Well killing simulation method, device, electronic equipment, storage medium and product

Abstract

Embodiments of the present application provide a simulation method and device for killing well, electronic equipment, storage medium and product. The method comprises: obtaining a killing well boundary matrix equation, wherein the killing well boundary matrix equation comprises different killing fluid densities and volumes corresponding to each killing fluid density; determining a first time length for killing fluid to reach the bottom of the simulated well drill string from the ground and a second time length for killing fluid to return to the ground from the bottom of the simulated well drill string through the annular space according to the obtained parameter information of the simulated well; and obtaining a third time length, and then determining the distribution data of the killing fluid with different densities in the drill string and the distribution data in the annular space according to the killing well boundary matrix equation, the first time length, the second time length and the third time length. The distribution data in the drill string and the distribution data in the annular space can be used to simulate the distribution state of the killing fluid with different densities in the well. The method improves the flexibility of the killing well simulation method.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of well control in oil drilling, and in particular to a simulation method and device for killing well, an electronic device, a storage medium and a product. BACKGROUND

[0002] In the technical field of well control in oil drilling, well killing operation is a key link to ensure the safety and efficiency of drilling. By pumping well killing fluid of a specific density into the well, the pressure balance in the wellbore is re-established, thereby ensuring the safety of downhole operation.

[0003] The well killing simulation method in the related art is difficult to flexibly cope with complex and variable downhole conditions, and has poor flexibility. SUMMARY

[0004] The embodiments of the present application provide a simulation method and device for killing well, an electronic device, a storage medium and a product, to achieve the technical effect of improving the flexibility of the well killing simulation method when facing complex and variable downhole conditions.

[0005] In a first aspect, the embodiments of the present application provide a simulation method for killing well, comprising:

[0006] obtaining a well killing boundary matrix equation, wherein the well killing boundary matrix equation includes different well killing fluid densities and volumes corresponding to each well killing fluid density;

[0007] determining a first time length for well killing fluid to reach the bottom of the drill string of the simulation well from the ground and a second time length for well killing fluid to return to the ground from the annular space of the simulation well according to parameter information of the simulation well;

[0008] obtaining a third time length, which represents the time length from the initial simulation time to the current simulation time;

[0009] determining distribution data of well killing fluid of different densities in the drill string and in the annular space in the well killing boundary matrix equation according to the well killing boundary matrix equation, the first time length, the second time length and the third time length, wherein the distribution data in the drill string and in the annular space is used to simulate the distribution state of well killing fluid of different densities in the well;

[0010] wherein the different well killing fluid densities in the well killing boundary matrix equation represent the well killing fluid densities used by at least two of the well killing methods, including the engineer method, the driller method and the method of gradually increasing the weight while circulating.

[0011] In a possible implementation, the parameter information includes well killing displacement of the simulation well, drill string volume and annular space volume.

[0012] determining, according to the parameter information of the simulated well, a first length of time for the kill fluid to reach the bottom of the simulated well drill string from the ground and a second length of time for the kill fluid to return to the ground from the annular space of the simulated well drill string, comprising:

[0013] dividing the drill string volume by the kill fluid displacement, and determining the division result as the first length of time;

[0014] adding the drill string volume and the annular space volume, and dividing the addition result by the kill fluid displacement, and determining the division result as the second length of time.

[0015] In a possible implementation, the determining, according to the kill boundary matrix equation, the first length of time, the second length of time and the third length of time, of the distribution data of the kill fluid with different densities in the drill string and the distribution data of the kill fluid with different densities in the annular space in the kill boundary matrix equation, comprises:

[0016] determining, according to the size relationship between the third length of time and the first length of time, the distribution data of the kill fluid with different densities in the drill string in the kill boundary matrix equation;

[0017] determining, according to the size relationship between the third length of time and the first length of time and the second length of time respectively, the distribution data of the kill fluid with different densities in the annular space in the kill boundary matrix equation.

[0018] In a possible implementation, the determining, according to the size relationship between the third length of time and the first length of time, of the distribution data of the kill fluid with different densities in the drill string in the kill boundary matrix equation, comprises:

[0019] if the third length of time is less than or equal to the first length of time, determining, according to the kill fluid density of the kill fluid currently being injected into the drill string entrance and the kill boundary matrix equation, a first length of the different kill fluids that have been injected in the drill string in the drill string;

[0020] determining, according to the first length of the different kill fluids that have been injected in the drill string in the drill string, the distribution data of the kill fluid with different densities in the drill string in the kill boundary matrix equation;

[0021] if the third length of time is greater than the first length of time, determining, according to the kill fluid density of the kill fluid currently being injected into the drill string entrance, the kill fluid density currently being injected into the annular space from the drill string and the kill boundary matrix equation, a second length of the different kill fluids that have been injected in the drill string in the drill string;

[0022] determining distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the second length of the different kill fluids injected in the drill string in the drill string and the third length of time.

[0023] In a possible implementation, the determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the third length of time and the size relationship between the first length of time and the second length of time includes:

[0024] if the third length of time is less than or equal to the first length of time, the different density kill fluids included in the kill boundary matrix equation do not exist in the annular space;

[0025] if the third length of time is greater than the first length of time and less than the second length of time, determining a third length of the different kill fluids that have flowed into the annular space in the annular space according to the kill fluid density of the kill fluid currently flowing into the annulus and the kill boundary matrix equation;

[0026] determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the third length of the different kill fluids that have flowed into the annular space in the annular space;

[0027] if the third length of time is greater than or equal to the second length of time, determining a fourth length of the different kill fluids that have flowed into the annular space in the annular space according to the kill fluid density of the kill fluid currently flowing into the annulus, the kill fluid density of the kill fluid currently returning to the ground from the annular space and the kill boundary matrix equation;

[0028] determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the fourth length of the different kill fluids that have flowed into the annular space in the annular space.

[0029] In a possible implementation, the method further includes:

[0030] inputting the kill boundary matrix equation into a pre-established wellbore multiphase flow model to obtain casing pressure change data and standpipe pressure change data over time;

[0031] The wellbore multiphase flow model is constructed according to a mass conservation equation and a momentum conservation equation.

[0032] In a second aspect, the embodiments of the present application provide a simulation device for killing well, including:

[0033] The obtaining module is configured to obtain a kill boundary matrix equation, the kill boundary matrix equation including different kill fluid densities and volumes corresponding to the kill fluid densities.

[0034] determining a first time length for the kill fluid to reach the bottom of the simulated drill string from the ground and a second time length for the kill fluid to return to the ground from the bottom of the simulated drill string via the annular space according to the parameter information of the simulated well;

[0035] The acquisition module is further configured to acquire a third time length, the third time length being used to represent a time length from a simulated initial time to a simulated current time.

[0036] The determination module is further configured to determine distribution data of the kill fluid with different densities in the drill string and in the annular space in the kill boundary matrix equation according to the kill boundary matrix equation, the first time length, the second time length and the third time length, the distribution data of the kill fluid with different densities in the drill string and in the annular space being used to simulate a distribution state of the kill fluid with different densities in the well.

[0037] The different kill fluid densities in the kill boundary matrix equation are used to represent kill fluid densities used by different kill methods, the kill methods including at least two of an engineer method, a driller method and a method of adding weight while circulating.

[0038] In a third aspect, an electronic device is provided, including a memory and a processor.

[0039] The memory stores computer-executed instructions.

[0040] The processor executes the computer-executed instructions stored in the memory, so that the processor executes the first aspect and / or various possible implementation manners of the first aspect.

[0041] In a fourth aspect, a computer readable storage medium is provided, the computer readable storage medium storing computer-executed instructions, the computer-executed instructions being executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0042] In a fifth aspect, a computer program product is provided, including a computer program, the computer program being executed by a processor to implement the first aspect and / or various possible implementation manners of the first aspect.

[0043] The simulation method, device, electronic equipment, storage medium and product provided by the embodiments of the present application are provided. The simulation method comprises the following steps: obtaining a well killing boundary matrix equation, wherein the well killing boundary matrix equation comprises different well killing fluid densities and volumes corresponding to the different well killing fluid densities; determining a first time length of well killing fluid from the ground to the bottom of the simulated well drilling string and a second time length of well killing fluid from the bottom of the simulated well drilling string to the ground through the annular space according to the obtained parameter information of the simulated well; and obtaining a third time length, wherein the third time length represents a time length from a simulated initial time to a simulated current time. Then, the distribution data of the well killing fluid with different densities in the drilling string and the distribution data of the well killing fluid with different densities in the annular space are determined according to the well killing boundary matrix equation, the first time length, the second time length and the third time length. The distribution data in the drilling string and the distribution data in the annular space can be used to simulate the distribution state of the well killing fluid with different densities in the well. The method provided by the present application can simulate well killing under complex and changeable downhole conditions by making multiple well killing methods work together, thereby improving the flexibility of the well killing simulation method. BRIEF DESCRIPTION OF DRAWINGS

[0044] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.

[0045] Figure 1 A flowchart of a well killing simulation method provided by the embodiments of the present application is shown in the figure.

[0046] Figure 2 A flowchart of a method for determining the distribution data of well killing fluid with different densities in the drilling string in the well killing boundary matrix equation provided by the embodiments of the present application is shown in the figure.

[0047] Figure 3 A flowchart of a method for determining the distribution data of well killing fluid with different densities in the annular space in the well killing boundary matrix equation provided by the embodiments of the present application is shown in the figure.

[0048] Figure 4 A length data diagram provided by the embodiments of the present application is shown in the figure.

[0049] Figure 5 A casing pressure / standpipe pressure-time relationship curve diagram provided by the embodiments of the present application is shown in the figure.

[0050] Figure 6A structural schematic diagram of a simulation device for well killing is provided for an embodiment of the present application.

[0051] Figure 7 A structural schematic diagram of an electronic device is provided for an embodiment of the present application.

[0052] The specific embodiments of the present application have been shown through the above-described drawings, and will be described in more detail hereinafter. The drawings and the written description are not intended to limit the scope of the present application in any way, but to explain the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0053] The exemplary embodiments will be described in detail hereinbelow with reference to the drawings. In the following description, the same drawings refer to the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not meant to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the present application as detailed in the appended claims.

[0054] In the description of the embodiments of the present application, the terms indicating the direction or position relationship of "in", "out", and the like are based on the direction or position relationship shown in the drawings, which is merely for the convenience of description, and does not indicate or imply that the device or member must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0055] First, the terms involved in the present application are explained:

[0056] Well killing: refers to a process in which, during oil drilling, when overflow (formation fluid entering the wellbore) occurs, etc., to prevent blowout, a well killing fluid with certain density and performance is pumped into the well to reestablish the pressure balance in the wellbore, so that the bottom hole pressure is equal to or slightly greater than the formation pressure, thereby preventing the formation fluid from continuing to flow into the wellbore;

[0057] Engineer method: a one-cycle method of well killing process, suitable for the situation where the well pressure balance needs to be quickly restored after overflow occurs. The operation steps include: first, the original slurry is used to circulate and discharge the contaminated drilling fluid in the well, and then the weighted drilling fluid is used to restore the well pressure to a balanced state in one cycle;

[0058] Driller method: also known as two-cycle method, is a process of well killing through two cycles. The first cycle uses the original slurry to discharge the formation fluid invading the well, and the second cycle uses the weighted drilling fluid to establish a new pressure balance;

[0059] The edge circulation and weighting method refers to a method of gradually increasing the drilling fluid density during well killing. This method allows the drilling fluid density to be greatly increased in a short time, and is suitable for the case where the reserve high-density drilling fluid has a large difference with the required drilling fluid density;

[0060] Drill string: In oil drilling, it is a combination of a series of tubular components connected to the drill bit, mainly including drill pipe, drill collar, kelly, etc. The function of the drill string is to transmit power from the ground to the drill bit to drive the drill bit to rotate and break rocks. It also has important functions such as transporting drilling fluid (pumping drilling fluid from the ground to the bottom of the well to carry cuttings back to the ground), supporting the drill bit and part of the downhole tools, etc.

[0061] Annular space: referred to as annulus, in oil drilling, it refers to the annular area formed between the outer surface of the drill string (drill pipe, drill collar, etc.) and the inner surface of the well wall. Drilling fluid circulates in the annulus, carrying the broken rock cuttings from the bottom of the well back to the ground. At the same time, the pressure change and other parameters of the annulus have important indicating effects on the judgment of downhole working conditions (such as overflow, well leakage, etc.).

[0062] Casing pressure: referred to as casing pressure, it is the pressure in the casing at the wellhead under the condition of closed well. It reflects the difference between the formation pressure and the annular fluid column pressure. It is one of the important parameters for judging whether overflow occurs in the well, the change of formation pressure, and the effect of well killing operation.

[0063] Standpipe pressure: also called standpipe pressure, it is the pressure of drilling fluid in the standpipe (a pipe connected between the outlet of the drilling pump and the drill string) during drilling operation. The change of standpipe pressure can reflect the working state of the drill bit, the change of drilling fluid performance, and whether there is an abnormal situation in the well, etc. It is an important parameter that needs to be closely monitored and controlled in drilling operation.

[0064] During drilling, the pressure in the wellbore needs to be relatively balanced with the formation pressure. When problems such as frequent gas invasion in ultra-deep complex formations and narrow safety density window cause abnormal formation pressure, this balance will be broken. Through well killing, this pressure balance can be re-established to ensure the safety and smooth progress of drilling operations.

[0065] When dealing with complex formations, the most commonly used well killing method is the throttling circulation well killing method such as the driller method, engineer method or edge circulation and weighting method. Through reasonable design of well killing parameters and well killing curve, the throttling circulation well killing method uses well killing fluid to safely circulate the formation fluid invading the wellbore out of the wellbore, so as to establish a new balance relationship between the wellbore pressure and the formation pressure.

[0066] In related technologies, when modeling well killing, a calculation model is usually established for only one well killing method, and simulation is performed through a single well killing method.

[0067] However, when facing some complex downhole conditions, for example, after overflow occurs in an ultra-deep complex formation, there are problems such as high standpipe pressure, high gas content, and the like, the formation pressure is not easy to evaluate due to high temperature and high pressure, in the case of high standpipe pressure, gradually increasing the density of the well killing fluid to avoid more serious gas invasion caused by pressure leakage of the formation, in the process of well killing in a narrow safety density window formation, there may be a large amount of well killing fluid leakage or secondary overflow, or temporary adjustment of well killing parameters during well killing, and the like, a plurality of well killing methods need to be used in cross to better perform well killing. Therefore, in the related art, it is difficult to simulate the wellbore flow state in a complex well killing process by using a single well killing simulation method, which brings great difficulties to well killing fluid interface tracking and key node calculation in the well killing process. The well killing simulation method in the related art cannot meet the use requirements and has poor flexibility.

[0068] Therefore, in view of the above technical problems in the prior art, the inventors have found, in the course of research, that if there is a well killing simulation method that can realize the coordinated regulation of multiple well killing methods, the flexibility of the well killing simulation method in the face of different downhole conditions can be effectively improved. Therefore, the present application proposes a well killing simulation method, device, electronic equipment, storage medium and product. Specifically, by establishing a well killing boundary matrix equation including the well killing fluid density corresponding to a plurality of well killing methods, and combining the key time nodes in the well killing process, i.e., the first time length for the well killing fluid to reach the bottom of the simulated well drill string from the ground, and the second time length for the well killing fluid to return to the ground from the bottom of the simulated well drill string through the annular space, the distribution data of the well killing fluid of different densities in the drill string and the distribution data of the well killing fluid of different densities in the annular space in the well killing boundary matrix equation are determined, and the distribution state of the well killing fluid of different densities in the well is simulated according to the distribution data of the well killing fluid of different densities in the drill string and the distribution data of the well killing fluid of different densities in the annular space.

[0069] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0070] Please refer to Figure 1 , Figure 1 A flowchart of a well killing simulation method provided by an embodiment of the present application is shown. The execution subject of the method can be a well killing simulation device, which can be realized by a computer program. It can also be realized by a medium storing a related computer program, such as a U disk and / or an optical disk, or it can also be realized by an entity device integrated or installed with a related computer program, such as a chip or an electronic device, which can be a server, a server cluster, a computer, or the like. The method includes the following steps:

[0071] S101, obtain a kill boundary matrix equation, the kill boundary matrix equation comprising: different kill fluid densities and volumes corresponding to each kill fluid density.

[0072] The different kill fluid densities in the kill boundary matrix equation are used to represent the kill fluid densities used by different kill methods, and the kill methods comprise at least two of the engineer method, the driller method, and the method of gradually increasing the weight while circulating.

[0073] In this embodiment, according to the kill process of the actual well to be simulated, the kill boundary matrix equation can be established according to the injection sequence of the kill fluid, and the kill boundary matrix equation can comprise the densities of the kill fluids used by different kill methods and the injection volumes corresponding to each kill fluid density. The injection volumes can be preset.

[0074] The obtained kill boundary matrix equation F(ρ L ,V L ) can be as shown in the following formula (1):

[0075]

[0076] Wherein, ρ L represents the kill fluid density; V L represents the volume of the kill fluid; and n represents the nth kill fluid.

[0077] In this embodiment, the kill boundary matrix equation corresponding to a single kill method can also be represented by the above kill boundary matrix equation.

[0078] For example, taking the engineer method as an example, a certain volume of kill fluid capable of balancing the formation pressure is injected, and then the kill boundary matrix equation F1(ρ L ,V L ) is as shown in the following formula (2):

[0079]

[0080] For example, taking the driller method as an example, a certain volume of original drilling fluid is first injected to circulate and discharge the annular gas out of the wellbore, and then a certain volume of another kill fluid capable of balancing the formation pressure is injected, and then the kill boundary matrix equation F2(ρ L ,V L ) is as shown in the following formula (3):

[0081]

[0082] For example, taking the example of the blowout control method of gradually increasing the density of the blowout control fluid, the density of the blowout control fluid gradually increases, and the density of the last blowout control fluid can balance the formation pressure. The number of times of increasing the density of the blowout control fluid and the volume of the blowout control fluid of each density can be determined according to the actual situation on site, and the blowout control boundary matrix equation F3(ρ L ,V L ) is as shown in the following formula (4):

[0083]

[0084] When the above-mentioned multiple methods are used simultaneously, the blowout control boundary matrix equation can be flexibly adjusted according to the order of use of each method and the density of the blowout control fluid used.

[0085] For example, it is assumed that the blowout control method used is only the engineer method, and the density of the blowout control fluid included in the blowout control boundary matrix equation can be as shown in the following formula (5) with the corresponding volume of the blowout control fluid:

[0086]

[0087] If the blowout control method is temporarily adjusted so that multiple blowout control methods are used simultaneously, 200m 3 of the blowout control fluid with a density of 1.80g / cm 3 is first injected, 100m 3 of the drilling fluid is found to be lost, 70m 3 of the blowout control fluid with a density of 1.77g / cm 3 is temporarily injected, and then 250m 3 of the blowout control fluid with a density of 1.80g / cm 3 is continuously injected, the density of the blowout control fluid included in the new blowout control boundary matrix equation obtained can be as shown in the following formula (6) with the corresponding volume of the blowout control fluid:

[0088]

[0089] It can be understood that the above examples are only for illustration and do not limit the present application.

[0090] S102, according to the parameter information of the simulation well, determining the first time length of the blowout control fluid from the ground to the bottom of the drill string of the simulation well and the second time length of the blowout control fluid from the bottom of the drill string of the simulation well to the ground through the annular space.

[0091] The parameter information of the simulation well can be pre-set according to the parameter information of the actual simulation well, wherein the parameter information includes but is not limited to: blowout control displacement, drill string volume, and annular space volume, etc.

[0092] Optionally, the drill string volume is divided by the blowout control displacement, and the result of the division is determined as the first time length t bottom, please refer to the following formula (7) :

[0093]

[0094] Wherein, V p Indicates the volume of the drill string; q pump Indicates the kill rate.

[0095] Optionally, the volume of the drill string is added to the volume of the annular space, and the addition result is divided by the kill rate, and the division result is determined as the second time length t top , please refer to the following formula (6) :

[0096]

[0097] Wherein, V a Indicates the volume of the annulus.

[0098] As can be seen from formula (7) and (8), the second time length is greater than the first time length.

[0099] By determining the first time length of the kill fluid from the ground to the bottom of the simulated drill string and the second time length of the kill fluid from the bottom of the simulated drill string to the ground through the annular space, the migration interface of the kill fluid in the simulation process is tracked.

[0100] S103, obtain the third time length.

[0101] Wherein, the third time length is used to represent the time length from the initial simulation time to the current simulation time.

[0102] In this embodiment, according to the different simulation time, the third time length can have multiple, for example, the third time length can be the time length before the first time length of the kill fluid from the ground to the bottom of the simulated drill string, also can be the time length after the first time length of the kill fluid from the ground to the bottom of the simulated drill string, also can be the time length between the first time length and the second time length, also can be the time length after the second time length of the kill fluid from the bottom of the simulated drill string to the ground through the annular space, etc.

[0103] S104, according to the kill boundary matrix equation, the first time length, the second time length and the third time length, determine the distribution data of the kill fluid with different densities in the drill string and the distribution data in the annular space in the kill boundary matrix equation, the distribution data in the drill string and the distribution data in the annular space are used to simulate the distribution state of the kill fluid with different densities in the well.

[0104] A possible implementation is:

[0105] According to the size relationship between the third time length and the first time length and the second time length in the well killing boundary matrix equation, the distribution data of the well killing fluids with different densities in the annular space in the well killing boundary matrix equation is determined.

[0106] According to the size relationship between the third time length and the first time length and the second time length in the well killing boundary matrix equation, the distribution data of the well killing fluids with different densities in the annular space in the well killing boundary matrix equation is determined.

[0107] According to the size relationship between the third time length and the first time length and the second time length in the well killing boundary matrix equation, the distribution data of the well killing fluids with different densities in the annular space in the well killing boundary matrix equation is determined.

[0108] In the above embodiment of the present application, by obtaining the well killing boundary matrix equation, the well killing boundary matrix equation includes different well killing fluid densities and volumes corresponding to each well killing fluid density, wherein the different well killing fluid densities in the well killing boundary matrix equation are used to represent the well killing fluid densities used by different well killing methods, and the well killing methods include at least two of the engineer method, the driller method and the edge circulation and weighting method. According to the obtained parameter information of the simulation well, the first time length of the well killing fluid from the ground to the bottom of the simulation well drill string and the second time length of the well killing fluid from the bottom of the simulation well drill string through the annular space back to the ground are determined, and the third time length is obtained, which is used to represent the time length from the simulation initial time to the current simulation time. Then, according to the well killing boundary matrix equation, the first time length, the second time length and the third time length, the distribution data of the well killing fluids with different densities in the drill string and in the annular space in the well killing boundary matrix equation is determined, and the distribution data in the drill string and in the annular space can be used to simulate the distribution state of the well killing fluids with different densities in the well. The method of the present application can realize the simulation of well killing under complex and variable downhole conditions by making multiple well killing methods work together, thereby improving the flexibility of the well killing simulation method, because there are multiple well killing fluids with different densities in the well killing boundary matrix equation, and the multiple well killing fluids with different densities correspond to the well killing fluids used by different well killing methods.

[0109] Further, on the basis of the above embodiment, the process of determining the distribution data of the well killing fluids with different densities in the drill string in the well killing boundary matrix equation according to the size relationship between the third time length and the first time length and the second time length in the well killing boundary matrix equation is illustrated by the following embodiment.

[0110] Please refer to Figure 2 , Figure 2A flowchart of a method for determining distribution data of different density kill fluids in a drill string in a kill boundary matrix equation provided by an embodiment of the present application can include the following steps:

[0111] S201, if the third time length is less than or equal to the first time length, determining a first length of different kill fluids injected in the drill string in the drill string according to a kill fluid density of the kill fluid currently injected at the drill string inlet and the kill boundary matrix equation.

[0112] S202, determining the distribution data of different density kill fluids in the drill string in the kill boundary matrix equation according to the first length of different kill fluids injected in the drill string in the drill string.

[0113] When the third time length t≤t bottom , it indicates that the kill fluid does not reach the bottom of the drill string, and at this time, the volume V p,in (t) of the kill fluid injected into the drill string is as shown in the following formula (9):

[0114] V p,in (t)=q pump t (9)

[0115] When the kill fluid density of the kill fluid currently injected at the drill string inlet is ρ L1 , because it is currently injected, the volume has not reached the preset volume V L1 in the kill boundary matrix equation corresponding to ρ L1 , i.e., V p,in (t)≤V L1 , and the length h p,L1 of the kill fluid with the density ρ L1 in the drill string can be determined by the following formula (10):

[0116]

[0117] Wherein, A p represents the cross-sectional area of the drill string.

[0118] According to the first length of different kill fluids injected in the drill string in the drill string, i.e., the length h p,L1 of the kill fluid with the density ρ L1 , the distribution data of different density kill fluids in the drill string in the kill boundary matrix equation is as shown in the following formula (11):

[0119]

[0120] Wherein, represents the distribution data in the drill string when the kill fluid density of the kill fluid currently injected at the drill string inlet is ρ L1 ; ρL0 This represents other kill fluids already present in the drill string that are not included in the kill fluid boundary matrix equation; h represents the length from the drill string inlet to a certain position inside the drill string.

[0121] When the kill fluid density currently being injected at the drill string inlet is ρ Lj At that time, based on the order of the kill fluids included in the kill fluid boundary matrix equation, it can be explained that the fluids ranked in the density ρ... Lj Other kill fluids preceding the corresponding kill fluid have been injected into the drill string, with a density ρ. Lj The injection is in progress, indicating that the volume has not yet reached the well control boundary matrix equation related to ρ. j The corresponding preset volume V Lj ,Right now Where j = 2, 3, ..., n, i represents the i-th kill fluid in the kill boundary matrix equation. The drill string contains a density ρ Lj The corresponding kill fluid and at density ρ Lj The density of other kill fluids preceding the corresponding kill fluid, i.e., ρ L1 ,ρ L2 ,…,ρ Lj The length of the kill fluid can be determined by the following formula (12):

[0122]

[0123] Based on the first length of the drill string containing different kill fluids, i.e., the density of the kill fluid is ρ L1 ,ρ L2 ,…,ρ Lj The length h of the corresponding kill fluid p,L1 ,h p,L2 ,…,h p,Lj The distribution data of the above-mentioned killing fluids of different densities in the drill string in the killing boundary matrix equation are determined as shown in the following formula (13):

[0124]

[0125] in, This indicates that the density of the kill fluid currently being injected at the drill string inlet is ρ. Lj At that time, the density of the kill fluid in the drill string is ρ L1 ,ρ L2 ,…,ρ Lj The distribution data; m represents the m-th kill fluid in the kill boundary matrix equation.

[0126] S203, if the third time length is greater than the first time length, determining the second length of the different kill fluids injected in the drill string in the drill string according to the kill fluid density of the kill fluid currently being injected at the drill string inlet, the kill fluid density of the kill fluid currently entering the annular space from the drill string, and the kill boundary matrix equation.

[0127] S204, determining the distribution data of the different density kill fluids in the drill string in the kill boundary matrix equation according to the second length of the different kill fluids injected in the drill string in the drill string.

[0128] When the third time length t>t bottom , it means that the kill fluid has reached the bottom of the drill string, and at this time the volume of the kill fluid entering the annulus from the drill string V p,out (t) is as shown in the following formula (14):

[0129] V p,out (t) = q pump (t-t bottom ) (14)

[0130] When the kill fluid density of the kill fluid currently being injected at the drill string inlet is still p L1 , because it is currently being injected, it means that the volume has not reached the preset volume V L1 in the kill boundary matrix equation corresponding to p L1 , that is, V p,in (t)≤V L1 , and at the same time, since the kill fluid with density p L1 has reached the bottom of the drill string, and enters the annulus from the drill string, the length of the kill fluid with density p L1 in the drill string h p,L1 =H depth , H depth represents the length of the drill string. The distribution data in the drill string is that the density of the fluid in the drill string is p L1 .

[0131] When the kill fluid density of the kill fluid currently being injected at the drill string inlet is p Lj , and the kill fluid with density p L1 is entering the annulus from the drill string, according to the order of the kill fluids included in the kill boundary matrix equation, it means that the other kill fluids before the kill fluid corresponding to the density p Lj have been injected into the drill string, and the density p Lj is being injected, which means that the volume has not reached the preset volume V Lj in the kill boundary matrix equation corresponding to p Lj , that is, where j=2, 3, …, n, i represents the i th kill fluid in the kill boundary matrix equation. At the same time, because the kill fluid with density p L1is being injected into the annulus from the drill string, which means the density of the inflow annulus is ρ L1 The volume of the kill fluid with the density of ρ L1 is less than the preset volume V p,out , i.e., V L1 (t)≤V Lj The drill string contains the kill fluid with the density of ρ Lj The corresponding kill fluid and the other kill fluids before the kill fluid with the density of ρ L1 , ρ L2 ,…, ρ Lj The length of the kill fluid with the density of ρ

[0132]

[0133] According to the second length of the different kill fluids injected in the drill string, i.e., the length of the kill fluid with the density of ρ L1 , ρ L2 ,…, ρ Lj The length of the corresponding kill fluid is h p,L1 , h p,L2 ,…, h p,Lj , the distribution data of the above different density kill fluids in the drill string in the kill boundary matrix equation is shown in the following formula (16):

[0134]

[0135] The distribution data of the kill fluids with the density of ρ Lj , ρ L1 ,…, ρ Lj in the drill string, when the kill fluid with the density of ρ L1 is being injected into the drill string, and the kill fluid with the density of ρ L2 is being injected into the annulus from the drill string; m represents the mth kill fluid in the kill boundary matrix equation.

[0136] According to the order of the kill fluids included in the kill boundary matrix equation, when the kill fluid with the density of ρ Lj is being injected into the drill string, and the kill fluid with the density of ρ Lk is being injected into the annulus from the drill string, it is shown that the other kill fluids before the kill fluid with the density of ρ Lk have been injected into the drill string, and the kill fluid with the density of ρ Lj is being injected, which means the volume has not reached the preset volume V j corresponding to the kill fluid with the density of ρ Lj , i.e., wherein, j = 2, 3…, n, i represents the ith kill fluid in the kill boundary matrix equation. Meanwhile, because the kill fluid with the density of ρLk The kill fluid is entering the annulus from the drill string, indicating that it is being discharged at a density ρ Lk Other kill fluids preceding the corresponding kill fluid have flowed into the annulus, with a density of ρ. Lk The volume of the kill fluid is less than the preset volume V. Lk ,therefore, Where k = 2, 3, ..., j-1, k represents the k-th kill fluid in the kill boundary matrix equation. The drill string contains a density ρ Lj The corresponding kill fluid and at density ρ Lj The density of other kill fluids preceding the corresponding kill fluid, i.e., ρ L1 ,ρ L2 ,…,ρ Lj The length of the kill fluid can be determined by the following formula (17):

[0137]

[0138] Based on the second length of the different kill fluids injected into the drill string, i.e., the density of the kill fluid is ρ L1 ,ρ L2 ,…,ρ Lj The length h of the corresponding kill fluid p,L1 ,h p,L2 ,…,h p,Lj The distribution data of the above-mentioned killing fluids of different densities in the drill string in the killing boundary matrix equation are determined as shown in the following formula (18):

[0139]

[0140] ρ p4 This indicates that the density of the kill fluid currently being injected at the drill string inlet is ρ. Lj And the density is ρ Lk When the kill fluid is entering the annulus from the drill string, the density of the kill fluid in the drill string is ρ. L1 ,ρ L2 ,…,ρ Lj Distribution data.

[0141] When the kill fluid density currently being injected at the drill string inlet is ρ Lj And the density is ρ Ln When the kill fluid is entering the annulus from the drill string, according to the order of the kill fluids included in the kill boundary matrix equation, the fluids with density ρ are arranged in order of... Ln Other kill fluids preceding the corresponding kill fluid have been injected into the drill string, with a density ρ. Lj The injection is in progress, indicating that the volume has not yet reached the well control boundary matrix equation related to ρ. Lj The corresponding preset volume V Lj ,Right now Where j = 2, 3, ..., n, i represents the i-th kill fluid in the kill boundary matrix equation. Also, because the density is ρ Ln The kill fluid is entering the annulus from the drill string, indicating that it is being discharged at a density ρ Ln Other kill fluids preceding the corresponding kill fluid have flowed into the annulus, with a density of ρ. Ln The volume of the kill fluid is less than the preset volume V. Ln ,therefore, Where n represents the nth, or last, kill fluid in the kill boundary matrix equation. The density contained within the drill string is ρ. L1 ,ρ L2 ,…,ρ Ln The length of the kill fluid can be determined by the following formula (19):

[0142]

[0143] When j = n, it means that only the drill string with density ρ exists at this time. Ln The corresponding kill fluid, therefore, the distribution data in the drill string is as shown in the following formula (20):

[0144]

[0145] in, This indicates that the density of the kill fluid currently being injected at the drill string inlet is ρ. Lj If j = n, it means that the kill fluid currently being injected at the drill string inlet is the same as the kill fluid entering the annulus from the drill string, both having a density of ρ. Ln The kill fluid is therefore, the distribution data in the drill string, i.e., the density of the kill fluid in the drill string, is ρ. Ln .

[0146] In the above embodiment of the present application, if the third time length is less than or equal to the first time length, the first length of the different kill fluids injected in the drill string is determined according to the kill fluid density of the kill fluid currently injected at the drill string inlet and the kill boundary matrix equation. If the third time length is greater than the first time length, the second length of the different kill fluids injected in the drill string is determined according to the kill fluid density of the kill fluid currently injected at the drill string inlet, the kill fluid density currently entering the annular space from the drill string, and the kill boundary matrix equation. Then, the distribution data of the different density kill fluids in the drill string in the kill boundary matrix equation is determined according to the first length and the second length of the different kill fluids injected in the drill string. The method of the embodiment determines the distribution data of the different density kill fluids in the drill string in the kill boundary matrix equation more accurately by simulating the time, i.e., the third time length, and combining the key time nodes in the kill process, i.e., the first time length of the kill fluid from the ground to the bottom of the simulated well drill string and the second time length of the kill fluid from the bottom of the simulated well drill string back to the ground through the annular space. Therefore, the distribution state of the different density kill fluids in the drill string simulated according to the determined distribution data is also more accurate.

[0147] Further, on the basis of the above embodiment, the process of determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the size relationship between the third time length and the first time length and the second time length is illustrated by the following embodiment.

[0148] Please refer to Figure 3 , Figure 3 A flowchart of a method for determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation provided by the embodiment of the present application, which can include the following steps:

[0149] S301, if the third time length is less than or equal to the first time length, the different density kill fluids included in the kill boundary matrix equation do not exist in the annular space.

[0150] When the third time length t≤t bottom , it indicates that the kill fluid has not reached the bottom of the drill string, so the kill fluid in the drill string will not flow into the annulus. At this time, the distribution data of the liquid phase in the annulus is ρ L0 , wherein ρ L0 represents other kill fluids already existing in the annulus, which do not belong to the kill fluids included in the kill boundary matrix equation.

[0151] S302, if the third time length is greater than the first time length and less than the second time length, determining a third length of the different kill fluids flowed into the annular space in the annular space according to the kill fluid density of the kill fluid currently flowing into the annular space from the drill string and the kill boundary matrix equation.

[0152] S303, determining distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the third length of the different kill fluids flowed into the annular space in the annular space.

[0153] When t bottom <third time length t≤t top , the kill fluid in the drill string reaches the bottom of the drill string and part of the kill fluid flows into the annulus, but does not flow out of the annular wellhead, the volume V a,in (t) of the kill fluid flowed into the annulus is equal to the volume V p,out (t) of the kill fluid flowed out of the drill string, that is, V a,in (t) = V p,out (t) = q pump (t-t bottom ).

[0154] When the kill fluid with density ρ L1 is flowing into the annulus from the drill string, because it is currently flowing, it means that the volume has not reached the preset volume V L1 in the kill boundary matrix equation corresponding to ρ L1 , that is, V a,in (t) < V L1 , the length h L1 of the kill fluid with density ρ a,L1 in the annulus can be determined by the following formula (21):

[0155]

[0156] Wherein, A a represents the cross-sectional area of the annulus.

[0157] According to the third length of the different kill fluids flowed into the annular space in the annular space, that is, the length h L1 of the kill fluid with density ρ a,L1 , the distribution data of the different density kill fluids in the drill string in the kill boundary matrix equation is shown in the following formula (22):

[0158]

[0159] Wherein, represents the distribution data in the annulus when the kill fluid flowed into the annulus has a kill fluid density of ρ L1 ; ρ L0This represents other kill fluids already present in the annulus, which are not included in the kill fluid boundary matrix equation; h′ represents the length from the annulus surface outlet to a certain location within the annulus; the depth of the annulus is the same as the depth of the drill string, i.e., both are H. depth .

[0160] When the density is ρ Lj When the kill fluid is flowing from the drill string into the annulus, according to the order of the kill fluids included in the kill boundary matrix equation, it can be explained that the fluids with density ρ are arranged in the order of the kill fluids. Lj The corresponding kill fluid, along with other kill fluids preceding it, has flowed from the drill string into the annulus, with a density ρ. Lj The kill fluid is flowing from the drill string into the annulus, indicating that the volume flowing into the annulus has not yet reached the kill boundary matrix equation corresponding to ρ. Lj The corresponding preset volume V Lj ,therefore, Where j = 2, 3, ..., n, i represents the i-th kill fluid in the kill boundary matrix equation. The annulus contains a density ρ Lj The corresponding kill fluid and at density ρ Lj The density of other kill fluids preceding the corresponding kill fluid, i.e., ρ L1 ,ρ L2 ,…,ρ Lj The length of the kill fluid can be determined by the following formula (23):

[0161]

[0162] Based on the third length of the different kill fluids that have flowed into the annulus, i.e., the density of the kill fluid is ρ L1 ,ρ L2 ,…,ρ Lj The length h of the corresponding kill fluid a,L1 ,h a,L2 ,…,h a,Lj The distribution data of the above-mentioned kill fluids of different densities in the annulus in the kill boundary matrix equation are determined as shown in the following formula (24):

[0163]

[0164] in, The density is represented by ρ Lj When the kill fluid is flowing from the drill string into the annulus, the density of the kill fluid in the annulus is ρ. L1 ,ρ L2 ,…,ρ Lj The distribution data; m represents the m-th kill fluid in the kill boundary matrix equation.

[0165] S304, if the third time length is greater than or equal to the second time length, determining a fourth length of the different kill fluids flowed into the annular space in the annular space according to the kill fluid density of the kill fluid currently flowing into the annular space through the drill string, the kill fluid density of the kill fluid currently returning to the ground through the annular space, and the kill boundary matrix equation.

[0166] S305, determining distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the fourth length of the different kill fluids flowed into the annular space in the annular space.

[0167] When the third time length t>t top , it indicates that the kill fluid in the annular space starts to return to the wellhead, and the volume V a,out (t) of the kill fluid discharged from the annular space is as shown in the following formula (25):

[0168] V a,out (t) = q pump (t-t top ) (25)

[0169] When the kill fluid with the density p L1 is still flowing into the annular space through the drill string, because it is currently flowing, it indicates that the volume has not reached the preset volume V L1 corresponding to p L1 in the kill boundary matrix equation, that is, V a,in (t) < V L1 , because the kill fluid in the annular space starts to return to the wellhead, according to the order of the kill fluid included in the kill boundary matrix equation, it indicates that the density of the kill fluid starting to return to the wellhead in the annular space is also p L1 , so at this time, the kill fluid in the annular space is all the kill fluid with the density p L1 , therefore, the length h a,L1 of the kill fluid with the density p L1 in the annular space is the total length of the annular space, that is, h a,L1 = H depth . The distribution data of the kill fluid in the annular space is as shown in the following formula (26):

[0170]

[0171] Among them, represents the distribution data of the kill fluid with the density p L1 in the annular space when the kill fluid with the density p L1 is still flowing into the annular space through the drill string.

[0172] When the kill fluid with the density p Lj is flowing into the annular space through the drill string, and the kill fluid with the density p L1When the kill fluid is being discharged from the annulus wellhead, according to the order of the kill fluid included in the kill boundary matrix equation, it can be explained that the fluid discharged at density ρ is... Lj The corresponding kill fluid, along with other kill fluids preceding it, has flowed from the drill string into the annulus, with a density ρ. Lj The injection is in progress, indicating that the volume has not yet reached the well control boundary matrix equation related to ρ. Lj The corresponding preset volume V Lj ,Right now Where j = 2, 3, ..., n, i represents the i-th kill fluid in the kill boundary matrix equation. Also, because the density is ρ L1 The kill fluid is being discharged from the annulus wellhead, indicating that the density of the fluid discharged from the annulus is ρ. L1 The volume of the kill fluid is less than the preset volume V. L1 V a,out (t)≤V L1 The annulus contains a density ρ Lj The corresponding kill fluid and at density ρ Lj The density of other kill fluids preceding the corresponding kill fluid, i.e., ρ L1 ,ρ L2 ,…,ρ Lj The length of the kill fluid can be determined by the following formula (27):

[0173]

[0174] Based on the fourth length of the different kill fluids that have flowed into the annulus, i.e., the density of the kill fluid is ρ L1 ,ρ L2 ,…,ρ Lj The length h of the corresponding kill fluid a,L1 ,h a,L2 ,…,h a,Lj The distribution data of the above-mentioned kill fluids of different densities in the annulus in the kill boundary matrix equation are determined as shown in the following formula (28):

[0175]

[0176] in, The density is represented by ρ Lj The kill fluid is flowing from the drill string into the annulus, and its density is ρ. L1 When the kill fluid is being discharged from the annulus wellhead, the density of the kill fluid in the drill string is ρ. L1 ,ρ L2 ,…,ρ Lj The distribution data; m represents the m-th kill fluid in the kill boundary matrix equation.

[0177] When the density is ρ Lj The kill fluid is flowing from the drill string into the annulus, and its density is ρ.Lk The well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lj corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lj corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lj corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lj corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p wherein j = 2, 3, …, n, i represents the i-th well control fluid in the well control boundary matrix equation. Meanwhile, because the well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p Lk corresponding to the well control fluid has been discharged from the annular wellhead, the well control fluid with density p wherein k = 2, 3, …, j-1, k represents the k-th well control fluid in the well control boundary matrix equation. The annular space contains the well control fluid with density p Lj corresponding to the well control fluid and the well control fluid with density p Lj corresponding to the well control fluid, and the well control fluid with density p L1 , p L2 , …, p Lj The length of the well control fluid with density p L1 , p L2 , …, p Lj can be determined by the following formula (29):

[0178]

[0179] According to the fourth length of the well control fluid with different densities p L1 , p L2 , …, p Lj in the annular space, i.e. the length h a,L1 , h a,L2 , …, h a,j of the well control fluid with density p L1 , p L2 , …, p Lj respectively, the distribution data of the well control fluid with different densities in the well control boundary matrix equation in the annular space can be determined as shown in the following formula (30):

[0180]

[0181] wherein, indicates that the well control fluid with density p Lj is flowing into the annular space from the drill string, and the well control fluid with density p LkThe kill fluid is being discharged from the annulus wellhead, and the density of the kill fluid in the drill string is ρ. L1 ,ρ L2 ,…,ρ Lj The distribution data; m represents the m-th kill fluid in the kill boundary matrix equation.

[0182] When the density is ρ Lj The kill fluid is flowing from the drill string into the annulus, and its density is ρ. Ln When the kill fluid is being discharged from the annulus wellhead, according to the order of the kill fluid included in the kill boundary matrix equation, it can be explained that the fluid discharged at density ρ is... Ln The corresponding kill fluid, along with other kill fluids, has been discharged from the annulus wellhead. (Density ρ) Lj The injection is in progress, indicating that the volume has not yet reached the well control boundary matrix equation related to ρ. Lj The corresponding preset volume V Lj ,Right now Where j = 2, 3, ..., n, i represents the i-th kill fluid in the kill boundary matrix equation. Also, because the density is ρ Ln The kill fluid is being discharged from the annulus wellhead, and it is discharged at a density ρ Ln The corresponding kill fluid and other kill fluids have already been discharged from the annulus wellhead, and because the density is ρ Ln The kill fluid is being discharged from the annulus wellhead, indicating that the density of the fluid discharged from the annulus is ρ. Ln The volume of the kill fluid is less than the preset volume V. Ln ,therefore, Where n represents the nth, or last, kill fluid in the kill boundary matrix equation. The density contained within the annulus is ρ. L1 ,ρ L2 ,…,ρ Ln The length of the kill fluid can be determined by the following formula (31):

[0183]

[0184] When j = n, it means that only the annulus with density ρ exists at this time. Ln The corresponding kill fluid, therefore, the distribution data in the annulus is shown in the following formula (32):

[0185]

[0186] in, The density is represented by ρ Lj The kill fluid is flowing from the drill string into the annulus. If j = n, it means that the kill fluid flowing into the annulus from the drill string is the same as the kill fluid currently being discharged from the annulus wellhead, both having a density of ρ. Ln The kill fluid is therefore distributed in the annulus, and the density of the kill fluid in the annulus is ρ. Ln .

[0187] In the above embodiment of the present application, if the third length is less than or equal to the first length, there is no different density of the kill fluid in the annular space included in the kill boundary matrix equation, if the third length is greater than the first length and less than the second length, according to the kill fluid density of the kill fluid currently flowing into the annulus of the drill string and the kill boundary matrix equation, the third length of the different kill fluid flowed into the annular space in the annular space is determined. If the third length is greater than or equal to the second length, according to the kill fluid density of the kill fluid currently flowing into the annulus of the drill string, the kill fluid density currently returning to the ground from the annular space and the kill boundary matrix equation, the fourth length of the different kill fluid flowed into the annular space in the annular space is determined. Further, according to the third length and the fourth length of the different kill fluid flowed into the annular space in the annular space, the distribution data of the different density of the kill fluid in the annular space in the kill boundary matrix equation is determined. The method of the embodiment, by simulating the time, i.e. the third length, in combination with the key time nodes in the kill process, i.e. the first length of the kill fluid from the ground to the bottom of the simulated well drill string and the second length of the kill fluid from the bottom of the simulated well drill string returning to the ground through the annular space, the distribution data of the different density of the kill fluid in the annulus in the kill boundary matrix equation is more accurate, and the distribution state of the different density of the kill fluid in the annulus simulated according to the determined distribution data is also more accurate.

[0188] Through the above embodiment, the length data of the different density of the kill fluid in the drill string and the length data in the annulus can be as shown in Figure 4 Figure 4 A length data schematic diagram provided by the embodiment of the present application, in Figure 4 ​The horizontal coordinate represents time, and the vertical coordinate represents the length of the kill fluid, including the 1# kill fluid, the 2# kill fluid, and the 3# kill fluid. In the drill string, the length of the kill fluid 1 increases from 0 meters to about 6400 meters in about 0-30 minutes, remains about 6400 meters in about 30-260 minutes, and decreases from about 6400 meters to 0 in about 260-300 minutes. The length of the kill fluid 1 in the drill string remains stable and decreases because the kill fluid 1 flows from the drill string to the annulus. In the annulus, the length of the kill fluid 1 increases from 0 meters to about 6400 meters in about 30 minutes, remains about 6400 meters in about 30-200 minutes, and decreases from about 6400 meters to 0 in about 250-450 minutes. The length of the kill fluid 1 in the annulus decreases because the kill fluid 1 flows out of the annulus. Correspondingly, the analysis of the kill fluid 2 and the kill fluid 3 is the same as that of the kill fluid 1, and will not be repeated here.

[0189] According to the kill boundary matrix equation in the present application, the change data of the casing pressure with time and the change data of the standpipe pressure with time can also be obtained.

[0190] Optionally, the kill boundary matrix equation is input into a pre-established wellbore multiphase flow model for calculation to obtain the change data of the casing pressure with time and the change data of the standpipe pressure with time.

[0191] The wellbore multiphase flow model is constructed according to the mass conservation equation and the momentum conservation equation.

[0192] The mass conservation equation can include the gas mass conservation equation shown in the following formula (33):

[0193]

[0194] and the liquid phase mass conservation equation shown in the following formula (34):

[0195]

[0196] The momentum conservation equation can include the mixed momentum conservation equation shown in the following formula (35):

[0197]

[0198] Wherein, p represents the density of the kill fluid; Δ represents the volume fraction of the kill fluid; A represents the cross-sectional area of the kill fluid flow space; v represents the flow rate; P represents the wellbore pressure; F represents the total external force suffered by the gas phase and the liquid phase; θ represents the deviation angle; z represents the circumferential distance along the wellbore; t represents time; g represents the gas phase; and L represents the liquid phase.

[0199] After inputting the kill boundary matrix equation into the pre-established wellbore multiphase flow model, the change data of the casing pressure with time and the change data of the standpipe pressure with time during the kill process are obtained based on a preset algorithm, such as the finite difference method, for example, the casing pressure-time relationship curve and the standpipe pressure-time relationship curve.

[0200] Exemplarily, assuming that the used kill method is only the engineer method, the kill fluid density included in the kill boundary matrix equation can be shown in the formula (5) mentioned above according to the corresponding kill fluid volume.

[0201] According to the above-mentioned kill boundary matrix equation and the pre-established wellbore multiphase flow model, the obtained casing pressure-time relationship curve and the standpipe pressure-time relationship curve can be shown as Figure 5 Figure 5 A casing pressure / standpipe pressure-time relationship curve schematic diagram provided by the embodiment of the present application, in which the horizontal coordinate represents time and the vertical coordinate represents pressure. The thin solid line represents the casing pressure-time relationship curve, and the thin dotted line represents the standpipe pressure-time relationship curve. Figure 5

[0202] Assuming that the used kill method includes multiple methods, for example, first injecting 200m 3 of the kill fluid with a density of 1.80g / cm 3 , and then injecting 100m 3 of the kill fluid with a density of 1.80g / cm 3 , it is found that the drilling fluid leaks 70m 3 , and then 250m 3 of the kill fluid with a density of 1.80g / cm 3 is continuously injected, the kill fluid density included in the new kill boundary matrix equation according to the corresponding kill fluid volume can be shown in the formula (6) mentioned above:

[0203] According to the above-mentioned kill boundary matrix equation and the pre-established wellbore multiphase flow model, the obtained casing pressure-time relationship curve is shown as the thick solid line in Figure 5 , and the obtained standpipe pressure-time relationship curve is shown as the thick dotted line in Figure 5 .

[0204] It can be understood that the above examples are only used for illustration and do not limit the present application. ​​

[0205] In the above embodiment of the present application, the casing pressure change data and the standpipe pressure change data of the casing under the cooperative operation of multiple kill methods can be obtained by inputting the kill boundary matrix equation into the pre-established wellbore multiphase flow model, which has good flexibility in the cooperative operation scene of multiple kill methods and is convenient for providing certain guidance for the field kill operation.

[0206] Figure 6 A structural schematic diagram of a simulation device for killing provided by an embodiment of the present application is shown in FIG. 1. The simulation device for killing provided by the embodiment includes: Figure 6

[0207] The obtaining module 601 is configured to obtain a kill boundary matrix equation, wherein the kill boundary matrix equation includes different kill fluid densities and volumes corresponding to the different kill fluid densities.

[0208] The determining module 602 is configured to determine, according to the parameter information of the simulation well, a first time length for the kill fluid to reach the bottom of the drill string of the simulation well from the ground and a second time length for the kill fluid to return to the ground from the annular space of the simulation well.

[0209] The obtaining module 601 is further configured to obtain a third time length, which represents a time length from an initial simulation time to a current simulation time.

[0210] The determining module 602 is further configured to determine, according to the kill boundary matrix equation, the first time length, the second time length, and the third time length, distribution data of the kill fluid with different densities in the drill string and distribution data of the kill fluid with different densities in the annular space, wherein the distribution data in the drill string and the distribution data in the annular space are used to simulate the distribution state of the kill fluid with different densities in the well.

[0211] The different kill fluid densities in the kill boundary matrix equation represent the kill fluid densities used by different kill methods, and the kill methods include at least one of the engineer method, the driller method, and the method of gradually increasing the weight while circulating.

[0212] In a possible implementation manner, the parameter information includes a kill displacement of the simulation well, a drill string volume, and an annular space volume, and the determining module 602 is specifically configured to:

[0213] divide the drill string volume by the kill displacement, and determine the division result as the first time length.

[0214] add the drill string volume and the annular space volume, divide the addition result by the kill displacement, and determine the division result as the second time length.

[0215] In a possible implementation manner, the determining module 602 is specifically configured to:​

[0216] According to the size relationship between the kill boundary matrix equation and the third time length and the first time length, distribution data of the kill fluids with different densities in the drill string in the kill boundary matrix equation is determined.

[0217] According to the size relationship between the kill boundary matrix equation and the third time length and the first time length and the second time length, respectively, distribution data of the kill fluids with different densities in the annular space in the kill boundary matrix equation is determined.

[0218] In a possible implementation, the determining module 602 is specifically configured to:

[0219] If the third time length is less than or equal to the first time length, the first length of the different kill fluids that have been injected in the drill string in the drill string is determined according to the kill fluid density of the kill fluid currently being injected at the drill string entrance and the kill boundary matrix equation.

[0220] According to the first length of the different kill fluids that have been injected in the drill string in the drill string, distribution data of the kill fluids with different densities in the drill string in the kill boundary matrix equation is determined.

[0221] If the third time length is greater than the first time length, the second length of the different kill fluids that have been injected in the drill string in the drill string is determined according to the kill fluid density of the kill fluid currently being injected at the drill string entrance, the kill fluid density of the kill fluid currently flowing into the annular space from the drill string, and the kill boundary matrix equation.

[0222] According to the second length of the different kill fluids that have been injected in the drill string in the drill string, distribution data of the kill fluids with different densities in the drill string in the kill boundary matrix equation is determined.

[0223] In a possible implementation, the determining module 602 is specifically configured to: if the third time length is less than or equal to the first time length, the different density kill fluids included in the kill boundary matrix equation do not exist in the annular space.

[0224] If the third time length is greater than the first time length and less than the second time length, the third length of the different kill fluids that have flowed into the annular space in the annular space is determined according to the kill fluid density of the kill fluid currently flowing into the annular space from the drill string and the kill boundary matrix equation.

[0225] According to the third length of the different kill fluids that have flowed into the annular space in the annular space, distribution data of the kill fluids with different densities in the annular space in the kill boundary matrix equation is determined.

[0226] If the third time length is greater than or equal to the second time length, a fourth length of different kill fluids that have flowed into the annular space is determined according to a kill fluid density of the kill fluid currently flowing into the annulus, a kill fluid density of the kill fluid currently returning to the ground from the annular space, and a kill boundary matrix equation.

[0227] Distribution data of the kill fluids of different densities in the annular space in the kill boundary matrix equation is determined according to the fourth length of the different kill fluids that have flowed into the annular space in the annular space.

[0228] In a possible implementation, the determining module 602 is further configured to:

[0229] The kill boundary matrix equation is input into a pre-established wellbore multiphase flow model to obtain data of changes of the casing pressure and the standpipe pressure over time.

[0230] The wellbore multiphase flow model is constructed according to a mass conservation equation and a momentum conservation equation.

[0231] The simulation device for killing provided in this embodiment can execute the method provided in the method embodiments, and has similar implementation principles and technical effects, which will not be described here again.

[0232] Figure 7 A structural schematic diagram of an electronic device provided in an embodiment of the present application is shown in FIG. 1. Figure 7 As shown in FIG. 1, the electronic device provided in this embodiment includes at least one processor 701 and a memory 702. Optionally, the electronic device further includes a communication component 703. The processor 701, the memory 702, and the communication component 703 are connected through a bus 704.

[0233] In the specific implementation process, the at least one processor 701 executes the computer execution instructions stored in the memory 702, so that the at least one processor 701 executes the method described above.

[0234] The specific implementation process of the processor 701 can refer to the method embodiments described above, and has similar implementation principles and technical effects, which will not be described here again.

[0235] In the above embodiments, it should be understood that the processor can be a central processing unit (CPU) and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), etc. The general-purpose processor can be a microprocessor or can also be any conventional processor. The steps of the method disclosed in combination with the application can be directly embodied as hardware processor execution or combined with hardware and software modules in the processor for execution.

[0236] The memory can include a random access memory (RAM) and can also include a non-volatile memory (NVM), such as at least one disk memory.

[0237] The bus can be an industry standard architecture (ISA) bus, a peripheral component (PCI) bus, an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, the bus in the drawings of the present application does not limit to only one bus or one type of bus.

[0238] The present application also provides a computer program product comprising a computer program which, when executed by a processor, implements the above method.

[0239] The present application also provides a computer readable storage medium having computer execution instructions stored therein, wherein when a processor executes the computer execution instructions, the above method is implemented.

[0240] The above readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The readable storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0241] An example readable storage medium is coupled to the processor such that the processor can read information from the readable storage medium and can write information to the readable storage medium. Of course, the readable storage medium can also be a part of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in the device.

[0242] The division of units is only a logical functional division, and in actual implementation, there can be another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0243] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, can be located in one place, or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment scheme.

[0244] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0245] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the part of the present application that essentially contributes to the prior art or the part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the embodiments of the present application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various program code storage media.

[0246] Those skilled in the art can understand that all or part of the steps of the above-mentioned method embodiments can be completed by program instruction related hardware. The foregoing program can be stored in a computer readable storage medium. The program executes to perform the steps of the above-mentioned method embodiments; and the foregoing storage medium includes various media capable of storing program codes, such as ROM, RAM, magnetic disk, or optical disk.

[0247] Finally, it should be noted that other embodiments of the present application will readily occur to those skilled in the art upon consideration of the specification and practice of the present application disclosed herein. The present application is intended to include all such variations as fall within the general scope of the application, and includes the generic principles disclosed and the best mode known to the inventors to be currently practiced as well as variations thereof, without departing from the scope of the present application as defined by the claims. The specification and examples give the best application of the present application as currently known, and together with the description of the application serve to best illustrate the principles of the application. The scope of the application is expressly set forth in the claims.

Claims

1. A method of simulating a well kill, characterized by, The method comprises the following steps: obtaining a kill boundary matrix equation, wherein the kill boundary matrix equation comprises different kill fluid densities and volumes corresponding to the different kill fluid densities; determining, according to parameter information of a simulated well, a first time length for kill fluid to reach a bottom of a drill string of the simulated well from the ground and a second time length for the kill fluid to return to the ground from the bottom of the drill string of the simulated well through an annular space; obtaining a third time length, wherein the third time length represents a time length from an initial simulation time to a current simulation time; determining, according to the kill boundary matrix equation, the first time length, the second time length and the third time length, distribution data of the different kill fluid densities in the drill string and distribution data of the different kill fluid densities in the annular space in the kill boundary matrix equation, wherein the distribution data of the different kill fluid densities in the drill string and the distribution data of the different kill fluid densities in the annular space are used to simulate distribution states of the different kill fluid densities in the well. The different kill fluid densities in the kill boundary matrix equation represent kill fluid densities used in at least two of the following kill methods: an engineer method, a driller method and a method of gradually increasing the kill fluid density while circulation.

2. The method of claim 1, wherein, The parameter information comprises a kill displacement of the simulated well, a drill string volume and an annular space volume. The determination of the first time length and the second time length according to the parameter information of the simulated well comprises the following steps: dividing the drill string volume by the kill displacement to obtain the first time length; adding the drill string volume and the annular space volume and dividing the sum by the kill displacement to obtain the second time length.

3. The method of claim 1, wherein, The determination of the distribution data of the different kill fluid densities in the drill string and the distribution data of the different kill fluid densities in the annular space according to the kill boundary matrix equation, the first time length, the second time length and the third time length comprises the following steps: determining the distribution data of the different kill fluid densities in the drill string according to a size relationship between the third time length and the first time length; determining the distribution data of the different kill fluid densities in the annular space according to size relationships between the third time length and the first time length and the second time length respectively.

4. The method of claim 3, wherein, The determination of the distribution data of the different kill fluid densities in the drill string according to the size relationship between the third time length and the first time length comprises the following steps: if the third time length is less than or equal to the first time length, determining a first length of the different kill fluid densities in the drill string according to a kill fluid density of kill fluid currently injected into the drill string inlet and the kill boundary matrix equation; determining the distribution data of the different kill fluid densities in the drill string according to the first length of the different kill fluid densities in the drill string. if the third length is greater than the first length, determining a second length of the different kill fluids that have been injected in the drill string in the drill string according to a kill fluid density of the kill fluid that is currently being injected by the drill string, a kill fluid density of the kill fluid that is currently flowing into the annular space by the drill string, and the kill boundary matrix equation; determining distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the second length of the different kill fluids that have been injected in the drill string in the drill string.

5. The method of claim 3, wherein, The determination of the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the size relationship between the third length and the first length and the second length in the kill boundary matrix equation includes: if the third length is less than or equal to the first length, there is no different density kill fluid included in the kill boundary matrix equation in the annular space; if the third length is greater than the first length and less than the second length, determining a third length of the different kill fluids that have flowed into the annular space in the annular space according to a kill fluid density of the kill fluid that is currently flowing into the annulus by the drill string and the kill boundary matrix equation; determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the third length of the different kill fluids that have flowed into the annular space in the annular space; if the third length is greater than or equal to the second length, determining a fourth length of the different kill fluids that have flowed into the annular space in the annular space according to a kill fluid density of the kill fluid that is currently flowing into the annulus by the drill string, a kill fluid density of the kill fluid that is currently returning to the ground from the annular space, and the kill boundary matrix equation; determining the distribution data of the different density kill fluids in the annular space in the kill boundary matrix equation according to the fourth length of the different kill fluids that have flowed into the annular space in the annular space.

6. The method of claim 1, wherein, Further comprising: inputting the kill boundary matrix equation into a pre-established wellbore multiphase flow model for calculation to obtain casing pressure change data and standpipe pressure change data over time; wherein the wellbore multiphase flow model is constructed according to mass conservation equation and momentum conservation equation.

7. A simulated blowout preventer, comprising: Comprising: an acquisition module configured to acquire a kill boundary matrix equation, the kill boundary matrix equation including different kill fluid densities and volumes corresponding to each kill fluid density; a determination module configured to determine a first length of kill fluid from the ground to the bottom of the drill string of the simulation well and a second length of kill fluid from the bottom of the drill string of the simulation well back to the ground through the annular space according to parameter information of the simulation well; the acquisition module is further configured to acquire a third length, the third length representing a length of time from a simulation initial time to a simulation current time; The determination module is further configured to determine distribution data of the kill fluids with different densities in the drill string and in the annular space in the kill boundary matrix equation according to the kill boundary matrix equation, the first time length, the second time length, and the third time length, the distribution data being used to simulate distribution states of the kill fluids with different densities in the well. In the kill boundary matrix equation, different kill fluid densities are used to represent kill fluid densities used in at least two of the following kill methods: an engineer method, a driller method, and a method of gradually increasing the density while circulating.

8. An electronic device, comprising: The method comprises: a memory and a processor; the memory stores computer-executable instructions; the processor executes the computer-executable instructions stored in the memory, so that the processor executes the method for simulating the well killing according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by the processor to implement the method for simulating the well killing according to any one of claims 1-6.

10. A computer program product, characterised in that, The computer program is executed by the processor to implement the method for simulating the well killing according to any one of claims 1-6.

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