Drilling fluid ground cooling apparatus and method
The drilling fluid surface cooling device, controlled by liquid nitrogen injection and a BP neural network model, solves the problem of low drilling fluid cooling efficiency, achieves high-efficiency cooling and cost control, and improves drilling efficiency and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2024-12-24
- Publication Date
- 2026-06-26
Smart Images
Figure CN122280472A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of oil and gas drilling engineering and geothermal drilling engineering, and in particular, to a drilling fluid surface cooling device and method. Background Technology
[0002] As oil and gas exploration and development extend into deeper formations, the high-temperature problems faced by drilling fluids and downhole tools are becoming increasingly prominent. Prolonged high-temperature drilling operations can alter the properties of drilling fluids, while also degrading or rendering electronic instruments and downhole power equipment unusable, severely impacting drilling efficiency. Currently, in conventional drilling processes, drilling fluid cooling primarily relies on extending the mud flow path to allow for natural cooling with air. This method has low cooling efficiency and limited effectiveness. For ultra-deep wells and geothermal wells, shell-type or plate heat exchangers are used for drilling fluid cooling. However, because these devices alter the cross-section of the cooling flow channel for the drilling fluid, they are prone to clogging, posing complex and potential accident risks. Summary of the Invention
[0003] The purpose of this invention is to provide a drilling fluid surface cooling device and method to solve the technical problem of low cooling efficiency of drilling fluid.
[0004] The above-mentioned objectives of the present invention can be achieved by the following technical solutions:
[0005] This invention provides a drilling fluid surface cooling device, comprising: a liquid nitrogen cooling tank having a liquid nitrogen cooling chamber and a liquid nitrogen injection port and a nitrogen recovery port communicating with the liquid nitrogen cooling chamber; a liquid nitrogen recovery mechanism having its input end connected to the nitrogen recovery port; a liquid nitrogen injection mechanism having its input end connected to the output end of the liquid nitrogen recovery mechanism, and the output end of the liquid nitrogen injection mechanism being connected to the liquid nitrogen injection port; and a drilling fluid cooling pipeline installed in the liquid nitrogen cooling chamber, with one end of the drilling fluid cooling pipeline extending from the liquid nitrogen cooling tank and forming a high-temperature drilling fluid inlet, and the other end of the drilling fluid cooling pipeline extending from the liquid nitrogen cooling tank and forming a cooling drilling fluid outlet, the drilling fluid cooling pipeline being connected to the surface portion of the drilling fluid circulation loop through the high-temperature drilling fluid inlet and the cooling drilling fluid outlet.
[0006] In an embodiment of the present invention, the liquid nitrogen recovery mechanism includes a nitrogen collector and a liquid nitrogen compressor connected along the conveying direction. The nitrogen collector is used to collect nitrogen gas output from the nitrogen recovery port, and the liquid nitrogen compressor is used to compress the nitrogen gas collected in the nitrogen collector into liquid nitrogen and store it.
[0007] In an embodiment of the present invention, the liquid nitrogen injection mechanism includes an injection pump, which is connected to the liquid nitrogen compressor and the liquid nitrogen injection port. The injection pump can inject liquid nitrogen in the liquid nitrogen compressor into the liquid nitrogen cooling chamber in a mist form from the liquid nitrogen injection port.
[0008] In an embodiment of the present invention, the drilling fluid surface cooling device further includes an injection control mechanism. The injection control mechanism includes an injection controller, a cooling chamber thermometer, and a cooling drilling fluid thermometer. The cooling chamber thermometer is located inside the liquid nitrogen cooling chamber and is positioned near the inlet of the high-temperature drilling fluid to measure the temperature of the liquid nitrogen cooling chamber. The cooling drilling fluid thermometer is positioned near the outlet of the cooling drilling fluid to measure the output temperature of the drilling fluid. The cooling chamber thermometer and the cooling drilling fluid thermometer are electrically connected to the injection controller, and the injection controller is connected to the liquid nitrogen injection mechanism.
[0009] In an embodiment of the present invention, the injection control mechanism further includes a high-temperature drilling fluid thermometer and a drilling fluid flow monitor. Both the high-temperature drilling fluid thermometer and the drilling fluid flow monitor are located near the high-temperature drilling fluid inlet and are electrically connected to the injection controller. The high-temperature drilling fluid thermometer is used to measure the input temperature of the drilling fluid, and the drilling fluid flow monitor is used to measure the input flow rate of the drilling fluid.
[0010] In an embodiment of the present invention, the cross-sectional area of the drilling fluid cooling pipeline is the same as the cross-sectional area of the drilling fluid circulation loop.
[0011] In an embodiment of the present invention, the liquid nitrogen injection port is located on one side of the lower part of the liquid nitrogen cooling tank, the nitrogen recovery port is located at the top of the liquid nitrogen cooling tank, the high-temperature drilling fluid inlet is located at the upper part of the liquid nitrogen cooling tank and on the same side as the liquid nitrogen injection port, and the cooling drilling fluid outlet is located at the lower part of the liquid nitrogen cooling tank and on opposite sides of the liquid nitrogen injection port.
[0012] In an embodiment of the present invention, the drilling fluid cooling pipeline is arranged in a tortuous manner within the liquid nitrogen cooling chamber.
[0013] This invention also provides a method for cooling drilling fluid on the surface, using the aforementioned drilling fluid surface cooling device; the method includes the following steps: a liquid nitrogen injection mechanism injects liquid nitrogen from the liquid nitrogen injection port into the liquid nitrogen cooling chamber; drilling fluid is introduced from the high-temperature drilling fluid inlet into the drilling fluid cooling pipeline, and then exchanges heat with the liquid nitrogen in the liquid nitrogen cooling chamber before being discharged from the cooling drilling fluid outlet; wherein, the liquid nitrogen injection volume of the liquid nitrogen injection mechanism is controlled to meet the cooling requirements of the drilling fluid.
[0014] In an embodiment of the present invention, controlling the liquid nitrogen injection rate of the liquid nitrogen injection mechanism includes: during the heat exchange process between the drilling fluid and the liquid nitrogen, monitoring and acquiring input data and analyzing the input data based on a BP neural network model to obtain output data, and then controlling the liquid nitrogen injection rate of the liquid nitrogen injection mechanism according to the output data; wherein, the input data includes the output temperature of the drilling fluid and the temperature of the liquid nitrogen cooling chamber.
[0015] In embodiments of the present invention, the input data further includes the input temperature and input flow rate of the drilling fluid.
[0016] In the embodiments of the present invention, the BP neural network model is a three-layer BP neural network model.
[0017] The features and advantages of this invention are:
[0018] The drilling fluid surface cooling device of the present invention installs the drilling fluid cooling pipeline in a liquid nitrogen cooling chamber and uses a liquid nitrogen injection mechanism to inject liquid nitrogen from the liquid nitrogen injection port into the liquid nitrogen cooling chamber. This allows the drilling fluid in the drilling fluid cooling pipeline to exchange heat efficiently with the liquid nitrogen, thereby achieving efficient cooling of the drilling fluid. This, in turn, ensures the stability of the fluid performance of downhole tools, reduces drilling risks, increases drilling efficiency, and shortens the drilling cycle. In addition, the nitrogen gas generated by the endothermic vaporization of liquid nitrogen can be output from the nitrogen recovery port to the liquid nitrogen recovery mechanism, where it is recompressed into liquid nitrogen and transported to the liquid nitrogen injection mechanism, thereby realizing the recovery and utilization of nitrogen gas without the need for additional nitrogen production, which can effectively control costs.
[0019] The drilling fluid surface cooling method of the present invention controls the liquid nitrogen injection volume of the liquid nitrogen injection mechanism to meet the cooling requirements of the drilling fluid, thereby improving the cooling efficiency and avoiding pipeline freezing caused by excessively low drilling fluid temperature. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a simplified schematic diagram of the drilling fluid surface cooling device in this invention.
[0022] Figure 2 This is a three-dimensional schematic diagram of the drilling fluid surface cooling device in this invention.
[0023] Figure 3 This is a schematic diagram of the installation of the drilling fluid surface cooling device in this invention.
[0024] Figure 4 This is a schematic diagram of the BP neural network model in this invention.
[0025] Figure 5 This is a schematic diagram illustrating the process of constructing, training, and analyzing the BP neural network model in this invention.
[0026] In the picture:
[0027] 1. Liquid nitrogen cooling chamber; 11. Liquid nitrogen cooling chamber; 12. Liquid nitrogen injection port; 13. Nitrogen recovery port;
[0028] 2. Liquid nitrogen recovery mechanism; 21. Nitrogen collector; 22. Liquid nitrogen compressor; 23. Nitrogen recovery pipeline;
[0029] 3. Liquid nitrogen injection mechanism; 31. Injection pump;
[0030] 4. Drilling fluid cooling pipeline; 41. High-temperature drilling fluid inlet; 42. Cooling drilling fluid outlet;
[0031] 5. Injection control mechanism; 51. Injection controller; 52. Cooling chamber thermometer; 53. Cooling drilling fluid thermometer; 54. High-temperature drilling fluid thermometer; 55. Drilling fluid flow monitoring instrument;
[0032] 6. Drilling fluid circulation loop; 61. Drilling fluid return pipeline; 62. Drilling fluid return pipeline; 63. Vibrating screen; 64. Circulation tank group; 65. Mud pump; 7. Kill manifold; 8. Choke manifold. Detailed Implementation
[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0034] Implementation Method 1
[0035] like Figure 1 and Figure 2As shown, the present invention provides a drilling fluid surface cooling device, comprising: a liquid nitrogen cooling tank 1 having a liquid nitrogen cooling chamber 11 and a liquid nitrogen injection port 12 and a nitrogen recovery port 13 communicating with the liquid nitrogen cooling chamber 11; a liquid nitrogen recovery mechanism 2, the input end of which is connected to the nitrogen recovery port 13; a liquid nitrogen injection mechanism 3, the input end of which is connected to the output end of the liquid nitrogen recovery mechanism 2, and the output end of the liquid nitrogen injection mechanism 3 is connected to the liquid nitrogen injection port 12; and a drilling fluid cooling pipeline 4 installed in the liquid nitrogen cooling chamber 11, with one end of the drilling fluid cooling pipeline 4 extending from the liquid nitrogen cooling tank 1 and forming a high-temperature drilling fluid inlet 41, and the other end of the drilling fluid cooling pipeline 4 extending from the liquid nitrogen cooling tank 1 and forming a cooling drilling fluid outlet 42.
[0036] The drilling fluid surface cooling device of the present invention installs the drilling fluid cooling pipeline 4 in the liquid nitrogen cooling chamber 11, and uses the liquid nitrogen injection mechanism 3 to inject liquid nitrogen from the liquid nitrogen injection port 12 into the liquid nitrogen cooling chamber 11. This allows the drilling fluid in the drilling fluid cooling pipeline 4 to exchange heat efficiently with the liquid nitrogen, thereby achieving efficient cooling of the drilling fluid. This, in turn, ensures the stability of the fluid performance of downhole tools, reduces drilling risks, improves drilling efficiency, and shortens the drilling cycle. In addition, the nitrogen gas generated by the heat absorption and vaporization of liquid nitrogen can be output from the nitrogen recovery port 13 to the liquid nitrogen recovery mechanism 2, where it is recompressed into liquid nitrogen and transported to the liquid nitrogen injection mechanism 3, thereby realizing the recovery and utilization of nitrogen gas without the need for additional nitrogen production, which can effectively control costs.
[0037] Combination Figure 3As shown, specifically, the cross-sectional area of the drilling fluid cooling pipeline 4 is the same as that of the drilling fluid circulation loop 6, thus not affecting the original circulation flow of the surface portion of the drilling fluid circulation loop 6. The drilling fluid circulation loop 6 includes a drilling fluid return pipeline 61 connected to the high-temperature drilling fluid inlet 41 at its output end and a drilling fluid return pipeline 62 connected to the cooling drilling fluid outlet 42 at its input end; wherein, the high-temperature drilling fluid inlet 41 and the drilling fluid return pipeline 61, as well as the cooling drilling fluid outlet 42 and the drilling fluid return pipeline 62, can be connected by flanges. A vibrating screen 63 is provided on the drilling fluid return pipeline 61, and a circulation tank group 64 and a mud pump 65 are sequentially provided on the drilling fluid return pipeline 62 along its conveying direction. A liquid nitrogen cooling box 1 is installed between the vibrating screen 63 and the circulation tank group 64, thus connecting the drilling fluid cooling pipeline 4 between the vibrating screen 63 and the circulation tank group 64. The high-temperature drilling fluid returned from the well is transported to the drilling fluid return pipeline 61, and after being separated by the vibrating screen 63, it is transported to the drilling fluid cooling pipeline 4. After being cooled by liquid nitrogen in the liquid nitrogen cooling chamber 11, it flows out and flows into the circulation tank group 64 for storage. Then, the cooled drilling fluid is pumped to the well by the mud pump 65. In addition, the downhole part of the drilling fluid circulation loop 6 is also connected to the kill manifold 7 and the choke manifold 8. The choke manifold 8 can be adjusted to achieve choke circulation and blowout, and can also adjust the pressure difference between the drilling pressure and the casing pressure; the kill manifold 7 can use high-pressure mud to control blowouts and kicks.
[0038] like Figure 1 and Figure 2 As shown, in this embodiment of the invention, the liquid nitrogen injection port 12 is located on one side of the lower part of the liquid nitrogen cooling tank 1, the nitrogen recovery port 13 is located at the top of the liquid nitrogen cooling tank 1, the high-temperature drilling fluid inlet 41 is located at the upper part of the liquid nitrogen cooling tank 1, and the cooling drilling fluid outlet 42 is located at the lower part of the liquid nitrogen cooling tank 1. The drilling fluid flows from the high-temperature drilling fluid inlet 41 to the cooling drilling fluid outlet 42 from top to bottom, while the liquid nitrogen flows from the liquid nitrogen injection port 12 to the nitrogen recovery port 13 from bottom to top, vaporizing and exchanging heat with the drilling fluid in a countercurrent manner, thereby enabling more uniform and faster cooling of the drilling fluid. Furthermore, the high-temperature drilling fluid inlet 41 and the liquid nitrogen injection port 12 are located on the same side of the liquid nitrogen cooling tank 1, which is more conducive to the initial cooling of the incoming drilling fluid by the nitrogen flowing to the top. The cooling drilling fluid outlet 42 and the liquid nitrogen injection port 12 are located on opposite sides of the liquid nitrogen cooling tank 1, which avoids liquid nitrogen from the liquid nitrogen injection port 12 directly spraying into the vicinity of the cooling drilling fluid outlet 42, causing the drilling fluid temperature to drop too low and resulting in blockage of the cooling drilling fluid outlet 42 due to the low temperature freezing of the drilling fluid. Specifically, the liquid nitrogen cooling tank 1 is made of a low-temperature resistant alloy, such as a nickel-based alloy or a titanium alloy. The nitrogen recovery port 13 is connected to the liquid nitrogen recovery mechanism 2 through the nitrogen recovery pipeline 23.
[0039] like Figure 1 and Figure 2 As shown, in order to ensure sufficient heat exchange between the drilling fluid and liquid nitrogen, the drilling fluid cooling pipeline 4 is laid out in a winding manner within the liquid nitrogen cooling chamber 11. Specifically, the drilling fluid cooling pipeline 4 has a generally meandering pipeline structure. After extending horizontally in one direction for a certain distance at the upper part of the liquid nitrogen cooling tank 1, the drilling fluid cooling pipeline 4 bends downward, and then extends horizontally in the opposite direction for a certain distance before bending downward again. This back-and-forth winding continues until it reaches the lower part of the liquid nitrogen cooling tank 1.
[0040] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the liquid nitrogen recovery mechanism 2 includes a nitrogen collector 21 and a liquid nitrogen compressor 22 connected along the conveying direction. The nitrogen collector 21 is used to collect nitrogen gas output from the nitrogen recovery port 13, and the liquid nitrogen compressor 22 is used to compress the nitrogen gas collected in the nitrogen collector 21 into liquid nitrogen and store it.
[0041] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the liquid nitrogen injection mechanism 3 includes an injection pump 31, which is connected to the liquid nitrogen compressor 22 and the liquid nitrogen injection port 12. The injection pump 31 can inject liquid nitrogen in the liquid nitrogen compressor 22 into the liquid nitrogen cooling chamber 11 in a mist form from the liquid nitrogen injection port 12.
[0042] like Figure 1 and Figure 2 As shown, in order to better meet the cooling requirements of drilling fluid and improve cooling efficiency while avoiding pipeline freezing due to excessively low drilling fluid temperature, the drilling fluid surface cooling device in this embodiment of the invention further includes an injection control mechanism 5, which controls the liquid nitrogen injection volume of the liquid nitrogen injection mechanism 3. Specifically, the injection control mechanism 5 is electrically connected to the injection pump 31, thereby controlling the injection pump 31 to perform injection.
[0043] like Figure 1 and Figure 2As shown, in some embodiments of the present invention, the injection control mechanism 5 includes an injection controller 51, a cooling chamber thermometer 52, and a cooling drilling fluid thermometer 53. The cooling chamber thermometer 52 is located inside the liquid nitrogen cooling chamber and is positioned near the high-temperature drilling fluid inlet 41 to measure the temperature of the liquid nitrogen cooling chamber, such that the temperature measured by the cooling chamber thermometer 52 is the lowest temperature of the liquid nitrogen cooling chamber. The cooling drilling fluid thermometer 53 is positioned near the cooling drilling fluid outlet 42 to measure the output temperature of the drilling fluid. The cooling chamber thermometer 52 and the cooling drilling fluid thermometer 53 are electrically connected to the injection controller 51, and the injection controller 51 is connected to the liquid nitrogen injection mechanism 3. The injection controller 51 can control the liquid nitrogen injection rate of the liquid nitrogen injection mechanism 3 according to the temperature of the liquid nitrogen cooling chamber and the output temperature of the drilling fluid. For example, when the temperature of the liquid nitrogen cooling chamber is too low, the injection controller 51 controls the liquid nitrogen injection mechanism 3 to reduce the liquid nitrogen injection rate to ensure that the temperature of the liquid nitrogen cooling chamber is not too low, thereby preventing the drilling fluid in the drilling fluid cooling pipeline 4 from freezing. When the output temperature of the drilling fluid is too low, the injection controller 51 controls the liquid nitrogen injection mechanism 3 to reduce the liquid nitrogen injection rate to ensure that the temperature of the cooled drilling fluid is not too low, thereby preventing the drilling fluid flowing into the drilling fluid return pipeline 62 from freezing. When the output temperature of the drilling fluid is too high, the injection controller 51 controls the liquid nitrogen injection mechanism 3 to increase the liquid nitrogen injection rate to improve the cooling efficiency of the drilling fluid.
[0044] Specifically, the cooling chamber thermometer 52 is installed on the inner top surface of the liquid nitrogen cooling tank 1 and near the high-temperature drilling fluid inlet 41. Alternatively, the cooling chamber thermometer 52 can be installed in other locations within the liquid nitrogen cooling tank 1 near the high-temperature drilling fluid inlet 41, such as the upper part of the inner side of the liquid nitrogen cooling tank 1. The cooling drilling fluid thermometer 53 is installed on the drilling fluid return pipeline 62 and near the cooling drilling fluid outlet 42. Alternatively, the cooling drilling fluid thermometer 53 can be installed in other locations within the liquid nitrogen cooling tank 1 near the cooling drilling fluid outlet 42, such as the portion of the drilling fluid cooling pipeline 4 extending from the lower part of the liquid nitrogen cooling tank 1.
[0045] like Figure 1 and Figure 2As shown, in some other embodiments of the present invention, the injection control mechanism 5 further includes a high-temperature drilling fluid thermometer 54 and a drilling fluid flow rate monitor 55. Both the high-temperature drilling fluid thermometer 54 and the drilling fluid flow rate monitor 55 are located near the high-temperature drilling fluid inlet 41 and electrically connected to the injection controller 51. The high-temperature drilling fluid thermometer 54 is used to measure the input temperature of the drilling fluid, and the drilling fluid flow rate monitor 55 is used to measure the input flow rate of the drilling fluid. The injection controller 51 can control the liquid nitrogen injection quantity of the liquid nitrogen injection mechanism 3 by combining the input temperature and input flow rate of the drilling fluid. For example, when the input temperature and / or input flow rate of the drilling fluid increases, the injection controller 51 controls the liquid nitrogen injection mechanism 3 to increase the liquid nitrogen injection quantity; when the input temperature and / or input flow rate of the drilling fluid decreases, the injection controller 51 controls the liquid nitrogen injection mechanism 3 to decrease the liquid nitrogen injection quantity.
[0046] Specifically, the high-temperature drilling fluid thermometer 54 and the drilling fluid flow meter 55 are both installed on the drilling fluid return pipeline 61 and positioned near the high-temperature drilling fluid inlet 41. The drilling fluid flow meter 55 includes, but is not limited to, an ultrasonic flow meter and / or a Doppler flow meter.
[0047] Combination Figures 4 to 5 As shown, in an embodiment of the present invention, the injection controller 51 controls the liquid nitrogen injection volume of the liquid nitrogen injection mechanism 3 based on a BP neural network model. The input data of the BP neural network model may include the temperature of the liquid nitrogen cooling chamber and the output temperature of the drilling fluid, as well as the input temperature and flow rate of the drilling fluid. It may also include parameters measured by existing online monitoring devices or other monitoring and measuring devices at the well site, such as the density and solid content of the drilling fluid. The output data of the BP neural network model includes the liquid nitrogen injection volume and may also include parameters such as the injection adjustment lag time.
[0048] Specifically, the BP neural network model is a three-layer BP neural network model, including an input layer, a hidden layer, and an output layer. The input data constitutes the neuron vector X = {X1, X2, ..., Xi} of the input layer. Here, Xi can represent input data such as the temperature of the liquid nitrogen cooling chamber, the output temperature of the drilling fluid, the input temperature of the drilling fluid, the input flow rate of the drilling fluid, the density of the drilling fluid, and the solid content of the drilling fluid, with i representing the number of input data points. Each neuron vector in the input layer is mapped to the hidden layer, where the vector H = {H1, H2, ..., Hm} represents intermediate data such as the temperature difference between the inlet and outlet of the drilling fluid (i.e., the difference between the output temperature and the input temperature of the drilling fluid), the temperature difference between the cryogenic nitrogen and the drilling fluid (i.e., the difference between the temperature of the liquid nitrogen cooling chamber and the output temperature of the drilling fluid), and heat exchange efficiency, with m representing the number of intermediate data points. The output data is the neuron vector Y = {Y1, Y2, ..., Yj} of the output layer obtained from the analysis. Yj can represent output data such as the liquid nitrogen injection rate and the injection adjustment lag time, with j representing the number of output data points.
[0049] like Figure 5 As shown, in the embodiments of the present invention, the process of constructing, training and analyzing the BP neural network model includes the following steps: S100, constructing an initial BP neural network model based on input data, intermediate data and output data; S200, training the BP neural network model; S300, using the trained BP neural network model as the BP neural network model of the target well to analyze and obtain the output data of the target well, and then controlling the liquid nitrogen injection mechanism 3 in the target well based on the output data of the target well.
[0050] Specifically, oil and gas development areas are divided into blocks, well areas, platforms, and single wells (i.e., target wells) from large to small. Training the BP neural network model specifically includes: using the input data corresponding to the block as the neuron vectors of the input layer (including the surface ambient temperature replacing the temperature of the liquid nitrogen cooling chamber), using the intermediate relationships of the data corresponding to the block as the neuron vectors of the hidden layer, and using the expected output data as the neuron vectors of the output layer, thus obtaining the first training sample; then inputting the neuron vectors of the input layer and the neuron vectors of the output layer from this training sample into the constructed BP neural network model to obtain the predicted neuron vectors of the hidden layer; inputting the neuron vectors of the input layer and the expected neuron vectors of the hidden layer from the training sample into the constructed BP neural network model to obtain the predicted neuron vectors of the output layer; performing hidden layer and output layer error judgment, that is, judging whether the error between the predicted hidden layer neuron vectors and the actual hidden layer neuron vectors (defined as hidden layer error) is less than a set threshold for hidden layer error. The system checks whether the error between the simulated output layer neuron vector and the expected output layer neuron vector (defined as the output layer error) is less than a set threshold for the output layer error. If so, a BP neural network model suitable for the block is obtained after training (other wells in the same block can be directly trained on this model for secondary training). If not, the simulated output data is adjusted according to the hidden layer error and the output layer error, thereby correcting the BP neural network model. Considering the formation differences in the same block, before implementation in a single well, the BP neural network model is trained again in the same way, using the input data, intermediate data, and simulated output data corresponding to the same well area or platform as the second training samples, thereby training a BP neural network model that is more suitable for the target well. The target well's input data is used as the neuron vector of the input layer for testing, which is then input into the trained BP neural network model to obtain the predicted neuron vector of the output layer. The liquid nitrogen injection volume of the liquid nitrogen injection mechanism 3 in the target well is then controlled according to the predicted neuron vector of the output layer.
[0051] By first training with block data, the model's generality is improved while ensuring sufficient training volume. Then, targeted training is performed using well area or platform data to improve model accuracy. Compared to training directly with platform data, this avoids the problem of insufficient training sample data affecting model error.
[0052] Implementation Method 2
[0053] Combination Figures 1 to 3As shown, the present invention also provides a method for cooling drilling fluid on the surface, using a drilling fluid surface cooling device. The drilling fluid surface cooling device in this embodiment has the same specific structure, working principle, and beneficial effects as the drilling fluid surface cooling device in Embodiment 1, and will not be repeated here. The drilling fluid surface cooling method of the present invention can be implemented with reference to the drilling fluid surface cooling device in Embodiment 1, and will not be repeated here.
[0054] The drilling fluid surface cooling method includes the following steps: the liquid nitrogen injection mechanism 3 injects liquid nitrogen from the liquid nitrogen injection port 12 into the liquid nitrogen cooling chamber 11; the drilling fluid is introduced into the drilling fluid cooling pipeline 4 from the high temperature drilling fluid inlet 41, and then exchanged heat with the liquid nitrogen in the liquid nitrogen cooling chamber 11 before being discharged from the cooling drilling fluid outlet 42; wherein, the liquid nitrogen injection volume of the liquid nitrogen injection mechanism 3 is controlled to meet the cooling requirements of the drilling fluid.
[0055] Combination Figures 4 to 5 As shown, in an embodiment of the present invention, controlling the liquid nitrogen injection rate of the liquid nitrogen injection mechanism 3 includes: during the heat exchange process between the drilling fluid and liquid nitrogen, monitoring and acquiring input data and analyzing the input data based on a BP neural network model to obtain output data, and then controlling the liquid nitrogen injection rate of the liquid nitrogen injection mechanism 3 according to the output data; wherein, the input data includes the output temperature of the drilling fluid and the temperature of the liquid nitrogen cooling chamber 11.
[0056] In embodiments of the present invention, the input data also includes the input temperature and input flow rate of the drilling fluid.
[0057] In the embodiments of the present invention, the BP neural network model is a three-layer BP neural network model.
[0058] The above descriptions are merely a few embodiments of the present invention. Those skilled in the art can make various modifications or variations to the embodiments of the present invention based on the content disclosed in the application documents without departing from the spirit and scope of the present invention.
Claims
1. A drilling fluid ground cooling device, characterized in that, The device comprises: a liquid nitrogen cooling box with a liquid nitrogen cooling chamber, a liquid nitrogen injection port and a nitrogen recovery port connected with the liquid nitrogen cooling chamber; a liquid nitrogen recovery mechanism, the input end of which is connected with the nitrogen recovery port; a liquid nitrogen injection mechanism, the input end of which is connected with the output end of the liquid nitrogen recovery mechanism, and the output end of which is connected with the liquid nitrogen injection port; a drilling fluid cooling pipeline, which is installed in the liquid nitrogen cooling chamber, one end of which extends out of the liquid nitrogen cooling box and constitutes a high-temperature drilling fluid inlet, and the other end of which extends out of the liquid nitrogen cooling box and constitutes a cooled drilling fluid outlet, and which is connected to the ground part of the drilling fluid circulation loop through the high-temperature drilling fluid inlet and the cooled drilling fluid outlet.
2. The drilling fluid ground cooling device according to claim 1, wherein the liquid nitrogen recovery mechanism comprises a nitrogen collector and a liquid nitrogen compressor connected in the conveying direction, the nitrogen collector is used to collect the nitrogen output from the nitrogen recovery port, and the liquid nitrogen compressor is used to compress the nitrogen collected in the nitrogen collector into liquid nitrogen and store it.
3. The drilling fluid ground cooling device according to claim 2, wherein the liquid nitrogen injection mechanism comprises an injection pump, the injection pump is connected with the liquid nitrogen compressor and the liquid nitrogen injection port, and the injection pump can inject the liquid nitrogen in the liquid nitrogen compressor into the liquid nitrogen cooling chamber in the form of mist from the liquid nitrogen injection port.
4. The drilling fluid ground cooling device according to claim 1, wherein the drilling fluid ground cooling device further comprises an injection control mechanism, the injection control mechanism comprises an injection controller, a cooling chamber temperature measuring instrument and a cooled drilling fluid temperature measuring instrument, the cooling chamber temperature measuring instrument is arranged in the liquid nitrogen cooling chamber and is arranged close to the high-temperature drilling fluid inlet to measure the temperature of the liquid nitrogen cooling chamber, the cooled drilling fluid temperature measuring instrument is arranged close to the cooled drilling fluid outlet to measure the output temperature of the drilling fluid, the cooling chamber temperature measuring instrument and the cooled drilling fluid temperature measuring instrument are respectively electrically connected with the injection controller, and the injection controller is connected with the liquid nitrogen injection mechanism.
5. The drilling fluid ground cooling device according to claim 4, wherein the injection control mechanism further comprises a high-temperature drilling fluid temperature measuring instrument and a drilling fluid flow monitoring instrument, the high-temperature drilling fluid temperature measuring instrument and the drilling fluid flow monitoring instrument are both arranged close to the high-temperature drilling fluid inlet and are electrically connected with the injection controller, the high-temperature drilling fluid temperature measuring instrument is used to measure the input temperature of the drilling fluid, and the drilling fluid flow monitoring instrument is used to measure the input flow of the drilling fluid.
6. The drilling fluid ground cooling device according to any one of claims 1 to 5, wherein the flow passage cross-sectional area of the drilling fluid cooling pipeline is the same as the flow passage cross-sectional area of the drilling fluid circulation loop.
7. The drilling fluid ground cooling device according to any one of claims 1 to 5, The liquid nitrogen injection port is located on one side of the lower part of the liquid nitrogen cooling tank, the nitrogen recovery port is located at the top of the liquid nitrogen cooling tank, the high-temperature drilling fluid inlet is located at the upper part of the liquid nitrogen cooling tank and on the same side as the liquid nitrogen injection port, and the cooling drilling fluid outlet is located at the lower part of the liquid nitrogen cooling tank and on opposite sides of the liquid nitrogen injection port.
8. The drilling fluid surface cooling device according to any one of claims 1 to 5, characterized in that, The drilling fluid cooling pipeline is laid out in a winding manner within the liquid nitrogen cooling chamber.
9. A method of ground cooling of a drilling fluid, characterized by, The drilling fluid surface cooling device according to any one of claims 1-8 is used; the drilling fluid surface cooling method includes the following steps: The liquid nitrogen injection mechanism injects liquid nitrogen from the liquid nitrogen injection port into the liquid nitrogen cooling chamber; Drilling fluid is introduced into the drilling fluid cooling pipeline from the high-temperature drilling fluid inlet, and then exchanged heat with liquid nitrogen in the liquid nitrogen cooling chamber before being discharged from the cooling drilling fluid outlet. Specifically, the liquid nitrogen injection volume of the liquid nitrogen injection mechanism is controlled to meet the cooling requirements of the drilling fluid.
10. The method of claim 9, wherein the drilling fluid is cooled to a temperature of about 10°C to about 30°C. The method of controlling the liquid nitrogen injection volume of the liquid nitrogen injection mechanism includes: during the heat exchange process between the drilling fluid and the liquid nitrogen, monitoring and acquiring input data, analyzing the input data based on a BP neural network model to obtain output data, and then controlling the liquid nitrogen injection volume of the liquid nitrogen injection mechanism according to the output data; wherein, the input data includes the output temperature of the drilling fluid and the temperature of the liquid nitrogen cooling chamber.
11. The method of ground cooling of a drilling fluid of claim 10, wherein, The input data also includes the input temperature and input flow rate of the drilling fluid.
12. The drilling fluid surface cooling method as described in claim 10, characterized in that, The BP neural network model is a three-layer BP neural network model.