Expansion pipe plugging method based on repeated fracturing cased well
阅读说明：本技术 一种基于重复压裂套管井的膨胀管封堵方法 (Expansion pipe plugging method based on repeated fracturing cased well ) 是由 赵涛 齐月魁 祝效华 石昌帅 易博 于 2019-07-12 设计创作，主要内容包括：本发明公开的一种基于重复压裂套管井的膨胀管封堵方法,包括步骤：第一步、对于在岩层(1)中油井具有的油井套管(10),对其内的原射孔段套管进行检测定位,并清洗油井套管(10)的内壁；第二步、将膨胀管(4)及配套膨胀系统,对应下放至原射孔段套管位置；第三步、连接地面的水泥车,准备通过膨胀管(4),来对需要封堵的原射孔段套管进行膨胀施工；第四步、启动膨胀管(4)进行膨胀施工,实现对原射孔段套管的封堵作业。本发明公开的一种基于重复压裂套管井的膨胀管封堵方法,其可以弥补目前压裂暂堵剂的缺点,节约成本、增加经济效益,降低了压裂施工风险,具有重大的生产实践意义。(The invention discloses an expansion pipe plugging method based on a repeated fracturing cased well, which comprises the following steps: firstly, detecting and positioning an oil well casing (10) of an oil well in a rock stratum (1) and cleaning the inner wall of the oil well casing (10); secondly, correspondingly lowering the expansion pipe (4) and a matched expansion system to the position of the casing pipe of the original perforation section; thirdly, a cement truck connected with the ground is prepared to carry out expansion construction on the original perforation section casing pipe needing to be plugged through an expansion pipe (4); and fourthly, starting the expansion pipe (4) to perform expansion construction, and realizing plugging operation on the casing pipe of the original perforation section. The invention discloses an expansion pipe plugging method based on a repeated fracturing cased well, which can make up for the defects of the conventional fracturing temporary plugging agent, save cost, increase economic benefit, reduce fracturing construction risk and has great production practice significance.)
1. An expansion pipe plugging method based on a repeated fracturing cased well is characterized by comprising the following steps:
firstly, detecting and positioning an oil well casing (10) of an oil well in a rock stratum (1) and cleaning the inner wall of the oil well casing (10);
secondly, correspondingly lowering the expansion pipe (4) and a matched expansion system to the position of the casing pipe of the original perforation section;
thirdly, a cement truck connected with the ground is prepared to carry out expansion construction on the original perforation section casing pipe needing to be plugged through an expansion pipe (4);
and fourthly, starting the expansion pipe (4) to perform expansion construction, and realizing plugging operation on the casing pipe of the original perforation section.
2. The method of claim 1, wherein in the first step, a caliper is used to measure the position of the casing in the original wellbore section in the well;
the original perforation section casing is an oil well casing (10) part which takes an original perforation (20) as a center and is preset with a first distance from top to bottom.
3. The method of claim 1, characterized in that the inner wall of the well casing (10) is cleaned by scraping the well casing (10) several times within the preset original perforation cleaning interval by lowering the external thickened tubing;
the preset original perforation cleaning well section is an oil well casing (10) part which takes the original perforation (20) as the center and is preset with a second distance from top to bottom.
4. The method of claim 1, characterized in that the inner wall of the well casing (10) is cleaned by scraping the well casing (10) several times within a predetermined original perforation cleaning interval by lowering a conical mill and an external heavy tubing;
the preset original perforation cleaning well section is an oil well casing (10) part which takes the original perforation (20) as the center and is preset with a second distance from top to bottom.
5. The method according to claim 1, characterized in that in the first step, it further comprises a pressure test step, in particular:
after the inner wall of the oil well casing (10) is cleaned, the pressure test is carried out on the external thickened oil pipe column through ball throwing, the test pressure is 45MPa, and when the pressure is not reduced after the pressure is stabilized for 30min, the internal pressure resistance of the external thickened oil pipe is judged to be qualified.
6. The method of claim 1, wherein in the second step, after the expansion pipe and the associated expansion system are installed at the casing position of the original perforation section, the fixed type anchor and the movable type anchor are installed on the expansion pipe, and simultaneously, the expansion pipe string is lowered while being connected, and after the expansion pipe string is connected in its entirety, the expansion pipe string is magnetically positioned.
7. A method according to claim 1, characterized in that in the third step, before the expansion of the expanded pipe has formally started, it is checked whether the oil pipe in the well casing (10) is full of water, and if not, the oil pipe in the well casing (10) is rapidly pumped by means of a pressure pump and the air in the oil pipe is exhausted.
8. A method according to claim 1, characterized in that in the fourth step the expansion vessel (4) is expanded against the casing of the original perforation interval.
9. The method of claim 1, further comprising, after the fourth step, the steps of:
fifthly, after the expansion construction is finished, carrying out pressure test on the original perforated section casing pipe, and judging whether the expansion plugging operation on the original perforated section casing pipe is qualified or not;
and sixthly, when the expansion plugging operation of the casing pipe of the original perforation section is qualified, continuing fracturing operation on the new position of the oil well to obtain a new fractured well section position with a new crack (6), and perforating the new fractured well section position to obtain a new perforation (5).
10. The method as claimed in claim 9, wherein in the fifth step, after the expansion construction of the expansion pipe is completed, the pressure of the casing pipe of the original perforation section to be blocked is tested for 60MPa, and when the pressure is stabilized for 30min and the pressure drop is less than 1MPa, the expansion blocking operation of the casing pipe of the original perforation section is judged to be qualified.
Technical Field
The invention relates to the technical field of petroleum and natural gas industry and mechanical engineering, in particular to an expansion pipe plugging method based on a repeated fracturing cased well.
Background
With the continuous progress of the modern petroleum industry, the petroleum exploitation realizes important breakthrough in process technology, and at present, the fracturing technology of an oil well plays an important role in the process of petroleum production operation for many years, and has an obvious effect of improving the exploitation efficiency of an oil field.
Along with the continuous deepening of the oil and gas reservoir development process, the stratum permeability is gradually reduced along with the development time, so that the oil yield of the oil well after the primary fracturing is continuously reduced, and the oil field yield is severely restricted.
The repeated fracturing is an effective method for solving three problems of low yield, low efficiency, low permeability and the like of an oil field at present, and is also a key means for increasing the yield of a single well, ensuring the stable yield of the oil field and improving the economic benefit of the low permeability oil field. In addition, the repeated fracturing process has obvious effect on the yield increase of the fractured old well. In the repeated fracturing technology, the performance parameters of the fracturing temporary plugging agent play a decisive role in the success of repeated fracturing construction. The fracturing temporary plugging agent is a material for temporarily plugging old fractures, and the design of the temporary plugging agent needs to be designed by combining a target stratum structure, so that the temporary plugging agent has the defects of high cost, low applicability and the like.
In view of the characteristics of high cost, large use risk and no universal applicability of the conventional fracturing temporary plugging agent, a new plugging mode is urgently needed to be developed, so that the defects of the conventional fracturing temporary plugging agent can be overcome, the cost is saved, the economic benefit is increased, and the fracturing construction risk is reduced.
Disclosure of Invention
The invention aims to provide an expansion pipe plugging method based on a repeated fracturing cased well, aiming at the technical defects in the prior art.
Therefore, the invention provides an expansion pipe plugging method based on a repeated fracturing cased well, which comprises the following steps:
firstly, detecting and positioning an oil well casing in a rock stratum, wherein the oil well casing is provided with an original perforation section casing, and cleaning the inner wall of the oil well casing;
secondly, correspondingly lowering the expansion pipe and a matched expansion system to the position of the casing pipe of the original perforation section;
thirdly, connecting a cement truck on the ground, and preparing to perform expansion construction on the original perforation section casing pipe to be plugged through an expansion pipe;
and fourthly, starting the expansion pipe to perform expansion construction, and realizing plugging operation on the casing pipe of the original perforation section.
In the first step, a caliper is adopted to measure the position of a casing pipe of a primary perforation section in an oil well;
the original perforation section casing is an oil well casing part with an original perforation as a center and a first distance preset up and down.
The method comprises the following steps of scraping the oil well casing in the range of a preset original perforation cleaning well section for multiple times by adopting a mode of lowering an external thickened oil pipe, so as to clean the inner wall of the oil well casing;
the preset original perforation cleaning well section is an oil well casing part with an original perforation as a center and with a second distance from top to bottom.
The method comprises the following steps that a conical mill shoe is lowered and an oil pipe is externally thickened, so that the oil well casing in the range of a preset original perforation cleaning well section is scraped for multiple times, and the inner wall of the oil well casing is cleaned;
the preset original perforation cleaning well section is an oil well casing part with an original perforation as a center and with a second distance from top to bottom.
Wherein, in the first step, still include the pressure testing step, specifically be:
after the inner wall of the oil well casing is cleaned, the pressure test is carried out on the external thickened oil pipe column through ball throwing, the test pressure is 45MPa, and when the pressure is not reduced after the pressure is stabilized for 30min, the internal pressure resistance of the external thickened oil pipe is judged to be qualified.
And in the second step, after the expansion pipe and a matched expansion system are installed at the position of the casing pipe of the original perforation section, a fixed anchor and a movable anchor are installed on the expansion pipe, meanwhile, the expansion pipe column is placed while being connected, and after all the expansion pipe columns are connected, the expansion pipe column is magnetically positioned.
And in the third step, before the expansion pipe formally begins to expand, checking whether the oil pipe in the oil well casing is full of water, if not, quickly pumping water to the oil pipe in the oil well casing through the pressure pump, and exhausting air in the oil pipe.
And in the fourth step, the expansion pipe directly faces the casing pipe of the original perforation section to perform expansion action.
Wherein, after the fourth step, the following steps are further included:
fifthly, after the expansion construction is finished, carrying out pressure test on the original perforated section casing pipe, and judging whether the expansion plugging operation on the original perforated section casing pipe is qualified or not;
and sixthly, when the expansion plugging operation of the casing pipe of the original perforation section is qualified, continuing fracturing operation on the new position of the oil well to obtain a new fractured well section position with new cracks, and perforating the new fractured well section position to obtain new perforations.
In the fifth step, after expansion construction of the expansion pipe is completed, pressure testing is carried out on the original perforation section casing pipe needing to be plugged for 60MPa, and when pressure stabilizing is carried out for 30min and the pressure drop is smaller than 1MPa, the expansion plugging operation on the original perforation section casing pipe is judged to be qualified.
Compared with the prior art, the technical scheme provided by the invention has the advantages that the expansion pipe plugging method based on the repeated fracturing cased well can make up for the defects of the conventional fracturing temporary plugging agent, saves the cost, increases the economic benefit, reduces the fracturing construction risk and has great production practice significance.
Drawings
FIG. 1 is a flow chart of an expansion pipe plugging method based on a re-fractured cased well according to the present invention;
FIG. 2 is a schematic diagram of the present invention in cleaning the well wall of an oil well and locating the original perforation position;
FIG. 3 is a schematic view of the present invention in the installation and accurate positioning of an expansion vessel;
FIG. 4 is a schematic diagram of the expansion construction of the expansion pipe and the position of a new perforation according to the invention;
FIG. 5 is a schematic view of the present invention in a fracturing operation;
in the figure: 1. rock stratum, 2. old crack, 3 casing well, 4. expansion pipe, 5. new perforation, 6. new crack;
10. oil well sleeve, 20. original perforation;
Detailed Description
In order that those skilled in the art will better understand the technical solution of the present invention, the following detailed description of the present invention is provided in conjunction with the accompanying drawings and embodiments.
Referring to fig. 1 to 5, the invention provides an expansion pipe plugging method based on a re-fractured cased well, which comprises the following steps:
firstly, detecting and positioning an oil well casing 10 of an oil well in a
secondly, correspondingly lowering the
thirdly, a cement truck connected with the ground is prepared to carry out expansion construction on the original perforation section casing pipe (namely the plugging section casing pipe) to be plugged through an
and fourthly, starting the
In the first step, in particular, a caliper is used to measure the position of the casing of the original perforation interval in the well, preferably the portion of the well casing (10) centered at the original perforation 20 and having a first distance (e.g. 5 meters) above and below. In which, the old crack 2 formed by the existing fracturing process is arranged beside the original perforation 20, as shown in fig. 2, so that the inner diameter variation and the accurate position of the casing at the original perforation section can be checked by logging to determine the specification of the expansion pipe and the thickness of the rubber ring, thereby increasing the success rate of expansion.
It should be noted that, for an oil well, the cementing string includes an oil well casing 10, the oil well casing 10 has an oil pipe therein, and an annular space between the oil pipe and the casing is an oil casing annulus.
In the first step, in the concrete implementation, the oil well casing 10 in the range of the preset original perforation cleaning well section is scraped for many times by adopting a mode of lowering an external thickened oil pipe, so that the inner wall (namely the wall of the oil well) of the oil well casing 10 is cleaned, and the inner wall of the casing of the plugging section (namely the patching section) in the oil well is ensured to be clean and have no dead angle;
the pre-set original perforation clean-out interval is preferably a portion of the well casing (10) that is pre-set a second distance (e.g., 10 meters) above and below the original perforation 20, the second distance being greater than the first distance.
In the first step, in the concrete implementation, the mode of lowering a conical mill and externally thickening an oil pipe can be adopted to scrape the oil well casing 10 within the range of the preset original perforation cleaning well section for many times, so that the inner wall of the oil well casing 10 (namely the wall of the oil well) is cleaned, and the inner wall of the casing of the plugging section (namely the patching section) in the oil well is ensured to be clean and have no dead angle;
the pre-set original perforation clean-out interval is preferably a portion of the well casing (10) that is pre-set a second distance (e.g., 10 meters) above and below the original perforation 20, the second distance being greater than the first distance.
In the first step, in concrete realization, still include the pressure testing step, specifically be:
after the inner wall of the oil well casing 10 is cleaned (namely, the well is cleaned), the externally thickened oil pipe column is subjected to pressure test by ball throwing, the test pressure is 45MPa, and when the pressure is stabilized for 30min and does not drop, the internal pressure resistance of the externally thickened oil pipe is judged to be qualified. It should be noted that this step is to ensure that the internal pressure resistance of the tubing is greater than the pressure required for expansion, thereby ensuring success rate.
In the second step, in the concrete realization, in former perforation section sleeve pipe position, with the inflation pipe and supporting expansion system installation back, install fixed anchor and movable anchor on the inflation pipe, simultaneously, the side is connected and is transferred the inflation pipe post, waits to connect whole inflation pipe posts after, carries out the magnetism location to the inflation pipe post.
It should be noted that, for the present invention, the expansion pipe and the matched expansion system may be any one of the common oil expansion pipes and matched expansion systems in the field of oil development, and the expansion pipe and the matched expansion system can only be driven by hydraulic or mechanical means to increase the diameter of the expansion pipe, which is the prior art and is not specifically described. For example, the expansion pipe and the matched expansion system which are produced by Huading hongji oil engineering technology (Beijing) and applied to oil field development can be adopted. Of course, other technically mature expansion pipes and matched expansion systems produced by other manufacturers can also be adopted.
In the present invention, it should be noted that in the expansion pipe and the expansion system, the fixed anchor is immovable and fixed on the oil pipe, and mainly functions to limit the axial displacement of the expansion pipe when the expansion pipe is expanded in the first stroke. The movable anchor is movable as the name suggests, and the main function is that when lifting the oil pipe, the movable anchor can not move along with the oil pipe and always keeps being connected with the expansion pipe, and after the first stroke is finished, the movable anchor has the same function as the fixed anchor and limits the axial movement of the expansion pipe.
It should be noted that the fixed anchor and the movable anchor are common devices used in conjunction with an expansion pipe, which is the prior art and is not specifically described.
In the third step, before the expansion pipe formally begins to expand, whether the oil pipe in the oil well casing 10 is full of water is checked, and if not, the oil pipe in the oil well casing 10 is rapidly pumped with water through the pressure pump to exhaust the air in the oil pipe.
In the present invention, the concrete implementation is that in the fourth step, the
It should be noted that, as shown in fig. 4 and 5, the pressure P1 is the pressure required for expanding the
In a specific implementation of the present invention, after the fourth step, the method further includes the following steps:
fifthly, after the expansion construction is finished, carrying out pressure test on the original perforated section casing pipe (namely the plugging section casing pipe), and judging whether the expansion plugging operation on the original perforated section casing pipe is qualified or not;
and sixthly, when the expansion plugging operation of the casing pipe of the original perforation section is qualified, continuing fracturing operation (namely, carrying out repeated fracturing process) on the new position of the oil well to obtain a new fractured well section position with a
In the fifth step, specifically, after the expansion construction of the expansion pipe is completed, the pressure of the casing pipe at the original perforation section to be plugged (namely, the casing pipe at the plugging section) is tested for 60MPa, and when the pressure is stabilized for 30min and the pressure drop is less than 1MPa, the expansion plugging operation of the original perforation section is judged to be qualified.
In particular, the pressure test can be performed on the casing of the original perforation section of the
In the sixth step, specifically, after the fracturing pressure is met, perforating is performed on the new fracturing position, and a repeated fracturing process is performed.
In the present invention, it is to be noted that, in the oil drilling and completion, the oil bed (rock bed) is perforated by using the existing perforating gun.
It should be noted that in the field of oil development, fracturing refers to a method for forming a fracture in an oil and gas layer by using the hydraulic action in the process of oil or gas production, and a fracturing process is a common oil development method and comprises various fracturing methods such as packer separate-layer fracturing, flow-limiting method separate-layer fracturing, plugging ball selective fracturing and the like.
Based on the technical scheme, the invention is an expansion pipe plugging technology based on a repeated fracturing cased well, and the original perforation is plugged by an external rubber ring of the expansion pipe in the fracturing well, so that the perforation and fracturing processes are carried out at a new position. The main process is that the pipe is put to a preset position (namely the position corresponding to the original perforation) and then expanded, perforation is carried out at the new fracturing position, and then the fracturing process is carried out.
Therefore, based on the above expression, compared with the prior art, the expansion pipe plugging method based on the repeated fracturing cased well provided by the invention can make up for the defects of the existing fracturing temporary plugging agent, save the cost, increase the economic benefit, reduce the fracturing construction risk and has great production practice significance.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
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