device, apply triaxial stress to the core sample, and pump fracturing fluid into the first wellbore to break the core sample to generate cracks, complete the first fracturing, and record the first fracturing curve of the simulated mother well; The second step is to perform three-dimensional imaging on the core sample after the first fracturing and to reconstruct the fracture network of the core sample in three dimensions; The third step is to pack the core sample after the first fracturing. According to the three-dimensional imaging results, a second borehole is drilled at the top of the packed core sample without cracks, and a second wellbore is installed as a simulated sub-well. The fourth step is to place the core sample processed in the third step into a triaxial fracturing device, pump fracturing fluid into the first wellbore for pre-pressurization, and then pump fracturing fluid into the second wellbore to complete the second fracturing, and record the second fracturing curve of the simulated mother well and the fracturing curve of the simulated child well; The fifth step is to detect the core samples after the second fracturing to obtain the crack conditions of the core samples.
2. The physical simulation experimental method for coping with well interference technology according to claim 1 is characterized in that In the first step, the core sample is in the shape of a cuboid, with a length, width, and height ranging from 20 cm to 45 cm, respectively.
3. The physical simulation experimental method for coping with well interference technology according to claim 1 or 2 is characterized in that In the first step, the distance between the center of the first drill hole and the center of the top surface of the core sample is 10 cm to 20 cm.
4. The physical simulation experimental method for coping with well interference technology according to any one of claims 1 to 3 is characterized in that In the second step, the specific operation of three-dimensional imaging is to use CT scanning or nuclear magnetic resonance technology to reconstruct the three-dimensional fractures while retaining the fracturing fluid in the core sample.
5. The physical simulation experimental method for coping with well interference technology according to any one of claims 1 to 4 is characterized in that In the third step, the specific operation of the wrapping treatment is: wrap the core sample of the first fracturing with a membrane cloth, then place the core sample in a mold, and seal the core sample with a sealant that can withstand pressure and has deformable properties. After the core sample is sealed, place it naturally in the mold to dry and demold it.
6. The physical simulation experimental method for coping with well interference technology according to claim 5 is characterized in that The sealant is epoxy resin, and the thickness of the sealant after drying is 1cm to 2cm.
7. The physical simulation experimental method for coping with well interference technology according to any one of claims 1 to 6 is characterized in that The specific operation of the fifth step is: use a microseismic detection device to detect the core sample after the second fracturing, obtain the crack generation or crack expansion of the core sample, and perform three-dimensional imaging of the core sample after the second fracturing to reconstruct the crack morphology in three dimensions.
8. A device for implementing the physical simulation experimental method for coping with well interference technology according to any one of claims 1 to 7, characterized in that The invention comprises a computer, a core sample, a first fracturing fluid pump, a second fracturing fluid pump and a triaxial fracturing device. The core sample is placed in the triaxial fracturing device. A first wellbore and a second wellbore are installed on the top surface of the core sample. The outlet of the first fracturing fluid pump is fixedly connected with the inlet of the first wellbore by a first fracturing fluid pipeline. A first pressure sensor is fixedly installed on the first fracturing fluid pipeline. The outlet of the second fracturing fluid pump is fixedly connected with the inlet of the second wellbore by a second fracturing fluid pipeline. A second pressure sensor is fixedly installed on the second fracturing fluid pipeline. Both the first pressure sensor and the second pressure sensor are communicatively connected with the computer.