Method and apparatus for determining wellbore pressure

Abstract

The present application discloses a method and device for determining wellbore pressure. The method comprises: obtaining the well depth of the calculation point under the current drilling condition; judging whether the well depth is greater than the sand bridge top depth; determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth when the well depth is greater than the sand bridge top depth; determining the wellbore pressure corresponding to the well depth according to the hydrostatic column pressure, friction pressure loss and osmotic pressure difference. The present application takes into account the influence of the sand bridge on the calculation of the wellbore pressure, and improves the calculation accuracy of the wellbore pressure under the drilling condition.

Description

Technical Field

[0001] The present invention relates to the field of oil exploration, and in particular to a method and device for determining wellbore pressure. Background Art

[0002] During the drilling operation of a drilling project, due to the collapse of the accumulated cuttings in the big belly section and the inclined section, the pushing effect of tools such as the centralizer or the drill bit, etc., the cuttings are easily accumulated in the wellbore annulus and form sand bridges. However, the traditional calculation of the wellbore pressure under the drilling operation does not take the effect of the sand bridge into consideration. Therefore, the calculation accuracy of the wellbore pressure under the drilling operation is poor in the existing technology. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a method and device for determining wellbore pressure, so as to solve the problem of poor calculation accuracy of wellbore pressure under drilling conditions in the prior art.

[0004] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for determining wellbore pressure, the method comprising:

[0005] Get the well depth of the calculation point under the current drilling condition;

[0006] Determine whether the well depth is greater than the sand bridge top depth;

[0007] When the well depth is greater than the depth of the sand bridge top, determine the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth;

[0008] The wellbore pressure corresponding to the well depth is determined based on the hydrostatic column pressure, friction pressure loss and osmotic pressure difference.

[0009] In the embodiment of the present application, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes:

[0010] When the well depth is greater than the sand bridge top depth, determine whether the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth;

[0011] When the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth, the hydrostatic column pressure, the friction pressure loss and the osmotic pressure difference corresponding to the well depth are determined by the first calculation method.

[0012] In the embodiment of the present application, in the first calculation method, the hydrostatic column pressure satisfies the following formula:

[0013] p s =ρgH;

[0014] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0015] The friction pressure loss satisfies the following formula:

[0016]

[0017] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H s is the depth of the sand bridge top, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0018] The osmotic pressure difference satisfies the following formula:

[0019]

[0020] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, v is the flow rate, H is the well depth, H s is the depth of the sand bridge top, K d is the permeability.

[0021] In the embodiment of the present application, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes:

[0022] When the well depth is greater than the sand bridge top depth, determine whether the well depth is greater than the sum of the sand bridge length and the sand bridge top depth and is not greater than the drill bit depth;

[0023] When the well depth is greater than the sum of the sand bridge length and the sand bridge top depth but not greater than the drill bit depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a second calculation method.

[0024] In the embodiment of the present application, in the second calculation method, the hydrostatic column pressure satisfies the following formula:

[0025] p s =ρgH;

[0026] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0027] The friction pressure loss satisfies the following formula:

[0028]

[0029] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0030] The osmotic pressure difference satisfies the following formula:

[0031]

[0032] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the length of the sand bridge, v is the flow velocity, K d is the permeability.

[0033] In the embodiment of the present application, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes:

[0034] When the well depth is greater than the sand bridge top depth, determine whether the well depth is greater than the drill bit depth and not greater than the wellbore depth;

[0035] When the well depth is greater than the drill bit depth but not greater than the wellbore depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a third calculation method.

[0036] In the embodiment of the present application, in the third calculation method, the hydrostatic column pressure satisfies the following formula:

[0037] p s =ρgH;

[0038] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0039] The friction pressure loss satisfies the following formula:

[0040]

[0041] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H b is the drill bit depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0042] The osmotic pressure difference satisfies the following formula:

[0043]

[0044] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the length of the sand bridge, v is the flow velocity, K d is the permeability.

[0045] In an embodiment of the present application, the method further includes:

[0046] When the well depth is not greater than the sand bridge top depth, the hydrostatic column pressure and the friction pressure loss corresponding to the well depth are determined by the fourth calculation method.

[0047] In the embodiment of the present application, in the fourth calculation method, the hydrostatic column pressure satisfies the following formula:

[0048] p s =ρgH;

[0049] Among them, p s is the static liquid column pressure, ρ is the drilling fluid density, g is the gravity acceleration, and H is the well depth; the friction pressure loss satisfies the following formula:

[0050]

[0051] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, ρ is the drilling fluid density, v is the flow rate, D w is the borehole diameter, D p is the outer diameter of the drill pipe.

[0052] A second aspect of the present application provides a device for determining wellbore pressure, comprising:

[0053] a memory configured to store instructions; and

[0054] The processor is configured to call instructions from the memory and implement the above method for determining wellbore pressure when executing the instructions.

[0055] Through the above technical scheme, when calculating the wellbore pressure under the drilling condition, the influence of the sand bridge is taken into account. When the well depth of the calculation point under the current drilling condition is greater than the depth of the sand bridge top, the static liquid column pressure and friction pressure loss corresponding to the well depth and the osmotic pressure difference are determined. The wellbore pressure corresponding to the well depth is determined based on the static liquid column pressure, friction pressure loss and osmotic pressure difference, thereby improving the calculation accuracy of the wellbore pressure under the drilling condition.

[0056] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0058] Figure 1 A schematic diagram of a process for determining wellbore pressure according to an embodiment of the present application is schematically shown;

[0059] Figure 2 The schematic diagram of the structure of the wellbore according to the embodiment of the present application is shown schematically;

[0060] Figure 3 The structural block diagram of the device for determining the wellbore pressure according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0062] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0063] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0064] Figure 1 The flowchart of the method for determining the wellbore pressure according to the embodiment of the present application is schematically shown. Figure 1 As shown, in an embodiment of the present application, a method for determining wellbore pressure is provided, and the method may include the following steps:

[0065] Step 102, obtaining the well depth of the calculation point under the current drilling condition;

[0066] Step 104, determining whether the well depth is greater than the sand bridge top depth;

[0067] Step 106: when the well depth is greater than the sand bridge top depth, determine the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth;

[0068] Step 108: Determine the wellbore pressure corresponding to the well depth according to the hydrostatic column pressure, friction pressure loss, and osmotic pressure difference.

[0069] In the embodiments of the present application, drilling refers to the work of drilling holes in the ground using mechanical equipment or manpower, usually referring to the project of drilling wells and large-diameter water supply wells for the exploration or development of gaseous minerals such as oil and natural gas. A shaft refers to a vertical or inclined project excavated from the ground to the ore body in underground mining or underground engineering construction. A vertical project is called a vertical shaft, and an inclined project is called an inclined shaft. Figure 2 The structural diagram of the wellbore according to the embodiment of the present application is schematically shown. Figure 2 As shown in the figure, taking the ground (H = 0) as a reference, calculate the depth H when drilling (0 ≤ H ≤ H w ) of the wellbore pressure p a Among them, H s is the depth of the sand bridge top, L s is the length of the sand bridge, H b is the drill bit depth, H w is the wellbore depth, D w is the borehole diameter, D p is the outer diameter of the drill pipe.

[0070] Sand bridge refers to the bridge formed when the diameter of the wellbore is irregular and the drilling fluid often generates eddies at the expansion point, causing the carried drill cuttings to sink and focus at the contraction point below. In the drilling operation of the drilling project, due to the collapse of the accumulated cuttings in the big belly well section and the inclined well section, the pushing effect of tools such as the stabilizer or the drill bit, etc., the cuttings are easily accumulated in the wellbore annulus and form sand bridges. However, the traditional calculation of the wellbore pressure under the drilling operation does not take into account the effect of the sand bridge, and the calculation accuracy of the wellbore pressure is poor. Therefore, the embodiment of the present application takes into account the influence of the sand bridge, and when the well depth of the calculation point under the current drilling operation is greater than the top depth of the sand bridge (that is, H>H s ), the sand bridge has an impact on the wellbore pressure at the depth of the well. Therefore, it is necessary to determine the static liquid column pressure and friction pressure loss corresponding to the well depth and determine the osmotic pressure difference through Darcy's law. s , friction pressure loss Δp f and the osmotic pressure difference Δp s Determine the wellbore pressure p corresponding to the well depth H a , where p a =p s -Δp f In one example, the osmotic pressure difference Δp sIt can be obtained by Darcy's law. Darcy's law (Darcy's law of seepage) refers to the basic law of fluid movement in porous materials, and is also a statistical law that describes the seepage process from a macroscopic perspective. In this way, the influence of sand bridges can be taken into account when calculating wellbore pressure, thereby improving the calculation accuracy of wellbore pressure under drilling conditions.

[0071] Through the above technical scheme, when calculating the wellbore pressure under the drilling condition, the influence of the sand bridge is taken into account. When the well depth of the calculation point under the current drilling condition is greater than the depth of the sand bridge top, the static liquid column pressure and friction pressure loss corresponding to the well depth and the osmotic pressure difference are determined. The wellbore pressure corresponding to the well depth is determined based on the static liquid column pressure, friction pressure loss and osmotic pressure difference, thereby improving the calculation accuracy of the wellbore pressure under the drilling condition.

[0072] In the embodiment of the present application, step 106, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth may include:

[0073] When the well depth is greater than the sand bridge top depth, determine whether the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth;

[0074] When the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth, the hydrostatic column pressure, the friction pressure loss and the osmotic pressure difference corresponding to the well depth are determined by the first calculation method.

[0075] Specifically, when the well depth H is greater than the sand bridge top depth H s And not greater than the sum of the sand bridge length and the sand bridge top depth (H s +L s ), that is, in H s <H≤H s +L s When the wellbore pressure p is determined by the first calculation method a , where the wellbore pressure p a is the hydrostatic column pressure p s Subtract friction pressure loss Δp f and osmotic pressure difference Δp s The value after that, that is, p a =p s -Δp f -Δp s .

[0076] In the embodiment of the present application, in the first calculation method, the hydrostatic column pressure can satisfy the following formula:

[0077] p s =ρgH;

[0078] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0079] The friction pressure loss can satisfy the following formula:

[0080]

[0081] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H s is the depth of the sand bridge top, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0082] Osmotic pressure difference Δp f The following formula can be satisfied:

[0083]

[0084] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, v is the flow rate, H is the well depth, H s is the depth of the sand bridge top, K d is the permeability.

[0085] Specifically, the flow velocity v in the friction pressure loss satisfies the following formula:

[0086]

[0087] Where v is the flow rate, ρ is the drilling fluid density, and v t is the drilling speed, D w is the borehole diameter, D p is the outer diameter of the drill pipe.

[0088] The friction coefficient f in the friction pressure loss satisfies the following formula:

[0089] When Re<2100,

[0090] When Re≥2100,

[0091] Where Re is the Reynolds number and n is the generalized flow index.

[0092] The above Reynolds number Re satisfies the following formula:

[0093]

[0094] Where Re is the Reynolds number, ρ is the drilling fluid density, v is the flow velocity, and D w is the borehole diameter, D p is the outer diameter of the drill pipe, μ is the plastic viscosity, and τ0 is the yield value.

[0095] The generalized fluidity index n satisfies the following formula:

[0096]

[0097] Where n is the generalized flow index, v is the flow velocity, and D w is the borehole diameter, D p is the outer diameter of the drill pipe, and γ is the shear rate.

[0098] The above shear rate γ satisfies the following formula:

[0099]

[0100] Where γ is the shear rate, v is the flow rate, and D w is the borehole diameter, D p is the outer diameter of the drill pipe, μ is the plastic viscosity, and τ0 is the yield value.

[0101] Through the above calculation method, the friction pressure loss Δp can be determined f Calculate the required parameters, such as friction coefficient f, flow velocity v, and thus calculate the friction pressure loss Δp f The value of osmotic pressure difference Δp s Calculated using Darcy's law.

[0102] By calculating the hydrostatic column pressure, the hydrostatic column pressure p s Subtract friction pressure loss Δp f and osmotic pressure difference Δp s The value after that can be obtained when the well depth H is greater than the sand bridge top depth H s And not greater than the sum of the sand bridge length and the sand bridge top depth (H s +L s ) under the condition of wellbore pressure p a The value of .

[0103] In the embodiment of the present application, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth may include:

[0104] When the well depth is greater than the sand bridge top depth, determine whether the well depth is greater than the sum of the sand bridge length and the sand bridge top depth and is not greater than the drill bit depth;

[0105] When the well depth is greater than the sum of the sand bridge length and the sand bridge top depth but not greater than the drill bit depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a second calculation method.

[0106] Specifically, when the well depth H is greater than the sum of the sand bridge length and the sand bridge top depth (H s +L s ) and not greater than the drill depth H b In the case of Hs +L s <H≤H b , determine the wellbore pressure p by the second calculation method a , where the wellbore pressure p a is the hydrostatic column pressure p s Subtract friction pressure loss Δp f and osmotic pressure difference Δp s The value after that, that is, p a =p s -Δp f -Δp s .

[0107] In the embodiment of the present application, in the second calculation method, the hydrostatic column pressure can satisfy the following formula:

[0108] p s =ρgH;

[0109] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0110] The friction pressure loss can satisfy the following formula:

[0111]

[0112] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0113] The osmotic pressure difference can satisfy the following formula:

[0114]

[0115] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the length of the sand bridge, v is the flow velocity, K d is the permeability.

[0116] Specifically, the calculation method of the friction coefficient f and the flow velocity v in the friction pressure loss is the same as that in the first calculation method. s Also calculated by Darcy's law.

[0117] By calculating the hydrostatic column pressure, the hydrostatic column pressure p s Subtract friction pressure loss Δp f and osmotic pressure difference Δp sThe value after that can be obtained when the well depth H is greater than the sum of the sand bridge length and the sand bridge top depth (H s +L s ) and not greater than the drill depth H b The wellbore pressure p a The value of .

[0118] In the embodiment of the present application, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss, and osmotic pressure difference corresponding to the well depth may include:

[0119] When the well depth is greater than the sand bridge top depth, determine whether the well depth is greater than the drill bit depth and not greater than the wellbore depth;

[0120] When the well depth is greater than the drill bit depth but not greater than the wellbore depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a third calculation method.

[0121] Specifically, when the well depth H is greater than the drill bit depth H b And not greater than the wellbore depth H w In the case of H b <H≤H w , determine the wellbore pressure p by the third calculation method a , where the wellbore pressure p a is the hydrostatic column pressure p s Subtract friction pressure loss Δp f and osmotic pressure difference Δp s The value after that, that is, p a =p s -Δp f -Δp s .

[0122] In the embodiment of the present application, in the third calculation method, the hydrostatic column pressure can satisfy the following formula:

[0123] p s =ρgH;

[0124] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0125] The friction pressure loss can satisfy the following formula:

[0126]

[0127] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H b is the drill bit depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D wis the borehole diameter, D p is the outer diameter of the drill pipe;

[0128] The osmotic pressure difference can satisfy the following formula:

[0129]

[0130] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the length of the sand bridge, v is the flow velocity, K d is the permeability.

[0131] Specifically, the calculation method of the friction coefficient f and the flow velocity v in the friction pressure loss is the same as that in the first calculation method. s Also calculated by Darcy's law.

[0132] By calculating the hydrostatic column pressure, the hydrostatic column pressure p s Subtract friction pressure loss Δp f and osmotic pressure difference Δp s The value after that can be obtained when the well depth H is greater than the drill bit depth H b And not greater than the wellbore depth H w The wellbore pressure p a The value of .

[0133] In an embodiment of the present application, the method may further include:

[0134] When the well depth is not greater than the sand bridge top depth, the hydrostatic column pressure and the friction pressure loss corresponding to the well depth are determined by the fourth calculation method.

[0135] Specifically, when the well depth H is not greater than the sand bridge top depth H s In the case of 0 <H≤H s When the sand bridge is used, the influence of the wellbore pressure on the wellbore pressure does not need to be considered, that is, the influence of the osmotic pressure difference does not need to be considered. Therefore, the wellbore pressure p is determined by the fourth calculation method. a , where the wellbore pressure p a is the hydrostatic column pressure p s Subtract friction pressure loss Δp f The value after that, that is, p a =p s -Δp f .

[0136] In the embodiment of the present application, in the fourth calculation method, the hydrostatic column pressure can satisfy the following formula:

[0137] p s =ρgH;

[0138] Among them, p sis the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0139] The friction pressure loss can satisfy the following formula:

[0140]

[0141] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, ρ is the drilling fluid density, v is the flow rate, D w is the borehole diameter, D p is the outer diameter of the drill pipe.

[0142] Specifically, the calculation method of the friction coefficient f and the flow velocity v in the friction pressure loss is the same as that in the first calculation method.

[0143] By calculating the hydrostatic column pressure, the hydrostatic column pressure p s Subtract friction pressure loss Δp f The value after that can be obtained when the well depth H is not greater than the drill bit depth H b The wellbore pressure p a The value of .

[0144] Figure 3 The structure block diagram of the device for determining the wellbore pressure according to the embodiment of the present application is schematically shown. Figure 3 As shown, an embodiment of the present application provides a device for determining wellbore pressure, which may include:

[0145] Memory 310, configured to store instructions; and

[0146] The processor 320 is configured to call instructions from the memory 310 and implement the above-mentioned method for determining wellbore pressure when executing the instructions.

[0147] Specifically, in the embodiment of the present application, the processor 320 may be configured to:

[0148] Get the well depth of the calculation point under the current drilling condition;

[0149] Determine whether the well depth is greater than the sand bridge top depth;

[0150] When the well depth is greater than the depth of the sand bridge top, determine the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth;

[0151] The wellbore pressure corresponding to the well depth is determined based on the hydrostatic column pressure, friction pressure loss and osmotic pressure difference.

[0152] Furthermore, the processor 320 may be configured to:

[0153] When the well depth is greater than the depth of the sand bridge top, the determination of the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes:

[0154] When the well depth is greater than the sand bridge top depth, determine whether the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth;

[0155] When the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth, the hydrostatic column pressure, the friction pressure loss and the osmotic pressure difference corresponding to the well depth are determined by the first calculation method.

[0156] In the embodiment of the present application, in the first calculation method, the hydrostatic column pressure satisfies the following formula:

[0157] p s =ρgH;

[0158] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0159] The friction pressure loss satisfies the following formula:

[0160]

[0161] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H s is the depth of the sand bridge top, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0162] The osmotic pressure difference satisfies the following formula:

[0163]

[0164] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, v is the flow rate, H is the well depth, H s is the depth of the sand bridge top, K d is the permeability.

[0165] Furthermore, the processor 320 may be configured to:

[0166] When the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes:

[0167] When the well depth is greater than the sand bridge top depth, determine whether the well depth is greater than the sum of the sand bridge length and the sand bridge top depth and is not greater than the drill bit depth;

[0168] When the well depth is greater than the sum of the sand bridge length and the sand bridge top depth but not greater than the drill bit depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a second calculation method.

[0169] In the embodiment of the present application, in the second calculation method, the hydrostatic column pressure satisfies the following formula:

[0170] p s =ρgH;

[0171] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0172] The friction pressure loss satisfies the following formula:

[0173]

[0174] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe;

[0175] The osmotic pressure difference satisfies the following formula:

[0176]

[0177] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the length of the sand bridge, v is the flow velocity, K d is the permeability.

[0178] Furthermore, the processor 320 may be configured to:

[0179] When the well depth is greater than the depth of the sand bridge top, the determination of the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes:

[0180] When the well depth is greater than the sand bridge top depth, determine whether the well depth is greater than the drill bit depth and not greater than the wellbore depth;

[0181] When the well depth is greater than the drill bit depth but not greater than the wellbore depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a third calculation method.

[0182] In the embodiment of the present application, in the third calculation method, the hydrostatic column pressure satisfies the following formula:

[0183] p s =ρgH;

[0184] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0185] The friction pressure loss satisfies the following formula:

[0186]

[0187] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H b is the drill bit depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D P is the outer diameter of the drill pipe;

[0188] The osmotic pressure difference satisfies the following formula:

[0189]

[0190] Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the length of the sand bridge, v is the flow velocity, K d is the permeability.

[0191] Furthermore, the processor 320 may be configured to:

[0192] When the well depth is not greater than the sand bridge top depth, the hydrostatic column pressure and the friction pressure loss corresponding to the well depth are determined by the fourth calculation method.

[0193] In the embodiment of the present application, in the fourth calculation method, the hydrostatic column pressure satisfies the following formula:

[0194] p s =ρgH;

[0195] Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth;

[0196] The friction pressure loss satisfies the following formula:

[0197]

[0198] Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, ρ is the drilling fluid density, v is the flow rate, D w is the borehole diameter, D p is the outer diameter of the drill pipe.

[0199] Through the above technical scheme, when calculating the wellbore pressure under the drilling condition, the influence of the sand bridge is taken into account. When the well depth of the calculation point under the current drilling condition is greater than the depth of the sand bridge top, the static liquid column pressure and friction pressure loss corresponding to the well depth and the osmotic pressure difference are determined. The wellbore pressure corresponding to the well depth is determined based on the static liquid column pressure, friction pressure loss and osmotic pressure difference, thereby improving the calculation accuracy of the wellbore pressure under the drilling condition.

[0200] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0201] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes 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 generate 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.

[0202] 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.

[0203] 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.

[0204] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0205] 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.

[0206] 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.

[0207] 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.

[0208] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for determining wellbore pressure, characterized in that The method comprises: Get the well depth of the calculation point under the current drilling condition; Determining whether the well depth is greater than the sand bridge top depth; When the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth; Determine the wellbore pressure corresponding to the well depth according to the hydrostatic column pressure, the friction pressure loss and the osmotic pressure difference; Wherein, when the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes: In the case where the well depth is greater than the sand bridge top depth, determining whether the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth; In the case where the well depth is not greater than the sum of the sand bridge length and the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth by a first calculation method; In the first calculation method, the hydrostatic column pressure satisfies the following formula: p s =ρhH; Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth; The friction pressure loss satisfies the following formula: Among them, Δp f is the friction pressure loss, f is the friction coefficient, H s is the depth of the sand bridge top, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe; The osmotic pressure difference satisfies the following formula: Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, v is the flow rate, H is the well depth, H s is the depth of the sand bridge top, K d is the permeability.

2. The method according to claim 1, characterized in that When the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes: In the case where the well depth is greater than the sand bridge top depth, determining whether the well depth is greater than the sum of the sand bridge length and the sand bridge top depth and is not greater than the drill bit depth; When the well depth is greater than the sum of the sand bridge length and the sand bridge top depth and is not greater than the drill bit depth, the hydrostatic column pressure, the friction pressure loss and the osmotic pressure difference corresponding to the well depth are determined by a second calculation method; Wherein, in the second calculation method, the hydrostatic column pressure satisfies the following formula: p s =ρgH; Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth; The friction pressure loss satisfies the following formula: Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow rate, D w is the borehole diameter, D p is the outer diameter of the drill pipe; The osmotic pressure difference satisfies the following formula: Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the sand bridge length, v is the flow velocity, K d is the permeability.

3. The method according to claim 1, characterized in that When the well depth is greater than the sand bridge top depth, determining the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth includes: In the case where the well depth is greater than the sand bridge top depth, determining whether the well depth is greater than the drill bit depth and not greater than the wellbore depth; When the well depth is greater than the drill bit depth but not greater than the wellbore depth, the hydrostatic column pressure, friction pressure loss and osmotic pressure difference corresponding to the well depth are determined by a third calculation method; Wherein, in the third calculation method, the hydrostatic column pressure satisfies the following formula: p s =ρgH; Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, p is the gravitational acceleration, and H is the well depth; The friction pressure loss satisfies the following formula: Among them, Δp f is the friction pressure loss, f is the friction coefficient, H b is the drill bit depth, L s is the sand bridge length, ρ is the drilling fluid density, v is the flow velocity, D w is the borehole diameter, D p is the outer diameter of the drill pipe; The osmotic pressure difference satisfies the following formula: Among them, Δp s is the osmotic pressure difference, μ is the plastic viscosity, L s is the sand bridge length, v is the flow velocity, K d is the permeability.

4. The method according to claim 1, characterized in that The method further comprises: In the case where the well depth is not greater than the sand bridge top depth, determining the hydrostatic column pressure and the friction pressure loss corresponding to the well depth by a fourth calculation method; Wherein, in the fourth calculation method, the hydrostatic column pressure satisfies the following formula: g s =ρgH; Among them, p s is the hydrostatic column pressure, ρ is the drilling fluid density, g is the gravitational acceleration, and H is the well depth; The friction pressure loss satisfies the following formula: Among them, Δp f is the friction pressure loss, f is the friction coefficient, H is the well depth, ρ is the drilling fluid density, v is the flow rate, D w is the borehole diameter, D p is the outer diameter of the drill pipe.

5. A device for determining wellbore pressure, characterized in that include: a memory configured to store instructions; as well as A processor is configured to call the instructions from the memory and implement the method for determining wellbore pressure according to any one of claims 1 to 4 when executing the instructions.

Images