An unconventional oil and gas interface riser minimum cycle time determination method and system

Abstract

This invention belongs to the field of drilling technology in oil and gas drilling engineering, specifically involving a method for determining the shortest circulation time for stand-up connection in unconventional oil and gas drilling. It aims to solve the problem of not considering the frictional resistance of cuttings on the drill string when determining the stand-up connection circulation time. The invention includes: acquiring basic data during the drilling process; obtaining standardized drilling data through standardization processing; obtaining predicted hook load and wellhead torque based on the standardized drilling data using a friction torque model; combining the measured hook load and wellhead torque to obtain the first and second circulation times; obtaining the cuttings distribution based on the standardized drilling data using a wellbore cleaning model; and obtaining the third circulation time based on the cuttings distribution in each well section during circulation; and extracting the maximum value from the first, second, and third circulation times to obtain the shortest circulation time. This invention can improve drilling efficiency by shortening the stand-up connection time without causing accident risks.

Description

Technical Field

[0001] This invention belongs to the field of drilling technology in oil and gas drilling engineering, and specifically relates to a method and system for determining the shortest circulation time of unconventional oil and gas connection columns. Background Technology

[0002] Unconventional oil and gas resources, mainly shale gas, are increasingly favored both domestically and internationally. The development of unconventional oil and gas reservoirs often uses horizontal wells, which have long open-hole sections. The annulus is prone to cuttings buildup or the formation of cuttings beds due to untimely wellbore cleaning, which can affect drilling efficiency or even lead to serious drilling accidents. Conversely, excessively long circulation time can also affect drilling efficiency and reduce profitability.

[0003] In the drilling process of unconventional oil and gas wells, a common practice is to stop drilling for a period of time after each drill string is drilled to remove the cuttings from the wellbore before drilling continues with the next drill string. The shortest circulation time between drill strings is determined by quantitatively and accurately optimizing the shortest circulation time based on the changes in hook load and torque after drilling stops and the movement of cuttings. This can effectively remove cuttings from the wellbore and maximize drilling efficiency.

[0004] Currently, the drilling cycle time for connecting the drill string during unconventional oil and gas well drilling is mainly determined based on the mud condition returning from the annulus. When the cuttings content at the mud outlet is observed to be low, it is assumed that the next drill string can be connected and drilling can continue. That is, the shortest stop-drilling cycle time should be equal to the time from the start of circulation after stopping drilling until no cuttings return to the mud outlet. However, this method does not consider the influence of cuttings on drill string friction. Simply equating the stop-drilling cycle time with the time to remove cuttings from the wellbore is obviously unreasonable. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, namely the failure to consider the frictional resistance of cuttings on the drill string when determining the connection cycle time, this invention provides a method for determining the shortest cycle time for unconventional oil and gas connection, the method comprising:

[0006] Step S100: Acquire basic data during the drilling process and obtain 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 standpipe pressure, and static drilling data of measured wellbore trajectory information, measured well body structure information, measured drill string assembly information and drilling fluid information;

[0007] Step S200: Based on the standardized drilling data, the predicted hook load and predicted wellhead torque under the condition of no cuttings are obtained through the friction torque model. The predicted hook load and predicted wellhead torque are compared with the measured hook load and measured wellhead torque to obtain the first cycle time T1 and the second cycle time T2.

[0008] Based on the standardized drilling data, the cuttings distribution is obtained through a wellbore cleaning model. Based on the cuttings distribution in each well section during circulation, the third circulation time T3 is obtained.

[0009] Step S300: Extract the maximum value from 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] Real-time logging data is extracted from the basic data and denoised to obtain denoised real-time logging data.

[0012] Based on the noise-reduced real-time logging data, outlier removal processing is performed to obtain real-time logging data with outliers removed.

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

[0014] Standardized drilling data is obtained by smoothing real-time logging data without gaps.

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

[0016] Based on the standardized drilling data, the predicted hook load is obtained using a friction torque model. m is the mth time step of the hook load;

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

[0018] When the actual measured hook load If the value is not greater than the first threshold, record the loop time as the first loop time T1:

[0019] T1 = t m -t0

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

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

[0022] Based on the standardized drilling data, the predicted wellhead torque is obtained using a friction torque model. n is the nth time step of the wellhead torque;

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

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

[0025] T2=t n -t0

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

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

[0028] Based on the standardized drilling data, a safe cuttings depth D is set. safe :

[0029]

[0030] D DOWN This refers to the bottom depth of the upper vertical well section. For the design of the column connection time, v is the cuttings settling velocity in the annular vertical well section;

[0031] Calculate the rock cuttings content above the safe position Rock fragment content below safe position

[0032]

[0033]

[0034] i is the time step, D hole C represents the bottom position of the well. i Let i be the rock cuttings concentration in the well section corresponding to time step i;

[0035] Set a third threshold coefficient ε, and calculate the third threshold value C based on the rock cuttings content above the safe position. TOP *ε;

[0036] When the rock debris content below the safe position is no greater than the third threshold:

[0037] C TOP *ε≥C DOWN

[0038] Record the current loop time as the third loop time T3:

[0039] T3 = t i -t0

[0040] t i Let t0 be the time corresponding to the i-th time step, and t0 be the start time of the loop.

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

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

[0043] Where T represents the shortest cycle time.

[0044] Another aspect of the present invention provides a system for determining the shortest circulation time of unconventional oil and gas connection standpipes. The system includes: a data processing module, which acquires basic data during the drilling process and obtains standardized drilling data through standardization processing; the basic data includes real-time logging data of measured hook load, measured wellhead torque, measured rotational speed, measured drilling pressure, measured drill bit torque, measured displacement, and measured standpipe pressure, as well as static drilling data of measured wellbore trajectory information, measured wellbore structure information, measured drill string assembly information, and drilling fluid information;

[0045] The cycle time calculation module, based on the standardized drilling data, obtains the predicted hook load and predicted wellhead torque under the condition of no cuttings influence through the friction torque model, compares the predicted hook load and predicted wellhead torque with the measured hook load and measured wellhead torque, and obtains the first cycle time T1 and the second cycle time T2.

[0046] Based on the standardized drilling data, the cuttings distribution is obtained through a wellbore cleaning model. Based on the cuttings distribution in each well section during circulation, the third circulation time T3 is obtained.

[0047] The loop time selection module extracts the maximum value from the first loop time T1, the second loop time T2, and the third loop time T3 to obtain the shortest loop time.

[0048] The beneficial effects of this invention are:

[0049] (1) This invention provides a method for determining the shortest cycle time for connecting the stand to an unconventional oil and gas well, which can effectively meet the needs of speeding up the operation on site, provide guidance for the shortest cycle of connecting the stand to the well, and improve drilling efficiency. Attached Figure Description

[0050] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0051] Figure 1 This is a flowchart illustrating a method for determining the shortest circulation time for connecting a support column in an unconventional oil and gas well, as described in an embodiment of the present invention.

[0052] Figure 2 This is a schematic diagram of the process for determining the recommended cycle time based on the changing trends of hook load and wellhead torque in an embodiment of the present invention.

[0053] Figure 3 This is a schematic diagram of the process for determining the recommended circulation time based on the real-time distribution of cuttings concentration in the wellbore, according to an embodiment of the present invention.

[0054] Figure 4 This is a schematic diagram of the preferred process for the shortest circulation time of unconventional oil and gas wells connected to the standpipe, according to an embodiment of the present invention. Detailed Implementation

[0055] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0056] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0057] This invention discloses a method for determining the shortest cycle time for connecting the stand to unconventional oil and gas wells, which can effectively meet the speed-up requirements of unconventional oil and gas well drilling sites and provide guidance on the shortest cycle time for connecting the stand to wells without causing accident risks.

[0058] To more clearly explain the method for determining the shortest circulation time of an unconventional oil and gas connection column according to the present invention, the following is in conjunction with... Figure 1 The steps in the embodiments of the present invention will be described in detail below.

[0059] An embodiment of the present invention provides a method for determining the shortest circulation time of an unconventional oil and gas connection column, comprising steps S100-S300, each step of which is described in detail below:

[0060] Step S100: Obtain basic data during the drilling process and obtain standardized drilling data through standardization processing;

[0061] 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 stand pressure, as well as static drilling data of measured wellbore trajectory information, measured well body structure information, measured drill string assembly information and drilling fluid information;

[0062] In this embodiment, the standardization process specifically includes:

[0063] Real-time logging data is extracted from the basic data and denoised to obtain denoised real-time logging data.

[0064] Based on the noise-reduced real-time logging data, outlier removal processing is performed to obtain real-time logging data with outliers removed.

[0065] Based on the real-time logging data after removing outliers, missing values ​​are processed by interpolation or removal to obtain real-time logging data without missing values.

[0066] Standardized drilling data is obtained by smoothing real-time logging data without gaps.

[0067] Step S200: Based on the standardized drilling data, the predicted hook load and predicted wellhead torque under the condition of no cuttings are obtained through the friction torque model. The predicted hook load and predicted wellhead torque are compared with the measured hook load and measured wellhead torque to obtain the first cycle time T1 and the second cycle time T2.

[0068] In this embodiment, the loop time calculation function is:

[0069]

[0070]

[0071] in; and These are the predicted and measured values ​​of the hook load, respectively, in kN. and These are the predicted and measured values ​​of the wellhead torque, respectively, in kN·m.

[0072] In this embodiment, the first cycle time T1 is calculated as follows: Figure 2 As shown, it includes:

[0073] Based on the standardized drilling data, the predicted hook load is obtained using a friction torque model. m is the m-th time step of the hook load; where m is dimensionless and takes values ​​in the range {0,1,2…}.

[0074] Set a first threshold coefficient μ, and calculate the first threshold value based on the predicted hook load. The first threshold coefficient μ is dimensionless and is set to 0.2;

[0075] When the actual measured hook load If the value is not greater than the first threshold, record the loop time as the first loop time T1:

[0076] Right now:

[0077] hour:

[0078] T1 = t m -t0

[0079] t m t is the time of the m-th time step of the hook load, and t0 is the start time of the cycle.

[0080] In this embodiment, the calculation method for the second cycle time T2 includes:

[0081] Based on the standardized drilling data, the predicted wellhead torque is obtained using a friction torque model. n is the nth time step of the wellhead torque; where n is dimensionless and takes the value range of {0,1,2…}.

[0082] Set a second threshold coefficient θ, and calculate the second threshold value based on the predicted wellhead torque. θ takes the value 0.2.

[0083] When the wellhead torque of the real-time logging data If the value is not greater than the second threshold, record the loop time as the second loop time T2:

[0084] Right now:

[0085] hour:

[0086] T2=t n -t0

[0087] t n t0 is the time of the nth time step of the wellhead torque, and t0 is the start time of the cycle.

[0088] Based on the standardized drilling data, the cuttings distribution is obtained through a wellbore cleaning model. Based on the cuttings distribution in each well section during circulation, the third circulation time T3 is obtained.

[0089] As the cycle continues, the rock cuttings in the annulus move upwards to the vertical well section. When the rock cuttings have been basically moved to the vertical well section, the rock cuttings will only settle in the vertical well section during the pump stop and column connection time. The rock cuttings depth at this time is the safe rock cuttings depth.

[0090] Record the cycle time T3 from the start of the drilling stop cycle to the measurement of the safe cuttings depth, in seconds;

[0091] The function for calculating cycle time T3 is:

[0092]

[0093] Among them, D safe For safe cuttings depth, the unit is meters (m); D holeε represents the bottom position of the well, in meters (m); D represents the well depth, in meters (m); C represents the cuttings concentration at the corresponding well section, dimensionless; H represents the cuttings bed height at the corresponding sounding position, in millimeters (mm); v represents the cuttings settling velocity in the annular vertical well section, in meters (m / s); ε represents the threshold value, dimensionless. The design time for connecting the column is in seconds; f3 is a function for calculating the optimal cycle time.

[0094] In this embodiment, the third cycle time T3 is calculated as follows: Figure 3 As shown, it includes:

[0095] Based on the standardized drilling data, a safe cuttings depth D is set. safe :

[0096]

[0097] D DOWN This refers to the bottom depth of the upper vertical well section. For the design of the column connection time, v is the cuttings settling velocity in the annular vertical well section;

[0098] Calculate the rock cuttings content above the safe position Rock fragment content below safe position

[0099]

[0100]

[0101] i is the time step, D hole C represents the bottom position of the well. i Let i be the rock cuttings concentration in the well section corresponding to time step i;

[0102] Set a third threshold coefficient ε, and calculate the third threshold value C based on the rock cuttings content above the safe position. TOP *ε;

[0103] When the rock debris content below the safe position is no greater than the third threshold:

[0104] C TOP *ε≥C DOWN

[0105] Record the current loop time as the third loop time T3:

[0106] T3 = t i -t0

[0107] t i Let t0 be the time corresponding to the i-th time step, and t0 be the start time of the loop.

[0108] Step S300: Extract the maximum value from the first cycle time T1, the second cycle time T2, and the third cycle time T3 to obtain the shortest cycle time.

[0109] In this embodiment, step S300 is as follows: Figure 4 As shown, it includes:

[0110] T = MAX(T1, T2, T3)

[0111] Where T represents the shortest cycle time.

[0112] A second embodiment of the present invention provides a system for determining the shortest circulation time of an unconventional oil and gas connection column, the system comprising:

[0113] The data processing module acquires basic data during the drilling process and obtains 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 standpipe pressure, as well as static drilling data of measured wellbore trajectory information, measured well body structure information, measured drill string assembly information, and drilling fluid information.

[0114] The cycle time calculation module, based on the standardized drilling data, obtains the predicted hook load and predicted wellhead torque under the condition of no cuttings influence through the friction torque model, compares the predicted hook load and predicted wellhead torque with the measured hook load and measured wellhead torque, and obtains the first cycle time T1 and the second cycle time T2.

[0115] Based on the standardized drilling data, the cuttings distribution is obtained through a wellbore cleaning model. Based on the cuttings distribution in each well section during circulation, the third circulation time T3 is obtained.

[0116] The loop time selection module extracts the maximum value from the first loop time T1, the second loop time T2, and the third loop time T3 to obtain the shortest loop time.

[0117] Although the steps in the above embodiments are described in the above order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not need to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple variations are all within the protection scope of this invention.

[0118] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process and related descriptions of the storage device and processing device described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0119] The terms “first”, “second”, etc., are used to distinguish similar objects, not to describe or indicate a specific order or sequence.

[0120] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent in such process, method, article, or apparatus / device.

[0121] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles 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 all fall within the scope of protection of the present invention.

Claims

1. A method for determining the shortest circulation time of an unconventional oil and gas connection column, characterized in that, The method includes: Step S100: Acquire basic data during the drilling process and obtain 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 standpipe pressure, and static drilling data of measured wellbore trajectory information, measured well body structure information, measured drill string assembly information and drilling fluid information; Step S200: Based on the standardized drilling data, the predicted hook load and predicted wellhead torque under the condition of no cuttings are obtained through the friction torque model. The predicted hook load and predicted wellhead torque are compared with the measured hook load and measured wellhead torque to obtain the first cycle time T1 and the second cycle time T2. Based on the standardized drilling data, the cuttings distribution is obtained through a wellbore cleaning model. Based on the cuttings distribution in each well section during circulation, the third circulation time T3 is obtained. Step S300: Extract the maximum value from 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 circulation time of an unconventional oil and gas connection column according to claim 1, characterized in that, The standardization process specifically includes: Real-time logging data is extracted from the basic data and denoised to obtain denoised real-time logging data. Based on the noise-reduced real-time logging data, outlier removal processing is performed to obtain real-time logging data with outliers removed. Based on the real-time logging data after removing outliers, missing values ​​are processed by interpolation or removal to obtain real-time logging data without missing values. Standardized drilling data is obtained by smoothing real-time logging data without gaps.

3. The method for determining the shortest circulation time of an unconventional oil and gas connection column according to claim 1, characterized in that, The first cycle time T1 is calculated using the following method: Based on the standardized drilling data, the predicted hook load is obtained using a friction torque model. m is the mth time step of the hook load; Set a first threshold coefficient μ, and calculate the first threshold value based on the predicted hook load. When the actual measured hook load If the value is not greater than the first threshold, record the loop time as the first loop time T1: T1=t m -t0 t m t is the time of the m-th time step of the hook load, and t0 is the start time of the cycle.

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

5. The method for determining the shortest circulation time of an unconventional oil and gas connection column according to claim 1, characterized in that, The calculation method for the third cycle time T3 includes: Based on the standardized drilling data, a safe cuttings depth D is set. safe : D DOWN This refers to the bottom depth of the upper vertical well section. For the design of the column connection time, v is the cuttings settling velocity in the annular vertical well section; Calculate the rock cuttings content above the safe position Rock fragment content below safe position i is the time step, D hole C represents the bottom position of the well. i Let i be the rock cuttings concentration in the well section corresponding to time step i; Set a third threshold coefficient ε, and calculate the third threshold value C based on the rock cuttings content above the safe position. TOP *ε; When the rock debris content below the safe position is no greater than the third threshold: C TOP *ε≥C DOWN Record the current loop time as the third loop time T3: T3=t i -t0 t i Let t0 be the time corresponding to the i-th time step, and t0 be the start time of the loop.

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

7. A system for determining the shortest circulation time of an unconventional oil and gas connection column, characterized in that, The system includes: The data processing module acquires basic data during the drilling process and obtains 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 standpipe pressure, as well as static drilling data of measured wellbore trajectory information, measured well body structure information, measured drill string assembly information, and drilling fluid information. The cycle time calculation module, based on the standardized drilling data, obtains the predicted hook load and predicted wellhead torque under the condition of no cuttings influence through the friction torque model, compares the predicted hook load and predicted wellhead torque with the measured hook load and measured wellhead torque, and obtains the first cycle time T1 and the second cycle time T2. Based on the standardized drilling data, the cuttings distribution is obtained through a wellbore cleaning model. Based on the cuttings distribution in each well section during circulation, the third circulation time T3 is obtained. The loop time selection module extracts the maximum value from the first loop time T1, the second loop time T2, and the third loop time T3 to obtain the shortest loop time.

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