Method for improving efficiency of sidetracked reentry wellbore

Abstract

The application discloses a method for improving the efficiency of a sidetracked reentry wellhole, and the method comprises the following steps: acquiring continuous inclinometer data and gyro logging data of an old well; determining an azimuth error interval according to the continuous inclinometer data and the gyro logging data; establishing an envelope line trajectory of the azimuth error interval and taking the envelope line trajectory as a target trajectory; performing sidetracking construction, and controlling a sidetracking trajectory according to the target trajectory until the old wellhole is found. By using the method, the complexity of the construction can be reduced, and the old wellhole can be found simply, quickly and efficiently.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas field old well operation construction, and particularly relates to a method for improving the efficiency of sidetracking reentry wellbore. BACKGROUND

[0002] In order to ensure that the complex old well can be successfully plugged, the old wellbore is firstly reentered, and then subsequent operation is carried out.

[0003] At present, there are many methods for reentering the old wellbore, and the sidetracking eye finding method is generally used. Since this method requires that the relevant data have high accuracy, the old well history data is missing, the data is imperfect or has errors, the measuring instruments are different, the strata change over time, and the like, the old wellbore is not easy to find, and the effect is not ideal. SUMMARY

[0004] The present application provides a method for improving the efficiency of sidetracking reentry wellbore, so as to simply and efficiently find the old wellbore.

[0005] Therefore, the present application provides the following technical scheme:

[0006] A method for improving the efficiency of sidetracking reentry wellbore, the system comprises:

[0007] Obtaining old well continuous inclinometer data and gyro logging data;

[0008] Determining a position error interval according to the old well continuous inclinometer data and the gyro logging data;

[0009] Establishing an envelope trajectory of the position error interval and taking it as a target trajectory;

[0010] Carrying out sidetracking construction, and controlling the sidetracking trajectory according to the target trajectory until the old wellbore is found.

[0011] Optionally, the old well continuous inclinometer data comprises a set of old well continuous azimuth and inclination angle data.

[0012] Optionally, the method further comprises:

[0013] Optionally, the method further comprises:

[0014] Obtaining geological logging original report records;

[0015] Checking the old well continuous inclinometer data according to the geological logging original report records to obtain checked continuous inclinometer data;

[0016] The determining of the azimuth error interval according to the old well continuous inclination measurement data and the gyro logging data comprises:

[0017] An azimuth error interval is determined based on the difference between the gyro logging data and the calibrated connected inclination data.

[0018] Optionally, the geological logging original report record includes any one or more of the following information: rock cutting description, geological layering data, old well casing data, drilling time changes, and gas logging data.

[0019] Optionally, performing the sidetracking construction and controlling the sidetracking trajectory according to the target trajectory until the old wellbore is found includes:

[0020] Conduct side drilling construction and perform real-time trajectory tracking measurement to obtain measurement data;

[0021] Generate actual drilling trajectory based on measurement data;

[0022] Correcting the actual drilling trajectory according to the target trajectory;

[0023] Determine whether old wellbore has been found;

[0024] If yes, it is determined that the re-entry into the old wellbore is successful and the sidetracking operation is stopped.

[0025] Optionally, performing real-time trajectory tracking measurement includes: performing real-time trajectory tracking measurement using an MWD wireless directional-while-drilling instrument.

[0026] Optionally, whether the old wellbore is found is determined based on any one or more of the following methods: engineering drilling rate changes, geological sand sample conditions, and trajectory anti-collision theory.

[0027] The method provided by the present invention improves the efficiency of sidetracking and re-entering a wellbore. It uses continuous inclination and gyroscopic logging data from old wells to determine an azimuth error interval. An envelope trajectory of this azimuth error interval is established and used as a target trajectory. During the sidetracking operation, the sidetracking trajectory is controlled according to this target trajectory until the old wellbore is found. This method can reduce the impact of inaccurate old wellbore data during sidetracking, reduce the complexity of the operation, and improve the efficiency of re-entering the wellbore, thereby achieving simple, rapid, and efficient tracing of the old wellbore.

[0028] Furthermore, the continuous inclination data of the old well is verified using the original geological logging report, so that the verified continuous inclination data is more accurate, thereby improving the accuracy of the target trajectory and furthermore being able to find the old wellbore more effectively.

[0029] Further, in the sidetracking process, whether the old wellbore is determined by various technical means, and the azimuth interval of the target position is corrected, so as to effectively improve the success rate of finding the wellbore, shorten the construction period, reduce the operation cost, and reduce the downhole operation risk. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a flow chart of the re-entry wellbore method provided by the present application;

[0031] Figure 2 is a schematic diagram of the sidetracking construction process in the method of the present application;

[0032] Figure 3 is a flow chart of controlling the sidetracking trajectory according to the target trajectory in the method of the present application;

[0033] Figure 4 is a schematic diagram of the horizontal projection of the actual drilling trajectory and the azimuth correction [-1, 2.5] trajectory of the inclination data in the method of the present application;

[0034] Figure 5 is a schematic diagram of the anti-collision scanning of the sidetracking trajectory and the envelope trajectory of the azimuth correction [-1, 2.5] of the inclination data in the method of the present application. DETAILED DESCRIPTION

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0036] The present application will be described in detail below in combination with the drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present application are not limited to the following embodiments.

[0037] In view of the problem that the existing sidetracking method for finding the wellbore needs accurate related data, and the finding effect is not ideal due to the imperfect or error existing in the related data of the old well, the present application provides a re-entry wellbore method, which uses the continuous inclination data and gyro logging data of the old well to determine the azimuth error interval, establishes an envelope trajectory of the azimuth error interval and takes it as a target trajectory, and then controls the sidetracking trajectory according to the target trajectory in the sidetracking construction process until the old wellbore is found, so that the old wellbore is found simply, quickly and efficiently.

[0038] As shown in FIG. Figure 1 is a flow chart of the re-entry wellbore method provided by the present application, which includes the following steps:

[0039] Step 101: Acquire continuous inclination survey data and gyro logging data of old wells.

[0040] The old well continuous inclination survey data may include but is not limited to the old well continuous azimuth, well inclination azimuth angle data set, etc.

[0041] The continuous inclination data of old wells can be obtained during the drilling process of old wells using professional measurement tools such as a directional-while-drilling instrument or a continuous inclinometer. A directional-while-drilling instrument is a professional tool used in drilling projects. Its main function is to continuously or repeatedly transmit information on the direction of the drill bit at the bottom of the hole, obtained by a probe tube in the hole, to a surface indicator device via a cable or electromagnetic waves. A continuous inclinometer can accurately measure the wellbore trajectory during the oil drilling process. By measuring changes in the ground perpendicular to the horizontal direction, it can determine changes in the horizontal displacement of the ground and obtain data such as the azimuth and well inclination of oil drilling and logging.

[0042] The gyro logging data refers to the data obtained by re-measuring the trajectory of the drilled well using a gyroscope before sidetracking, that is, the data obtained by gyro re-measurement, which may specifically include but is not limited to well depth, well inclination, azimuth, and well inclination and azimuth data of each point from the wellhead to the bottom of the well.

[0043] Step 102: Determine an azimuth error interval based on the old well continuous inclination measurement data and the gyro logging data.

[0044] Specifically, the azimuth error interval is determined according to the difference between the gyro logging data and the old well continuous inclination measurement data.

[0045] In order to further ensure the accuracy of the data, in another non-limiting embodiment, the original report records of geological logging can also be obtained, and the continuous inclination data of the old well is first calibrated according to the original report records of geological logging to obtain the calibrated continuous inclination data, and then the azimuth error range is determined based on the difference between the gyro logging data and the calibrated continuous inclination data.

[0046] The original geological logging report records include any one or more of the following information: rock cutting description, geological layering data, old well casing data, drilling time changes, and gas logging data.

[0047] Step 103: Establish an envelope trajectory of the azimuth error interval and use it as a target trajectory.

[0048] Step 104 , performing sidetracking construction and controlling the sidetracking trajectory according to the target trajectory until the old wellbore is found.

[0049] The schematic diagram of side drilling construction is as follows Figure 2 As shown, the solid line represents the actual drilling trajectory of the old well, and the dotted line represents the trajectory after side drilling, which eventually hits the old wellbore.

[0050] like Figure 3 FIG. 1 is a flow chart of controlling the sidetracking trajectory according to the target trajectory in the method of the present invention, comprising the following steps:

[0051] Step 301, start side drilling construction.

[0052] For example, start sidetracking from 2800m, adjust the trajectory direction according to the direction of the old well after sidetracking, and finally re-enter the old wellbore.

[0053] Step 302: Perform real-time trajectory tracking measurement during the sidetracking construction process to obtain measurement data.

[0054] For example, a wireless MWD (Measurement While Drilling) instrument can be used to perform real-time trajectory tracking measurements. The measurement data may include, but is not limited to, well depth, well inclination, azimuth, and other data.

[0055] Step 303: Generate a real drilling trajectory based on the measurement data.

[0056] Step 304: Correct the actual drilling trajectory according to the target trajectory.

[0057] It should be noted that, in order to avoid a large error between the actual drilling trajectory and the target trajectory, the control segment can be divided into several small segments, each of which has a fixed or different length, which is not limited in the embodiment of the present invention. Trajectory correction is performed within each small segment to ensure that the entire actual drilling trajectory matches the target trajectory.

[0058] Step 305 , determining whether an old wellbore is found; if so, executing step 306 ; otherwise, returning to step 301 , continuing the sidetracking operation.

[0059] In specific applications, multiple methods can be used to determine whether an old wellbore has been found. For example, one or more of the following methods can be used to determine whether an old wellbore has been found: engineering drilling rate changes, geological sand sample conditions, and trajectory collision prevention theory.

[0060] Drilling rate change refers to the change in the drilling speed of a certain layer. For example, a faster drilling speed indicates that an old wellbore has been drilled.

[0061] The geological sand sample refers to whether the sand returned from a certain layer corresponds to the original. If the drilling is carried out into an old wellbore, the sand return situation will change. For example, if cement blocks appear in the vibrating screen during cementing, it means that the drilling is carried out into an old wellbore.

[0062] Track collision avoidance is the process of creating a collision avoidance map by comparing actual drilling data with old well data. This map clearly shows whether the wells have theoretically collided. If the wellbore is re-entered, the collision avoidance map will show a collision avoidance distance of 0.

[0063] Through one or more of the above methods, it can be accurately determined whether the old wellbore is found.

[0064] Step 306: Determine that the re-entry into the old wellbore is successful, and stop the sidetracking operation.

[0065] The method provided by the present invention improves the efficiency of sidetracking and re-entering a wellbore. It uses continuous inclination and gyroscopic logging data from old wells to determine an azimuth error interval. An envelope trajectory of this azimuth error interval is established and used as a target trajectory. During the sidetracking operation, the sidetracking trajectory is controlled according to this target trajectory until the old wellbore is found. This method can reduce the impact of inaccurate old wellbore data during sidetracking, reduce the complexity of the operation, and improve the efficiency of re-entering the wellbore, thereby achieving simple, rapid, and efficient tracing of the old wellbore.

[0066] The following examples further illustrate the process of finding old wellbores using the method of the present invention.

[0067] 1. For old wells, azimuth corrections are performed through data verification and error analysis. For example, if the true trajectory of the horizontal and vertical coordinates of the azimuth map is [-1, 2], the error interval correction value is [-1.5, 2.5]. If the azimuth is 32.5°, then based on the correction value [-1.5, 2.5], the azimuth correction value is 31° to 35°, that is, the old well trajectory is searched between 31° and 35°.

[0068] 2. Establish the envelope trajectory of the azimuth error interval as the target trajectory. The target trajectory includes the target trajectory of any azimuth value in the azimuth correction interval. By colliding the actual drilling trajectory with the target trajectory, the actual drilling trajectory can realize the eye finding of the azimuth interval correction.

[0069] like Figure 4 As shown, Figure 4 The horizontal projection diagram of the actual drilling trajectory and the azimuth [-1, 2.5] trajectory corrected by the inclination data is shown.

[0070] Among them, the horizontal axis represents the east-west azimuth coordinate, the vertical axis represents the north-south azimuth coordinate, curve 41 is the old well trajectory, curve 42 is the trajectory adjusted in real time after side drilling, and other straight lines are the theoretical trajectories after modification. It is necessary to find the hole within the modified azimuth range.

[0071] 3. Adopt a staged directional drilling approach, targeting the corrected wellbore trajectory of the old well. Use the nearest wellbore trajectory control method and design a drill-in-place design. Use a steerable drilling tool assembly with a build rate approximately 10-20% higher than the designed build rate for directional drilling. Based on the predicted results, use a rotary table composite drilling method to slightly decrease the inclination for a section, and then conduct directional drilling again based on the trajectory requirements. Composite drilling has a tendency to slightly decrease the inclination, which can fully utilize the natural build rate of the drill tool to improve target accuracy.

[0072] 4. Trajectory on-target analysis: Use the collision avoidance scan diagram to determine if a specific well section is on-target. For example, the existing Landmark software tool can be used to input measurement data and old well inclination data into the software to generate an collision avoidance scan diagram. Specifically, the target trajectory is generated based on the old well inclination data, and the real-time trajectory (i.e., the sidetracking trajectory) is generated based on the measurement data. The target trajectory and the real-time trajectory form the collision avoidance scan diagram, which allows for intuitive visualization of the relative distance between the real-time trajectory and the old well trajectory.

[0073] like Figure 5 As shown, Figure 5 A schematic diagram of the anti-collision scanning of the side drilling trajectory and the corrected azimuth [-1, 2.5] envelope trajectory of the inclined data is shown.

[0074] Each curve represents the corrected azimuth value, with a correction interval of (-1, +2.5). The corrected azimuth values ​​corresponding to each curve are as follows:

[0075] Curve 1 is the curve trajectory with an orientation value of -1 (corrected curve);

[0076] Curve 2 is the curve trajectory with an orientation value of -0.5 (corrected curve);

[0077] Curve 3 is the curve trajectory with an orientation value of +0 (original curve);

[0078] Curve 4 is the curve trajectory with an orientation value of +0.5 (corrected curve);

[0079] Curve 5 is the curve trajectory with an orientation value of +1 (corrected curve);

[0080] Curve 6 is the curve trajectory with an azimuth value of +1.5 (corrected curve);

[0081] Curve 7 is the curve trajectory of the azimuth value +2 (corrected curve);

[0082] Curve 8 is a curve trajectory with an azimuth value of +2.5 (corrected curve).

[0083] When the corrected curve approaches the actual drilling trajectory represented by the horizontal line, the distance will become smaller and smaller. Theoretically, when the distance is 0m, it means that the re-entry into the old wellbore is successful.

[0084] 5. Analyze and determine whether the wellbore has been successfully re-entered by combining changes in the drilling rate and the rock cuttings returned from the well logging. For example, this can be determined by changes in the drilling rate and / or sand return, which is not limited in this embodiment of the present invention.

[0085] Through the above Figure 5 The anti-collision scanning diagram shown, combined with the changes in engineering drilling speed and the rock cuttings return from logging, can more accurately analyze and judge whether the old wellbore has been successfully re-entered.

[0086] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products or apparatuses.

[0087] Each embodiment in this specification is described in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. Moreover, the system embodiments described above are merely schematic, in which the modules and units described as separate components may or may not be physically separated, that is, they may be located on one network unit, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. A person of ordinary skill in the art can understand and implement it without making any creative effort.

[0088] The embodiments of the present invention are described in detail above. Specific implementation methods are used herein to illustrate the present invention. The description of the above embodiments is only used to help understand the method and system of the present invention. They are only embodiments of a part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention, and the content of this specification should not be understood as limiting the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for improving the efficiency of sidetracking re-entry into a wellbore, characterized in that: The method comprises: Obtain continuous inclination survey data from old wells and gyro logging data obtained from re-surveying of old wells; determining an azimuth error interval based on the old well continuous inclination measurement data and the gyro logging data; Establishing an envelope trajectory of the azimuth error interval and using it as a target trajectory; the target trajectory includes a target trajectory of any azimuth value in the azimuth correction interval, and the actual drilling trajectory collides with the target trajectory, that is, the actual drilling trajectory can achieve eye finding with azimuth interval correction; Perform sidetracking construction and control the sidetracking trajectory according to the target trajectory until the old wellbore is found.

2. The method for improving the efficiency of sidetracking re-entry into a wellbore according to claim 1, characterized in that: The old well continuous inclination survey data includes: a continuous azimuth and well inclination azimuth angle data set of the old well.

3. The method for improving the efficiency of sidetracking re-entry into a wellbore according to claim 1, characterized in that: The determining of the azimuth error interval according to the old well continuous inclination measurement data and the gyro logging data comprises: An azimuth error interval is determined based on the difference between the gyro logging data and the old well continuous inclination measurement data.

4. The method for improving the efficiency of sidetracking re-entry into a wellbore according to claim 3, characterized in that: The method further comprises: Obtain original geological logging report records; Verifying the continuous inclination measurement data of the old well according to the original geological logging report to obtain verified continuous inclination data; The determining of the azimuth error interval according to the old well continuous inclination measurement data and the gyro logging data comprises: An azimuth error interval is determined based on the difference between the gyro logging data and the calibrated connected inclination data.

5. The method for improving the efficiency of sidetracking re-entry into a wellbore according to claim 4, characterized in that: The original geological logging report records include any one or more of the following information: rock cutting description, geological layering data, old well casing data, drilling time changes, and gas logging data.

6. The method for improving the efficiency of sidetracking and re-entering the wellbore according to any one of claims 1 to 5, characterized in that: The sidetracking construction and controlling the sidetracking trajectory according to the target trajectory until the old wellbore is found include: Conduct side drilling construction and perform real-time trajectory tracking measurement to obtain measurement data; Generate actual drilling trajectory based on measurement data; Correcting the actual drilling trajectory according to the target trajectory; Determine whether old wellbore has been found; If yes, it is determined that the re-entry into the old wellbore is successful and the sidetracking operation is stopped.

7. The method for improving the efficiency of sidetracking and re-entering the wellbore according to claim 6, characterized in that: The real-time trajectory tracking measurement comprises: The MWD wireless directional drilling instrument is used for real-time trajectory tracking measurement.

8. The method for improving the efficiency of sidetracking and re-entering the wellbore according to claim 6, characterized in that: Determine whether an old wellbore has been found based on any one or more of the following methods: changes in engineering drilling speed, geological sand sample conditions, and trajectory anti-collision theory.

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