阅读说明：本技术 一种用于套管补贴井的一趟钻作业管柱及作业方法 (One-trip drilling operation pipe column for casing patching well and operation method ) 是由 席仲琛 苏敏文 兰建平 隆世明 陈雄 柳瑞军 李星星 田文超 廖作杰 李景彬 左 于 2019-09-03 设计创作，主要内容包括：本发明提供了一种用于套管补贴井的一趟钻作业管柱及作业方法,选择多层系储层老井作为改造的目标井,将目标井内的层系分为两类,一类是未压裂过的新层,另一类是已通过套管补贴临时封堵的老层,改造目标井时,先下放一趟钻作业管柱改造新层,对新层进行射孔、压裂、排液,然后继续利用一趟钻作业管柱对老层进行打孔,最后对全井筒进行冲砂作业,一次下入一趟钻作业管柱完成对新层的全部改造,以及对老层的继续动用,实现新老合层生产,提高多层系储层老井的开发速度和开发效率。(The invention provides a one-trip drilling operation tubular column for a casing patching well and an operation method, wherein a multi-layer system reservoir old well is selected as a modified target well, the layer system in the target well is divided into two types, one type is a new layer which is not fractured, and the other type is an old layer which is temporarily blocked by casing patching, when the target well is modified, the one-trip drilling operation tubular column is firstly put down to modify the new layer, the new layer is subjected to perforation, fracturing and liquid drainage, then the one-trip drilling operation tubular column is continuously utilized to punch the old layer, finally, the whole well barrel is subjected to sand washing operation, the one-trip drilling operation tubular column is put in once to complete the complete modification of the new layer, and the old layer is continuously used, so that the production of the new and old layer is realized, and the development speed and the development efficiency of the multi-layer system reservoir old well are improved.)

1. The utility model provides a one trip drilling operation tubular column for casing patching well which characterized in that, it includes coiled tubing (1), connector (2), bypass valve (3), check valve (4), giving up (5), centralizer (6), sprayer (7), packer (8), sleeve pipe festival hoop locator (9), end cap (10) that from last to connecting gradually down, sprayer (7) have three nozzle, and the diameter of each nozzle is 5.2 mm.

2. A drill string for a casing patching well as in claim 1, characterized in that the bypass valve (3) is a sliding sleeve type bypass valve; the check valve (4) is a double-valve flap type check valve, and double valve flaps of the check valve are connected to the one-trip drilling operation pipe column body through eccentric pin shafts.

3. A method of operating a drill string for casing patching a well according to claim 1 or 2, comprising the steps of:

step S1, selecting a multilayer system reservoir old well with part of opened layers and adopting casing patching to plug perforation holes as a target well, wherein the casing patching plugged perforation holes are patched and the earlier fractured layer is called an old layer of the target well, and the un-perforated and fractured layer is called a new layer of the target well;

step S2, assembling a one-trip drilling operation pipe column for the casing patching well, and lowering the one-trip drilling operation pipe column into the target well;

step S3, perforating and fracturing the new layer of the target well;

step S4, lifting a drill operation pipe column for annular open flow liquid drainage until the casing pressure is reduced to be lower than the stratum closing pressure;

step S5, repeating the step S3 and the step S4, and completing the reconstruction of all new layers in the target well layer by layer from bottom to top, wherein the reconstruction comprises perforation, fracturing and annular open flow liquid drainage;

step S6, performing hydraulic sand blasting and punching on all old layers layer by layer from bottom to top by adopting a hydraulic sand blasting mode to complete the punching of all old layers;

step S7, lowering the coiled tubing (1), circulating sand washing from top to bottom to the bottom of the artificial well, carrying out sand washing operation on the whole well casing, and after the sand washing operation is finished, pulling out a drilling operation pipe column;

and step S8, after all old layers and all new layers in the target well are transformed, putting the oil well production pipe column into the target well, and carrying out the combined layer production of the new and old layers.

4. The method of operating a drill string for subsiding a well in casing of claim 3, wherein the step of lowering the drill string into the target well at step S2 comprises the steps of:

step S201, lowering the one-trip drilling operation pipe column to a new layer of the lowest layer, enabling the lower end face of the ejector (7) to be lower than the bottom boundary of the perforation section of the new layer of the lowest layer by at least 30m, and stopping lowering;

step S202, lifting the coiled tubing (1) at a constant speed of not more than 5m/min, and performing depth correction and positioning on a pipe column in one drilling operation;

and step S203, after the depth correction and the positioning are finished, stopping lifting the coiled tubing (1).

5. The method of operating a drill string for casing a complemental well of claim 3, wherein the perforating and fracturing of the new zone of the target well of step S3 comprises the steps of:

step S301, injecting perforating fluid and perforating sand into the coiled tubing (1), wherein the perforating fluid carries the perforating sand to descend along the coiled tubing (1);

step S302, when the layer descends to a new layer to be modified, perforating fluid carries perforating sand to be sprayed out from a nozzle of an injector (7), and perforating operation is carried out on the new layer to be modified;

and step S303, after perforation is finished, continuously pumping and injecting perforating fluid into the pipe of the continuous oil pipe (1), simultaneously pumping and injecting sand-carrying fluid into the hollow part of the oil sleeve ring, and enabling the sand-carrying fluid to descend into a perforation hole to perform fracturing operation.

6. The method of claim 5, wherein the perforating sand in the step S301 is silica sand, the velocity of the silica sand ejected from the nozzle is not less than 185m/S, and the sand concentration is 120kg/m³And the injection time is not less than 8 min.

7. The method of claim 3, wherein the step S4 of raising the drill string to perform annular blowout and drainage until the casing pressure drops below the formation closure pressure comprises the steps of:

step S401, carrying out a formation closing pressure test, and recording the formation closing pressure as Pc;

step S402, closing the casing gate, and lifting the coiled tubing (1) at a speed of not more than 15m/S until the lower end face of the plug (10) is higher than the top boundary of the new layer perforation section to be reconstructed by more than 30 m;

and S403, opening the casing gate, performing open-flow drainage by using a ground throttle valve, adjusting the opening of the ground throttle valve, and ensuring that the drainage liquid amount is not more than 400L/min until the casing pressure measured on the ground is 5MPa less than the stratum closing pressure Pc, and finishing the open-flow drainage.

8. The method of claim 3, wherein the step S6 of perforating all old layers from bottom to top by hydraulic blasting comprises the steps of:

step S601, injecting perforating fluid and perforating sand into the coiled tubing (1), wherein the perforating fluid carries the perforating sand to descend along the coiled tubing (1);

step S602, when the perforating fluid descends to the old layer to be reconstructed, the perforating fluid carries perforating sand to be sprayed out from a nozzle of the sprayer (7), the patching pipe is eroded, a hole communicated with the old layer to be reconstructed and the shaft is formed, the perforating fluid carries the perforating sand to ascend and return to the ground along the annular space of the oil sleeve, and the hydraulic sand-blasting perforating operation is completed.

9. The method of claim 8, wherein the perforating sand of step S602 is silica sand, the velocity of the silica sand ejected from the nozzle is not less than 185m/S, and the sand concentration is 120kg/m³The spraying time is not less than 4.5 min; and S604, the displacement of the pump for injecting clear water is not less than 500L/min.

10. The method of claim 3, wherein the step S7 of positive circulation of sand washing from top to bottom to the bottom of the artificial well for sand washing operation of the whole well bore comprises the steps of:

step S701, putting steel balls into the coiled tubing (1), and opening a bypass channel of a bypass valve (3) through pressure build-up;

and S702, injecting clean water into the pipe of the coiled tubing (1) by a pump, wherein the clean water descends along the coiled tubing (1), flows out of a bypass channel of the bypass valve (3), ascends along the oil sleeve annulus, and carries the sand deposited in the shaft to the ground to finish sand washing operation.

Technical Field

The invention belongs to the technical field of oilfield development, and particularly relates to a one-trip drilling operation tubular column for a casing patching well and an operation method.

Background

In the old well of oil field, if some layer has been opened and the fracturing transformation is carried out, and plan to open and fracture the rest layer, and keep the productivity of the original old layer, the following process technology is usually adopted:

and transforming the fracturing pipe column of the first packer and the second packer.

Be connected with two packers in the tubular column, the interval between the packer is greater than the distance between waiting to reform transform the position perforation section top border and the bottom border, and the pit shaft is kept apart from waiting to reform transform the top bottom border of interval respectively to upper and lower packer, and fracturing fluid is down from the intraductal of fracturing tubular column, flows out from the sand blaster in the middle of two packers, then gets into and waits to reform transform the position.

The process method can effectively isolate the layer to be reconstructed and the reconstructed layer, avoids interlayer interference, can only add sand in the pipe, and has small construction discharge and limited reconstruction scale.

And secondly, temporarily blocking the modified layer by adopting a chemical temporary blocking agent, and then fracturing the layer to be modified according to a conventional process.

However, this process technology has limited application since there are no reliable chemical temporary blocking agents available at present.

Disclosure of Invention

The embodiment of the invention provides a one-trip drilling operation tubular column for a casing patching well and an operation method, and aims to solve the problems of small construction displacement and low operation efficiency when a double packer fracturing tubular column is used for transforming a reservoir old well; the second purpose is to solve the problem of limited application of the chemical temporary plugging agent in plugging the transformed layer of the old layer.

In order to solve the technical problem, the invention provides a one-trip drilling operation tubular column for a casing patching well, which comprises a continuous oil pipe, a connector, a bypass valve, a one-way valve, a releasing hand, a centralizer, an ejector, a packer, a casing joint hoop positioner and a plug which are sequentially connected from top to bottom, wherein the ejector is provided with three nozzles, and the diameter of each nozzle is 5.2 mm.

Preferably, the bypass valve adopts a sliding sleeve type bypass valve; the check valve is a double-valve flap type check valve, and a double-layer valve flap of the check valve is connected to the one-trip drilling operation pipe column body through an eccentric pin shaft.

The invention also discloses an operation method of the one-trip drilling operation tubular column for the casing patching well, which comprises the following steps:

step S1, selecting a multilayer system reservoir old well with part of opened layers and adopting casing patching to plug perforation holes as a target well, wherein the casing patching plugged perforation holes are patched and the earlier fractured layer is called an old layer of the target well, and the un-perforated and fractured layer is called a new layer of the target well;

step S2, assembling a one-trip drilling operation pipe column for the casing patching well, and lowering the one-trip drilling operation pipe column into the target well;

step S3, perforating and fracturing the new layer of the target well;

step S4, lifting a drill operation pipe column for annular open flow liquid drainage until the casing pressure is reduced to be lower than the stratum closing pressure;

step S5, repeating the step S3 and the step S4, and completing the reconstruction of all new layers in the target well layer by layer from bottom to top, wherein the reconstruction comprises perforation, fracturing and annular open flow liquid drainage;

step S6, performing hydraulic sand blasting and punching on all old layers layer by layer from bottom to top by adopting a hydraulic sand blasting mode to complete the punching of all old layers;

step S7, lowering the coiled tubing, circulating sand washing from top to bottom to the bottom of the artificial well, carrying out sand washing operation on the whole well casing, and after the sand washing operation is finished, taking out a drilling operation pipe column;

and step S8, after all old layers and all new layers in the target well are transformed, putting the oil well production pipe column into the target well, and carrying out the combined layer production of the new and old layers.

Further, lowering the one-trip drilling operation string into the target well at step S2 includes the following steps:

step S201, lowering the one-trip drilling operation pipe column to a new layer of the lowest layer, enabling the lower end face of the ejector to be lower than the bottom boundary of the perforation section of the new layer of the lowest layer by at least 30m, and stopping lowering;

step S202, lifting the coiled tubing at a constant speed of not more than 5m/min, and performing depth correction and positioning on the tubular column in one drilling operation;

and step S203, after the depth correction and the positioning are finished, stopping lifting the coiled tubing.

Further, perforating and fracturing a new layer of the target well in step S3 includes the following steps:

step S301, injecting perforating fluid and perforating sand into the pipe of the continuous oil pipe, wherein the perforating fluid carries the perforating sand to descend along the continuous oil pipe;

step S302, when the layer descends to a new layer to be modified, perforating fluid carries perforating sand to be sprayed out from a nozzle of an injector, and perforating operation is carried out on the new layer to be modified;

and step S303, after perforation is finished, continuously pumping and injecting perforating fluid into the pipe of the continuous oil pipe, simultaneously pumping and injecting sand-carrying fluid into the hollow part of the oil sleeve ring, and enabling the sand-carrying fluid to descend into a perforation hole to perform fracturing operation.

Preferably, the perforating sand in the step S301 is quartz sand, the speed of the quartz sand ejected by the nozzle is not less than 185m/S, and the sand concentration is 120kg/m³And the injection time is not less than 8 min.

Further, the step S4 of lifting a drill string to perform annular blowout and liquid drainage until the casing pressure drops below the formation closure pressure comprises the following steps:

step S401, carrying out a formation closing pressure test, and recording the formation closing pressure as Pc;

step S402, closing the casing gate, and lifting the continuous oil pipe at the speed of not more than 15m/S until the lower end face of the plug is higher than the top boundary of the perforation section of the new layer to be reconstructed by more than 30 m;

and S403, opening the casing gate, performing open-flow drainage by using a ground throttle valve, adjusting the opening of the ground throttle valve, and ensuring that the drainage liquid amount is not more than 400L/min until the casing pressure measured on the ground is 5MPa less than the stratum closing pressure Pc, and finishing the open-flow drainage.

Further, step S6 is to perform hydraulic sand blasting and punching on all old layers layer by layer from bottom to top by using a hydraulic sand blasting method, and includes the following steps:

step S601, injecting perforating fluid and perforating sand into the pipe of the continuous oil pipe, wherein the perforating fluid carries the perforating sand to descend along the continuous oil pipe;

step S602, when the hole goes down to the old layer to be modified, the perforating fluid carries perforating sand to be sprayed out from a nozzle of the sprayer, the patching pipe is eroded, a hole communicating the old layer to be modified and the shaft is formed, the perforating fluid carries the perforating sand to go up and return to the ground along the oil sleeve annulus, and the hydraulic sand-blasting and perforating operation is completed.

Preferably, the perforating sand of step S602 is quartz sand, the speed of the quartz sand ejected from the nozzle is not less than 185m/S, and the sand concentration is 120kg/m³Injection timeNot less than 4.5 min; the discharge capacity of the pump for injecting clear water in the step S604 is not less than 500L/min.

Further, the step S7 of positively circulating sand washing from top to bottom to the bottom of the artificial well to perform sand washing operation on the whole well casing includes the following steps:

step S701, putting steel balls into the pipe of the coiled tubing 1, and opening a bypass channel of a bypass valve 3 through pressure build-up;

step S702, injecting clean water into the pipe of the coiled tubing 1 by a pump, wherein the clean water descends along the coiled tubing 1, flows out of a bypass channel of the bypass valve 3, ascends along the oil casing annulus, carries the sand deposited in the shaft to the ground, and completes sand washing operation

The invention has the following beneficial effects:

the invention selects a multi-layer system reservoir old well as a modified target well, and divides the layer system in the target well into two types, wherein one type is a new layer which is not fractured, and the other type is an old layer which is temporarily blocked by casing patching.

In order to make the aforementioned and other objects of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

FIG. 1 is a schematic diagram of a one-trip drill string for casing patching a well.

Description of reference numerals:

1. a coiled tubing; 2. a connector; 3. a bypass valve; 4. a one-way valve; 5. releasing the hands; 6. a centralizer; 7. an ejector; 8. a packer; 9. a casing joint hoop positioner; 10. and (7) a plug.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

It should be noted that, in the present invention, the upper, lower, left and right in the drawings are regarded as the upper, lower, left and right of one-trip drilling operation string for casing patching well described in the present specification.

The exemplary embodiments of the present invention will now be described with reference to the accompanying drawings, however, the present invention may be embodied in many different forms and is not limited to the embodiments described herein, which are provided for complete and complete disclosure of the present invention and to fully convey the scope of the present invention to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, the same units/elements are denoted by the same reference numerals.

Unless otherwise defined, terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Further, it will be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

In the following embodiments, a new layer is modified first and then an old layer is modified in the sequence from bottom to top, during modification, an interval to be modified and an opened interval below the interval need to be isolated by a packer, and in the center of perforation fracturing technology, the above technology belongs to the conventional technology in the field of oil production, and will not be described in detail here.

First embodiment

The first embodiment of the invention relates to a one-trip drilling operation tubular column for casing patching wells, which comprises a coiled tubing 1, a connector 2, a bypass valve 3, a one-way valve 4, a releasing hand 5, a centralizer 6, an ejector 7, a packer 8, a casing joint hoop positioner 9 and a plug 10 which are sequentially connected from top to bottom, wherein the ejector 7 is provided with three nozzles, and the diameter of each nozzle is 5.2 mm.

Specifically, the connector is of the slip + pin type; the releasing tool is a ball-throwing opening type hydraulic releasing tool; the centralizer is a rigid tool; 3 nozzles are arranged on the injector, the diameter of each nozzle is 5.2mm, and the nozzles are made of high-strength alloy materials (the number of the nozzles and the diameter of the nozzles of the injector adopt the data no matter what the inner diameter of a reservoir casing and the outer diameter of a coiled tubing of a well are); setting and unsetting the packer mechanically; the casing joint hoop positioner is a mechanical structure tool.

The connector, the bypass valve, the one-way valve, the release, the centralizer, the ejector, the packer, the casing joint hoop positioner and the plug are all known tools in the industry at present.

The invention relates to a method for improving a multi-layer system reservoir old well, which comprises the steps of selecting the multi-layer system reservoir old well as a target well for improvement, dividing layer systems in the target well into two types, wherein one type is a new layer which is not fractured, and the other type is an old layer which is temporarily blocked by casing patching.

Second embodiment

The second embodiment of the invention relates to a one-trip drilling operation pipe column for casing patching wells, which comprises a coiled tubing 1, a connector 2, a bypass valve 3, a one-way valve 4, a releasing hand 5, a centralizer 6, an ejector 7, a packer 8, a casing joint hoop positioner 9 and a plug 10 which are sequentially connected from top to bottom, wherein the ejector 7 is provided with three nozzles, and the diameter of each nozzle is 5.2 mm.

Bypass valve 3 adopts sliding sleeve formula bypass valve, specifically is applied to the sand washing operation, includes: and (3) injecting clean water into the pipe of the coiled tubing 1 by a pump, wherein the clean water descends along the coiled tubing 1, flows out of a bypass channel of the bypass valve 3, ascends along the oil sleeve annulus, and carries the sand deposited in the shaft to the ground to finish sand washing operation.

In addition, the bypass passage of the bypass valve 3 has a larger drift diameter and a smaller throttle pressure than the passage of the injector nozzle.

The check valve 4 is a double-valve flap type check valve, and the double valve flaps of the check valve are connected to the one-trip drilling operation pipe column body through eccentric pin shafts. Specifically, the one-way valve allows fluid to flow down the coiled tubing, through the one-way valve, out the nozzle of the injector and into the annulus; the fluid in the annular space is prevented from entering from the nozzle of the ejector, flowing through the one-way valve and then going upwards along the coiled tubing, namely, the high-pressure fluid in the stratum is prevented from entering a drilling operation tubular column pipe from the nozzle of the ejector and going upwards along the coiled tubing.

Third embodiment

The invention also discloses an operation method of the one-trip drilling operation tubular column for the casing patching well, which comprises the following steps:

step S1, selecting a multilayer system reservoir old well with part of opened layers and adopting casing patching to plug perforation holes as a target well, wherein the casing patching plugged perforation holes are patched and the earlier fractured layer is called an old layer of the target well, and the un-perforated and fractured layer is called a new layer of the target well;

step S2, assembling a one-trip drilling operation pipe column for the casing patching well, and lowering the one-trip drilling operation pipe column into the target well;

step S3, perforating and fracturing the new layer of the target well;

step S4, lifting a drill operation pipe column for annular open flow liquid drainage until the casing pressure is reduced to be lower than the stratum closing pressure;

step S5, repeating the step S3 and the step S4, and completing the reconstruction of all new layers in the target well layer by layer from bottom to top, wherein the reconstruction comprises perforation, fracturing and annular open flow liquid drainage;

step S6, performing hydraulic sand blasting and punching on all old layers layer by layer from bottom to top by adopting a hydraulic sand blasting mode to complete the punching of all old layers;

step S7, lowering the coiled tubing 1, circulating sand washing from top to bottom to the bottom of the artificial well, carrying out sand washing operation on the whole well casing, and after the sand washing operation is finished, pulling out a drilling operation pipe column;

and step S8, after all old layers and all new layers in the target well are transformed, putting the oil well production pipe column into the target well, and carrying out the combined layer production of the new and old layers.

Specifically, a multi-layer old reservoir well is selected as a target well, the layer system in the target well is divided into two types, one type is a new layer which is not fractured, and the other type is an old layer which is temporarily blocked by casing patching, when the target well is reformed, a drilling operation pipe column is firstly put down to reform the new layer, perforation, fracturing and liquid drainage are carried out on the new layer, and then the drilling operation pipe column is continuously utilized to carry out drilling operation on the old layer.

The reason why the non-perforated and fractured layer (new layer) needs to be opened is that the current technical conditions are sufficient, the fund is sufficient, and all the residual non-perforated and fractured layers are determined to be opened for accelerating the development speed of the oil field, so that the production of the old layer and the new layer is realized.

When perforation and fracturing earlier stage not opened the position, need carry out the casing subsidy shutoff with earlier stage opened position (adopt the casing subsidy mode shutoff to open the perforation porthole of position), its reason is: the interlayer interference in the fracturing process is avoided, namely, the fracturing fluid and the propping agent pumped and injected from the ground in the fracturing process are prevented from entering the earlier opened layer.

The method is characterized in that perforation holes are plugged by casing patching, the earlier fractured layer is called as an old layer for short, and the earlier unopened layer (obviously, plugging is carried out without casing patching) is called as a new layer for short.

Fourth embodiment

Based on the third embodiment, the step S2 of lowering a drill pipe string into the target well includes the following steps:

step S201, lowering the one-trip drilling operation pipe column to a new layer of the lowest layer, enabling the lower end face of the ejector 7 to be lower than the bottom boundary of the perforation section of the new layer of the lowest layer by at least 30m, and stopping lowering;

step S202, lifting the coiled tubing 1 at a constant speed of not more than 5m/min, and performing depth correction and positioning on a pipe column in one drilling operation;

and step S203, after the depth correction and the positioning are finished, stopping lifting the coiled tubing 1.

A trip pipe string is lowered below the new zone at the lowermost portion of the wellbore to ensure that the location of the lower end face of the injector is no less than 30m below the bottom boundary of the perforated section of the new zone, the method of determining the perforated section being well known in the industry and outside the scope of the present invention.

And slowly lifting the coiled tubing at the speed of not more than 5m/min, and performing depth correction and positioning on the coiled tubing according to a method known in the industry.

After the depth correction and the positioning are finished, the continuous oil pipe is stopped to lift, and the position of the drilling operation pipe column (namely the position of each tool in the drilling operation pipe column in the shaft) is determined.

The purpose of this step is: the preparation work before the new layer is reformed is characterized in that the positions of all tools in a drilling operation tubular column in a shaft are determined so as to accurately realize perforation and fracturing of a corresponding perforation section.

Fifth embodiment

Unlike the third embodiment, the perforating and fracturing of the new zone of the target well of step S3 includes the following steps:

step S301, injecting perforating fluid and perforating sand into the pipe of the continuous oil pipe 1, wherein the perforating fluid carries the perforating sand to descend along the continuous oil pipe 1;

step S302, when the layer descends to a new layer to be reconstructed, the perforating fluid carries perforating sand to be ejected from a nozzle of the ejector 7, perforating operation is carried out on the new layer to be reconstructed, the perforating sand is quartz sand, the mesh number of the quartz sand is 40-70 meshes, the speed of ejecting the quartz sand from the nozzle is not less than 185m/S, and the sand concentration is 120kg/m³The injection time is not less than 8 min;

and step S303, after perforation is finished, continuously pumping and injecting perforating fluid into the pipe of the continuous oil pipe 1, simultaneously pumping and injecting sand-carrying fluid into the hollow part of the oil sleeve ring, and enabling the sand-carrying fluid to descend into a perforation hole to perform fracturing operation.

In the field of oilfield exploitation, the perforating fluid is a conventional perforating option, and preferably/exemplarily, the perforating fluid of the embodiment is prepared by hydroxypropyl guar gum and clear water.

After perforation, continuously pumping and injecting perforating fluid into the coiled tubing pipe (stopping pumping and injecting quartz sand), then pumping and injecting sand-carrying fluid into the oil sleeve annulus, and starting fracturing until fracturing is finished.

The method for fracturing by pumping non-sand-carrying liquid into the coiled tubing pipe and pumping sand-carrying liquid into the annulus is a method disclosed in the industry.

Sixth embodiment

Unlike the third embodiment, the step S4 of raising one trip of the drill string to perform annular blowout and drainage until the casing pressure drops below the formation closure pressure comprises the following steps:

step S401, carrying out a formation closing pressure test, and recording the formation closing pressure as Pc;

step S402, closing the casing gate, and lifting the continuous oil pipe 1 at a speed of not more than 15m/S until the lower end face of the plug 10 is higher than the top boundary of the new layer perforation section to be reconstructed by more than 30 m;

and S403, opening the casing gate, performing open-flow drainage by using a ground throttle valve, adjusting the opening of the ground throttle valve, and ensuring that the drainage liquid amount is not more than 400L/min until the casing pressure measured on the ground is 5MPa less than the stratum closing pressure Pc, and finishing the open-flow drainage.

Specifically, after the fracturing pump injection is completed, the pump can be stopped, the ground data acquisition system continues to acquire relevant pressure parameters, and the formation closing pressure is acquired and recorded as Pc according to the procedures and methods known in the industry.

Then closing the casing gate, wherein high-pressure fluid in the stratum cannot flow out through the annulus after the casing gate is closed; on the other hand, because the one-way valve is connected in the one-time drilling operation pipe column (the one-way valve allows the fluid to flow downwards along the coiled tubing, pass through the one-way valve, flow out from the nozzle of the ejector and enter the annular space, but can prevent the fluid in the annular space from entering from the nozzle of the ejector, flowing through the one-way valve and going upwards along the coiled tubing), the high-pressure fluid in the stratum is prevented from entering a pipe of a drilling operation pipe column from the nozzle of the ejector and going upwards along the coiled tubing.

And after measuring the formation closing pressure Pc and closing the casing gate, lifting the coiled tubing at a speed of not higher than 15m/s, and lifting the one-trip drilling operation tubular column to be 30m above the layer section to be reconstructed, namely ensuring that the lower end surface of a plug in the one-trip drilling operation tubular column is higher than the top boundary of the perforation section of the layer section by more than 30 m.

And finally, opening the casing gate, performing open-flow liquid drainage by adopting a ground throttle valve, controlling the opening of the throttle valve, ensuring that the liquid drainage amount is not higher than 400L/min until the casing pressure measured on the ground is 5MPa less than the Pc value (obviously, the Pc value is more than 5 MPa), and finishing the open-flow liquid drainage.

Seventh embodiment

Different from the third embodiment, the step S6 of performing the hydraulic blasting punching on all old layers layer by layer from bottom to top by using the hydraulic blasting method includes the following steps:

step S601, injecting perforating fluid and perforating sand into the pipe of the continuous oil pipe 1, wherein the perforating fluid carries the perforating sand to descend along the continuous oil pipe 1;

step S602, when the sand flows down to the old layer to be reformed, the perforating fluid carries perforating sand to be ejected from a nozzle of the ejector 7, the repairing pipe is eroded, a hole communicating the old layer to be reformed and the shaft is formed, the perforating fluid carries the perforating sand to flow back to the ground along the oil sleeve annulus, the hydraulic sand blasting and perforating operation is completed, the perforating sand is quartz sand, the speed of the quartz sand ejected by the nozzle is not less than 185m/S, and the sand concentration is 120kg/m³The spraying time is not less than 4.5 min; the discharge capacity of the pump for injecting clear water in the step S604 is not less than 500L/min.

The hydraulic sand blasting method for perforating refers to a one-trip drilling operation pipe column for perforating, and a plurality of holes are formed in the patching pipe for plugging the old layer in an erosion mode, so that old layer fluid can enter a shaft through the holes and the stratum of the old layer is communicated with the shaft.

After the perforation is finished, the formation fluid enters the shaft along the hole punched on the formation-original perforation blasthole-patching pipe.

The method specifically comprises the following steps: viscous liquid and quartz sand are pumped into the coiled tubing, the perforating fluid carries the quartz sand to move downwards along the coiled tubing, the quartz sand is ejected out at high speed by a nozzle of the ejector, and the jet erosion patching tube forms holes on the jet erosion patching tube.

The perforating fluid is prepared from hydroxypropyl guanidine gum and clear waterThe quartz sand is 40-70 meshes. Ensuring that the speed of the quartz sand sprayed out of the nozzle is not less than 185m/s and the sand concentration is 120kg/m³And the spraying time is not more than 4.5 min.

Eighth embodiment

Unlike the third embodiment, the step S7 of positive circulating sand washing from top to bottom to the bottom of the artificial well to perform sand washing operation on the whole well casing includes the following steps:

step S701, putting steel balls into the pipe of the coiled tubing 1, and opening a bypass channel of a bypass valve 3 through pressure build-up;

and S702, injecting clean water into the pipe of the coiled tubing 1 by a pump, wherein the clean water descends along the coiled tubing 1, flows out of a bypass channel of the bypass valve 3, ascends along the oil sleeve annulus, and carries the sand deposited in the shaft to the ground to finish sand washing operation.

Sand washing operation: after the punching operation is finished, steel balls are put into the coiled tubing, a bypass channel of a bypass valve in a drilling operation tubular column is opened in a pressure-building mode, and the opening program and method of the bypass channel of the bypass valve are well known in the industry. The bypass passage of the bypass valve has a larger drift diameter and a lower throttling pressure than the passage of the injector nozzle.

The sand washing operation adopts a positive circulation mode, and the sand washing liquid is the viscous liquid.

Clean water is pumped into the coiled tubing pipe, the clean water descends along the coiled tubing pipe, flows out of the bypass channel of the bypass valve and ascends along the annulus, sand deposited in the shaft is carried to the ground, and the sand washing discharge capacity is not less than 500L/min.

Ninth embodiment

In the embodiment, according to the once drilling operation pipe column and the operation method protected by the invention, one old well with multiple reservoir layers of a certain oil field is transformed, as shown in fig. 1, the well is respectively provided with 5 oil layers from bottom to top, 2 oil layers in the well are perforated and fractured at the early stage, the two oil layers are sequentially named as an old layer L1 and an old layer L2 from bottom to top, and the perforation holes of the two oil layers are plugged in a casing patching mode at present.

The 3 unopened oil layers of the well are named as a new layer X1, a new layer X2 and a new layer X3 from bottom to top in sequence.

The inner diameter of the oil layer casing of the well is 124.26mm, the bottom of the artificial well is 3000.0m, and the top boundary and the bottom boundary depth of the perforation sections of the new layer and the old layer are respectively as follows in sequence (oil layer name: top boundary depth-bottom boundary depth):

new layer X3: 2400.0-2405.0m

Old layer L2 of 2500.0-2505.0m

New layer X2: 2600.0-2605.0m

Old layer L1: 2700.0-2705.0m

New layer X1: 2800.0-2805.0m

Assembling and putting a one-time drilling operation tubular column, wherein the outer diameter of the coiled tubing is 50.8mm, and the coiled tubing is sequentially connected with a connector 2, a bypass valve 3, a one-way valve 4, a release 5, a centralizer 6, an ejector 7, a packer 8, a casing joint hoop positioner 9 and a plug 10 from top to bottom.

The maximum outer diameter of the connector 2 is 73mm, and the connector is in an outer slip and pin type;

the bypass valve 3 is of a sliding sleeve structure, the maximum outer diameter is 73mm, the straight diameter before the bypass hole is not opened is 45mm, a steel ball of 48mm is thrown to suppress the pressure to 40MPa or above, a bypass channel can be opened, and the bypass channel is 2 lateral holes with the diameter of 20 mm;

the largest outer diameter of the releasing gadget 5 is 73mm, and the tool can be disconnected by throwing a 43mm steel ball and suppressing the pressure to 38MPa or above;

the centralizer 6 is a rigid centralizer, and the maximum outer diameter is 89 mm;

the maximum outer diameter of the ejector 7 is 73mm, 3 nozzles are arranged, and the diameter of each nozzle is 5.2 mm;

the maximum outer diameter of the packer 8 is 75mm, and the packer is a Y221 type packer;

the maximum outer diameter of the casing joint hoop positioner 9 is 110mm, and the casing joint hoop positioner is a mechanical casing joint hoop positioner;

the maximum outer diameter of the plug 10 is 60mm, and the plug is a solid tool.

And (3) running the coiled tubing 1, stopping running when the lower end face of the injector in the string of one drilling operation reaches 2850.0m, lifting the coiled tubing at the speed of 4.5m/min to finish depth correction and positioning of the coiled tubing, and after the positioning is finished, locating the injector in the string of one drilling operation between 2802.0 m and 2803.0m to prepare for starting perforation and fracturing operation.

The perforation mode is hydraulic sand blasting perforation. The viscosity of the perforating fluid is 15mPa & s, and the tackifier is hydroxypropyl guar gum; the perforating sand is 40-70 mesh quartz sand; the sand concentration is 120kg/m³(ii) a The perforation discharge capacity is 750L/min; the perforating fluid and the quartz sand are injected from the coiled tubing, descend along the coiled tubing, are sprayed out by a nozzle of an injector, and then ascend along the annular space to return to the ground, so that open circulation is realized; the jet velocity was 193 m/s; the spraying time is 10 min.

After the perforation is finished, liquid with the viscosity of 10mPa & s is pumped and injected in the coiled tubing at the discharge capacity of 400L/min, and simultaneously liquid is pumped and injected by the annular space at the discharge capacity of 7000L/min (the front liquid is sequentially pumped and injected by 30 m)³150m of sand-carrying liquid³And 20m of displacing liquid³(ii) a The pad fluid and the displacing fluid are non-crosslinking fluids, and the sand carrying fluid is a crosslinking fluid). Adding sand 30m³The fracturing sand is 40-70 mesh quartz sand.

And after the fracturing pump injection procedure is finished, stopping the pump, measuring pressure drop data, and measuring the formation closing pressure to be 18 MPa. The sleeve gate is closed. And (4) lifting the coiled tubing at the speed of 12m/s, and stopping lifting when the depth of the lower end face of the plug in the pipe column for one-time drilling operation is 2750 m.

And (3) opening a casing gate, and controlling open flow and liquid drainage by adopting a ground throttle valve, wherein the open flow discharge capacity is 380L/min, and the open flow is carried out until the casing pressure is reduced to 11.0 MPa.

And repeating the steps and the procedures, and sequentially modifying the new layer X2 and the new layer X3 from bottom to top, namely sequentially completing perforation, fracturing and open flow drainage operations of the new layer X2 and the new layer X3.

After the blowout and liquid drainage operation of the new layer X3 is completed, the casing gate and the ground throttle valve are kept fully opened, and the coiled tubing is lowered, so that the ejector in the drilling operation string of one trip is ensured to be positioned in the middle of the perforation section of the old layer L1, namely the ejector is ensured to be positioned between 2702.0 and 2703.0 m. And starting the hydraulic sand blasting and punching operation.

The liquid viscosity is 15 mPa.s, and the tackifier is hydroxypropyl guar gum; quartz sand of 40-70 meshes is adopted; the sand concentration is 120kg/m³(ii) a The discharge capacity is 750L/min; the viscous liquid and the quartz sand are injected from the coiled tubing, go down along the coiled tubing, are sprayed out by a nozzle of an injector, and then go up along the annular space and return to the ground, so that open circulation is realized;the jet velocity was 193 m/s; the injection time is 4 min.

And repeating the steps to finish the hydraulic sand blasting and punching operation of the old layer L2.

After the punching operation is finished, 1 steel ball with the diameter of 48mm is thrown into the coiled tubing, and after 15min, the pressure in the coiled tubing is suppressed to 42MPa, and a bypass channel of the bypass valve is opened. Clean water is injected by a positive circulation pump with the discharge capacity of 550L/min, sand washing operation is carried out from top to bottom, and sand is washed to the bottom of the artificial well.

And (5) taking out the operation pipe column once, and putting the production pipe column into the operation pipe column to produce the new and old layers in a combined layer mode.

In conclusion, the multi-layer system old reservoir well is selected as a modified target well, the layer system in the target well is divided into two types, one type is a new layer which is not fractured, the other type is an old layer which is temporarily blocked by casing patching, when the target well is modified, a drill operation pipe column is firstly put down to modify the new layer, perforation, fracturing and liquid drainage are carried out on the new layer, then the drill operation pipe column is continuously utilized to perforate the old layer, finally, sand washing operation is carried out on the whole well casing, the drill operation pipe column is put down once to complete all modification of the new layer, and the old layer is continuously used, so that the production of the new old layer is realized, and the development speed and the development efficiency of the multi-layer system old reservoir well are improved.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.