Method and system for determining shortest circulation time of unconventional oil and gas connecting stand column

Abstract

The invention belongs to the technical field of drilling of petroleum and natural gas drilling engineering, particularly relates to a method for determining the shortest circulation time of unconventional oil and gas connection stand columns, and aims to solve the problem that friction resistance of rock debris to a drilling tool is not considered when the circulation time of connection stand columns is determined. The method comprises the steps that basic data in the drilling process are obtained, and standardized drilling data are obtained through standardization processing; according to the standardized drilling data, the predicted hook load and wellhead torque are obtained through a friction torque model, and the actually measured hook load and wellhead torque are combined to obtain the first cycle time and the second cycle time; according to the standardized drilling data, the rock debris distribution condition is obtained through a borehole cleaning model, and third circulation time is obtained based on rock debris distribution of all well sections during circulation; and extracting the maximum value from the first cycle time, the second cycle time and the third cycle time to obtain the shortest cycle time. The drilling efficiency can be improved by shortening the stand column connecting time on the premise that no accident risk is caused.

Description

Background Art

[0002] Unconventional oil and gas resources, mainly shale gas, are becoming more and more popular both at home and abroad. Horizontal wells are mostly used to develop unconventional oil and gas reservoirs. The open hole section is long, and the annulus is prone to cuttings retention or formation of cuttings beds due to untimely wellbore cleaning, thereby affecting drilling efficiency and even causing serious drilling accidents. Conversely, too long a circulation time will affect drilling efficiency and reduce benefits.

[0003] In the process of drilling unconventional oil and gas wells, it is common practice to stop drilling and circulate for a period of time after drilling a column to remove the cuttings in the wellbore before continuing to drill the next column. The shortest cycle time for connecting columns is determined by quantitatively and accurately optimizing the shortest cycle time based on the changes in the load and torque of the big hook after stopping drilling and the migration of cuttings, so that the cuttings in the wellbore can be effectively removed and the drilling efficiency can be maximized.

[0004] At present, the column connection cycle time during the drilling of unconventional oil and gas wells is mainly judged based on the mud conditions returning from the annulus. When it is observed that the cuttings content at the mud outlet is low, it is considered that the next column can be connected to continue drilling. That is, the shortest drilling stop cycle time should be equal to the time from the start of the cycle after drilling is stopped to the time when no cuttings are returned from the mud outlet. However, this method does not take into account the effect of cuttings on the friction of the drill bit. It is obviously unreasonable to simply equate the drilling stop cycle time with the time to discharge the cuttings in the wellbore. Summary of the invention

[0005] In order to solve the above-mentioned problem in the prior art, that is, the problem of the friction of cuttings on the drill bit is not considered when determining the connection column cycle time, the present invention provides a method for determining the shortest cycle time of an unconventional oil and gas connection column, the method comprising:

[0006] Step S100, acquiring basic data during the drilling process, and obtaining standardized drilling data through standardization processing; the basic data includes real-time logging data of measured hook load, measured wellhead torque, measured rotation speed, measured drilling pressure, measured drill bit torque, measured displacement and measured standing pressure, and static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drilling tool assembly information and drilling fluid information;

[0007] Step S200, according to the standardized drilling data, a predicted hook load and a predicted wellhead torque under the condition of no rock debris influence are obtained by using a friction torque model, and the predicted hook load and the predicted wellhead torque are compared with the measured hook load and the measured wellhead torque to obtain a first cycle time T1 and a second cycle time T2;

[0008] According to the standardized drilling data, the cuttings distribution is obtained through the wellbore cleaning model, and the third cycle time T3 is obtained based on the cuttings distribution of each well section during the cycle;

[0009] Step S300, extracting the maximum value among the first cycle time T1, the second cycle time T2 and the third cycle time T3 to obtain the shortest cycle time.

[0010] In some preferred embodiments, the standardization process specifically includes:

[0011] Extract the real-time logging data from the basic data, and obtain the noise-reduced real-time logging data through noise reduction processing;

[0012] According to the real-time logging data with reduced noise, outlier removal processing is performed to obtain real-time logging data without outliers;

[0013] Based on the real-time logging data with outliers removed, the missing values ​​are processed by interpolation or removal to obtain the real-time logging data without missing values;

[0014] Based on the real-time logging data without missing values, standardized drilling data is obtained through smoothing.

[0015] In some preferred embodiments, the first cycle time T1 is calculated by:

[0016] According to the standardized drilling data, the predicted hook load is obtained through the friction torque model. m is the mth time step of the hook load;

[0017] Set the first threshold coefficient μ and calculate the first threshold based on the predicted hook load.

[0018] When the measured hook load When it is not greater than the first threshold value, the cycle time is recorded as the first cycle time T1:

[0019] T1=t m -t0

[0020] t m is the time of the mth time step of the hook load, and t0 is the start cycle time.

[0021] In some preferred embodiments, the second cycle time T2 is calculated by:

[0022] According to the standardized drilling data, the predicted wellhead torque is obtained through the friction torque model. n is the nth time step of the wellhead torque;

[0023] Set the second threshold coefficient θ, and calculate the second threshold based on the predicted wellhead torque

[0024] When the wellhead torque of real-time logging data When it is not greater than the second threshold value, the cycle time is recorded as the second cycle time T2:

[0025] T2=t n -t0

[0026] t n is the time of the nth time step of the wellhead torque, and t0 is the start cycle time.

[0027] In some preferred embodiments, the third cycle time T3 is calculated by:

[0028] According to the standardized drilling data, the safe cuttings depth D is set. safe :

[0029]

[0030] D DOWN is the bottom depth of the upper vertical well section, is the design time for connecting the columns, v is the settling velocity of the cuttings in the vertical well section of the annulus;

[0031] Calculate the rock cuttings content above the safe position and rock cuttings content below the safety position

[0032]

[0033]

[0034] i is the time step, D hole is the bottom position, C i is the cuttings concentration in the well section corresponding to time step i;

[0035] Set the third threshold coefficient ε, and calculate the third threshold C according to the rock cuttings content above the safe position. TOP *ε;

[0036] When the rock debris content below the safety position is not greater than the third threshold value:

[0037] C TOP *ε≥C DOWN

[0038] Record the cycle time at this time as the third cycle time T3:

[0039] T3=t i -t0

[0040] t i is the time corresponding to the i-th time step, and t0 is the start cycle time.

[0041] In some preferred embodiments, the step S300 includes:

[0042] T=MAX(T1,T2,T3)

[0043] Where T represents the shortest cycle time. Another aspect of the present invention provides a system for determining the shortest cycle time of an unconventional oil and gas connection column, the system comprising: a data processing module, which acquires basic data during the drilling process and obtains standardized drilling data through standardized processing; the basic data comprises real-time logging data of measured hook load, measured wellhead torque, measured rotation speed, measured drilling pressure, measured drill bit torque, measured displacement and measured standing pressure, and static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drilling tool assembly information and drilling fluid information; A cycle time calculation module, based on the standardized drilling data, obtains a predicted hook load and a predicted wellhead torque under the condition of no rock debris influence by means of a friction torque model, compares the predicted hook load and the predicted wellhead torque with the measured hook load and the measured wellhead torque, and obtains a first cycle time T1 and a second cycle time T2; According to the standardized drilling data, the cuttings distribution is obtained through the wellbore cleaning model, and the third cycle time T3 is obtained based on the cuttings distribution of each well section during the cycle;

[0044] The cycle time selection module extracts the maximum value among the first cycle time T1, the second cycle time T2 and the third cycle time T3 to obtain the shortest cycle time.

[0045] Beneficial effects of the present invention:

[0046] (1) The present invention provides a method for determining the shortest cycle time for connecting columns in unconventional oil and gas wells, which can effectively meet the speed-up requirements on site, provide guidance on the shortest cycle time for connecting columns for drilling construction, and improve drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0048] Figure 1 It is a flow chart of a method for determining the shortest cycle time of a connection column in an unconventional oil and gas well according to an embodiment of the present invention;

[0049] Figure 2 It is a flow chart of obtaining a recommended cycle time based on a change trend of a hook load and a wellhead torque according to an embodiment of the present invention;

[0050] Figure 3is a flow chart of obtaining a recommended cycle time based on the real-time distribution of cuttings concentration in a wellbore according to an embodiment of the present invention;

[0051] Figure 4 It is a schematic diagram of an optimal flow chart for the shortest cycle time of connecting columns in unconventional oil and gas wells according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0053] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0054] The present invention discloses a method for determining the shortest cycle time of an unconventional oil and gas connection column, which can effectively meet the speed-up requirements of unconventional oil and gas well drilling sites, and provide guidance on the shortest cycle time of the connection column for drilling construction without causing accident risks.

[0055] In order to more clearly explain the method for determining the shortest cycle time of an unconventional oil and gas connection column of the present invention, the following is combined with Figure 1 Each step in the embodiment of the present invention is described in detail.

[0056] A method for determining the shortest cycle time of an unconventional oil and gas connection column according to an embodiment of the present invention includes steps S100 to S300, each of which is described in detail as follows:

[0057] Step S100, acquiring basic data in the drilling process, and obtaining standardized drilling data through standardization processing;

[0058] The basic data include real-time logging data of measured hook load, measured wellhead torque, measured rotation speed, measured drilling pressure, measured drill bit torque, measured displacement and measured standing pressure, and static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drilling tool assembly information and drilling fluid information;

[0059] In this embodiment, the standardization process specifically includes:

[0060] Extract the real-time logging data from the basic data, and obtain the noise-reduced real-time logging data through noise reduction processing;

[0061] According to the real-time logging data with reduced noise, outlier removal processing is performed to obtain real-time logging data without outliers;

[0062] Based on the real-time logging data with outliers removed, the missing values ​​are processed by interpolation or removal to obtain the real-time logging data without missing values;

[0063] Based on the real-time logging data without missing values, standardized drilling data is obtained through smoothing.

[0064] Step S200, according to the standardized drilling data, a predicted hook load and a predicted wellhead torque under the condition of no rock debris influence are obtained by using a friction torque model, and the predicted hook load and the predicted wellhead torque are compared with the measured hook load and the measured wellhead torque to obtain a first cycle time T1 and a second cycle time T2;

[0065] In this embodiment, the cycle time calculation function is:

[0066] in; and are the predicted value and measured value of the hook load, in kN; and are the predicted and measured values ​​of the wellhead torque, respectively, in kN·m;

[0067] In this embodiment, the first cycle time T1 is calculated as follows: Figure 2 As shown, including:

[0068] According to the standardized drilling data, the predicted hook load is obtained through the friction torque model. m is the mth time step of the hook load; m is dimensionless and its value range is {0,1,2…};

[0069] Set the first threshold coefficient μ and calculate the first threshold based on the predicted hook load. The first threshold coefficient μ is dimensionless and is set to 0.2;

[0070] When the measured hook load When it is not greater than the first threshold value, the cycle time is recorded as the first cycle time T1:

[0071] Right now:

[0072] hour:

[0073] T1=t m -t0

[0074] t m is the time of the mth time step of the hook load, and t0 is the start cycle time.

[0075] In this embodiment, the second cycle time T2 is calculated by:

[0076] According to the standardized drilling data, the predicted wellhead torque is obtained through the friction torque model. n is the nth time step of the wellhead torque; n is dimensionless and ranges from {0, 1, 2…};

[0077] Set the second threshold coefficient θ, and calculate the second threshold based on the predicted wellhead torque The value of θ is 0.2.

[0078] When the wellhead torque of real-time logging data When it is not greater than the second threshold value, the cycle time is recorded as the second cycle time T2:

[0079] Right now:

[0080] hour:

[0081] T2=t n -t0

[0082] t n is the time of the nth time step of the wellhead torque, and t0 is the start cycle time.

[0083] According to the standardized drilling data, the cuttings distribution is obtained through the wellbore cleaning model, and the third cycle time T3 is obtained based on the cuttings distribution of each well section during the cycle;

[0084] As the circulation proceeds, the cuttings in the annulus move upward to the vertical well section. When the cuttings have basically moved to the vertical well section, the cuttings will only settle in the vertical well section during the pump stop and column connection time. The cuttings depth at this time is the safe cuttings depth.

[0085] Record the cycle time T3 from the start of the drilling stop cycle to the measurement of the safe cuttings depth, in seconds;

[0086] The calculation function of cycle time T3 is:

[0087] Among them, D safe is the safe cuttings depth, in m; D hole is the bottom position, in m; D is the well depth, in m; C is the cuttings concentration at the corresponding well section, dimensionless; H is the height of the cuttings bed at the corresponding depth measurement position, in mm; v is the cuttings settling velocity in the annular vertical well section, in m / s; ε is the threshold value, dimensionless; is the design time for connecting the columns, in seconds; f3 is the function for calculating the optimal cycle time;

[0088] In this embodiment, the third cycle time T3 is calculated as follows: Figure 3 As shown, including:

[0089] According to the standardized drilling data, the safe cuttings depth D is set. safe :

[0090]

[0091] D DOWN is the bottom depth of the upper vertical well section, is the design time for connecting the columns, v is the settling velocity of the cuttings in the vertical well section of the annulus;

[0092] Calculate the rock cuttings content above the safe position and rock cuttings content below the safety position

[0093]

[0094]

[0095] i is the time step, D hole is the bottom position, C i is the cuttings concentration in the well section corresponding to time step i;

[0096] Set the third threshold coefficient ε, and calculate the third threshold C according to the rock cuttings content above the safe position. TOP *ε;

[0097] When the rock debris content below the safety position is not greater than the third threshold value:

[0098] C TOP *ε≥C DOWN

[0099] Record the cycle time at this time as the third cycle time T3:

[0100] T3=t i -t0

[0101] t i is the time corresponding to the i-th time step, and t0 is the start cycle time.

[0102] Step S300, extracting the maximum value among the first cycle time T1, the second cycle time T2 and the third cycle time T3 to obtain the shortest cycle time.

[0103] In this embodiment, the step S300 is as follows: Figure 4 As shown, including:

[0104] T=MAX(T1,T2,T3)

[0105] Where T represents the shortest cycle time.

[0106] A second embodiment of the present invention provides a system for determining the shortest cycle time of an unconventional oil and gas connection column, the system comprising:

[0107] The data processing module acquires basic data during the drilling process and obtains standardized drilling data through standardized processing; the basic data includes real-time logging data of measured hook load, measured wellhead torque, measured rotation speed, measured drilling pressure, measured drill bit torque, measured displacement and measured vertical pressure, and static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drilling tool assembly information and drilling fluid information;

[0108] A cycle time calculation module, based on the standardized drilling data, obtains a predicted hook load and a predicted wellhead torque under the condition of no rock debris influence by means of a friction torque model, compares the predicted hook load and the predicted wellhead torque with the measured hook load and the measured wellhead torque, and obtains a first cycle time T1 and a second cycle time T2;

[0109] According to the standardized drilling data, the cuttings distribution is obtained through the wellbore cleaning model, and the third cycle time T3 is obtained based on the cuttings distribution of each well section during the cycle;

[0110] The cycle time selection module extracts the maximum value among the first cycle time T1, the second cycle time T2 and the third cycle time T3 to obtain the shortest cycle time.

[0001] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art can understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of the present invention.

[0002] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the storage device and processing device described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0003] The terms "first", "second", etc. are used to distinguish similar objects rather than to describe or indicate a particular order or sequence.

[0004] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0005] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for determining the shortest cycle time of an unconventional oil and gas connection column, characterized in that: The method comprises: Step S100, acquiring basic data during the drilling process, and obtaining standardized drilling data through standardization processing; the basic data includes real-time logging data of measured hook load, measured wellhead torque, measured rotation speed, measured drilling pressure, measured drill bit torque, measured displacement and measured standing pressure, and static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drilling tool assembly information and drilling fluid information; Step S200, according to the standardized drilling data, a predicted hook load and a predicted wellhead torque under the condition of no rock debris influence are obtained by using a friction torque model, and the predicted hook load and the predicted wellhead torque are compared with the measured hook load and the measured wellhead torque to obtain a first cycle time T1 and a second cycle time T2; According to the standardized drilling data, the cuttings distribution is obtained through the wellbore cleaning model, and the third cycle time T3 is obtained based on the cuttings distribution of each well section during the cycle; Step S300, extracting the maximum value among the first cycle time T1, the second cycle time T2 and the third cycle time T3 to obtain the shortest cycle time.

2. The method for determining the shortest cycle time of an unconventional oil and gas connection column according to claim 1, characterized in that: The standardization process specifically includes: Extract the real-time logging data from the basic data, and obtain the noise-reduced real-time logging data through noise reduction processing; According to the real-time logging data with reduced noise, outlier removal processing is performed to obtain real-time logging data without outliers; Based on the real-time logging data with outliers removed, the missing values ​​are processed by interpolation or removal to obtain the real-time logging data without missing values; Based on the real-time logging data without missing values, standardized drilling data is obtained through smoothing.

3. The method for determining the shortest cycle time of an unconventional oil and gas connection column according to claim 1, characterized in that: The calculation method of the first cycle time T1 includes: According to the standardized drilling data, the predicted hook load is obtained through the friction torque model. m is the mth time step of the hook load; Set the first threshold coefficient μ and calculate the first threshold based on the predicted hook load. When the measured hook load When it is not greater than the first threshold value, the cycle time is recorded as the first cycle time T1: T1=t m -t0 t m is the time of the mth time step of the hook load, and t0 is the start cycle time.

4. The method for determining the shortest cycle time of an unconventional oil and gas connection column according to claim 1 is characterized in that: The second cycle time T2 is calculated by: According to the standardized drilling data, the predicted wellhead torque is obtained through the friction torque model. n is the nth time step of the wellhead torque; Set the second threshold coefficient θ, and calculate the second threshold based on the predicted wellhead torque When the wellhead torque of real-time logging data When it is not greater than the second threshold value, the cycle time is recorded as the second cycle time T2: T2=t n -t0 t n is the time of the nth time step of the wellhead torque, and t0 is the start cycle time.

5. The method for determining the shortest cycle time of an unconventional oil and gas connection column according to claim 1, characterized in that: The third cycle time T3 is calculated by: According to the standardized drilling data, the safe cuttings depth D is set. safe : D DOWN is the bottom depth of the upper vertical well section, is the design time for connecting the columns, v is the settling velocity of the cuttings in the vertical well section of the annulus; Calculate the rock cuttings content above the safe position and rock cuttings content below the safety position i is the time step, D hole is the bottom position, C i is the cuttings concentration in the well section corresponding to time step i; Set the third threshold coefficient ε, and calculate the third threshold C according to the rock cuttings content above the safe position. TOP *ε; When the rock debris content below the safety position is not greater than the third threshold value: C TOP *ε≥C DOWN Record the cycle time at this time as the third cycle time T3: T3=t i -t0 t i is the time corresponding to the i-th time step, and t0 is the start cycle time.

6. The method for determining the shortest cycle time of an unconventional oil and gas connection column according to claim 1, characterized in that: The step S300 includes: T=MAX(T1,T2,T3) Where T represents the shortest cycle time.

7. A system for determining the shortest cycle time of an unconventional oil and gas connection column, characterized in that: The system comprises: The data processing module acquires basic data during the drilling process and obtains standardized drilling data through standardized processing; the basic data includes real-time logging data of measured hook load, measured wellhead torque, measured rotation speed, measured drilling pressure, measured drill bit torque, measured displacement and measured vertical pressure, and static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drilling tool assembly information and drilling fluid information; A cycle time calculation module, based on the standardized drilling data, obtains a predicted hook load and a predicted wellhead torque under the condition of no rock debris influence by means of a friction torque model, compares the predicted hook load and the predicted wellhead torque with the measured hook load and the measured wellhead torque, and obtains a first cycle time T1 and a second cycle time T2; According to the standardized drilling data, the cuttings distribution is obtained through the wellbore cleaning model, and the third cycle time T3 is obtained based on the cuttings distribution of each well section during the cycle; The cycle time selection module extracts the maximum value among the first cycle time T1, the second cycle time T2 and the third cycle time T3 to obtain the shortest cycle time.

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