Method and device for determining equivalent circulation density of well drilling and storage medium

Abstract

The invention discloses a well drilling equivalent cycle density determination method and device and a storage medium. The method comprises the following steps: determining a heat source type of a target drilling well and a heat generation amount corresponding to the heat source type based on a working condition type executed on the target drilling well; according to the heat generation amount corresponding to the heat source type, a preset initial temperature field is adjusted, and a target temperature field of the target drilling well is determined; determining circulating pressure consumption corresponding to multiple sections of wellbores included in the target drilling well in the target temperature field; and obtaining the target equivalent circulation density of the target drilling well based on the circulation pressure consumption corresponding to the multiple sections of wellbores. The technical problem that in the prior art, the limitation of obtaining the underground equivalent cycle density is large is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of petroleum exploration and drilling engineering, and in particular to a method, a device and a storage medium for determining drilling equivalent circulation density. Background Art

[0002] At present, the engineering difficulty in the drilling process of drilling projects is that if the annular pressure monitor (PWD) is not used, there is no effective means in the relevant technology to monitor the downhole equivalent circulating density (ECD). Therefore, when leakage or overflow occurs, the true fracture pressure coefficient or pore pressure coefficient cannot be determined based on the ground mud density alone, which cannot provide a true basis for subsequent geological design and engineering design, and may even lead to misleading conclusions. There is a high limitation in obtaining the drilling equivalent circulating density.

[0003] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0004] The embodiments of the present invention provide a method, device and storage medium for determining drilling equivalent circulating density, so as to at least solve the technical problem that obtaining downhole equivalent circulating density in the related art is relatively limited.

[0005] According to one aspect of an embodiment of the present invention, a method for determining a drilling equivalent circulating density is provided, comprising: determining a heat source type of the target drilling and a heat generation amount corresponding to the heat source type based on the type of working condition performed on the target drilling; adjusting a predetermined initial temperature field according to the heat generation amount corresponding to the heat source type to determine a target temperature field of the target drilling; determining the circulating pressure losses corresponding to each of the multiple wellbores included in the target drilling under the target temperature field; and obtaining a target equivalent circulating density of the target drilling based on the circulating pressure losses corresponding to each of the multiple wellbores.

[0006] Optionally, the predetermined initial temperature field is adjusted according to the heat generated by the heat source type to determine the target temperature field of the target drilling, including: based on the operating condition type being a drilling condition, determining that the heat source types include formation temperature, drilling fluid heat exchange, and friction heat; determining the frictional heat generated by the drilling equipment in the target drilling; based on the frictional heat generated by the drilling equipment, the heat generated corresponding to the formation temperature, and the circulating pressure consumption heat generated corresponding to the drilling fluid heat exchange, adjusting the initial temperature field to determine the target temperature field.

[0007] Optionally, the drilling equipment includes a drilling tool and a drill bit, and determining the frictional heat generated by the drilling equipment in the target drilling includes: determining the mechanical loads and rotational speeds corresponding to the drilling tool and the drill bit, respectively; determining a first heat generated by the drilling tool based on the mechanical load and rotational speed corresponding to the drilling tool; determining a second heat generated by the drilling tool based on the mechanical load and rotational speed corresponding to the drill bit; and determining the frictional heat generated by the drilling equipment based on the first heat generated and the second heat generated.

[0008] Optionally, determining the circulating pressure losses corresponding to the multiple sections of the wellbore included in the target drilling under the target temperature field includes: obtaining the drilling fluid density, displacement, wellbore size, casing size, and drill tool size corresponding to the multiple sections of the wellbore; and determining the circulating pressure losses corresponding to the multiple sections of the wellbore based on the corresponding drilling fluid density, displacement, wellbore size, casing size, and drill tool size.

[0009] Optionally, obtaining the target equivalent circulating density of the target well based on the circulating pressure losses corresponding to the multiple sections of the wellbore respectively includes: determining the riser pressure loss in the target well; determining the equivalent static density based on the target temperature field and the riser pressure loss; and determining the target equivalent circulating density based on the equivalent static density.

[0010] Optionally, the circulating pressure loss includes the internal pressure loss of the drill tool and the annular space pressure loss, the annular space is the space between the drill tool and the corresponding section of the wellbore, and the determining of the riser pressure loss in the target drilling includes: obtaining the total annular space pressure loss based on the annular space pressure losses corresponding to the multiple sections of the wellbore respectively; determining the riser pressure loss based on the internal pressure loss of the drill tool corresponding to the multiple sections of the wellbore respectively and the total annular space pressure loss.

[0011] Optionally, before determining the heat source type of the target drilling and the heat generation corresponding to the heat source type based on the type of working condition performed on the target drilling, the method also includes: determining the drilling processing time for the target drilling; when the drilling processing time is greater than a predetermined time, determining that the target drilling is in a thermal quasi-static state, and pausing the drilling equipment in the target drilling.

[0012] According to another aspect of an embodiment of the present invention, a device for determining a drilling equivalent circulating density is provided, comprising: a first determination module, for determining a heat source type of the target drilling and a heat generation amount corresponding to the heat source type based on the type of working condition performed on the target drilling; an adjustment module, for adjusting a predetermined initial temperature field according to the heat generation amount corresponding to the heat source type, and determining a target temperature field of the target drilling; a second determination module, for determining the circulating pressure losses corresponding to each of the multiple wellbores included in the target drilling under the target temperature field; and an acquisition module, for obtaining the target equivalent circulating density of the target drilling based on the circulating pressure losses corresponding to each of the multiple wellbores.

[0013] According to another aspect of an embodiment of the present invention, a non-volatile storage medium is provided, wherein the non-volatile storage medium stores a plurality of instructions, wherein the instructions are suitable for being loaded by a processor and executing any one of the methods for determining drilling equivalent circulation density.

[0014] According to another aspect of an embodiment of the present invention, there is provided an electronic device, comprising: one or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement any one of the methods for determining drilling equivalent circulating density.

[0015] In the embodiment of the present invention, a hydraulic calculation method under high temperature and high pressure conditions is adopted, and the heat source type of the target drilling and the heat generation corresponding to the heat source type are determined based on the type of working condition performed on the target drilling; the predetermined initial temperature field is adjusted according to the heat generation corresponding to the heat source type to determine the target temperature field of the target drilling; the circulating pressure loss corresponding to the multiple sections of the wellbore included in the target drilling under the target temperature field is determined; based on the circulating pressure loss corresponding to the multiple sections of the wellbore, the target equivalent circulating density of the target drilling is obtained. The purpose of establishing a fine mathematical model under high temperature and high pressure conditions and improving the accuracy of obtaining the equivalent circulating density of the drilling is achieved, and the technical effect of reducing the dependence on specific acquisition equipment and reducing the limitations of the equivalent circulating density is achieved, thereby solving the technical problem of the large limitations of obtaining downhole equivalent circulating density in the related technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 is a flow chart of an optional method for determining drilling equivalent circulating density provided according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of a heat exchange model of an optional method for determining drilling equivalent circulating density provided in accordance with an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of friction heat generation of an optional method for determining drilling equivalent circulating density provided in an embodiment of the present invention;

[0020] Figure 4 is a schematic diagram of segmented circulation pressure loss of an optional method for determining drilling equivalent circulation density provided in an embodiment of the present invention;

[0021] Figure 5 It is a schematic diagram of an optional drilling equivalent circulating density determination device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] For the convenience of description, some nouns or terms involved in the embodiments of the present application are explained below:

[0025] Equivalent Circular Diameter (ECD) refers to a method of controlling the bottom hole pressure by circulating mud or water during the drilling process to maintain wellbore stability and prevent blowouts. It is achieved by adjusting the density of the circulating mud. The density of the circulating mud needs to be balanced with the formation pressure to prevent the bottom hole pressure from being too high or too low, which can lead to dangerous situations such as blowouts or well collapse. The control of circulating density is a very important operation in drilling engineering.

[0026] Circulating pressure loss refers to the pressure loss caused by the circulation of drilling fluid in the wellbore during the drilling process. When the drilling fluid is injected into the wellbore from the wellhead and flows to the bottom of the well, and then flows back to the wellhead through the drill pipe, due to the effects of friction resistance, fluid viscosity and other factors, the drilling fluid will produce a certain pressure loss, which is the circulating pressure loss. The magnitude of the circulating pressure loss depends on many factors, including well depth, drill pipe length, drilling fluid properties, flow rate, wellbore size, etc. Under normal circumstances, the circulating pressure loss will increase with the increase of well depth and decrease with the increase of drill pipe length. Circulating pressure loss directly affects the circulation of drilling fluid and the pressure distribution inside the wellbore during drilling. Reasonable control of circulating pressure loss can improve drilling efficiency and reduce the occurrence of drilling accidents. Therefore, in drilling engineering, it is necessary to reasonably select parameters such as drilling fluid properties, drill pipe size and flow rate according to actual conditions to reduce circulating pressure loss and ensure the safety and smooth progress of drilling operations.

[0027] The equivalent static density (ESD) of drilling refers to the equivalent density generated by the pressure of drilling fluid on the formation during the drilling process. It is related to the density of drilling fluid, which in turn is related to factors such as its composition, concentration and temperature. The calculation of ESD is usually based on the physical parameters and concentration of various additives in the drilling fluid to determine the pressure exerted by the drilling fluid on the formation. It is used to evaluate the impact of drilling fluid on the formation, including plugging the wellbore, stabilizing the formation, and controlling well leakage.

[0028] According to an embodiment of the present invention, a method embodiment for determining drilling equivalent circulating density is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0029] Figure 1 is a flow chart of a method for determining drilling equivalent circulating density according to an embodiment of the present invention. Figure 1 As shown, the method comprises the following steps:

[0030] Step S102, based on the type of working condition performed on the target drilling, determining the heat source type of the target drilling and the heat generation corresponding to the heat source type;

[0031] It is understandable that the target drilling may perform a variety of working conditions, such as drilling down, drilling in, lifting off the bottom of the well, circulating cleaning before pulling out, pulling out, etc., which have an impact on the type of heat source in the target drilling and also have an impact on the corresponding heat generation.

[0032] In an optional embodiment, before determining the heat source type of the target drilling and the heat generation corresponding to the heat source type based on the type of working condition performed on the target drilling, the method further includes: determining the drilling processing duration for the target drilling; when the drilling processing duration is greater than a predetermined duration, determining that the target drilling is in a thermal quasi-static state, and pausing the drilling equipment in the target drilling.

[0033] It can be understood that when the drilling process time of the target well is longer than the predetermined time, the heat exchange in the target well satisfies the quasi-static state. After the drilling equipment in the target well is suspended, the equivalent circulating density is determined. It should be noted that the type of working condition executed by the target well does not refer to the current openness, but to the working condition executed before the suspension. Due to the need to obtain relevant parameters such as drilling fluid and pressure loss, it is necessary to suspend the operation of the drilling equipment.

[0034] Optionally, the heat sources under different working conditions are classified as shown in Table 1, which is a schematic diagram of the heat source types under different working conditions.

[0035] Table 1 Heat sources under different working conditions

[0036]

[0037] It can be seen that when the target drilling condition is drilling, the corresponding heat source type is the formation temperature. When the target drilling condition is drilling, the corresponding heat source type is the formation temperature, circulating pressure consumption heat, drill tool friction heat, and drill bit friction heat. When the target drilling condition is lifting from the bottom of the well, the corresponding heat source type is the formation temperature, circulating pressure consumption heat, and drill tool friction heat. When the target drilling condition is circulation cleaning before pulling out of the well, the corresponding heat source type is the formation temperature, circulating pressure consumption heat, and drill tool friction heat. When the target drilling condition is pulling out of the well, the corresponding heat source type is the formation temperature.

[0038] For ease of understanding, an example is given. The working conditions in the drilling project will have a great impact on heat conduction and heat exchange. For example, after the pump is turned on for more than 6 hours, its heat conduction and heat exchange meet the quasi-static (Steady-State) state. At this time, the heat sources of heat conduction and heat exchange mainly come from the formation temperature, the heat exchange of the drilling fluid during the flow process, and the friction heat generated by the rotation of the drill bit on the formation. Figure 2 : is a schematic diagram of a heat exchange model of an optional method for determining drilling equivalent circulating density according to an embodiment of the present invention. Considering the temperature field calculation in the wellbore, the following method can be used:

[0039]

[0040]

[0041] Where ρ is the mud density, C p is the specific heat of mud, h o is the heat transfer coefficient near the wellbore wall, q is the mud displacement, Q a is the heat source in the annulus, Q p is the heat source in the tube, r i is the inner diameter of the tube wall, r o is the outer diameter of the tube wall, r p is the average radius of the tube wall, r w is the wellbore radius. t is the time, T f is the formation temperature, T p is the temperature inside the tube, T a is the annular temperature, U is the total heat transfer coefficient of the drilling tool, and z is the depth. When the wellbore is assumed to be a steady-state field model, the partial derivative of temperature with respect to time is zero. Therefore, efficient and accurate solution of the above equations becomes the key to accurately predict the temperature field T. To accurately solve the temperature field equations, the formation temperature distribution T must be obtained. f 2. The friction between the drill bit and the formation during drilling generates heat, that is, the heat source Q in the annulus a , and the frictional heat generated by the drilling fluid flowing in the drill bit, that is, the heat source Q in the pipe p The above-mentioned annulus is the abbreviation of annular space.

[0042] Q p is the heat source in the tube, wherein the represents the vertical heat conduction of the heat source in the tube, 2πr p U(T p -T a ) represents the radial heat conduction of the heat source in the tube, Indicates the heat accumulation of the heat source in the tube. a The heat source in the annulus is represents the heat accumulation of the heat source in the annulus, represents the vertical heat conduction of the heat source in the annulus, 2πr p U(T p -T a ) represents the heat conduction between the heat source in the annulus and the pipe string, 2πr w h o (T f -T a ) represents the heat conduction between the heat source in the annulus and the formation.

[0043] Step S104, adjusting the predetermined initial temperature field according to the heat generation corresponding to the above heat source type to determine the target temperature field of the above target drilling;

[0044] It can be understood that the predetermined initial temperature field is under ideal conditions. For the actual target drilling conditions, it is necessary to adjust the heat generated by the heat source to determine the target temperature field. For the study of drilling fluid performance under high temperature and high pressure environment, the following aspects become the difficulty of modeling, and also constitute the main control factors of the accuracy of high temperature and high pressure hydraulic calculation: on the one hand, it is difficult to predict the temperature field in high temperature and high pressure wells, and on the other hand, there are only rheological test results at room temperature during the actual drilling process on site, and it is impossible to use the high temperature and high pressure rheological performance parameters obtained in the laboratory to guide on-site construction.

[0045] It should be noted that during the drilling process, the target temperature field can help determine the physical properties of the rock formation: the temperature field can provide temperature information of the formation, and the physical parameters such as thermal conductivity and heat capacity of the formation can be inferred through temperature changes. These parameters are crucial for the characteristics of the formation and the assessment of oil reserves. In addition, it also affects the performance of the drilling fluid. The drilling fluid is an important part of the drilling process, and the temperature field can affect the performance of the drilling fluid. Through the analysis of the temperature field, the density, viscosity, stability and other parameters of the drilling fluid can be determined, and then the formulation of the drilling fluid can be adjusted to ensure the smooth progress of drilling. Changes in the temperature field will also affect the stability of the wellbore. High-temperature formations may cause rock expansion and cracks, affecting the stability of the wellbore wall; while low-temperature formations may cause the wellbore wall to shrink and form a collapse zone. Through the determination of the temperature field, the stability risk of the wellbore can be evaluated and corresponding measures can be taken to ensure the safety of the wellbore.

[0046] In an optional embodiment, the predetermined initial temperature field is adjusted according to the heat generated corresponding to the above-mentioned heat source type to determine the target temperature field of the above-mentioned target drilling, including: based on the above-mentioned working condition type being a drilling condition, determining that the above-mentioned heat source types include formation temperature, drilling fluid heat exchange, and friction heat; determining the friction heat generated by the drilling equipment in the above-mentioned target drilling; based on the friction heat generated by the above-mentioned drilling equipment, the heat generated corresponding to the above-mentioned formation temperature, and the circulating pressure consumption heat generated corresponding to the above-mentioned drilling fluid heat exchange, adjusting the above-mentioned initial temperature field to determine the above-mentioned target temperature field.

[0047] It can be understood that when the working condition type is drilling condition, the heat source type corresponding to the current working condition includes formation temperature, drilling fluid heat exchange, and friction heat. The main thing that needs to be calculated and determined is the friction heat generated by the drilling equipment in the target drilling. Based on the friction heat generated by the drilling equipment, the heat generated corresponding to the formation temperature, and the circulation pressure consumption heat generated corresponding to the drilling fluid heat exchange, the initial temperature field is adjusted to determine the target temperature field. The above processing is conducive to improving the accuracy of the target temperature field.

[0048] In an optional embodiment, the drilling equipment includes a drill tool and a drill bit, and the above-mentioned determination of the frictional heat generated by the drilling equipment in the above-mentioned target drilling includes: determining the mechanical load and rotation speed corresponding to the above-mentioned drill tool and the above-mentioned drill bit, respectively; determining a first heat generated by the above-mentioned drill tool based on the mechanical load and rotation speed corresponding to the above-mentioned drill tool; determining a second heat generated by the above-mentioned drill tool based on the mechanical load and rotation speed corresponding to the above-mentioned drill bit; and determining the above-mentioned frictional heat generated by the above-mentioned drilling equipment based on the above-mentioned first heat generated and the above-mentioned second heat generated.

[0049] It can be understood that the "soft rod model" is used to model any unit node in the entire well to solve the mechanical load. Figure 3 It is a schematic diagram of frictional heat generation of an optional method for determining drilling equivalent circulating density provided according to an embodiment of the present invention. When the corresponding working conditions are determined, since the drilling equipment is divided into a drill tool and a drill bit, the corresponding heat generation can be determined respectively according to their mechanical load and rotation speed, thereby obtaining the frictional heat generation of the entire drilling equipment.

[0050] Step S106, determining the circulating pressure losses corresponding to the multiple wellbores included in the target drilling under the target temperature field;

[0051] It can be understood that after the temperature field is modeled according to the steady-state field model to obtain the target temperature field, the target wellbore can be calculated in sections to determine the circulating pressure losses corresponding to the multiple sections of the wellbore.

[0052] It should be noted that the effect of the downhole temperature field on the rheological properties of the drilling fluid is to reduce its viscosity. When the drilling fluid is exposed to a high temperature environment, its viscosity will decrease, resulting in an increase in its fluidity. This may increase the flow rate of the drilling fluid in the pores, thereby increasing the efficiency of the drilling fluid circulation. The effect of the drilling fluid on the circulation pressure loss is to increase the circulation pressure by increasing the density and viscosity of the drilling fluid. The higher the density and viscosity of the drilling fluid, the greater the pump work required for its circulation, thereby increasing the circulation pressure loss. In addition, the viscosity of the drilling fluid will also affect the pressure distribution at the bottom of the well, thereby affecting the flow of the drilling fluid and the efficiency of the mud circulation.

[0053] In an optional embodiment, the above-mentioned determination of the circulating pressure losses corresponding to the multiple sections of the wellbore included in the above-mentioned target drilling under the above-mentioned target temperature field includes: obtaining the drilling fluid density, displacement, wellbore size, casing size, and drill tool size corresponding to the above-mentioned multiple sections of the wellbore; based on the corresponding drilling fluid density, displacement, wellbore size, casing size, and drill tool size, determining the circulating pressure losses corresponding to the above-mentioned multiple sections of the wellbore.

[0054] It can be understood that the circulating pressure loss at each different wellbore position is affected by the parameters of drilling fluid density, displacement, wellbore size, casing size, and drill bit size. The circulating pressure loss corresponding to multiple wellbore sections can be determined based on the above parameters.

[0055] Optionally, Figure 4 is a schematic diagram of segmented circulation pressure loss of an optional method for determining drilling equivalent circulation density provided according to an embodiment of the present invention, such as Figure 4 As shown in Figure 1, the pipeline for wellhead pressure and flow. It connects the wellhead and the control console, and adjusts the wellhead pressure by controlling the flow of fluid to ensure that the wellhead pressure is within a safe range and control the wellhead flow. The circulating pressure loss corresponding to the i-th wellbore in the multi-stage wellbore is recorded as ΔPi, which is obtained by the following method:

[0056]

[0057] Among them, ρ is the density of drilling fluid, V is the displacement, L is the wellbore size, d is the casing size and drilling tool size, and f is the Fanning friction coefficient related to ρ.

[0058] Step S108, obtaining the target equivalent circulating density of the target wellbore based on the circulating pressure losses corresponding to the above-mentioned multiple sections of the wellbore.

[0059] It can be understood that after the circulating pressure losses corresponding to the multiple sections of the wellbore are obtained, they can be accumulated to obtain the target equivalent circulating density in the entire target drilling.

[0060] In an optional embodiment, the target equivalent circulating density of the target drilling is obtained based on the circulating pressure losses corresponding to the above-mentioned multiple sections of the wellbore, including: determining the riser pressure loss in the above-mentioned target drilling; determining the equivalent static density based on the above-mentioned target temperature field and the above-mentioned riser pressure loss; determining the above-mentioned target equivalent circulating density based on the above-mentioned equivalent static density.

[0061] It can be understood that in drilling engineering, the riser pressure loss refers to the pressure loss caused by friction when the drilling fluid flows in the riser. The riser is a pipeline system used to transport drilling fluid during drilling, which connects the drilling wellhead and the ground equipment. Due to the high flow rate of the drilling fluid in the riser, friction occurs between the liquid and the pipe wall, which slows down the flow rate of the drilling fluid and generates pressure loss. The size of the riser pressure loss depends on many factors, including the length and diameter of the riser, the flow rate of the drilling fluid, the viscosity and density of the fluid, etc. The target temperature field has an important influence on the rheology. Based on the target temperature field and the riser pressure loss, the equivalent static density can be determined. The equivalent static density can be used to evaluate the performance of the drilling fluid under specific conditions. It refers to the density of the drilling fluid at a specific temperature and pressure, so that the flow rate and circulating pressure loss of the drilling fluid in the riser meet the expected requirements. By determining the equivalent static density, it can be ensured that the flow rate and circulating pressure loss of the drilling fluid in the riser are within a controllable range to meet the requirements of the drilling operation. If the equivalent static density is too high, it may cause excessive riser pressure loss, affecting the circulation capacity of the drilling fluid and the bottom hole pressure control; if the equivalent static density is too low, it may cause the flow rate of the drilling fluid to be too fast, affecting the flushing and chip removal capacity of the drilling fluid. There is a certain relationship between the equivalent static density and the equivalent circulating density. They are both parameters calculated under specific conditions by considering the flow and circulation characteristics of the drilling fluid.

[0062] Optionally, the target equivalent circulation density is denoted as ECD, which can be obtained by:

[0063]

[0064] Among them, the equivalent static density is recorded as ESD, DP annuli is the total annular space pressure loss, g is the gravitational acceleration, and H is the vertical depth of any point.

[0065] In an optional embodiment, the above-mentioned circulating pressure loss includes the internal pressure loss of the drill tool and the annular space pressure loss. The above-mentioned annular space is the space between the above-mentioned drill tool and the corresponding section of the wellbore. The above-mentioned determination of the riser pressure loss in the above-mentioned target drilling includes: obtaining the total annular space pressure loss based on the annular space pressure losses corresponding to the above-mentioned multiple sections of the wellbore respectively; determining the riser pressure loss based on the internal pressure loss of the drill tool corresponding to the above-mentioned multiple sections of the wellbore respectively, and the above-mentioned total annular space pressure loss.

[0066] It can be understood that the total annular space pressure loss is obtained by accumulating, and the riser pressure loss is determined based on the internal pressure losses of the drilling tools corresponding to the multiple sections of the wellbore and the total annular space pressure loss.

[0067] It should be noted that the riser pressure loss has an important impact on drilling operations. Excessive riser pressure loss will weaken the circulation capacity of the drilling fluid, affect the flushing of the drilling fluid and the removal of drill cuttings, and may cause abnormal increase in bottom hole pressure and wellbore stability problems. Therefore, during the drilling process, it is necessary to reasonably design the riser system and control the drilling fluid flow to ensure that the riser pressure loss is within an acceptable range and ensure the safety and smooth progress of the drilling operation.

[0068] Optionally, the riser pressure loss is recorded as SPP, which can be obtained by the following method:

[0069]

[0070]

[0071] in, represents the internal pressure loss of the drilling tool in the i-th section of the wellbore, It represents the annular space pressure loss in the i-th wellbore section, and there are N wellbores in total.

[0072] Through the above steps S102 to S108, it is possible to achieve the purpose of establishing a fine mathematical model under high temperature and high pressure conditions, improve the accuracy of obtaining the drilling equivalent circulating density, and achieve the technical effect of reducing the dependence on specific acquisition equipment and reducing the limitations of the equivalent circulating density, thereby solving the technical problem of the large limitations on obtaining the downhole equivalent circulating density in the related technology.

[0073] Based on the above embodiments and optional embodiments, the present invention proposes an optional implementation mode, in which the target drilling is suspended in the pump-off state, and the initial temperature field is determined. The hydrostatic pressure of the mud and the mud density at the temperature and pressure can be calculated according to the initial temperature. According to the actual working conditions before the pump is stopped, the type of heat source in the target drilling is determined. Based on the heat generation corresponding to the heat source type, the initial temperature field can be adjusted to determine the target temperature field.

[0074] Under the assumption of drilling conditions, the frictional heat generated by the drilling equipment, the heat generated corresponding to the formation temperature, and the circulating pressure consumption heat generated corresponding to the drilling fluid heat exchange are determined, the initial temperature field is adjusted, and the target temperature field is determined.

[0075] The target wellbore is divided into sections to determine the circulating pressure loss. The circulating pressure loss in each section of the wellbore is closely related to the rheological properties. It is affected by the parameters of drilling fluid density, displacement, wellbore size, casing size, and drill tool size. The circulating pressure loss of each section of the wellbore can be calculated. After obtaining the circulating pressure losses corresponding to multiple sections of the wellbore, they can be accumulated to obtain the target equivalent circulating density in the entire target wellbore.

[0076] The above implementation method can be used to verify the algorithm with any five wells. In any drilling trip randomly selected during the drilling process, the predicted value obtained by modeling the present invention is compared with the measured value, and the relative error RelError is defined as:

[0077]

[0078] Among them, SPP_Pred j is the j-th prediction result, SPP_Real j is the measured value of the jth item, M is the number of samples, and when the calculation results of 5 wells are obtained, M=5. The comparison is shown in Table 2. Table 2 is a statistical table of relative errors.

[0079] Table 2 Relative error statistics

[0080] hashtag Test well section Relative error Well 1 3210–3430 1.7％ Well 2 3450–3660 2.9％ Well 3 3970–4120 3.9％ Well 4 6092–6297 3.2％ Well 5 8060–8173 2.9％

[0081] The above optional implementation can achieve the following effects: after obtaining the temperature field distribution of the whole wellbore under different states, the equivalent refined density is accurately calculated; the circulating pressure loss in the unit cell is solved by rheological parameters, so as to obtain the circulating pressure loss in the whole wellbore; and the pressure loss is corrected by the rheological properties of the drilling fluid and the rheological properties of high temperature and high pressure, so as to finally obtain the circulating pressure loss and equivalent circulating density under high temperature and high pressure conditions of the whole wellbore. By accurately predicting the wellbore temperature field distribution and the rheological properties of the oil-based drilling fluid under high temperature and high pressure conditions, the accuracy of the calculation of the equivalent circulating density ECD and the equivalent static density ESD method of the multiphase mixed fluid can be improved, providing theoretical support for the design of drilling fluid density in ultra-deep narrow density window formations and the precise control of downhole pressure for special operations such as fine pressure-controlled drilling cementing and hole expansion while drilling.

[0082] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0083] In this embodiment, a drilling equivalent circulating density determination device is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made will not be repeated. As used below, the terms "module" and "device" can implement a combination of software and / or hardware for a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0084] According to an embodiment of the present invention, there is also provided an embodiment of a device for implementing a method for determining drilling equivalent circulating density. Figure 5is a schematic diagram of a drilling equivalent circulating density determination device according to an embodiment of the present invention. Figure 5 As shown, the drilling equivalent circulating density determination device includes: a first determination module 502, an adjustment module 504, a second determination module 506, and an acquisition module 508. The device is described below.

[0085] A first determination module 502 is used to determine the heat source type of the target drilling and the heat generation corresponding to the heat source type based on the type of working condition performed on the target drilling;

[0086] The adjustment module 504 is connected to the first determination module 502 and is used to adjust the predetermined initial temperature field according to the heat generation corresponding to the above heat source type to determine the target temperature field of the above target drilling;

[0087] The second determination module 506 is connected to the adjustment module 504 and is used to determine the circulation pressure loss corresponding to the multiple wellbore sections included in the target drilling under the target temperature field;

[0088] The acquisition module 508 is connected to the second determination module 506 and is used to obtain the target equivalent circulating density of the target drilling based on the circulating pressure losses corresponding to the multiple sections of the wellbore.

[0089] In a drilling equivalent circulating density determination device provided by an embodiment of the present invention, a first determination module 502 is used to determine the heat source type of the target drilling and the heat generation corresponding to the heat source type based on the type of working condition performed on the target drilling; an adjustment module 504 is connected to the first determination module 502, and is used to adjust the predetermined initial temperature field according to the heat generation corresponding to the heat source type, and determine the target temperature field of the target drilling; a second determination module 506 is connected to the adjustment module 504, and is used to determine the circulation pressure loss corresponding to the multiple sections of the wellbore included in the target drilling under the target temperature field; an acquisition module 508 is connected to the second determination module 506, and is used to obtain the target equivalent circulating density of the target drilling based on the circulation pressure loss corresponding to the multiple sections of the wellbore. The purpose of establishing a fine mathematical model under high temperature and high pressure conditions and improving the accuracy of obtaining the drilling equivalent circulating density is achieved, and the technical effect of reducing the dependence on specific acquisition equipment and reducing the limitations of the equivalent circulating density is achieved, thereby solving the technical problem of the large limitations of obtaining downhole equivalent circulating density in the related art.

[0090] It should be noted that the above modules can be implemented by software or hardware. For example, for the latter, it can be implemented in the following ways: the above modules can be located in the same processor; or the above modules can be located in different processors in any combination.

[0091] It should be noted that the first determination module 502, the adjustment module 504, the second determination module 506, and the acquisition module 508 correspond to steps S102 to S108 in the embodiment, and the examples and application scenarios implemented by the modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above embodiment. It should be noted that the modules as part of the device can be run in a computer terminal.

[0092] It should be noted that the optional or preferred implementation of this embodiment can refer to the relevant description in the embodiment, which will not be repeated here.

[0093] The above-mentioned drilling equivalent circulating density determination device may also include a processor and a memory. The first determination module 502, the adjustment module 504, the second determination module 506, the acquisition module 508, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize the corresponding functions.

[0094] The processor includes a kernel, which retrieves the corresponding program unit from the memory. There can be one or more kernels. The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one storage chip.

[0095] An embodiment of the present invention provides a non-volatile storage medium on which a program is stored. When the program is executed by a processor, a method for determining drilling equivalent circulation density is implemented.

[0096] An embodiment of the present invention provides an electronic device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented: based on the type of working condition performed on the target drilling, the heat source type of the target drilling and the heat generation corresponding to the heat source type are determined; according to the heat generation corresponding to the heat source type, the predetermined initial temperature field is adjusted to determine the target temperature field of the target drilling; the circulation pressure loss corresponding to the multiple sections of the wellbore included in the target drilling under the target temperature field is determined; based on the circulation pressure loss corresponding to the multiple sections of the wellbore, the target equivalent circulation density of the target drilling is obtained. The device in this article can be a server, a PC, etc.

[0097] The present invention also provides a computer program product, which, when executed on a data processing device, is suitable for executing an initialization program having the following method steps: based on the type of working condition performed on the target drilling, determining the heat source type of the above-mentioned target drilling and the heat generation corresponding to the above-mentioned heat source type; adjusting the predetermined initial temperature field according to the heat generation corresponding to the above-mentioned heat source type to determine the target temperature field of the above-mentioned target drilling; determining the circulation pressure losses corresponding to the multiple sections of the wellbore included in the above-mentioned target drilling under the above-mentioned target temperature field; and obtaining the target equivalent circulation density of the above-mentioned target drilling based on the circulation pressure losses corresponding to the above-mentioned multiple sections of the wellbore.

[0098] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0099] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0100] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0101] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0102] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0103] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0104] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0105] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0106] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0107] The above are only embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A method for determining drilling equivalent circulating density, characterized in that: include: Determining the heat source type of the target well and the heat generation corresponding to the heat source type based on the type of working condition performed on the target well; According to the heat generation corresponding to the heat source type, the predetermined initial temperature field is adjusted to determine the target temperature field of the target wellbore; Determine the circulating pressure losses corresponding to the multiple wellbores included in the target drilling under the target temperature field; Based on the circulating pressure losses corresponding to the multiple sections of the wellbore, the target equivalent circulating density of the target well is obtained.

2. The method according to claim 1, characterized in that The amount of heat generated according to the type of heat source, Adjusting the predetermined initial temperature field to determine the target temperature field of the target drilling includes: Based on the operating condition type being a drilling condition, determining that the heat source type includes formation temperature, drilling fluid heat exchange, and friction heat; Determining the amount of frictional heat generated by drilling equipment in the target well; Based on the frictional heat generated by the drilling equipment, the heat generated corresponding to the formation temperature, and the circulation pressure consumption heat generated corresponding to the drilling fluid heat exchange, the initial temperature field is adjusted to determine the target temperature field.

3. The method according to claim 2, characterized in that The drilling equipment includes a drilling tool and a drill bit, and determining the frictional heat generated by the drilling equipment in the target drilling includes: Determine the mechanical load and rotation speed corresponding to the drilling tool and the drill bit respectively; Determine a first heat generation amount of the drilling tool based on a mechanical load and a rotation speed corresponding to the drilling tool; Determining a second heat generation amount of the drilling tool based on the mechanical load and rotation speed corresponding to the drill bit; The frictional heat generation amount of the drilling equipment is determined based on the first heat generation amount and the second heat generation amount.

4. The method according to claim 1, characterized in that: The determining of the circulating pressure losses respectively corresponding to the multiple wellbores included in the target drilling under the target temperature field comprises: Obtain the drilling fluid density, displacement, wellbore size, casing size, and drilling tool size corresponding to the multiple sections of the wellbore respectively; Based on the corresponding drilling fluid density, displacement, wellbore size, casing size, and drilling tool size, the circulating pressure losses corresponding to the multiple sections of the wellbore are determined.

5. The method according to claim 1, characterized in that The target equivalent circulating density of the target wellbore is obtained based on the circulating pressure losses corresponding to the multiple wellbores, including: determining a riser pressure loss in the target well; Determining an equivalent static density based on the target temperature field and the standpipe pressure loss; Based on the equivalent rest density, the target equivalent circulating density is determined.

6. The method according to claim 5, characterized in that The circulating pressure loss includes the internal pressure loss of the drilling tool and the annular space pressure loss, wherein the annular space is the space between the drilling tool and the corresponding section of the wellbore. The determining of the riser pressure loss in the target drilling includes: Based on the annular space pressure losses respectively corresponding to the multiple sections of the wellbore, a total annular space pressure loss is obtained; The riser pressure loss is determined based on the internal pressure losses of the drilling tools corresponding to the multiple sections of the wellbore, respectively, and the total annular space pressure loss.

7. The method according to any one of claims 1 to 6, characterized in that: Before determining the heat source type of the target well and the amount of heat generated by the heat source type based on the type of working condition performed on the target well, the method further includes: Determining a drilling processing duration for opening the target well; In the case that the drilling process duration is longer than a predetermined duration, it is determined that the target wellbore is in a thermal quasi-static state, and the drilling equipment in the target wellbore is suspended.

8. A drilling equivalent circulating density determination device, characterized in that: include: A first determination module is used to determine the heat source type of the target drilling and the heat generation corresponding to the heat source type based on the type of working condition performed on the target drilling; An adjustment module, used to adjust a predetermined initial temperature field according to the amount of heat generated by the heat source type, and determine a target temperature field for the target wellbore; The second determination module is used to determine the circulating pressure losses corresponding to the multiple wellbores included in the target drilling under the target temperature field; The acquisition module is used to obtain the target equivalent circulating density of the target well based on the circulating pressure losses corresponding to the multiple sections of the wellbore.

9. A non-volatile storage medium, characterized in that: The non-volatile storage medium stores a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the method for determining the drilling equivalent circulation density according to any one of claims 1 to 7.

10. An electronic device, characterized in that: include: One or more processors and a memory, wherein the memory is used to store one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method for determining the drilling equivalent circulating density as described in any one of claims 1 to 7.

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