Monitoring operation method of underground video acquisition equipment

Abstract

The invention discloses a monitoring operation method of underground video acquisition equipment. Comprising the steps that according to the length of a perforation interval of a target horizontal well and the total hole number, the estimated shooting duration of monitoring operation of the perforation interval of the target horizontal well by video collection equipment is determined; according to the first preset shooting time point, the shooting estimated duration and the pressure drop rate data of well closing of the target horizontal well, determining a first operation minimum pressure value of the video acquisition equipment on perforation interval monitoring operation; when the first operation minimum pressure value is smaller than or equal to the fracture closing pressure value of the target horizontal well, water injection and energy supplementation operation is conducted on the target horizontal well, so that the first operation minimum pressure value is larger than the fracture closing pressure value of the target horizontal well; and the video acquisition equipment is conveyed to the perforation position of the target horizontal well, and video shooting is carried out at least from the first preset shooting time point. The invention can effectively solve the problem that the screen of the underground television is shielded by the returned fluid at the position of the horizontal section.

Description

Technical Field

[0001] The invention belongs to the field of oil production engineering, and in particular relates to a monitoring operation method of downhole video acquisition equipment. Background Art

[0002] With the continuous innovation of fracture monitoring methods, fracture characterization technology has gradually moved towards more refinement and precision, and horizontal well volume fracturing technology has achieved good results in the development of shale oil and gas reservoirs. At present, commonly used fracture monitoring methods include microseismic, optical fiber, tracer, downhole television, etc. Different monitoring methods have different principles and advantages. Among them, downhole television is a monitoring method that uses high-temperature, high-pressure downhole cameras and logging cable high-speed transmission systems to directly obtain real-time video images downhole. Through image enhancement, transformation, calibration, quantitative analysis, target recognition, real-scene modeling and other related processing, real and reliable wellbore information is obtained to eliminate the uncertainty of downhole conditions. Downhole television is widely used and can monitor the integrity of oil casing, find water and leaks, monitor liquid production profiles, etc. In hydraulic fracturing, it is mainly used to monitor the abrasion of perforation holes and evaluate multi-cluster uniformity.

[0003] However, in the actual downhole television monitoring process, due to the serious filtration loss of slick water fracturing fluid, the bottom hole pressure was below the closing pressure, and the formation fluid returned, causing the screen of the downhole television to be blocked by the returned fluid in some positions of the horizontal section, affecting the smooth progress of the monitoring work and reducing the success rate of the monitoring operation. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a monitoring operation method for downhole video acquisition equipment, thereby avoiding the problem of the screen of the downhole television being blocked by the returned fluid in some positions of the horizontal section, and improving the success rate of downhole television monitoring.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for monitoring an underground video acquisition device includes the following steps:

[0007] S1, according to the length of the perforation section of the target horizontal well, determining the estimated shooting time of the perforation section monitoring operation of the target horizontal well by the video acquisition device;

[0008] S2, determining a first minimum operating pressure value of the video acquisition device for monitoring the perforation section according to a first predetermined shooting time point of the video acquisition device, an estimated shooting time, and the pressure drop rate data of the target horizontal well;

[0009] S3, when the first operation minimum pressure value is less than or equal to the fracture closure pressure value of the target horizontal well, perform water injection and energy replenishment operation on the target horizontal well to make the first operation minimum pressure value greater than the fracture closure pressure of the target horizontal well; when the first operation minimum pressure value is greater than the fracture closure pressure value of the target horizontal well, proceed to S4;

[0010] S4, transporting the video acquisition device to the perforation section of the target horizontal well, starting video shooting from a first predetermined shooting time point, and obtaining first video data.

[0011] Preferably, in S1, the total length of the perforation section of the target horizontal well is determined according to the length of the horizontal section of the target horizontal well and the positions of the perforation holes.

[0012] Preferably, the specific process of S2 is: according to the estimated shooting time and the pressure drop rate data of the target horizontal well, the minimum pressure calculation value of the video acquisition equipment for the perforation section monitoring operation is obtained; according to the minimum pressure calculation value and the preset additional pressure value, the first operation minimum pressure value of the video acquisition equipment for the perforation section monitoring operation is determined.

[0013] Preferably, the preset additional pressure value is in the range of 1-2 MPa.

[0014] Preferably, in S3, before performing water injection and energy replenishment operations on the target horizontal well, a well flushing operation is performed on the horizontal well.

[0015] Preferably, in S4, when it is determined according to the first video data that the screen of the video acquisition device is blocked, water injection and energy replenishment operations are performed again on the target horizontal well;

[0016] The video acquisition device is transported to the perforation section of the target horizontal well to shoot the video and obtain the second video data.

[0017] Further, the process of performing the water injection and energy replenishment operation again is: increasing the value of the preset additional pressure value, and determining the second operation minimum pressure value of the video acquisition device for the perforation section monitoring operation according to the first predetermined shooting time point of the video acquisition device, the estimated shooting time, the pressure drop rate data of the target horizontal well and the increased preset additional pressure value;

[0018] The target horizontal well is injected with water to replenish energy, so that the second operation minimum pressure value is greater than the fracture closure pressure of the target horizontal well.

[0019] Preferably, in S4, when it is determined according to the first video data that the screen of the video acquisition device is not blocked, a real-time measurement of the bottom hole pressure of the target horizontal well is obtained;

[0020] Whether to open the well and release the fluid is determined based on the real-time measured bottom hole pressure of the target horizontal well and the fracture closure pressure of the target horizontal well.

[0021] Preferably, in S3, a small-scale fracturing test is performed on the target horizontal well to obtain test data of the target horizontal well; and the test data of the target horizontal well is analyzed using a G function curve analysis method to obtain a fracture closure pressure value of the target horizontal well.

[0022] Preferably, in S3, the fracture closure pressure value of the target horizontal well is obtained according to the fracture closure pressure value of at least one adjacent well; wherein the adjacent well is a horizontal well located in the same block as the target horizontal well.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention determines the estimated shooting duration of the perforation section monitoring operation of the target horizontal well by the video acquisition device according to the total length of the perforation section of the target horizontal well; determines the first minimum operating pressure value of the perforation section monitoring operation of the video acquisition device according to the first predetermined shooting time point of the video acquisition device, the estimated shooting duration and the pressure drop rate data of the target horizontal well; when the first minimum operating pressure value is less than or equal to the fracture closure pressure value of the target horizontal well, the target horizontal well is injected with water to replenish energy, so that the first minimum operating pressure value is greater than the fracture closure pressure of the target horizontal well; the video acquisition device is transported to the perforation position of the target horizontal well, and video shooting is performed at least from the first predetermined shooting time point to obtain the first video data; the implementation method realizes the adjustment of the bottom hole pressure, and at the same time achieves the purpose of the bottom hole pressure being greater than the closure pressure and improving the pressure balance degree between sections, solves the problem of formation fluid returning and blocking the screen, and thus improves the success rate of downhole television monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The present invention is a flow chart of the underground video acquisition equipment monitoring operation method. DETAILED DESCRIPTION

[0026] The technical solutions 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 only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0027] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] Example 1

[0030] like Figure 1 As shown, this embodiment discloses a method for monitoring operation of a downhole video acquisition device, including:

[0031] Step S10, determining an estimated duration of the video acquisition device's filming of the perforation section monitoring operation of the target horizontal well according to the perforation section length of the target horizontal well.

[0032] In this embodiment, a target horizontal well to be monitored is selected, and the length of the perforation section is obtained, so that the estimated shooting time required after the video acquisition device is lowered can be obtained, thereby improving efficiency and saving resources.

[0033] Optionally, the total length of the perforation section of the target horizontal well is determined according to the length of the horizontal section of the target horizontal well and the total number of holes in the perforation section.

[0034] The total length of the perforation section of the target horizontal well can be obtained by the horizontal section length of the target horizontal well and the total number of holes in the perforation section.

[0035] Step S20, determining a first minimum operating pressure value of the video acquisition device for monitoring the perforation section according to a first predetermined shooting time point of the video acquisition device, an estimated shooting time, and the pressure drop rate data of the target horizontal well.

[0036] In this embodiment, when the video acquisition device performs monitoring operations on the perforation section, the bottom hole pressure needs to be greater than or equal to the first operation minimum pressure value, and the first operation minimum pressure value is determined by the first predetermined shooting time point of the video acquisition device, the estimated shooting time, and the pressure drop rate data of the target horizontal well.

[0037] Optionally, determining the first operating minimum pressure value of the video acquisition device for the perforation section monitoring operation based on the estimated shooting time and the pressure drop rate data of the target horizontal well includes: obtaining the calculated minimum pressure value of the video acquisition device for the perforation section monitoring operation based on the estimated shooting time and the pressure drop rate data of the target horizontal well; and determining the first operating minimum pressure value of the video acquisition device for the perforation section monitoring operation based on the calculated minimum pressure and a preset additional pressure value.

[0038] Among them, the first operation minimum pressure value of the video acquisition equipment for the perforation section monitoring operation is determined by the minimum pressure calculation value and the preset additional pressure value. The minimum pressure calculation value is determined by the estimated shooting time and the pressure drop rate data of the target horizontal well. By adding the preset additional pressure value, it can be ensured that the cracks will not close during the shooting process, thereby improving the one-time success rate of the operation.

[0039] Furthermore, the preset additional pressure value ranges from 1 to 2 MPa.

[0040] The preset additional pressure value is set to offset the influence of the deviation of the minimum pressure value of the first operation of each section caused by reservoir heterogeneity.

[0041] Step S30, when the first operation minimum pressure value is less than or equal to the fracture closure pressure value of the target horizontal well, water injection and energy replenishment operation is performed on the target horizontal well to make the first operation minimum pressure value greater than the fracture closure pressure of the target horizontal well.

[0042] In this embodiment, when the video acquisition device is shooting, the first operation minimum pressure value needs to be greater than the fracture closure pressure of the target horizontal well. If the first operation minimum pressure value is less than or equal to the fracture closure pressure value of the target horizontal well, it is necessary to perform water injection and energy replenishment operations on the target horizontal well.

[0043] Optionally, before performing water injection and energy replenishment operations on the target horizontal well, a well flushing operation is performed on the horizontal well. By performing well flushing operations on the horizontal well and then performing water injection and energy replenishment operations, the bottom hole pressure is made greater than the fracture closure pressure value of the target horizontal well, which can ensure clear shooting.

[0044] The role of injecting clean water to replenish energy is, on the one hand, to make the pressure at each hole greater than the closing pressure, so that the oil, sand, etc. in the cracks cannot enter the wellbore; on the other hand, it promotes pressure balance between sections.

[0045] The method for obtaining the fracture closure pressure value of the target horizontal well can be more direct and accurate by performing a small-scale fracturing test on the target horizontal well and analyzing the test data of the target horizontal well using the G function curve analysis method to obtain the fracture closure pressure value of the target horizontal well.

[0046] If a small-scale fracturing test has not been carried out on the target horizontal well, the fracture closure pressure value of the target horizontal well will be converted according to the fracture closure pressure gradient obtained from the small-scale fracturing test analysis of the adjacent wells in the same block. This can achieve lower construction costs while ensuring the accuracy of the fracture closure pressure value. The adjacent wells are horizontal wells located in the same block as the target horizontal well.

[0047] Step S40, the video acquisition device is transported to the depth of the perforation section through the coiled tubing to complete the acquisition of all holes. If the screen is still blocked during the acquisition process, it indicates that the additional pressure is too small. The original additional pressure is increased, the pressure required at the wellhead is recalculated, the well is re-washed and recharged, and the coiled tubing is lowered to carry the downhole television to monitor the hole shape until all holes are recorded.

[0048] Specifically: a video acquisition device is transported to a perforation section of a target horizontal well, and video shooting is performed at least from a first predetermined shooting time point to obtain first video data.

[0049] In this embodiment, the video acquisition device is lowered into the perforation section of the target horizontal well to start video shooting at least from a first predetermined shooting time point to obtain first video data.

[0050] Optionally, when it is determined based on the first video data that the screen of the video acquisition device is blocked, water injection and energy replenishment operations are performed again on the target horizontal well; the video acquisition device is transported to the perforation section of the target horizontal well for video shooting to obtain second video data.

[0051] If the screen is blocked during video shooting, it means that the target horizontal well needs to be re-injected with water to replenish energy. On the one hand, this can make the pressure at each hole greater than the fracture closure pressure, and the oil, sand, etc. in the fracture cannot enter the wellbore. On the other hand, it can promote pressure balance between sections and reduce the impact of reservoir heterogeneity.

[0052] Furthermore, when it is determined based on the first video data that the screen of the video acquisition device is blocked, water injection and energy replenishment operations are performed again on the target horizontal well, including: increasing the value of the preset additional pressure value, and determining the second minimum operating pressure value of the video acquisition device for the perforation section monitoring operation based on the first predetermined shooting time point of the video acquisition device, the estimated shooting duration, the pressure drop rate data of the target horizontal well and the increased preset additional pressure value; and performing water injection and energy replenishment operations on the target horizontal well so that the second minimum operating pressure value is greater than the fracture closure pressure of the target horizontal well.

[0053] Among them, in order to avoid the phenomenon that the screen of the video acquisition device is blocked, it is necessary to increase the value of the preset additional pressure value, and adjust the second operating minimum pressure value of the video acquisition device for the perforation section monitoring operation according to the first predetermined shooting time point of the video acquisition device, the estimated shooting duration, the pressure drop rate data of the target horizontal well and the increased preset additional pressure value, so that the second operating minimum pressure value is greater than the fracture closure pressure of the target horizontal well, ensuring that subsequent shooting is normal.

[0054] Optionally, after the operation is completed, when it is determined based on the first video data that the screen of the video acquisition device is not blocked, the real-time measurement of the bottom hole pressure of the target horizontal well is obtained; based on the real-time measurement value of the bottom hole pressure of the target horizontal well and the fracture closure pressure of the target horizontal well, it is determined whether to perform the well opening and blowout operation.

[0055] Among them, when the screen of the video acquisition device is not blocked, the bottom hole pressure of the target horizontal well is measured in real time, and combined with the fracture closure pressure of the target horizontal well, it is judged whether the fracture is closed and the subsequent construction operations are adjusted.

[0056] Among them, the bottom hole pressure value can be converted by the wellhead pressure value.

[0057] If the wellhead pressure shows that the formation fractures have not closed, continue to block the well until the fractures are closed, then open the well for blowout. If the wellhead pressure shows that the formation fractures have closed, open the well directly for blowout.

[0058] It can be seen from the above embodiments that the present invention determines the estimated shooting duration of the video acquisition device for the perforation section monitoring operation of the target horizontal well according to the perforation section length of the target horizontal well; determines the first minimum operating pressure value of the video acquisition device for the perforation section monitoring operation according to the first predetermined shooting time point of the video acquisition device, the estimated shooting duration and the pressure drop rate data of the target horizontal well; when the first minimum operating pressure value is less than or equal to the fracture closure pressure value of the target horizontal well, performs water injection and energy replenishment operation on the target horizontal well so that the first minimum operating pressure value is greater than the fracture closure pressure of the target horizontal well; transports the video acquisition device to the perforation section of the target horizontal well, and performs video shooting at least from the first predetermined shooting time point to obtain the first video data; realizes the adjustment of the bottom hole pressure, and at the same time achieves the purpose of achieving the bottom hole pressure greater than the closure pressure and improving the pressure balance between sections, solves the problem of formation fluid returning and blocking the screen, and thus improves the success rate of downhole television monitoring.

[0059] Example 2

[0060] This embodiment provides a method for monitoring an underground video acquisition device, which includes the following specific steps:

[0061] In order to explore the liquid inflow of each cluster in the segment and the erosion of the perforations during the fracturing process, Well H1 was selected to carry out downhole high-definition video imaging monitoring after multi-cluster fracturing of the horizontal well. The shape parameters and images of the perforations at different perforation positions in the horizontal section were obtained, the changes in the shape and size of the perforations before and after fracturing were analyzed, and the opening degree and transformation effect of different perforation clusters were evaluated, providing guidance for the optimization design of horizontal well volume fracturing.

[0062] Step 1: Well H1 is a horizontal well with 71 layers of drilling, 3267m of drilling depth and 1700m of vertical depth. DMS soluble ball seat segmented multi-cluster fracturing technology was used for fracturing transformation. A total of 23 stages were fractured. A small-scale fracturing test was carried out before the first stage of fracturing. The calculated closing pressure was 23.8MPa, and the converted wellhead pressure was 6.8MPa. Affected by the work system, Well H1 was sealed for a long time after fracturing. The wellhead pressure dropped to 4MPa (lower than the closing pressure) for 61 days. Therefore, the wellbore was directly treated with oil and pressure after sealing.

[0063] Step 2: The horizontal section of H1 well is 1300m long, with a total of 23 sections cleaned, and the estimated wellbore treatment operation time is 3 days. According to the pressure drop curve of H1 well in the early stage, the pressure drop rate is about 1MPa / d. Therefore, in order to ensure that the bottom hole pressure is always greater than the closing pressure during the operation, the minimum pressure required at the wellhead is predicted to be 9MPa.

[0064] Step 3: Circulate the coiled tubing to wash the well. After circulating the well twice at 1900m-3100m, flush at 3100m until the inlet and outlet liquids are consistent. Circulate and flush to the wellhead, take the return fluid and put it in a bucket. Use the downhole video instrument to test the recording effect. If the handwriting on the card can be clearly seen, it means the well washing is qualified. Then inject clean water into the well and monitor the change of wellhead pressure in real time. Stop water injection when the wellhead pressure reaches 9MPa.

[0065] Step 4: Use the oil connection to transport the video acquisition device to the depth of the first section of the perforation, start recording the first section of the hole shape, and then pull back to record the second section until all sections of the hole shape are recorded.

[0066] Step 5: After the downhole TV monitoring operation is completed, the wellhead pressure is 8MPa, which is still 1.2MPa higher than the closing pressure. Continue to seal the well until the fractures are closed, and then open the well for blowout.

[0067] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0068] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A method for monitoring operation of underground video acquisition equipment, characterized in that: The process includes: S1, according to the length of the perforation section of the target horizontal well, determining the estimated shooting time of the perforation section monitoring operation of the target horizontal well by the video acquisition device; S2, determining a first minimum operating pressure value of the video acquisition device for monitoring the perforation section according to a first predetermined shooting time point of the video acquisition device, an estimated shooting time, and the pressure drop rate data of the target horizontal well; S3, when the first operation minimum pressure value is less than or equal to the fracture closure pressure value of the target horizontal well, perform water injection and energy replenishment operation on the target horizontal well to make the first operation minimum pressure value greater than the fracture closure pressure of the target horizontal well; when the first operation minimum pressure value is greater than the fracture closure pressure value of the target horizontal well, proceed to S4; S4, transporting the video acquisition device to the perforation section of the target horizontal well, starting video shooting from a first predetermined shooting time point, and obtaining first video data.

2. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: In S1, the total length of the perforation section of the target horizontal well is determined according to the horizontal section length and the perforation hole positions of the target horizontal well.

3. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: The specific process of S2 is: according to the estimated shooting time and the pressure drop rate data of the target horizontal well, the minimum pressure calculation value of the video acquisition equipment for the perforation section monitoring operation is obtained; according to the minimum pressure calculation value and the preset additional pressure value, the first operation minimum pressure value of the video acquisition equipment for the perforation section monitoring operation is determined.

4. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: The preset additional pressure value range is 1-2MPa.

5. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: In S3, before performing water injection and energy replenishment operations on the target horizontal well, a well flushing operation is performed on the horizontal well.

6. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: In S4, when it is determined according to the first video data that the screen of the video acquisition device is blocked, water injection and energy replenishment operations are performed again on the target horizontal well; The video acquisition device is transported to the perforation section of the target horizontal well to shoot the video and obtain the second video data.

7. The method for monitoring operation of underground video acquisition equipment according to claim 6, characterized in that: The process of performing the water injection and energy replenishment operation again is: increasing the value of the preset additional pressure value, and determining the second operation minimum pressure value of the video acquisition device for the perforation section monitoring operation according to the first predetermined shooting time point of the video acquisition device, the estimated shooting time, the pressure drop rate data of the target horizontal well and the increased preset additional pressure value; The target horizontal well is injected with water to replenish energy, so that the second operation minimum pressure value is greater than the fracture closure pressure of the target horizontal well.

8. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: In S4, when it is determined according to the first video data that the screen of the video acquisition device is not blocked, a real-time measurement of the bottom hole pressure of the target horizontal well is obtained; Whether to open the well and release the fluid is determined based on the real-time measured bottom hole pressure of the target horizontal well and the fracture closure pressure of the target horizontal well.

9. The method for monitoring operation of underground video acquisition equipment according to claim 1, characterized in that: In S3, a small-scale fracturing test is performed on the target horizontal well to obtain test data of the target horizontal well; the test data of the target horizontal well is analyzed using a G function curve analysis method to obtain a fracture closure pressure value of the target horizontal well.

10. The underground video acquisition equipment monitoring operation method according to claim 1, characterized in that: In S3, the fracture closure pressure value of the target horizontal well is obtained according to the fracture closure pressure value of at least one adjacent well; wherein the adjacent well is a horizontal well located in the same block as the target horizontal well.

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