A method and apparatus for determining the parameters of casing construction in ultra-deep wells with controlled pressure and accelerated speed.

Abstract

This invention provides a method and apparatus for determining the parameters of casing installation in ultra-deep wells with controlled pressure and accelerated installation, relating to the field of drilling technology. The method includes obtaining the maximum activation pressure and low-density drilling fluid density during casing installation; determining the amount of low-density drilling fluid and weighted drilling fluid used; determining the drilling fluid circulation speed during drilling as the injection speed; and determining the maximum controlled pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure and a safe pressure window. The apparatus executes the above method. The method and apparatus provided by this invention can install casing at a normal speed while avoiding induced well leakage, and are easy to operate.

Description

Technical Field

[0001] This invention relates to the field of drilling construction technology, specifically to a method and apparatus for determining the parameters of casing construction in ultra-deep wells with controlled pressure and accelerated speed. Background Technology

[0002] Casing installation refers to the operation of lowering steel casing into the wellbore during drilling. Specifically, during casing installation, the drilling rig lowers the casing one casing pipe at a time into the wellbore. Cement is then injected through the casing into the annulus between the wellbore and the formation to secure the casing and seal the formation. The cement is then allowed to solidify, forming a strong cement sheath. This achieves the goals of reinforcing the wellbore, preventing collapse, isolating different formations, and controlling downhole fluids.

[0003] In ultra-deep well operations, the surge pressure generated during casing installation can easily induce well leakage. Since the surge pressure is positively correlated with the casing installation speed—that is, the higher the speed, the greater the surge pressure—on-site operators often use a lower casing installation speed to avoid generating excessive surge pressure and inducing well leakage. However, a lower installation speed increases the installation time, thus increasing the project duration and development costs. Therefore, current casing installation processes incorporate special devices to control pressure during installation, ensuring the casing installation proceeds at a normal speed while preventing well leakage. For example, by adding a special sealing device, pressure control begins during the initial casing installation phase, effectively reducing bottom hole leakage.

[0004] However, controlling pressure during casing installation using the aforementioned method requires the pre-installation of specialized devices. Furthermore, during actual casing installation, these devices must be operated according to the progress of the installation to achieve pressure control. This undoubtedly increases the complexity and cost of casing installation in ultra-deep wells. Therefore, it is particularly necessary to provide a method for casing installation in ultra-deep wells that allows for normal installation speeds, avoids inducing well leakage, and is easy to operate. Summary of the Invention

[0005] To address the problems in the prior art, this invention provides a method and apparatus for determining the casing construction parameters for ultra-deep well pressure-controlled acceleration, which can at least partially solve the problems existing in the prior art.

[0006] On the one hand, this invention proposes a method for determining the construction parameters of casing in ultra-deep wells with controlled pressure and accelerated installation, including:

[0007] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0008] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0009] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0010] The step of obtaining the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling baseline data includes:

[0011] The resistance generated by the drilling fluid network structure is calculated based on the drilling foundation data.

[0012] The frictional resistance generated by the drilling fluid flow caused by the discharge of annular fluid is calculated based on the casing speed and the drilling foundation data.

[0013] The inertial force caused by the change in casing velocity is calculated based on the casing acceleration and the drilling foundation data.

[0014] The maximum value among the resistance, frictional resistance, and inertial force is taken as the maximum excitation pressure of the lower sleeve.

[0015] The drilling baseline data includes drilling fluid static shear force, well depth, annular outer diameter, and annular inner diameter; correspondingly, the resistance force generated by the drilling fluid network structure calculated based on the drilling baseline data includes:

[0016] The resistance is calculated using the following formula:

[0017]

[0018] Where p1 is the resistance generated by the drilling fluid network structure, τ w H is the static shear force of the drilling fluid, H is the well depth, D is the outer diameter of the annulus, and d is the inner diameter of the annulus.

[0019] The drilling baseline data includes fluid flow state, original drilling fluid consistency coefficient, well depth, original drilling fluid flowability index, annular outer diameter, and annular inner diameter; correspondingly, the frictional resistance generated by the drilling fluid flow caused by the discharged annular fluid, calculated based on the casing running speed and the drilling baseline data, includes:

[0020] The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter.

[0021] If the fluid flow state is determined to be laminar flow, the frictional resistance is calculated based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus.

[0022] The step of calculating the annular return velocity based on the lower sleeve velocity, the annular outer diameter, and the annular inner diameter includes:

[0023] The annular return velocity is calculated using the following formula:

[0024]

[0025] Among them, V a It is the circular return speed, V p d is the casing speed, D is the outer diameter of the annulus, and d is the inner diameter of the annulus.

[0026] The calculation of the frictional resistance based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus includes:

[0027] The frictional resistance is calculated using the following formula:

[0028]

[0029] Where p2 is the frictional resistance, K is the original drilling fluid consistency coefficient, H is the well depth, n is the original drilling fluid flowability index, and V is the original drilling fluid fluid viscosity coefficient. a It is the annular return velocity, D is the outer diameter of the annular space, and d is the inner diameter of the annular space.

[0030] The drilling baseline data includes fluid flow state, drilling fluid friction coefficient, original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the frictional resistance generated by the drilling fluid flow caused by the discharged annular fluid, calculated based on the casing running speed and the drilling baseline data, includes:

[0031] The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter.

[0032] If the fluid flow state is determined to be turbulent, the frictional resistance is calculated based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus.

[0033] The step of calculating the frictional resistance based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus includes:

[0034] The frictional resistance is calculated using the following formula:

[0035]

[0036] Where p2 is the frictional resistance, H is the well depth, and V is the frictional resistance. a ρ is the annular return velocity, D is the outer diameter of the annulus, d is the inner diameter of the annulus, f is the drilling fluid friction coefficient, and ρ is the annular return velocity. 原 It is the original drilling fluid density.

[0037] The drilling baseline data includes the original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the inertial force caused by the casing velocity change calculated based on the casing acceleration and the drilling baseline data includes:

[0038] The inertial force is calculated using the following formula:

[0039]

[0040] Where p3 is the inertial force, ρ 原 H is the original drilling fluid density, D is the well depth, d is the annulus outer diameter, d is the annulus inner diameter, and a is the casing running acceleration.

[0041] The process of obtaining the low-density drilling fluid density based on the original drilling fluid density includes:

[0042] The decrease in drilling fluid density is determined based on the original drilling fluid density and the preset correspondence.

[0043] The preset correspondence is the correspondence between the preset original drilling fluid density and the preset decrease value of drilling fluid density;

[0044] The difference between the original drilling fluid density and the decrease in drilling fluid density is taken as the density of the low-density drilling fluid.

[0045] The step of determining the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window for ultra-deep wells includes:

[0046] The dosage of the low-density drilling fluid is calculated using the following formula:

[0047]

[0048] Among them, V 低 This refers to the dosage of low-density drilling fluid, where D is the outer diameter of the annulus, d is the inner diameter of the annulus, and p... max It is the maximum excitation pressure of the lower casing, p 窗口 It is the aforementioned safety pressure window, ρ 原 It is the original drilling fluid density, ρ低 ρ is the density of low-density drilling fluid, and g is the acceleration due to gravity.

[0049] The step of determining the amount of weighted drilling fluid used based on the density of the weighted drilling fluid, the density of the original drilling fluid, the maximum excitation pressure of the casing, and the basic drilling data includes:

[0050] The amount of weighted drilling fluid used is calculated using the following formula:

[0051]

[0052] Among them, V 加重 It increases the amount of drilling fluid used, D is the outer diameter of the annulus, d is the inner diameter of the annulus, and ρ is the weighting fluid usage. 加重 It increases the density of the drilling fluid, ρ 原 ρ is the original drilling fluid density, and g is the acceleration due to gravity.

[0053] The step of determining the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window includes:

[0054] The difference between the maximum activation pressure of the lower bushing and the safe pressure window is taken as the maximum control pressure value during the pump shutdown period.

[0055] The step of determining the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window includes:

[0056] The maximum excitation pressure of the lower sleeve is negativeed, and the negative value of the maximum excitation pressure of the lower sleeve is taken as the left endpoint value of the safety fluctuation range.

[0057] The difference between the maximum excitation pressure of the lower casing and the safety pressure window is taken as the right endpoint value of the safety fluctuation range.

[0058] Prior to the step of obtaining the low-density drilling fluid density based on the original drilling fluid density, the method for determining the casing installation parameters for ultra-deep well pressure-controlled acceleration further includes:

[0059] If it is determined that the maximum excitation pressure of the casing is greater than the safe pressure window of the ultra-deep well, then the steps of obtaining the low-density drilling fluid density based on the original drilling fluid density and subsequent steps are executed.

[0060] On one hand, this invention proposes a device for determining the construction parameters of casing in ultra-deep wells with controlled pressure and accelerated installation, comprising:

[0061] The acquisition unit is used to obtain the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration and drilling base data, and to obtain the density of the low-density drilling fluid based on the original drilling fluid density.

[0062] The first determining unit is used to determine the amount of low-density drilling fluid based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling base data, and the safety pressure window of the ultra-deep well; and to determine the amount of weighting drilling fluid based on the weighting drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling base data.

[0063] The second determining unit is used to determine the drilling fluid circulation speed during drilling as the injection speed, and to determine the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0064] In another aspect, embodiments of the present invention provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the following method:

[0065] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0066] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0067] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0068] This invention provides a computer-readable storage medium, comprising:

[0069] The computer-readable storage medium stores a computer program that, when executed by a processor, implements the following method:

[0070] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0071] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0072] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0073] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the following method:

[0074] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0075] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0076] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0077] The method and apparatus for determining casing running parameters for controlled pressure and accelerated drilling in ultra-deep wells provided in this invention obtain the maximum excitation pressure of the casing running based on the casing running speed, casing running acceleration, and drilling foundation data, and obtain the density of the low-density drilling fluid based on the original drilling fluid density; determine the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing running, the drilling foundation data, and the safe pressure window for ultra-deep wells; determine the amount of weighting drilling fluid used based on the density of the weighting drilling fluid, the original drilling fluid density, the maximum excitation pressure of the casing running, and the drilling foundation data; determine the drilling fluid circulation speed during drilling as the injection speed; and determine the maximum controlled pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing running and the safe pressure window, respectively. This method allows for casing running at a normal speed while avoiding induced well leakage, and is easy to operate. Attached Figure Description

[0078] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0079] Figure 1 This is a flowchart illustrating a method for determining casing construction parameters for ultra-deep wells with controlled pressure and accelerated speed, according to an embodiment of the present invention.

[0080] Figure 2 This is a schematic diagram illustrating the change over time of factors that cause excitation pressure, as provided in an embodiment of the present invention.

[0081] Figure 3 This is a schematic diagram illustrating the relationship between low-density drilling fluid value and annular height provided in an embodiment of the present invention.

[0082] Figure 4 This is a schematic diagram of the distribution of annular fluid types during the casing construction process provided in an embodiment of the present invention.

[0083] Figure 5 This is a schematic diagram of the device for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated speed, provided in an embodiment of the present invention.

[0084] Figure 6 This is a schematic diagram of the physical structure of a computer device provided in an embodiment of the present invention. Detailed Implementation

[0085] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments and descriptions of the present invention are used to explain the present invention, but are not intended to limit the present invention. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0086] Figure 1 This is a flowchart illustrating a method for determining casing construction parameters for ultra-deep well pressure control and speed-up according to an embodiment of the present invention, as shown below. Figure 1 As shown in the embodiment of the present invention, the method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation includes:

[0087] Step S1: Obtain the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling base data, and obtain the low-density drilling fluid density based on the original drilling fluid density.

[0088] Step S2: Determine the amount of low-density drilling fluid to be used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well; and determine the amount of weighted drilling fluid to be used based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0089] Step S3: Determine the drilling fluid circulation speed during drilling as the injection speed, and determine the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing and the safe pressure window.

[0090] In step S1 above, the device obtains the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling foundation data, and obtains the density of the low-density drilling fluid based on the original drilling fluid density. The device can be a computer device that executes this method. The acquisition, storage, use, and processing of data in this application's technical solution all comply with relevant regulations. The casing running speed can be set according to construction needs, and can be selected as 0.3 m / s; the casing running acceleration can also be set according to construction needs, and can be selected as 0.06 m / s. 2 .

[0091] The drilling basic data includes many data items, which will be described in detail in subsequent embodiments.

[0092] The maximum excitation pressure during casing installation refers to the maximum instantaneous increase in well pressure caused by rapid casing movement or obstruction of drilling fluid flow during casing installation.

[0093] The process of obtaining the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling baseline data includes:

[0094] The resistance generated by the drilling fluid network structure is calculated based on the drilling foundation data.

[0095] The frictional resistance generated by the drilling fluid flow caused by the discharge of annular fluid is calculated based on the casing speed and the drilling foundation data.

[0096] The inertial force caused by the change in casing velocity is calculated based on the casing acceleration and the drilling foundation data.

[0097] The maximum value among the resistance, frictional resistance, and inertial force is taken as the maximum activation pressure of the casing. Alternatively, starting from the casing installation, the activation pressure can be calculated based on the current downhole data at regular intervals or at intervals, and the maximum pressure among all calculated activation pressures can be selected as the maximum activation pressure of the casing.

[0098] The drilling baseline data includes drilling fluid static shear force, well depth, annular outer diameter, and annular inner diameter; correspondingly, the resistance generated by the drilling fluid network structure calculated based on the drilling baseline data includes:

[0099] The resistance is calculated using the following formula:

[0100]

[0101] Where p1 is the resistance generated by the drilling fluid network structure, τ w τ is the static shear force of the drilling fluid, H is the well depth, D is the outer diameter of the annulus, and d is the inner diameter of the annulus. p1 is the resistance generated by the drilling fluid network structure, in MPa; τ w H is the static shear force of the drilling fluid, in Pa; H is the well depth, in m; D is the outer diameter of the annulus, in m; d is the inner diameter of the annulus, in m.

[0102] like Figure 2 As shown, the resistance generated by the drilling fluid mesh structure disappears after the drilling fluid flows. However, for safety reasons, an overestimation method is used, assuming that this force exists continuously during casing installation, and the maximum value of the three pressures is taken.

[0103] The drilling baseline data includes fluid flow state, original drilling fluid consistency coefficient, well depth, original drilling fluid flowability index, annular outer diameter, and annular inner diameter; correspondingly, the frictional resistance generated by the drilling fluid flow caused by the discharged annular fluid, calculated based on the casing running speed and the drilling baseline data, includes:

[0104] The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter.

[0105] If the fluid flow state is determined to be laminar flow, the frictional resistance is calculated based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus.

[0106] The calculation of the annular return speed based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter includes:

[0107] The annular return velocity is calculated using the following formula:

[0108]

[0109] Among them, V a It is the circular return speed, V p V is the casing speed, D is the annular outer diameter, and d is the annular inner diameter. a It is the annular return velocity, in m / s; V p1 is the casing speed, in m / s; D is the annular outer diameter, in m; d is the annular inner diameter, in m.

[0110] In addition to the formulas mentioned above, the annular return velocity can also be obtained through actual measurements, or the specific coefficients in the formulas can be adjusted according to the actual conditions of ultra-deep wells. No restrictions are imposed here.

[0111] The frictional resistance is calculated based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus, including:

[0112] The frictional resistance is calculated using the following formula:

[0113]

[0114] Where p2 is the frictional resistance, K is the original drilling fluid consistency coefficient, H is the well depth, n is the original drilling fluid flowability index, and V is the original drilling fluid fluid viscosity coefficient. a It is the annular return velocity, D is the outer diameter of the annular space, and d is the inner diameter of the annular space.

[0115] Where p2 is the frictional resistance generated by the flow of drilling fluid due to the discharge of annular fluid, in MPa; K is the original drilling fluid consistency coefficient, in Pa·s. n H is the well depth in meters (m); n is the original drilling fluid flowability index, which is dimensionless; V a is the annular return velocity, in m / s; D is the outer diameter of the annular cavity, in m; d is the inner diameter of the annular cavity, in m.

[0116] The drilling baseline data includes fluid flow state, drilling fluid friction coefficient, original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the frictional resistance generated by the drilling fluid flow caused by the discharged annular fluid, calculated based on the casing running speed and the drilling baseline data, includes:

[0117] The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0118] If the fluid flow state is determined to be turbulent, the frictional resistance is calculated based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus. The calculation of the frictional resistance based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus includes:

[0119] The frictional resistance is calculated using the following formula:

[0120]

[0121] Where p2 is the frictional resistance, H is the well depth, and V is the frictional resistance. a ρ is the annular return velocity, D is the outer diameter of the annulus, d is the inner diameter of the annulus, f is the drilling fluid friction coefficient, and ρ is the annular return velocity. 原 It is the original drilling fluid density.

[0122] Where p2 is the frictional resistance generated by the flow of drilling fluid due to the discharge of annular fluid, in MPa; H is the well depth, in m; V a ρ is the annular return velocity, in m / s; D is the annular outer diameter, in m; d is the annular inner diameter, in m; f is the drilling fluid friction coefficient, dimensionless; ρ 原 This is the original drilling fluid density, in kg / m³. 3 .

[0123] The drilling baseline data includes the original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the inertial force caused by the change in casing velocity calculated based on the casing acceleration and the drilling baseline data includes:

[0124] The inertial force is calculated using the following formula:

[0125]

[0126] Where p3 is the inertial force, ρ 原 H is the original drilling fluid density, D is the well depth, d is the annulus outer diameter, d is the annulus inner diameter, and a is the casing running acceleration.

[0127] Where p3 is the inertial force caused by the change in casing velocity, with units of MPa; ρ 原 This is the original drilling fluid density, in kg / m³. 3 H is the well depth in meters (m); D is the outer diameter of the annulus in meters (m); d is the inner diameter of the annulus in meters (m); a is the casing acceleration in meters per second (m / s²). 2 .

[0128] The process of obtaining the low-density drilling fluid density based on the original drilling fluid density includes:

[0129] The decrease in drilling fluid density is determined based on the original drilling fluid density and the preset correspondence.

[0130] The preset correspondence is the relationship between the preset original drilling fluid density and the preset decrease in drilling fluid density. Specifically, the preset correspondence can be a curve representing the relationship between the preset original drilling fluid density and the preset decrease in drilling fluid density. The preset original drilling fluid density and the preset decrease in drilling fluid density show a positive correlation, and the preset decrease in drilling fluid density can range from a preset range of 200 to 400 kg / m³.3 The value is taken from the data range, assuming the original drilling fluid density is preset to 2000 kg / m³. 3 The corresponding preset drilling fluid density reduction value is 300 kg / m³. 3 If the original drilling fluid density is preset to 3300 kg / m³ 3 The corresponding preset drilling fluid density reduction value is 350 kg / m³. 3 In this embodiment of the invention, the original drilling fluid density is 2000 kg / m³. 3 For example, the corresponding value for the decrease in drilling fluid density is determined to be 300 kg / m³. 3 .

[0131] The difference between the original drilling fluid density and the decrease in drilling fluid density is taken as the density of the low-density drilling fluid. Referring to the example above, the density of the low-density drilling fluid is 1700 kg / m³. 3 .

[0132] like Figure 3 As shown, low drilling fluid density is positively correlated with annular height. Therefore, annular pressure can be reduced directly by decreasing drilling fluid density. The reduction in annular pressure is directly proportional to the height of the low-density drilling fluid in the annulus (i.e., annular height) and inversely proportional to the density of the low-density drilling fluid. To ensure that the wellbore fluid column pressure is reduced to the target value, the height of the low-density drilling fluid in the annulus is directly proportional to its density; that is, the higher the density of the low-density drilling fluid, the higher its annular height. It should be noted that wellbore fluid column pressure is a fundamental component of annular pressure, but annular pressure also includes additional pressure under dynamic operating conditions.

[0133] Before the step of obtaining the low-density drilling fluid density based on the original drilling fluid density, the method for determining the casing installation parameters for ultra-deep well controlled pressure and accelerated installation further includes:

[0134] If it is determined that the maximum excitation pressure of the casing is greater than the safe pressure window of the ultra-deep well, then the steps of obtaining the low-density drilling fluid density based on the original drilling fluid density and subsequent steps are executed.

[0135] The safe pressure window can be obtained by subtracting the formation fracture pressure from the formation pore pressure. When the maximum excitation pressure of the casing is greater than the safe pressure window of the ultra-deep well, it means that the excitation pressure generated by the casing at the current rate is greater than the formation fracture pressure, which may lead to well leakage. In this case, the drilling fluid density can be reduced to decrease the bottom hole pressure and thus avoid well leakage.

[0136] The density of the low-density drilling fluid refers to the density of the drilling fluid used during subsequent casing installation, while the density of the original drilling fluid refers to the density of the currently used drilling fluid. The replacement of the original drilling fluid with the low-density drilling fluid is a gradual process. The maximum excitation pressure and the size of the safe pressure window during casing installation can control and prevent well leakage. The outer and inner diameters of the annulus in ultra-deep wells can characterize the amount of drilling fluid used downhole.

[0137] In step S2 above, the device determines the amount of low-density drilling fluid to be used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. It also determines the amount of weighted drilling fluid to be used based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0138] Ultra-deep wells refer to oil and gas wells with depths exceeding a certain standard (usually 8,000 meters or more). These wells are unique due to their great depth, complex geological conditions, and high technical difficulty.

[0139] The safe pressure window refers to the permissible range of fluid pressure within the wellbore between pore pressure and fracture pressure. Pore pressure refers to the pressure of fluids within the formation pores. If the drilling fluid pressure is below this value, formation fluids may enter the wellbore, causing a well kick or blowout. Fracture pressure, on the other hand, is the maximum pressure the formation can withstand. If the total downhole operating pressure exceeds this value, it can lead to formation fracturing, drilling fluid loss, and potentially wellbore collapse or stuck pipe.

[0140] The safe pressure window and the maximum activation pressure of the casing can be calculated from data in relevant ultra-deep well documentation, or directly obtained from data already acquired by on-site personnel to improve the efficiency of obtaining these parameters. The specific methods for obtaining these parameters are not limited here.

[0141] The determination of the low-density drilling fluid dosage based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safe pressure window for ultra-deep wells includes:

[0142] The dosage of the low-density drilling fluid is calculated using the following formula:

[0143]

[0144] Among them, V 低 This refers to the dosage of low-density drilling fluid, where D is the outer diameter of the annulus, d is the inner diameter of the annulus, and p... max It is the maximum excitation pressure of the lower casing, p 窗口 It is the aforementioned safety pressure window, ρ 原It is the original drilling fluid density, ρ 低 ρ is the density of low-density drilling fluid, and g is the acceleration due to gravity.

[0145] Among them, V 低 This refers to the dosage of low-density drilling fluid, measured in cubic meters (m³). 3 D is the outer diameter of the annulus, in meters (m); d is the inner diameter of the annulus, in meters (m); p max This is the maximum excitation pressure of the lower casing, in MPa; p 窗口 This refers to the size of the safety pressure window, measured in MPa; ρ 原 This is the original drilling fluid density, in kg / m³. 3 ;ρ 低 It is the density of low-density drilling fluid, with units of kg / m³. 3 .

[0146] Weighted drilling fluid is a type of drilling fluid whose density is increased by adding high-density materials (such as barite, hematite, etc.). It is used to balance or control downhole formation pressure and prevent well kicks, blowouts, or wellbore instability.

[0147] In order to control formation pressure, stabilize the wellbore, carry cuttings, cool and lubricate the drill bit, provide buoyancy, adapt to complex formations, and protect the environment, and to ensure the safety and efficiency of drilling operations, weighted drilling fluid is also required in the wellbore.

[0148] The step of determining the amount of weighted drilling fluid to be used based on the density of the weighted drilling fluid, the density of the original drilling fluid, the maximum excitation pressure of the casing, and the basic drilling data includes:

[0149] The amount of weighted drilling fluid used is calculated using the following formula:

[0150]

[0151] Among them, V 加重 It increases the amount of drilling fluid used, D is the outer diameter of the annulus, d is the inner diameter of the annulus, and ρ is the weighting fluid usage. 加重 It increases the density of the drilling fluid, ρ 原 ρ is the original drilling fluid density, and g is the acceleration due to gravity.

[0152] Among them, V 加重 This refers to the amount of drilling fluid used, measured in cubic meters (m³). 3 D is the outer diameter of the annulus, in meters (m); d is the inner diameter of the annulus, in meters (m); ρ 加重 It increases the density of the drilling fluid, measured in kg / m³. 3 ;ρ 原 This is the original drilling fluid density, in kg / m³. 3 .

[0153] like Figure 4As shown, as the low-density drilling fluid is injected into the annulus, the weighted drilling fluid is also injected into the bottom of the drill pipe, but the drill pipe and the upper part of the annulus are still filled with the original drilling fluid.

[0154] In step S3 above, the device determines the drilling fluid circulation speed during drilling as the injection speed, and determines the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0155] The injection rate can be selected as the drilling fluid circulation rate during drilling. It can also be accelerated based on the original drilling fluid circulation rate to improve the efficiency of casing installation.

[0156] The determination of the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window includes:

[0157] The difference between the maximum activation pressure of the lower bushing and the safe pressure window is taken as the maximum control pressure value during the pump shutdown period.

[0158] The determination of the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window includes:

[0159] The maximum excitation pressure of the lower sleeve is negativeed, and the negative value of the maximum excitation pressure of the lower sleeve is taken as the left endpoint value of the safety fluctuation range.

[0160] The difference between the maximum excitation pressure of the lower casing and the safety pressure window is taken as the right endpoint value of the safety fluctuation range.

[0161] Injection rate and injection pump pressure refer to the speed and pump pressure used when low-density drilling fluid is injected into the annulus to replace the original drilling fluid.

[0162] When determining the injection rate, the original drilling fluid circulation rate can be used, which allows for seamless connection between the injection of low-density drilling fluid and the circulation of the original drilling fluid, thereby improving the injection efficiency of low-density drilling fluid, which in turn improves the drilling fluid density reduction efficiency, improves the efficiency of determining casing installation parameters, and further improves casing installation efficiency.

[0163] When determining the injection pump pressure, it is necessary to adjust accordingly based on the fluid performance parameters within the wellbore, ensuring that fluctuations remain within safe limits to prevent well leakage or overflow. Fluid performance parameters can include viscosity, density, and rheological properties. Specifically, high-viscosity fluids require higher pump pressures. High-density fluids generate greater hydrostatic pressure. The rheological properties of the fluid affect flow resistance and the required pump pressure. As low-density drilling fluid is injected into the wellbore, the fluid performance parameters of the mixture of the original drilling fluid and the low-density drilling fluid continuously change. Determining the injection pump pressure in real-time or repeatedly based on these changing fluid performance parameters enables precise injection of low-density drilling fluid, improving casing speed while effectively preventing well leakage or overflow.

[0164] The pump shutdown pressure control value (i.e. the maximum pressure control value during pump shutdown) refers to the pressure value that needs to be maintained at the wellhead or bottom of the well after the pump is shut down during drilling, completion or fracturing operations, in order to ensure wellbore stability and prevent formation fluid intrusion or blowout.

[0165] When determining the pump shutdown control pressure value, it can be based on the previously determined maximum activation pressure of the lower bushing and the safety pressure window. The higher the maximum activation pressure of the lower bushing, the higher the pump shutdown control pressure value. The larger the safety pressure window, the lower the pump shutdown control pressure value. The specific calculation method for determining the pump shutdown control pressure value based on this relationship can be adjusted according to actual needs, and is not limited here.

[0166] The density of low-density drilling fluid, the amount of low-density drilling fluid used, the amount of weighted drilling fluid used, the injection rate, the safe fluctuation range of the injection pump pressure, and the maximum controlled pressure value during pump shutdown can be used as parameters for casing installation. For example... Figure 4 As shown, during casing installation, a low-density drilling fluid is first obtained based on a determined low-density drilling fluid density. Then, the low-density drilling fluid is injected into the wellbore at a determined volume, following a predetermined injection rate and pump pressure. Simultaneously, a weighting drilling fluid is injected at a determined volume, also following a determined injection rate and pump pressure. Finally, after the low-density drilling fluid injection is complete, pressure is controlled at the wellhead according to the determined maximum pressure control value during pump shutdown.

[0167] This invention's method, based on the maximum activation pressure during casing runs, determines when lost circulation is likely. It directly reduces the density of the drilling fluid from the original density, achieving a rapid decrease. Furthermore, by combining the low-density drilling fluid density, the original drilling fluid density, the maximum activation pressure during casing runs, the size of the safety pressure window, and the outer and inner diameters of the annulus in ultra-deep wells, it accurately and quickly determines the amount of low-density drilling fluid to be used. Corresponding adjustments are made to casing run parameters such as the weighted drilling fluid usage, injection rate, injection pump pressure, and pump shutdown control value. This allows for an increase in casing run speed from the previously slow speed, even reaching the ideal design speed, while preventing lost circulation. It provides a simple and convenient way to accelerate casing run in ultra-deep wells while ensuring downhole safety.

[0168] The method for determining the casing construction parameters for ultra-deep well pressure-controlled and accelerated installation provided in this embodiment of the invention is further illustrated by the following examples:

[0169] Well A is an ultra-deep well in marine carbonate rock formation. Due to its narrow safety density window, the casing running speed, designed using conventional methods, was too slow to avoid well leakage during casing running, severely impacting the well's drilling progress. According to requirements, the maximum casing running speed needs to be increased to 0.3 m / s and the acceleration to 0.06 m / s² when the casing reaches the bottom of the well. 2 .

[0170] 1. First, find the relevant data for this well: The well depth is 7000m, the outer diameter of the annulus is 0.2413m, the inner diameter of the annulus is 0.2m, the formation pore pressure is 140MPa, the formation fracturing pressure is 145MPa, and the original drilling fluid density is 2000kg / m³. 3 The original drilling fluid consistency coefficient was 0.63 Pa·s n The original drilling fluid flowability index was 0.54, the static shear stress was 1.5 Pa, and the density of the weighted drilling fluid was 2400 kg / m³. 3 Increase drilling fluid pressure p 加重 It must be the same as the maximum excitation pressure of the lower casing.

[0171] 2. Based on the data retrieved, calculate the safety pressure window and the maximum excitation pressure of the lower casing.

[0172] The safe pressure window is:

[0173] p 窗口 =145-140×5MPa.

[0174] The circum-return speed is:

[0175]

[0176] The resistance generated by the drilling fluid mesh structure is:

[0177]

[0178] The frictional resistance generated by the drilling fluid flow due to the discharge of annular fluid is:

[0179]

[0180] The inertial force caused by the change in casing velocity is calculated as follows:

[0181]

[0182] Therefore, the maximum activation pressure of the casing is 8.35 MPa. Since the maximum activation pressure of the casing is greater than the safe pressure window, it is necessary to design the density and quantity of low-density drilling fluid.

[0183] 3. Calculate the parameters of low-density drilling fluid.

[0184] The density of low-density drilling fluid is:

[0185] ρ 低 =2000-300=1700kg / m 3 .

[0186] The dosage of low-density drilling fluid is:

[0187]

[0188] 4. Calculate other parameters related to construction.

[0189] The dosage of weighted drilling fluid is:

[0190]

[0191] Injection rate is the drilling fluid circulation rate during drilling.

[0192] The injection pump pressure is within a safe fluctuation range of -8.35MPa to 3.35MPa.

[0193] The maximum pressure control value during pump shutdown is: p b =8.35-5=3.35MPa.

[0194] In summary, to achieve a casing running speed of 0.3 m / s at the bottom of the well, the following construction parameters were determined: the injection rate was determined based on the drilling fluid circulation speed during drilling, and the density of the low-density drilling fluid was 1700 kg / m³. 3 The low-density drilling fluid usage is 16.30m³. 3 The density of the weighted drilling fluid is 2400 kg / m³. 3 The amount of weighted drilling fluid used was 30.49m³. 3The safe fluctuation range of the injection pump pressure is -8.35MPa to 3.35MPa, and the maximum pressure control value during pump shutdown is 3.35MPa. Therefore, the casing is installed according to the above design and construction plan.

[0195] The method for determining the parameters of casing running in ultra-deep wells with controlled pressure and accelerated operation provided in this invention obtains the maximum activation pressure of the casing running based on the casing running speed, casing running acceleration, and drilling foundation data, and obtains the density of the low-density drilling fluid based on the original drilling fluid density; determines the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum activation pressure of the casing running, the drilling foundation data, and the safe pressure window of the ultra-deep well; and determines the amount of weighting drilling fluid used based on the density of the weighting drilling fluid, the original drilling fluid density, the maximum activation pressure of the casing running, and the drilling foundation data; determines the drilling fluid circulation speed during drilling as the injection speed; and determines the maximum controlled pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the casing running and the safe pressure window, respectively. This method allows for casing running at a normal speed while avoiding induced well leakage, and is easy to operate.

[0196] Furthermore, the step of obtaining the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling baseline data includes:

[0197] The resistance generated by the drilling fluid network structure is calculated based on the drilling foundation data; the above embodiments can be referred to for explanation, and will not be repeated here.

[0198] The frictional resistance generated by the drilling fluid flow caused by the discharge of annular fluid is calculated based on the casing speed and the drilling foundation data; the above embodiments can be referred to for explanation, and will not be repeated here.

[0199] The inertial force caused by the change in casing velocity is calculated based on the casing acceleration and the drilling foundation data; the above embodiments can be referred to for explanation, and will not be repeated here.

[0200] The maximum value among the resistance force, the frictional resistance, and the inertial force is taken as the maximum excitation pressure of the lower sleeve. This can be referred to the above embodiment for further explanation, and will not be repeated here.

[0201] Furthermore, the drilling baseline data includes drilling fluid static shear force, well depth, annular outer diameter, and annular inner diameter; correspondingly, the resistance force generated by the drilling fluid network structure calculated based on the drilling baseline data includes:

[0202] The resistance is calculated using the following formula:

[0203]

[0204] Where p1 is the resistance generated by the drilling fluid network structure, τw H is the static shear force of the drilling fluid, D is the well depth, and d is the outer diameter of the annulus and the inner diameter of the annulus. Refer to the above examples for further details.

[0205] Further, the drilling baseline data includes fluid flow state, original drilling fluid consistency coefficient, well depth, original drilling fluid flowability index, annular outer diameter, and annular inner diameter; correspondingly, the calculation of the frictional resistance generated by the drilling fluid flow due to the discharge of annular fluid based on the casing running speed and the drilling baseline data includes:

[0206] The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0207] If the fluid flow state is determined to be laminar, the frictional resistance is calculated based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus. This can be referred to the above embodiments for further explanation and will not be repeated here.

[0208] Further, the step of calculating the annular return speed based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter includes:

[0209] The annular return velocity is calculated using the following formula:

[0210]

[0211] Among them, V a It is the circular return speed, V p Where D is the casing speed, D is the outer diameter of the annulus, and d is the inner diameter of the annulus. Refer to the above embodiments for further details; they will not be repeated here.

[0212] Further, the calculation of the frictional resistance based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus includes:

[0213] The frictional resistance is calculated using the following formula:

[0214]

[0215] Where p2 is the frictional resistance, K is the original drilling fluid consistency coefficient, H is the well depth, n is the original drilling fluid flowability index, and V is the original drilling fluid fluid viscosity coefficient. a Where D is the annular return velocity, d is the outer diameter of the annular cavity, and d is the inner diameter of the annular cavity. Refer to the above embodiments for further explanation; details will not be repeated here.

[0216] Further, the drilling baseline data includes fluid flow state, drilling fluid friction coefficient, original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the calculation of the frictional resistance generated by the drilling fluid flow due to the discharge of annular fluid based on the casing running speed and the drilling baseline data includes:

[0217] The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter; this can be referred to the above embodiment for explanation, and will not be repeated here.

[0218] If the fluid flow state is determined to be turbulent, the frictional resistance is calculated based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus. This can be referred to the above embodiments for further explanation and will not be repeated here.

[0219] Further, the calculation of the frictional resistance based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus includes:

[0220] The frictional resistance is calculated using the following formula:

[0221]

[0222] Where p2 is the frictional resistance, H is the well depth, and V is the frictional resistance. a ρ is the annular return velocity, D is the outer diameter of the annulus, d is the inner diameter of the annulus, f is the drilling fluid friction coefficient, and ρ is the annular return velocity. 原 This refers to the original drilling fluid density. Please refer to the above examples for further details; further explanation is unnecessary.

[0223] Furthermore, the drilling baseline data includes the original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the calculation of the inertial force caused by the casing velocity change based on the casing acceleration and the drilling baseline data includes:

[0224] The inertial force is calculated using the following formula:

[0225]

[0226] Where p3 is the inertial force, ρ 原 Where H is the original drilling fluid density, D is the well depth, d is the annulus outer diameter, d is the annulus inner diameter, and a is the casing running acceleration. Refer to the above examples for further details.

[0227] Furthermore, the process of obtaining the low-density drilling fluid density based on the original drilling fluid density includes:

[0228] The decrease in drilling fluid density is determined based on the original drilling fluid density and the preset correspondence; this can be referred to the above embodiments for explanation, and will not be repeated here.

[0229] The preset correspondence is the correspondence between the preset original drilling fluid density and the preset decrease value of drilling fluid density; this can be referred to the above embodiments for explanation, and will not be repeated here.

[0230] The difference between the original drilling fluid density and the decrease in drilling fluid density is taken as the density of the low-density drilling fluid. This can be referred to the above embodiments for further explanation, and will not be repeated here.

[0231] Further, determining the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safe pressure window for ultra-deep wells includes:

[0232] The dosage of the low-density drilling fluid is calculated using the following formula:

[0233]

[0234] Among them, V 低 This refers to the dosage of low-density drilling fluid, where D is the outer diameter of the annulus, d is the inner diameter of the annulus, and p... max It is the maximum excitation pressure of the lower casing, p 窗口 It is the aforementioned safety pressure window, ρ 原 It is the original drilling fluid density, ρ 低 Where is the density of the low-density drilling fluid, and g is the acceleration due to gravity. Refer to the above examples for further details; they will not be repeated here.

[0235] Further, determining the amount of weighted drilling fluid used based on the density of the weighted drilling fluid, the density of the original drilling fluid, the maximum excitation pressure of the casing, and the basic drilling data includes:

[0236] The amount of weighted drilling fluid used is calculated using the following formula:

[0237]

[0238] Among them, V 加重 It increases the amount of drilling fluid used, D is the outer diameter of the annulus, d is the inner diameter of the annulus, and ρ is the weighting fluid usage. 加重 It increases the density of the drilling fluid, ρ 原 Where is the original drilling fluid density, and g is the acceleration due to gravity. Refer to the above examples for further details; they will not be repeated here.

[0239] Further, determining the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window respectively includes:

[0240] The difference between the maximum activation pressure of the lower bushing and the safety pressure window is used as the maximum control pressure value during the pump shutdown period. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0241] Further, determining the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window respectively includes:

[0242] The maximum excitation pressure of the lower sleeve is negativeed, and the negative value of the maximum excitation pressure of the lower sleeve is taken as the left endpoint value of the safe fluctuation range; the above embodiment can be referred to for explanation, and will not be repeated here.

[0243] The difference between the maximum excitation pressure of the lower bushing and the safety pressure window is taken as the right endpoint value of the safety fluctuation range. This can be referred to the above embodiment for explanation, and will not be repeated here.

[0244] Furthermore, prior to the step of obtaining the low-density drilling fluid density based on the original drilling fluid density, the method for determining the casing construction parameters for ultra-deep well pressure-controlled acceleration also includes:

[0245] If it is determined that the maximum excitation pressure of the casing is greater than the safe pressure window for ultra-deep wells, then the steps of obtaining the low-density drilling fluid density based on the original drilling fluid density and subsequent steps are executed. Refer to the above embodiments for further details.

[0246] Figure 5 This is a schematic diagram of the device for determining the casing construction parameters for ultra-deep well pressure control and speed-up according to an embodiment of the present invention, as shown below. Figure 5 As shown, the device for determining the parameters of ultra-deep well casing construction with controlled pressure and accelerated speed-up provided in this embodiment of the invention includes an acquisition unit 501, a first determination unit 502, and a second determination unit 503, wherein:

[0247] The acquisition unit 501 is used to acquire the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling basic data, and to obtain the low-density drilling fluid density based on the original drilling fluid density; the first determination unit 502 is used to determine the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling basic data, and the safety pressure window for ultra-deep wells, and to determine the amount of weighting drilling fluid used based on the weighting drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling basic data; the second determination unit 503 is used to determine the drilling fluid circulation speed during drilling as the injection speed, and to determine the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing and the safety pressure window, respectively.

[0248] Specifically, the acquisition unit 501 in the device is used to acquire the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling basic data, and to obtain the low-density drilling fluid density based on the original drilling fluid density; the first determination unit 502 is used to determine the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling basic data, and the safety pressure window for ultra-deep wells, and to determine the amount of weighting drilling fluid used based on the weighting drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling basic data; the second determination unit 503 is used to determine the drilling fluid circulation speed during drilling as the injection speed, and to determine the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing and the safety pressure window, respectively.

[0249] The device for determining the parameters of casing running in ultra-deep wells with controlled pressure and accelerated operation provided in this invention obtains the maximum excitation pressure of the casing running based on the casing running speed, casing running acceleration, and drilling foundation data, and obtains the density of the low-density drilling fluid based on the original drilling fluid density; it determines the amount of low-density drilling fluid used based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing running, the drilling foundation data, and the safe pressure window of the ultra-deep well; it also determines the amount of weighting drilling fluid used based on the density of the weighting drilling fluid, the original drilling fluid density, the maximum excitation pressure of the casing running, and the drilling foundation data; it determines the drilling fluid circulation speed during drilling as the injection speed; and it determines the maximum controlled pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing running and the safe pressure window, respectively. This device enables casing running at a normal speed while avoiding induced well leakage, and is easy to operate.

[0250] The embodiments of the present invention provide a device for determining the construction parameters of casing in ultra-deep wells with controlled pressure and accelerated speed. Specifically, it can be used to execute the processing flow of the above-described method embodiments. Its functions will not be repeated here, but can be referred to the detailed description of the above-described method embodiments.

[0251] Figure 6 This is a schematic diagram of the physical structure of a computer device provided in an embodiment of the present invention, such as... Figure 6 As shown, the computer device includes: a memory 601, a processor 602, and a computer program stored in the memory 601 and executable on the processor 602. When the processor 602 executes the computer program, it implements the following method:

[0252] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0253] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0254] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0255] This embodiment discloses a computer program product, which includes a computer program that, when executed by a processor, implements the following method:

[0256] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0257] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0258] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0259] This embodiment provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the following method:

[0260] The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density.

[0261] The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data.

[0262] The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively.

[0263] Compared with existing technologies, the method for determining casing installation parameters for controlled pressure and accelerated drilling in ultra-deep wells provided by this invention obtains the maximum activation pressure of the casing based on the casing installation speed, casing installation acceleration, and drilling foundation data, and obtains the density of the low-density drilling fluid based on the original drilling fluid density. The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum activation pressure of the casing, the drilling foundation data, and the safe pressure window for ultra-deep wells. The amount of weighting drilling fluid used is also determined based on the density of the weighting drilling fluid, the original drilling fluid density, the maximum activation pressure of the casing, and the drilling foundation data. The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum controlled pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown are determined based on the maximum activation pressure of the casing and the safe pressure window, respectively. This method allows for casing installation at a normal speed while avoiding induced well leakage, and is easy to operate.

[0264] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied 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.

[0265] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0266] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0267] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0268] In the description of this specification, the references to terms such as "an embodiment," "a specific embodiment," "some embodiments," "for example," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0269] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for determining the parameters of casing installation in ultra-deep wells with controlled pressure and accelerated installation, characterized in that, include: The maximum excitation pressure of the casing is obtained based on the casing running speed, casing running acceleration and drilling base data, and the density of the low-density drilling fluid is obtained based on the original drilling fluid density. The amount of low-density drilling fluid used is determined based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safety pressure window of the ultra-deep well. The amount of weighted drilling fluid used is determined based on the weighted drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling baseline data. The drilling fluid circulation speed during drilling is determined as the injection speed. The maximum control pressure value during pump shutdown and the safe fluctuation range of the injection pump pressure are determined based on the maximum excitation pressure of the casing and the safe pressure window, respectively. The process of obtaining the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration, and drilling baseline data includes: The resistance generated by the drilling fluid network structure is calculated based on the drilling foundation data. The frictional resistance generated by the drilling fluid flow caused by the discharge of annular fluid is calculated based on the casing speed and the drilling foundation data. The inertial force caused by the change in casing velocity is calculated based on the casing acceleration and the drilling foundation data. The maximum value among the resistance, frictional resistance, and inertial force is taken as the maximum excitation pressure of the lower sleeve; The determination of the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum activation pressure of the lower bushing and the safe pressure window includes: The difference between the maximum excitation pressure of the lower bushing and the safety pressure window is taken as the maximum control pressure value during the pump shutdown period; The maximum excitation pressure of the lower sleeve is negativeed, and the negative value of the maximum excitation pressure of the lower sleeve is taken as the left endpoint value of the safety fluctuation range. The difference between the maximum excitation pressure of the lower sleeve and the safety pressure window is taken as the right endpoint value of the safety fluctuation range. Before the step of obtaining the low-density drilling fluid density based on the original drilling fluid density, the method for determining the casing installation parameters for ultra-deep well controlled pressure and accelerated installation further includes: If it is determined that the maximum excitation pressure of the casing is greater than the safe pressure window of the ultra-deep well, then the steps of obtaining the low-density drilling fluid density based on the original drilling fluid density and subsequent steps are executed.

2. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 1, characterized in that, The drilling baseline data includes drilling fluid static shear force, well depth, annular outer diameter, and annular inner diameter; correspondingly, the resistance force generated by the drilling fluid network structure calculated based on the drilling baseline data includes: The resistance is calculated using the following formula: ； in, p 1 is the resistance generated by the drilling fluid network structure. τ w It is the static shear force of the drilling fluid. H It is a deep well. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus.

3. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 1, characterized in that, The drilling baseline data includes fluid flow state, original drilling fluid consistency coefficient, well depth, original drilling fluid flowability index, annular outer diameter, and annular inner diameter; correspondingly, the frictional resistance generated by the drilling fluid flow caused by the discharged annular fluid, calculated based on the casing running speed and the drilling baseline data, includes: The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter. If the fluid flow state is determined to be laminar flow, the frictional resistance is calculated based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus.

4. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 3, characterized in that, The calculation of the annular return speed based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter includes: The annular return velocity is calculated using the following formula: ； in, V a It is a circular return velocity. V p It is the casing speed. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus.

5. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 3, characterized in that, The frictional resistance is calculated based on the annular return velocity, the original drilling fluid consistency coefficient, the well depth, the original drilling fluid flowability index, the outer diameter of the annulus, and the inner diameter of the annulus, including: The frictional resistance is calculated using the following formula: ； in, p 2 is the frictional resistance, K It is the original drilling fluid consistency coefficient. H It is a deep well. n It is the original drilling fluid flowability index. V a It is a circular return velocity. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus.

6. The method for determining the casing construction parameters for ultra-deep well pressure-controlled and speed-up construction according to any one of claims 1 to 5, characterized in that, The drilling baseline data includes fluid flow state, drilling fluid friction coefficient, original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the frictional resistance generated by the drilling fluid flow caused by the discharged annular fluid, calculated based on the casing running speed and the drilling baseline data, includes: The annular return speed is calculated based on the lower sleeve speed, the annular outer diameter, and the annular inner diameter. If the fluid flow state is determined to be turbulent, the frictional resistance is calculated based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus.

7. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 6, characterized in that, The frictional resistance is calculated based on the annular return velocity, the drilling fluid friction coefficient, the original drilling fluid density, the well depth, the outer diameter of the annulus, and the inner diameter of the annulus, including: The frictional resistance is calculated using the following formula: ； in, p 2 is the frictional resistance, H It is a deep well. V a It is a circular return velocity. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus. f It is the drilling fluid friction coefficient. ρ 原 It is the original drilling fluid density.

8. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 1, characterized in that, The drilling baseline data includes the original drilling fluid density, well depth, annular outer diameter, and annular inner diameter; correspondingly, the inertial force caused by the change in casing velocity calculated based on the casing acceleration and the drilling baseline data includes: The inertial force is calculated using the following formula: ； in, p 3 is the inertial force mentioned above. ρ 原 It is the original drilling fluid density ，H It is a deep well. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus. a It is the acceleration of the lower casing.

9. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated installation according to claim 1, characterized in that, The process of obtaining the low-density drilling fluid density based on the original drilling fluid density includes: The decrease in drilling fluid density is determined based on the original drilling fluid density and the preset correspondence. The preset correspondence is the correspondence between the preset original drilling fluid density and the preset decrease value of drilling fluid density; The difference between the original drilling fluid density and the decrease in drilling fluid density is taken as the density of the low-density drilling fluid.

10. The method for determining the casing construction parameters for ultra-deep well pressure-controlled and speed-up casing installation according to claim 1, characterized in that, The determination of the low-density drilling fluid dosage based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling baseline data, and the safe pressure window for ultra-deep wells includes: The dosage of the low-density drilling fluid is calculated using the following formula: ； in, V 低 This refers to the dosage of low-density drilling fluid. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus. p max It is the maximum excitation pressure of the lower casing. p 窗口 This is the aforementioned safety pressure window. ρ 原 It is the original drilling fluid density. ρ 低 ρ is the density of low-density drilling fluid, and g is the acceleration due to gravity.

11. The method for determining the casing construction parameters for ultra-deep wells with controlled pressure and accelerated speed-up as described in claim 1, characterized in that, The step of determining the amount of weighted drilling fluid to be used based on the density of the weighted drilling fluid, the density of the original drilling fluid, the maximum excitation pressure of the casing, and the basic drilling data includes: The amount of weighted drilling fluid used is calculated using the following formula: ； in, V 加重 It increases the amount of drilling fluid used. D It is the outer diameter of the annulus. d It is the inner diameter of the annulus. ρ 加重 It increases the density of the drilling fluid. ρ 原 ρ is the original drilling fluid density, and g is the acceleration due to gravity.

12. A device for determining the parameters of casing construction in ultra-deep wells with controlled pressure and accelerated speed, characterized in that, include: The acquisition unit is used to obtain the maximum excitation pressure of the casing based on the casing running speed, casing running acceleration and drilling base data, and to obtain the density of the low-density drilling fluid based on the original drilling fluid density. The first determining unit is used to determine the amount of low-density drilling fluid based on the original drilling fluid density, the low-density drilling fluid density, the maximum excitation pressure of the casing, the drilling base data, and the safety pressure window of the ultra-deep well; and to determine the amount of weighting drilling fluid based on the weighting drilling fluid density, the original drilling fluid density, the maximum excitation pressure of the casing, and the drilling base data. The second determining unit is used to determine the drilling fluid circulation speed during drilling as the injection speed, and to determine the maximum control pressure value and the safe fluctuation range of the injection pump pressure during pump shutdown based on the maximum excitation pressure of the casing and the safe pressure window, respectively. The acquisition unit is specifically used for: The resistance generated by the drilling fluid network structure is calculated based on the drilling foundation data. The frictional resistance generated by the drilling fluid flow caused by the discharge of annular fluid is calculated based on the casing speed and the drilling foundation data. The inertial force caused by the change in casing velocity is calculated based on the casing acceleration and the drilling foundation data. The maximum value among the resistance, frictional resistance, and inertial force is taken as the maximum excitation pressure of the lower sleeve; The second determining unit is specifically used for: The difference between the maximum excitation pressure of the lower bushing and the safety pressure window is taken as the maximum control pressure value during the pump shutdown period; The maximum excitation pressure of the lower sleeve is negativeed, and the negative value of the maximum excitation pressure of the lower sleeve is taken as the left endpoint value of the safety fluctuation range. The difference between the maximum excitation pressure of the lower sleeve and the safety pressure window is taken as the right endpoint value of the safety fluctuation range. Before the step of obtaining the low-density drilling fluid density based on the original drilling fluid density, the device for determining the parameters of ultra-deep well controlled pressure and accelerated casing installation is also used for: If it is determined that the maximum excitation pressure of the casing is greater than the safe pressure window of the ultra-deep well, then the steps of obtaining the low-density drilling fluid density based on the original drilling fluid density and subsequent steps are executed.

13. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 11.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 11.

15. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 11.

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