Control method, device and equipment for drilling operation and readable storage medium

Abstract

The invention discloses a control method, device and equipment for drilling operation and a readable storage medium, belongs to the field of petroleum engineering, and is used for improving the control precision of the drilling operation. According to the method, the shaft can be divided into the pre-divided sub-sections in advance, the pressure values of the pre-divided sub-sections of the shaft are iteratively determined according to the wellhead pressure and the multiphase pipe flow model, and then the temperature values of the pre-divided sub-sections are determined according to the determined shaft temperature profile in the well shut-in state; the sub-segment sound velocity value of each pre-divided sub-segment is calculated according to the temperature value and the pressure value, and the average value of the sound velocity values of all the sub-segments serves as the wellbore sound velocity value to determine the wellbore liquid level depth. Therefore, the control reliability of the drilling operation is improved, and the potential safety hazard of the drilling operation is reduced.

Description

Technical Field

[0001] The present invention relates to the field of petroleum engineering, and in particular to a control method for drilling operations. The present invention also relates to a control device, equipment and a readable storage medium for drilling operations. Background Art

[0002] Drilling operations are required in petroleum engineering. During the drilling operation, the liquid level depth in the wellbore needs to be accurately measured, so that the drilling operation can be controlled according to the liquid level depth in the wellbore to ensure the safety of the drilling operation. However, it is difficult to accurately determine the liquid level depth in the wellbore in the existing technology, resulting in poor accuracy of the determined wellbore liquid level, making it difficult to reliably control the drilling operation, which poses a safety hazard to the drilling operation.

[0003] Therefore, how to provide a solution to the above technical problems is a problem that those skilled in the art need to solve at present. Summary of the invention

[0004] An object of the present invention is to provide a control method for drilling operations. Since the accuracy of the determined wellbore sound velocity can be improved by using a segmented determination and averaging method, the control reliability of the drilling operation is improved and the safety hazards of the drilling operation are reduced. Another object of the present invention is to provide a control device, equipment and readable storage medium for drilling operations. Since the accuracy of the determined wellbore sound velocity can be improved by using a segmented determination and averaging method, the control reliability of the drilling operation is improved and the safety hazards of the drilling operation are reduced.

[0005] In order to solve the above technical problems, the present invention provides a control method for drilling operations, comprising:

[0006] Iteratively determine the pressure value of each pre-divided subsection of the wellbore according to the wellhead pressure and the multiphase pipe flow model;

[0007] Determining the temperature value of each of the pre-divided sub-segments according to the determined wellbore temperature profile in the shut-in state;

[0008] Determine the sub-segment sound velocity value of each of the pre-divided sub-segments according to the pressure value and the temperature value of each of the pre-divided sub-segments, and take the average value of all the sub-segment sound velocity values ​​as the wellbore sound velocity value;

[0009] The depth of the liquid level in the wellbore is determined according to the wellbore sound velocity value, so that the drilling operation can be controlled according to the liquid level depth.

[0010] Preferably, the temperature value of each pre-divided sub-segment is determined according to the determined wellbore temperature profile in the shut-in state as follows:

[0011] Determine the inflection point temperature value of the wellbore at the gradient inflection point in the wellbore ...

[0012] According to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, and the temperature and depth of the well bottom, determine a first slope of the wellbore temperature profile in a shut-in state within a depth interval from the wellhead to the gradient inflection point, and a second slope within a depth interval from the gradient inflection point to the well bottom;

[0013] Obtaining the wellbore temperature profile in a shut-in state according to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, the temperature and depth of the well bottom, the first slope, and the second slope;

[0014] Determining the temperature value of each of the pre-divided sub-segments according to the wellbore temperature profile in the shut-in state;

[0015] Wherein, the gradient inflection point is the preset depth of the wellbore.

[0016] Preferably, the pressure values ​​of each pre-divided sub-segment of the wellbore are determined iteratively based on the wellhead pressure and the multiphase pipe flow model as follows:

[0017] Based on the wellhead pressure, the pressure values ​​of each pre-divided subsection of the wellbore are iteratively determined according to the Berggs-Brill BB pipe flow model.

[0018] Preferably, the inflection point temperature value of the wellbore at the gradient inflection point in the shut-in state is determined according to the wellbore temperature calculation method in the shut-in state as follows:

[0019] T h =[T f -T ei ]e (-a.t') +T ei ;

[0020]

[0021] a=wL R / [m(1+C T )];

[0022]

[0023]

[0024]

[0025] t D =K c t / (ρ c C c r w2 );

[0026]

[0027] Among them, T f is the wellbore flow temperature, K; T h is the static temperature of the wellbore, that is, the wellbore temperature in the shut-in state, K; T ei is the formation temperature, K; drilling time at time t, h; t′ is the shut-in time before the test, h; z is the calculated position, m; L is the well depth, m; L R is the distance relaxation parameter; w is the fluid mass flow rate, kg / s; C T is the thermal melting coefficient; m is the mass of the fluid in the control volume, kg; C p is the specific heat capacity at constant pressure, J / (kg·℃); g t is the static temperature gradient, °C / m; r to is the outer diameter of the oil pipe, m; U to is the wellbore heat transfer coefficient; K c is the formation heat transfer coefficient; T D is the transient heat transfer function; t D is the dimensionless heat conduction time; r w is the wellbore radius in m; C c is the specific heat of formation rock J / kg.℃; ρ c is the formation rock density, kg / m 3 ; F is the coke coefficient; g 1t Yes T The static temperature gradient above, ℃ / m; g 2t Yes T The following static temperature gradients are in °C / m; z is the calculation position m; z T is the gradient inflection point of the preset depth.

[0028] Preferably, the sub-segment sound velocity value of each of the pre-divided sub-segments is determined according to the pressure value and temperature value of each of the pre-divided sub-segments, and the average value of all the sub-segment sound velocity values ​​is used as the wellbore sound velocity value:

[0029] Determining the compression factor corresponding to each of the pre-divided sub-segments based on the pressure value and the temperature value of each of the pre-divided sub-segments;

[0030] Determining the specific heat capacity at constant pressure and the specific heat capacity at constant volume of each of the pre-divided sub-segments according to the temperature value and the compression factor of each of the pre-divided sub-segments;

[0031] According to the specific heat capacity at constant pressure, specific heat capacity at constant volume and compression factor of each pre-divided sub-segment, the sub-segment sound velocity value of each pre-divided sub-segment is determined, and the average value of all the sub-segment sound velocity values ​​is taken as the wellbore sound velocity value.

[0032] Preferably, the compression factor corresponding to each of the pre-divided sub-segments is determined based on the pressure value and the temperature value of each of the pre-divided sub-segments as follows:

[0033] Based on the pressure value and temperature value of each of the pre-divided sub-segments, the compression factor corresponding to each of the pre-divided sub-segments is determined by the Peng-Robinson PR equation.

[0034] Preferably, after determining the temperature value of each of the pre-divided sub-segments according to the wellbore temperature profile in the shut-in state, the method for controlling the drilling operation further includes:

[0035] Collecting the actual temperature value of each of the pre-divided sub-segments by a temperature collecting device;

[0036] Comparing the actual temperature value of each of the pre-divided sub-segments with the temperature value determined by the wellbore temperature profile to evaluate the accuracy of the wellbore temperature profile in the shut-in state;

[0037] The control prompter prompts the accuracy, the actual temperature value of each of the pre-divided sub-segments, and the temperature value determined by the wellbore temperature profile.

[0038] In order to solve the above technical problems, the present invention also provides a control device for drilling operations, comprising:

[0039] A pressure determination module, used to iteratively determine the pressure value of each pre-divided sub-section of the wellbore according to the wellhead pressure and the multiphase pipe flow model;

[0040] A temperature determination module, used to determine the temperature value of each of the pre-divided sub-segments according to the determined wellbore temperature profile in the shut-in state;

[0041] A sound velocity determination module, used to determine the sub-segment sound velocity value of each of the pre-divided sub-segments according to the pressure value and the temperature value of each of the pre-divided sub-segments, and take the average value of all the sub-segment sound velocity values ​​as the wellbore sound velocity value;

[0042] The control module is used to determine the liquid level depth of the wellbore according to the wellbore sound velocity value, so as to control the drilling operation according to the liquid level depth.

[0043] In order to solve the above technical problems, the present invention also provides a control device for drilling operations, comprising:

[0044] Memory for storing computer programs;

[0045] The processor is used to implement the steps of the control method of the drilling operation as described above when executing the computer program.

[0046] In order to solve the above technical problems, the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the control method for drilling operations as described above are implemented.

[0047] The present invention provides a control method for drilling operations. Considering that the determination of the wellbore liquid level depth requires a high accuracy of the wellbore sound velocity, and the wellbore sound velocity has high accuracy requirements on the wellbore temperature and the wellbore pressure, the wellbore can be pre-divided into various pre-divided sub-segments in the present application, and the pressure values ​​of each pre-divided sub-segment of the wellbore are iteratively determined according to the wellhead pressure and the multiphase pipe flow model, and then the temperature values ​​of each pre-divided sub-segment are determined according to the determined wellbore temperature profile in the shut-in state, and then the sub-segment sound velocity value of each pre-divided sub-segment is calculated according to the temperature value and the pressure value, and the average value of all the sub-segment sound velocity values ​​is used as the wellbore sound velocity value to determine the wellbore liquid level depth. Since the accuracy of the determined wellbore sound velocity can be improved by the method of segmented determination and averaging, the control reliability of the drilling operation is improved, and the safety hazards of the drilling operation are reduced.

[0048] The present invention also provides a control device, equipment and computer-readable storage medium for drilling operations, which have the same beneficial effects as the above control method for drilling operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 A schematic flow chart of a control method for drilling operations provided by the present invention;

[0051] Figure 2 A logical schematic diagram of a wellbore pressure segmentation calculation provided by the present invention;

[0052] Figure 3 A schematic diagram of a wellbore temperature profile during shut-in measurement provided by the present invention;

[0053] Figure 4 A schematic diagram of comparison between a wellbore temperature profile and the measured temperature provided by the present invention;

[0054] Figure 5 A schematic diagram of the structure of a control device for drilling operations provided by the present invention;

[0055] Figure 6A schematic structural diagram of a control device for drilling operations provided by the present invention. DETAILED DESCRIPTION

[0056] The core of the present invention is to provide a control method for drilling operations. Since the accuracy of the determined wellbore sound velocity can be improved by using a segmented determination and averaging method, the control reliability of the drilling operation is improved and the safety hazards of the drilling operation are reduced. Another core of the present invention is to provide a control device, equipment and readable storage medium for drilling operations. Since the accuracy of the determined wellbore sound velocity can be improved by using a segmented determination and averaging method, the control reliability of the drilling operation is improved and the safety hazards of the drilling operation are reduced.

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] Please refer to Figure 1 , Figure 1 A flow chart of a control method for a drilling operation provided by the present invention, the control method for a drilling operation comprises:

[0059] S101: Iteratively determining the pressure value of each pre-divided sub-section of the wellbore according to the wellhead pressure and the multiphase pipe flow model;

[0060] Specifically, taking into account the technical problems in the above background technology, and considering that the determination of the wellbore liquid level depth requires a higher accuracy of the wellbore sound velocity, and the wellbore sound velocity is determined based on the wellbore temperature and the wellbore pressure, if you want to improve the control accuracy of the drilling operation, you need to improve the accuracy of the wellbore temperature and the wellbore pressure. Considering that the depth of the drilling wellbore is large, there are differences in the environment of each section in the wellbore. If you simply determine a temperature value and a pressure value for the wellbore as a whole, it is obviously not conducive to the final control of the drilling operation. Therefore, in an embodiment of the present invention, the wellbore is first divided into a plurality of pre-divided sub-segments, and then the temperature and pressure values ​​of each pre-divided sub-segment are determined. Finally, the average temperature of each pre-divided sub-segment is used as the wellbore temperature value, and the average pressure of each pre-divided sub-segment is used as the wellbore pressure value. This can improve the accuracy of the wellbore temperature value and pressure value, thereby ultimately improving the control accuracy of the drilling operation.

[0061] Therefore, in the embodiment of the present invention, the pressure values ​​of each pre-divided sub-segment of the wellbore are first determined, and the multiphase pipe flow model itself can be used for iterative calculation of the pressure values ​​of each sub-segment of the wellbore. Therefore, in the embodiment of the present invention, the pressure values ​​of each pre-divided sub-segment of the wellbore can be first determined based on the wellhead pressure and the multiphase pipe flow model, so as to use it as the data basis for subsequent steps.

[0062] S102: determining the temperature value of each pre-divided sub-segment according to the determined wellbore temperature profile in the shut-in state;

[0063] Specifically, considering that drilling is a closed environment in the shut-in state, it is conducive to calculating a more accurate sound speed. Therefore, in an embodiment of the present invention, the temperature value of each pre-divided sub-segment can be determined according to the determined wellbore temperature profile in the shut-in state, so as to use it as the data basis for subsequent steps.

[0064] S103: determining the sub-segment sound velocity value of each pre-divided sub-segment according to the pressure value and temperature value of each pre-divided sub-segment, and taking the average value of all sub-segment sound velocity values ​​as the wellbore sound velocity value;

[0065] Specifically, based on the pressure values ​​and temperature values ​​of each pre-divided sub-segment obtained in the aforementioned steps, the sub-segment sound velocity value of each pre-divided sub-segment can be determined, and the average value of all sub-segment sound velocity values ​​can be used as the wellbore sound velocity value. Since the sound velocity value is calculated in segments, the wellbore sound velocity value finally obtained in the embodiment of the present invention has higher accuracy, which is conducive to calculating the liquid level depth with higher accuracy and more precise control of the drilling operation, and is conducive to improving the safety of the drilling operation.

[0066] S104: Determine the depth of the liquid level in the wellbore according to the wellbore sound velocity value, so as to control the drilling operation according to the liquid level depth.

[0067] Specifically, in this step, the liquid level depth in the wellbore can be determined based on the wellbore sound velocity value obtained above, so that the drilling operation can be controlled according to the liquid level depth, which is conducive to more precise control of the drilling operation, thereby improving the safety of the drilling operation.

[0068] The present invention provides a control method for drilling operations. Considering that the determination of the wellbore liquid level depth requires a high accuracy of the wellbore sound velocity, and the wellbore sound velocity has high accuracy requirements on the wellbore temperature and the wellbore pressure, the wellbore can be pre-divided into various pre-divided sub-segments in the present application, and the pressure values ​​of each pre-divided sub-segment of the wellbore are iteratively determined according to the wellhead pressure and the multiphase pipe flow model, and then the temperature values ​​of each pre-divided sub-segment are determined according to the determined wellbore temperature profile in the shut-in state, and then the sub-segment sound velocity value of each pre-divided sub-segment is calculated according to the temperature value and the pressure value, and the average value of all the sub-segment sound velocity values ​​is used as the wellbore sound velocity value to determine the wellbore liquid level depth. Since the accuracy of the determined wellbore sound velocity can be improved by the method of segmented determination and averaging, the control reliability of the drilling operation is improved, and the safety hazards of the drilling operation are reduced.

[0069] Based on the above embodiments:

[0070] As a preferred embodiment, the temperature values ​​of each pre-divided sub-segment are determined according to the determined wellbore temperature profile in the shut-in state as follows:

[0071] Determine the inflection point temperature value of the wellbore at the gradient inflection point in the wellbore ...

[0072] According to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, and the temperature and depth of the well bottom, a first slope of the wellbore temperature profile in the shut-in state within the depth interval from the wellhead to the gradient inflection point and a second slope within the depth interval from the gradient inflection point to the well bottom are determined;

[0073] According to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, the temperature and depth of the bottom of the well, the first slope and the second slope, the wellbore temperature profile in the shut-in state is obtained;

[0074] Determine the temperature value of each pre-divided subsection according to the wellbore temperature profile in the shut-in state;

[0075] The gradient inflection point is the preset depth of the wellbore.

[0076] Specifically, considering that for a wellbore, the ambient temperature has a significant effect on the wellbore temperature close to the wellhead, but has no effect on the temperature of the deep part of the wellbore, when determining the wellbore temperature profile, the wellbore temperature profile can be analyzed in sections. Therefore, in the embodiment of the present invention, the preset depth of the wellbore is used as the gradient inflection point, that is, the temperature of the wellbore at a depth above the gradient inflection point is affected by the ambient temperature, while the temperature at a depth below the gradient inflection point is not affected by the ambient temperature. In addition, considering that the temperature profile of the wellbore is divided into two sections by the gradient inflection point (that is, the corresponding relationship between depth and temperature) can be regarded as a linear relationship, therefore, in the embodiment of the present invention, it can be considered that the relationship between the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, the temperature and depth of the bottom of the well, the first slope of the wellbore temperature profile in the shut-in state within the depth interval from the wellhead to the gradient inflection point, and the depth interval from the gradient inflection point to the bottom of the well can be used to determine the relationship. The second slope in the depth interval from the wellhead to the gradient inflection point is used to construct the wellbore temperature profile in the shut-in state. Therefore, in the embodiment of the present invention, the temperature and depth of the wellhead and the temperature and depth of the wellbore bottom can be determined in advance, and then the inflection point temperature value of the wellbore in the shut-in state at the gradient inflection point is determined according to the wellbore temperature calculation method in the shut-in state. Then, according to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead and the temperature and depth of the wellbore bottom, the first slope of the wellbore temperature profile in the shut-in state in the depth interval from the wellhead to the gradient inflection point and the second slope in the depth interval from the gradient inflection point to the wellbore bottom are determined. At this point, all the basic data for determining the wellbore temperature profile are obtained, so that the wellbore temperature profile in the shut-in state can be obtained. Then, according to the wellbore temperature profile in the shut-in state, the temperature value of each pre-divided sub-segment can be determined, so as to subsequently calculate the sound velocity value of each pre-divided sub-segment.

[0077] The preset depth may be set independently, for example, 50 m, etc., and the embodiment of the present invention does not limit this.

[0078] As a preferred embodiment, the pressure values ​​of each pre-divided sub-segment of the wellbore are determined iteratively based on the wellhead pressure and the multiphase pipe flow model as follows:

[0079] Based on the wellhead pressure, the pressure values ​​of each pre-divided subsection of the wellbore are iteratively determined according to the Berggs-Brill BB pipe flow model.

[0080] Among them, the BB (Beggs-Brill) pipe flow model has the advantages of high accuracy and simple model.

[0081] Of course, in addition to the BB pipe flow model, the multiphase pipe flow model may also be of other types, which are not limited in the embodiment of the present invention.

[0082] Specifically, to better illustrate the embodiments of the present invention, please refer to Figure 2 , Figure 2 A logical schematic diagram of segmented calculation of wellbore pressure provided by the present invention.

[0083] Calculation idea: After discretizing the wellbore, it is assumed that the physical parameters of each small section are consistent. Taking the first small section as an example, the outlet pressure p1, temperature T1 and compression factor Z1 of the first small section are obtained by taking the wellhead pressure as the boundary, that is, Δp is solved by p0 (wellhead pressure), T0, Z0 and ΔH, p1=p0+Δp, and then p2, T2 and Z2 are solved according to p1, T1 and Z1, and so on. The solution is solved by iterative method. When the cumulative length is greater than the well depth, the solved p n is the bottom hole pressure, T n It is the mud surface temperature, which is divided into n+1 pre-divided sub-segments in total, where p represents pressure, T represents temperature, and Z represents compression factor. Figure 2 This is a physical diagram of the calculation idea. It mainly includes the following steps:

[0084] Step 1: Calculate the outlet pressure, temperature and compressibility factor of each small section

[0085] (1) Calculate the outlet pressure of each small section

[0086] We use the BB (Beggs-Brill) model to calculate the wellbore pressure in sections according to the multiphase pipe flow model. The total pressure gradient equation for single-phase or multiphase pipe flow is:

[0087]

[0088] Where: is the acceleration pressure gradient, is the gravitational pressure gradient, is the friction pressure gradient.

[0089] By the inclination angle θ, the no-slip liquid holdup E l , Froude number N Fr The liquid holdup is corrected by the fluid velocity. The values ​​of parameters a, b, and c are shown in Table 1:

[0090] Horizontal liquid holdup:

[0091]

[0092] Corrected liquid holdup:

[0093] H l (θ)=ψH l (0) (3)

[0094] Where ψ is the tilt correction coefficient, H l (0) is the horizontal liquid holdup, H l(θ) is the liquid holdup after correction based on the tilt correction factor.

[0095] The correlation formula of the tilt correction coefficient regressed according to the experimental results is:

[0096]

[0097] The coefficient C in formula (4) is related to the no-slip liquid holdup E l 、Froude number N Fr and liquid velocity number N vl For the values ​​of parameters d, e, f, and g, see Table 2.

[0098] C=(1-E1)ln[d(E1) e (N vl ) f (N Fr ) g ] (5)

[0099]

[0100] Where v ol is the liquid phase converted velocity; σ is the liquid surface tension and g′ is the gravitational acceleration.

[0101] Table 1 a, b, c parameter table

[0102] Flow pattern a b c Separation Flow 0.98 0.4846 0.0868 Intermittent Flow 0.845 0.5351 0.0173 Dispersed Flow 10.065 0.5929 0.0609

[0103] Table 2 d, e, f, g parameter table

[0104]

[0105] Total pressure gradient calculation steps:

[0106] ①、Calculate N at pressure p and temperature T Fr , gas phase density ρ g , liquid density ρ l , gas flow rate v g , liquid flow rate v l , mixture flow rate v m And other related parameters;

[0107] ② Calculate L1 and L2 according to the following formula and determine the flow pattern;

[0108]

[0109]

[0110] Among them, L1 and L2 are related boundaries for distinguishing flow types, and X=ln(λ).

[0111] ③. Calculate the horizontal liquid holdup H based on the flow pattern and the above formula l (0) and the coefficient C, and then calculate the new liquid holdup H l (θ) according to the corrected liquid holdup formula (3);

[0112] ④. Calculate the friction factor λ along the way as follows:

[0113] λ = λ1e s (8)

[0114] Where: λ1 is the friction factor of the gas-liquid two-phase flow without slip, and S is the coefficient related to E1 and H1(θ).

[0115]

[0116]

[0117] When 1 < y < 1.2:

[0118] S = ln(2.2y - 1.2)

[0119] The friction factor λ1 of the gas-liquid two-phase flow without slip:

[0120]

[0121] Where N Re.m is the Reynolds number of the gas-liquid two-phase flow:

[0122] Among them, D is the tubing diameter (m), μ l is the liquid phase viscosity (mPa·s), μ g is the gas phase viscosity (mPa·s).

[0123] ⑤. Calculate the pressure gradient according to formula (1) to complete the calculation of the entire wellbore pressure profile.

[0124] As a preferred embodiment, determine the inflection point temperature value at the inflection point of the wellbore under the shut-in state according to the wellbore temperature calculation method under the shut-in state, specifically:

[0125]

[0126] T h = [T f - T ei e (-a.t') + T ei (11);

[0127]

[0128]

[0129]

[0130] Among them, T f is the wellbore flow temperature, K; T h is the static temperature of the wellbore, that is, the wellbore temperature in the shut-in state, K; T ei is the formation temperature, K; drilling time at time t, h; t′ is the shut-in time before the test, h; z is the calculated position, m; L is the well depth, m; L R is the distance relaxation parameter; w is the fluid mass flow rate, kg / s; C T is the thermal melting coefficient; m is the mass of the fluid in the control volume, kg; C p is the specific heat capacity at constant pressure, J / (kg·℃); g t is the static temperature gradient, °C / m; r to is the outer diameter of the oil pipe, m; U to is the wellbore heat transfer coefficient; K c is the formation heat transfer coefficient; T D is the transient heat transfer function; t D is the dimensionless heat conduction time; r w is the wellbore radius in m; C c is the specific heat of formation rock J / kg.℃; ρ c is the formation rock density, kg / m 3 ; F is the coke coefficient; g 1t Yes T The static temperature gradient above, ℃ / m; g 2t Yes T The following static temperature gradients are in °C / m; z is the calculation position m; z T is the gradient inflection point of the preset depth.

[0131] Specifically, temperature is an important influencing factor of pressure, critical flow coefficient, isentropic index and constant pressure specific heat capacity, so it is necessary to calculate the wellbore temperature profile more accurately. In the wellhead test, since the wellhead temperature is greatly affected by the ambient temperature, its test curve also changes during the day and night. Therefore, the influence of ambient temperature must also be considered when calculating the wellbore temperature profile.

[0132] The drilling is a pressure recovery test. The wellbore temperature calculation formulas during drilling are as shown in formulas 10 and 11. The drilling is a pressure recovery test. Formula 10 is the wellbore temperature calculation formula during drilling. Formula 11 is the wellbore temperature calculation formula when the well is shut in. The variables in formulas 10-11 are shown in formulas 12-13. After verification: the coke coefficient is calculated using "The Application of Coke Coefficient in Optimization Calculation and Throttling Production of High-Pressure Gas Wells", and the wellbore heat transfer coefficient U to It is more reliable to calculate using "Heavy Oil Thermal Recovery Technology".

[0133] Through calculation, it can be seen that when the well is shut in, the wellbore temperature gradually decreases, and the rate of decrease decreases from the wellhead to the bottom of the well, and the bottom of the well temperature remains unchanged. However, during the well test, the ambient temperature will affect the wellhead temperature, so the influence of the ambient temperature needs to be considered.

[0134] The ambient temperature has a significant impact on the wellhead temperature only, and is almost unaffected when the depth is large. Therefore, this paper defines the gradient inflection point. The temperature from the wellhead to this point is greatly affected by the ambient temperature, and the temperature from this point to the bottom of the well is almost unaffected by it, and this point is farthest from the bottom of the well. The temperature gradient g of the temperature profile t It is divided into sections, which is expressed as shown in Equation 14. It is known that the static temperature gradient g 2t The wellhead temperature and bottom hole temperature can be used to 1t To solve.

[0135] The temperature profile calculation steps are:

[0136] ② According to the measured data in production, the gradient inflection point z is given based on experience T 50m;

[0137] ② First calculate the values ​​of each parameter using formula (12) and (13), and then substitute it into formula (10) to calculate the gradient inflection point z T The temperature during drilling is T f , and then substitute into formula (11) to calculate the gradient inflection point z T The temperature of the wellbore at the shut-in point;

[0138] ③According to the wellhead temperature and z T The temperature at which the slope of the straight line above the gradient inflection point can be calculated;

[0139] ④According to the bottom hole temperature and z T The temperature at which the slope of the straight line below the gradient inflection point can be calculated;

[0140] ⑤ Connect the two straight lines to obtain the temperature profile of the entire wellbore.

[0141] To better illustrate the embodiments of the present invention, please refer to Figure 3 as well as Figure 4 , Figure 3 A schematic diagram of a wellbore temperature profile during shut-in measurement provided by the present invention. Figure 4 A schematic diagram of the comparison between a wellbore temperature profile and the measured temperature provided by the present invention, Figure 3 and Figure 4 The horizontal axis is temperature, and the vertical axis is well depth. Figure 3 The parallel broken lines in the figure are the temperature profiles of the wellbore after being shut in for different lengths of time.

[0142] After wellhead temperature correction, the wellbore temperature profile during shut-in measurement is as follows Figure 3As shown in Figure 2, the wellbore temperature above the gradient inflection point is affected by the air temperature and conducts heat with the atmosphere; below the gradient inflection point, it is basically not affected by the air temperature and conducts heat with the wellbore gas. The wellbore flow temperature is also verified, and the verification results are shown in Figure 2. Figure 4 The results show that the treatment method is reliable.

[0143] As a preferred embodiment, the sub-segment sound velocity value of each pre-divided sub-segment is determined according to the pressure value and temperature value of each pre-divided sub-segment, and the average value of all sub-segment sound velocity values ​​is used as the wellbore sound velocity value, specifically:

[0144] Determine the compression factor corresponding to each pre-divided sub-segment based on the pressure value and temperature value of each pre-divided sub-segment;

[0145] Determine the specific heat capacity at constant pressure and the specific heat capacity at constant volume of each pre-divided sub-segment according to the temperature value and the compression factor of each pre-divided sub-segment;

[0146] According to the specific heat capacity at constant pressure, specific heat capacity at constant volume and compression factor of each pre-divided sub-segment, the sub-segment sound velocity value of each pre-divided sub-segment is determined, and the average value of all sub-segment sound velocity values ​​is taken as the wellbore sound velocity value.

[0147] Specifically,

[0148] As a preferred embodiment, based on the pressure value and temperature value of each pre-divided sub-segment, the compression factor corresponding to each pre-divided sub-segment is determined as follows:

[0149] Based on the pressure value and temperature value of each pre-divided sub-segment, the compression factor corresponding to each pre-divided sub-segment is determined by the Peng-Robinson PR equation.

[0150] Specifically, during the drilling process, there are many gas components, and the conventional natural gas compression factor method cannot be used for calculation. It is necessary to consider the component factors for calculation, so the deviation factor Z is calculated according to the PR (Peng-Robinson) equation. Gas state equation:

[0151]

[0152] The state equation is converted into the equation expressed in terms of compression factor:

[0153] Z 3 -(1-A)Z 2 +(B-3A 2 -2A)Z-(AB-A 2 -A 3 )=0 (16)

[0154] The calculation of each parameter is as follows:

[0155]

[0156] K i,j =1.41263-0.02461T+1.40764×10 -4 T 2 -2.55299×10 -7 T 3 ;

[0157]

[0158]

[0159] Where: p is pressure, MPa; R is the molar gas constant, J / (mol·K); T is temperature, K; V m is the molar volume, m 3 / mol; a, α i , α j , b, b i , β i , β j is the type of components contained in the mixture; a i,j is the cross coefficient of components i and j; x z,i 、x z,j is the mole fraction of components i and j; N is the number of components in the mixture; T c,i is the critical temperature of component i, K; p c,i is the critical pressure of component i, MPa; K i,j is the binary interaction coefficient; ω i is the eccentricity factor of component i; T r,i is the comparative temperature of component i, and A and B are constants related to the type and state of the components contained in the mixture.

[0160] Among them, a and b in Formula 17 are different from a and b of the liquid holdup coefficient, and a and b in Formula 17 are coefficients used to calculate A and B.

[0161] Substitute the calculated wellbore pressure and temperature into equation (16) and calculate the outlet compression factor Z based on the solution of the cubic equation.

[0162] Step 2: Calculate the constant volume heat capacity C v and constant pressure heat capacity C p

[0163]

[0164]

[0165] In the formula, ρ m is the density of the mixture, is the specific heat of an ideal gas at constant pressure.

[0166] Step 3: Calculate the wellbore sound velocity

[0167] The basic relationship for the speed of sound can be expressed as:

[0168]

[0169] In the formula, C v and C p is the heat capacity of the gas at constant volume and pressure, M r is the molar mass of the gas.

[0170] Specifically, the average value of the sound velocity values ​​of all pre-divided sub-segments is used as the sound velocity value of the entire wellbore for calculating the liquid level depth of the wellbore.

[0171] As a preferred embodiment, after determining the temperature value of each pre-divided sub-segment according to the wellbore temperature profile in the shut-in state, the control method for the drilling operation further includes:

[0172] The actual temperature value of each pre-divided sub-segment is collected by a temperature collection device;

[0173] Compare the actual temperature values ​​of each pre-divided sub-segment with the temperature values ​​determined by the wellbore temperature profile to evaluate the accuracy of the wellbore temperature profile in the shut-in state;

[0174] The control prompter prompts the accuracy, the actual temperature value of each pre-divided sub-segment, and the temperature value determined by the wellbore temperature profile.

[0175] Specifically, in order to ensure the control accuracy of the method in the embodiment of the present invention for the drilling operation, the embodiment of the present invention can be compared and verified based on the measured wellbore temperature value and the wellbore temperature value reflected by the wellbore temperature profile. If the two are ensured to be similar, then the control accuracy of the method in the embodiment of the present invention for the drilling operation can be ensured. The comparison diagram of the two can be seen in Figure 4 .

[0176] The prompter may be of various types, such as a display, etc., which is not limited in the embodiment of the present invention.

[0177] Please refer to Figure 5 , Figure 5 The present invention provides a structural schematic diagram of a control device for drilling operations, wherein the control device for drilling operations comprises:

[0178] A pressure determination module 51 is used to iteratively determine the pressure value of each pre-divided sub-section of the wellbore according to the wellhead pressure and the multiphase pipe flow model;

[0179] A temperature determination module 52, for determining the temperature value of each pre-divided sub-segment according to the determined wellbore temperature profile in the shut-in state;

[0180] The sound velocity determination module 53 is used to determine the sub-segment sound velocity value of each pre-divided sub-segment according to the pressure value and temperature value of each pre-divided sub-segment, and take the average value of all sub-segment sound velocity values ​​as the wellbore sound velocity value;

[0181] The control module 54 is used to determine the depth of the liquid level in the wellbore according to the wellbore sound velocity value, so as to control the drilling operation according to the liquid level depth.

[0182] For an introduction to the control device for drilling operations provided by an embodiment of the present invention, please refer to the aforementioned embodiment of the control method for drilling operations, and the embodiment of the present invention will not be described in detail here.

[0183] Please refer to Figure 6 , Figure 6 A schematic diagram of the structure of a control device for drilling operations provided by the present invention, the control device for drilling operations comprises:

[0184] A memory 61, used for storing computer programs;

[0185] The processor 62 is used to implement the steps of the control method for drilling operations in the above-mentioned embodiment when executing the computer program.

[0186] For an introduction to the control device for drilling operations provided by an embodiment of the present invention, please refer to the aforementioned embodiment of the control method for drilling operations, and the embodiment of the present invention will not be described in detail here.

[0187] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the control method for drilling operations in the aforementioned embodiment are implemented.

[0188] For an introduction to the computer-readable storage medium provided in the embodiment of the present invention, please refer to the aforementioned embodiment of the method for controlling drilling operations, and the embodiment of the present invention will not be described in detail here.

[0189] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the element.

[0190] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling drilling operations, characterized in that: include: Iteratively determine the pressure value of each pre-divided subsection of the wellbore according to the wellhead pressure and the multiphase pipe flow model; Determining the temperature value of each of the pre-divided sub-segments according to the determined wellbore temperature profile in the shut-in state; Determine the sub-segment sound velocity value of each of the pre-divided sub-segments according to the pressure value and the temperature value of each of the pre-divided sub-segments, and take the average value of all the sub-segment sound velocity values ​​as the wellbore sound velocity value; The depth of the liquid level in the wellbore is determined according to the wellbore sound velocity value, so that the drilling operation can be controlled according to the liquid level depth.

2. The method for controlling drilling operations according to claim 1, characterized in that: The temperature values ​​of each pre-divided sub-segment are determined according to the determined wellbore temperature profile in the shut-in state as follows: Determine the inflection point temperature value of the wellbore at the gradient inflection point in the wellbore ... According to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, and the temperature and depth of the well bottom, determine a first slope of the wellbore temperature profile in a shut-in state within a depth interval from the wellhead to the gradient inflection point, and a second slope within a depth interval from the gradient inflection point to the well bottom; Obtaining the wellbore temperature profile in a shut-in state according to the depth and temperature of the gradient inflection point, the temperature and depth of the wellhead, the temperature and depth of the well bottom, the first slope, and the second slope; Determining the temperature value of each of the pre-divided sub-segments according to the wellbore temperature profile in the shut-in state; Wherein, the gradient inflection point is the preset depth of the wellbore.

3. The control method for drilling operation according to claim 2, characterized in that: The pressure values ​​of each pre-divided sub-segment of the wellbore are determined iteratively based on the wellhead pressure and the multiphase pipe flow model as follows: Based on the wellhead pressure, the pressure values ​​of each pre-divided subsection of the wellbore are iteratively determined according to the Berggs-Brill BB pipe flow model.

4. The method for controlling drilling operations according to claim 2, characterized in that: The inflection point temperature value of the wellbore at the gradient inflection point in the wellbore ... T h =[T f -T ei ]e (-a.t') +T ei ; a=wL R / [m(1+C T )]; t D =K c t / (ρ c C c r w 2 ); Among them, T f is the wellbore flow temperature, K; T h is the static temperature of the wellbore, that is, the wellbore temperature in the shut-in state, K; T ei is the formation temperature, K; t is the drilling time, h; t′ is the shut-in time before the test, h; z is the calculated position, m; L is the well depth, m; L R is the distance relaxation parameter; w is the fluid mass flow rate, kg / s; C T is the thermal melting coefficient; m is the mass of the fluid in the control volume, kg; C p is the specific heat capacity at constant pressure, J / (kg·℃); g t is the static temperature gradient, °C / m; r to is the outer diameter of the oil pipe, m; U to is the wellbore heat transfer coefficient; K c is the formation heat transfer coefficient; T D is the transient heat transfer function; t D is the dimensionless heat conduction time; r w is the wellbore radius in m; C c is the specific heat of formation rock J / kg.℃; ρ c is the formation rock density, kg / m 3 ; F is the coke coefficient; g 1t Yes T The static temperature gradient above, ℃ / m; g 2t Yes T The following static temperature gradients are in °C / m; z is the calculation position m; z T is the gradient inflection point of the preset depth.

5. The method for controlling drilling operations according to claim 2, characterized in that: The sub-segment sound velocity value of each pre-divided sub-segment is determined according to the pressure value and temperature value of each pre-divided sub-segment, and the average value of all the sub-segment sound velocity values ​​is used as the wellbore sound velocity value. Specifically, it is: Determining the compression factor corresponding to each of the pre-divided sub-segments based on the pressure value and the temperature value of each of the pre-divided sub-segments; Determining the specific heat capacity at constant pressure and the specific heat capacity at constant volume of each of the pre-divided sub-segments according to the temperature value and the compression factor of each of the pre-divided sub-segments; According to the specific heat capacity at constant pressure, specific heat capacity at constant volume and compression factor of each pre-divided sub-segment, the sub-segment sound velocity value of each pre-divided sub-segment is determined, and the average value of all the sub-segment sound velocity values ​​is taken as the wellbore sound velocity value.

6. The method for controlling drilling operations according to claim 5, characterized in that: The compression factor corresponding to each of the pre-divided sub-segments is determined based on the pressure value and the temperature value of each of the pre-divided sub-segments as follows: Based on the pressure value and temperature value of each of the pre-divided sub-segments, the compression factor corresponding to each of the pre-divided sub-segments is determined by the Peng-Robinson PR equation.

7. The method for controlling drilling operations according to any one of claims 2 to 6, characterized in that: After determining the temperature value of each of the pre-divided sub-segments according to the wellbore temperature profile in the shut-in state, the method for controlling the drilling operation further includes: Collecting the actual temperature value of each of the pre-divided sub-segments by a temperature collecting device; Comparing the actual temperature value of each of the pre-divided sub-segments with the temperature value determined by the wellbore temperature profile to evaluate the accuracy of the wellbore temperature profile in the shut-in state; The control prompter prompts the accuracy, the actual temperature value of each of the pre-divided sub-segments, and the temperature value determined by the wellbore temperature profile.

8. A control device for drilling operations, characterized in that: include: A pressure determination module, used to iteratively determine the pressure value of each pre-divided sub-section of the wellbore according to the wellhead pressure and the multiphase pipe flow model; A temperature determination module, used to determine the temperature value of each of the pre-divided sub-segments according to the determined wellbore temperature profile in the shut-in state; A sound velocity determination module, used to determine the sub-segment sound velocity value of each of the pre-divided sub-segments according to the pressure value and the temperature value of each of the pre-divided sub-segments, and take the average value of all the sub-segment sound velocity values ​​as the wellbore sound velocity value; The control module is used to determine the liquid level depth of the wellbore according to the wellbore sound velocity value, so as to control the drilling operation according to the liquid level depth.

9. A control device for drilling operations, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the method for controlling drilling operations as claimed in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for controlling drilling operations according to any one of claims 1 to 7 are implemented.

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