CN113445960A - Water plugging method for oil well casing damage - Google Patents
Water plugging method for oil well casing damage Download PDFInfo
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- CN113445960A CN113445960A CN202110706196.6A CN202110706196A CN113445960A CN 113445960 A CN113445960 A CN 113445960A CN 202110706196 A CN202110706196 A CN 202110706196A CN 113445960 A CN113445960 A CN 113445960A
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- 238000000034 method Methods 0.000 title claims abstract description 93
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 76
- 239000003129 oil well Substances 0.000 title claims abstract description 48
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 84
- 238000010276 construction Methods 0.000 claims abstract description 52
- 239000004576 sand Substances 0.000 claims abstract description 47
- 238000002347 injection Methods 0.000 claims abstract description 40
- 239000007924 injection Substances 0.000 claims abstract description 40
- 238000005406 washing Methods 0.000 claims abstract description 36
- 238000004519 manufacturing process Methods 0.000 claims abstract description 21
- 238000005086 pumping Methods 0.000 claims abstract description 17
- 238000011084 recovery Methods 0.000 claims abstract description 5
- 238000012360 testing method Methods 0.000 claims description 41
- 238000011010 flushing procedure Methods 0.000 claims description 25
- 239000000700 radioactive tracer Substances 0.000 claims description 17
- 238000007790 scraping Methods 0.000 claims description 15
- 238000012856 packing Methods 0.000 claims 1
- 239000003921 oil Substances 0.000 description 91
- 238000011049 filling Methods 0.000 description 15
- 238000005516 engineering process Methods 0.000 description 14
- 239000004568 cement Substances 0.000 description 13
- 230000008569 process Effects 0.000 description 12
- 239000012530 fluid Substances 0.000 description 11
- 230000002147 killing effect Effects 0.000 description 11
- 230000000087 stabilizing effect Effects 0.000 description 11
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- 210000002445 nipple Anatomy 0.000 description 7
- 230000008719 thickening Effects 0.000 description 7
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 5
- 238000004140 cleaning Methods 0.000 description 5
- 241000710124 Human rhinovirus A2 Species 0.000 description 4
- 239000001110 calcium chloride Substances 0.000 description 4
- 229910001628 calcium chloride Inorganic materials 0.000 description 4
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- 238000002156 mixing Methods 0.000 description 4
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Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices, or the like
- E21B33/14—Methods or devices for cementing, for plugging holes, crevices, or the like for cementing casings into boreholes
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B47/00—Survey of boreholes or wells
- E21B47/10—Locating fluid leaks, intrusions or movements
Abstract
The invention provides a water plugging method for oil well casing damage, which comprises the following steps of determining the damage position of the oil well casing before water plugging construction; a water plugging construction step of injecting a plugging agent at the damaged position of the oil well casing by an intermittent injection method; and the steps of sand washing, well completion and production recovery. Wherein the intermittent injection method for injecting the plugging agent comprises injecting the plugging agent into the damaged position of the oil well casing by pumping for multiple times. The invention innovatively uses a low-pressure intermittent injection method to repeatedly squeeze and inject the plugging agent for many times, so that the plugging agent can penetrate into the stratum more deeply, and the success rate of primary water plugging is improved.
Description
Technical Field
The application relates to the field of oil and gas fields, in particular to a water plugging method for damage of an oil well casing.
Background
Along with the development time of the oil field, the partial casing of some oil-water wells is corroded or is deformed or even broken due to stratum stress extrusion, the normal production of a production well is seriously influenced, even environmental pollution is possibly caused, and the plugging process for the damaged part of the casing is objectively needed.
The oil well casing plugging technology generally adopts a shaft plug retention plugging process, and the drilling and plugging process has long construction time and high cost. The plugging process without leaving a plug requires that the plugging agent can be retained in the stratum and flushed out from the shaft. The existing technology for plugging without leaving a plug in the oil extraction industry only depends on the water loss change rate based on temperature to carry out thickening control on the plugging agent, only one control quantity of time is needed, and the thixotropy of the plugging agent is utilized to wash out redundant plugging agent at a proper time point to realize plugging without leaving a plug. For example, wanghai went and Jiang river also explain in detail the existing plugging process without plug in the composite plugging agent method without plug in the leaking well in 2018, 11 th. However, if the construction time is short, water cannot be effectively blocked, and if the construction time is too long, accidents of cement consolidation of the pipe column can occur, so that the one-time success rate is low, the construction requirement is high, and the risk is high.
Disclosure of Invention
In order to solve the technical problem, the application provides a novel method for blocking water of damaged oil well casing pipes, so that the success rate of once water blocking is improved, and the construction risk is reduced. Namely, the main object of the present invention is to provide a water plugging method for oil well casing damage, comprising the following steps:
s1, determining the damage position of the oil well casing before water plugging construction;
s2, water plugging construction, namely, injecting a plugging agent by an intermittent injection method;
s3 sand washing, well completion and production recovery;
wherein the intermittent injection method for injecting the plugging agent comprises injecting the plugging agent into the damaged position of the oil well casing by pumping for multiple times.
In one embodiment of the invention, the damaged position of the oil well casing is determined before water plugging construction, so as to determine the stratum plugged by a plugging agent pipeline in the water re-plugging construction step. The method for determining the damaged position of the oil well casing can select a tracer leakage finding technology, namely finding out the possible damaged position of the casing by using the tracer leakage finding technology. The tracer leak finding method can be used, for example, as described in detail in application of well-logging information to development of oil and gas fields (Tantana et al eds., Petroleum industry Press, 1991 edition). The tracer leak detection method is well known to those skilled in the art and in one embodiment of the invention, the leak detection method may be used with the inclusion of an isotopic tracer.
In one embodiment of the invention, the method for determining the damage location of the well casing may be a method for selecting a caliper test, the method for determining the caliper test comprising determining the damage location of the well casing using a caliper. In one embodiment of the invention, the determining the oil well casing damage position by using the caliper comprises determining the oil well casing damage position by using a small-diameter caliper which performs a side test on the casing (research on casing well diameter testing technology (Zhao Qinghai, et al, first international conference on mechanical engineering).
In one embodiment of the present invention, the method for determining the damage position of the casing pipe of the oil well can be firstly determined by the tracer, and then the verification of the damage position of the casing pipe of the oil well determined by the tracer is carried out by the caliper. Alternatively, the method for determining the damage position of the oil well casing can be performed by firstly determining through a caliper and then verifying the damage position of the oil well casing determined by the caliper through a tracer.
In one embodiment of the invention, before the method for determining the damage position of the oil well casing, the method further comprises the step of flushing and killing the well; in one embodiment of the invention, the step of flushing the well comprises flushing the oil well in a reverse circulation flushing manner, and after the flushing operation is finished, configuring the calcium chloride well-killing hydraulic well according to the formation pressure. In one embodiment of the invention, the reverse circulation well flushing comprises flushing with flushing fluid from the oil jacket annulus, which is the space between the tubing and the casing, from the air into and back out of the tubing.
In one embodiment of the invention, the calcium chloride kill fluid comprises a density of 1.0g/cm3～1.12g/cm3The calcium chloride solution of (1). In one embodiment of the invention, the killing includes killing the well in a reverse cycle kill mode; in one embodiment of the invention, said killing said well in a reverse circulation kill mode comprises using 10m at a pressure of 8MPa3The flow rate/h injects kill fluid from the oil collar annulus, which returns from the tubing to kill the well.
In one embodiment of the invention, a tripping string is also included prior to the method of determining the location of an oil well casing failure, and after the kill; the well tubular column of getting out of the well is including getting out of the well original production tubular column, the well original production tubular column includes sucker rod post and oil pipe tubular column in the well.
In one embodiment of the invention, the method for determining the damage position of the oil well casing further comprises the steps of well dredging and washing, well scraping and washing, setting and testing and sand filling.
In one embodiment of the invention, the well dredging and flushing comprises the steps of selecting a drift gauge (diameter D139.9mm sleeve) with the outer diameter of 118mm and a thickened oil pipe with the diameter of D73mm for dredging, flushing with normal-temperature well flushing fluid in 2-3 times of the volume of a well bore after the drift exceeds a construction well section, pulling out a drift tubular column, and checking the drift gauge condition. The drifting tubular column selected in the flushing well comprises a drifting gauge and a thickened oil pipe, which are well known to those skilled in the art, and can be adjusted according to the conditions of an oil well and an oil well casing.
In one embodiment of the invention, said scraping the well-wash comprises scraping with a scraper + heavy tubing; scraping the well section to be constructed, flushing the well with a well killing fluid, taking out the scraping pipe column, and checking the scraper. In one embodiment of the invention, the scraper may be selected from the scraper type GX-T140 (139.9 mm outer diameter casing) and the heavy gauge tubing may be selected from the heavy gauge tubing having a diameter D73mm, for example. In one embodiment of the invention, the scraping in the required construction well section can be performed for example 12-15 times; in one embodiment of the invention, the flushing with kill fluid comprises flushing with a medium temperature kill fluid using 2-3 times the wellbore volume at the interval where the construction is desired. The GX-T140 scraper or the thickened oil pipe with the diameter of D73mm is a common well repairing operation tool (commercially available in the market) for the oil field, and is recorded in the text of 'thick oil cold production method at the edge of the oil reservoir structure of North China oil field' published in No. 39, No. 2 of 2017, 3 and 39. Other scraped well cleaning tools or methods are known to those skilled in the art and it will be appreciated by those skilled in the art that other scraped well cleaning tools or methods may be used to effect the scraped well cleaning.
In one embodiment of the invention, the setting and testing sleeve comprises a lower testing sleeve string, and the sealing condition is observed through multiple times of pressing, pressure stabilizing and pressure reducing; in one embodiment of the invention, the casing string comprises a tubing hanger + external heavy wall tubing of diameter D73mm + stab + tubing nipple + diameter D73mm flat tubing nipple + Y211-114 packer + diameter D73mm external heavy wall screen + diameter D73mm external heavy wall tubing + stinger. In one embodiment of the invention, a 1.5m diameter D73mm flat tubing nipple is connected to a tubing hanger, the string is lifted by 1.4m by using oil well operation equipment, and then slowly lowered, pressurized by 70KN, the tubing hanger is set, and the top jackscrew is set to be qualified. 5MPa pressure stabilization is carried out for 10 minutes from the casing pipe, and the pressure drop is observed; increasing the pressure to 10MPa, stabilizing the pressure for 10 minutes, and observing the pressure drop; and continuously increasing the pressure to 15MPa, stabilizing the pressure for 10 minutes, and observing the pressure drop. After the test sleeve is qualified, slowly lifting the pipe string for 1-1.5m to unseal, and pulling out the setting test sleeve string. Wherein, the instruments such as the tubing hanger, the tubing hanger and the like or related methods are recorded in detail in the text of application of wellhead integrity technology in Luimala oil field on the 2 nd volume 6 < unconventional oil and gas > of 12 months in 2015. The qualification of setting the tubing hanger and the top jackscrew is a method or an instrument well known to those skilled in the art. The guide cone is a common fitting for an oil field, is sold in the market, or is detailed in the text of 'application discussion of integrated tubular column for pump blowout prevention under perforation' published in 32 nd 2 nd report of Jianghan oil workers in 2019, 3.32.8. The Y211-114 packer is common equipment in the oil field and is commercially available; the guide cone is recorded in detail in a text of inclined shaft layered oil extraction and sand control combined process technology which is published in No. 4 petroleum field machinery on volume 47 of 8 th month in 2018 of Y211-114 packer. The diameter D73mm external thickened oil pipe, the diameter D73mm flat oil pipe short section and the diameter D73mm external thickened screen pipe are common equipment in oil fields and are sold in the market. The variable buckle connected between the external thickened oil pipe with the diameter D73mm and the flat oil pipe nipple with the diameter D73mm is common equipment for oil fields and is sold in the market. Other setting, casing testing tools or processes are known to those skilled in the art, and it is understood by those skilled in the art that other setting, casing testing tools or processes may be used to implement the setting, casing testing tools or processes.
In one embodiment of the invention, the sand filling comprises the steps of putting a sand filling pipe string to a construction position, washing a well from a positive circulation of an oil pipe, filling sand to a designed sand surface position according to a geological and engineering design scheme after an oil sleeve is ensured to be unblocked, temporarily plugging a lower sleeve, lifting the outer thickened oil pipe, closing the well for sand setting, detecting the sand surface, lifting the thickened oil pipe after the sand surface is qualified, and completing plugging construction preparation. In one embodiment of the invention, the sandpack string comprises D73mm diameter outer riser + flare. Other sand-pack and sand-face-finding tools and methods are known to those skilled in the art, and it will be appreciated by those skilled in the art that other sand-pack and sand-face-finding tools and methods may be used to accomplish the sand-pack and sand-face-finding operations.
In one embodiment of the present invention, the water shutoff construction includes the steps of injecting a shutoff agent by an intermittent injection method; specifically, the intermittent injection method for injecting the plugging agent comprises the step of injecting the plugging agent into the damaged position of the oil well casing in the step S1 multiple times through pumping pressure.
In one embodiment of the invention, the intermittent injection method for injecting the plugging agent comprises the steps of lowering the plugging agent injection string to 10-20 m above the damaged position of the oil well casing, and injecting the plugging agent for multiple times through a pump pressure in a positive extrusion mode, wherein the positive injection mode comprises the modes of closing the casing and extruding the fluids in a well bore and a pump truck into the stratum through the pump pressure.
In one embodiment of the invention, the intermittent injection method further comprises a step of pumping in a positive circulation mode at the damaged position of the oil well casing before injecting the plugging agent; in one embodiment of the invention, the pump pressure for injecting the clean water comprises 2-3 MPa; in another embodiment of the invention, the displacement of the injected fresh water comprises 400L/min, and the fresh water is squeezed for 5 min.
In one embodiment of the invention, the pump pressure for injecting the plugging agent by the intermittent injection method comprises 8MPa to 12 MPa; in another embodiment of the present invention, the pump pressure for injecting the plugging agent by the intermittent injection method comprises 8MPa, 9MPa, 10MPa, 11MPa and 12 MPa. In one embodiment of the present invention, each pumping time for injecting the plugging agent by the intermittent injection method comprises 10 minutes to 30 minutes; in another embodiment of the present invention, each pumping time for injecting the plugging agent in the intermittent injection method comprises 10 minutes. In one embodiment of the invention, the pumping pressure times for injecting the plugging agent by the intermittent injection method comprise 3-10 times; in another embodiment of the present invention, the number of times of pumping for injecting the plugging agent by the intermittent injection method comprises 3 times.
In one embodiment of the present invention, the step of injecting the plugging agent by the intermittent injection method comprises:
1) adjusting the pipe column to the damaged position of the oil well casing, pumping at 2-3MPa and discharge capacity of 400L/min, and extruding clean water for 5min to enter the well at 0.26m3；
2) The positive extrusion blocking agent is divided into three times and is 4.5-7.5m3(ii) a Each forward extrusion is 0.3-4m32.5m of clear water is extruded positively3Controlling the pump pressure within 8MPa in the first two times, and closing the well 1Diffusion for 0 min; the third pump was pumped at 12MPa for 10 min. During the first two times of plugging agent injection and well shut-in periods, the pressure fluctuation in the shaft is ensured to be less than 6 MPa;
3) washing the well by using clean water in a reverse circulation manner, washing out the redundant plugging agent in the well until the properties of an inlet and an outlet are consistent;
4) 3 external thickened oil pipes of D73mm are added, and the clear water is 15m3And (4) backwashing the well, washing out the redundant plugging agent until the liquid properties of the inlet and the outlet are consistent, and washing the well to be qualified.
In one embodiment of the invention, the plugging agent comprises a pressure-sensitive thixotropic agent, an inorganic composite plugging agent and clear water which are added according to the depth of a construction well, and the density of a blending sleeve of the inorganic composite plugging agent and the clear water in a stirring tank is 1.83g/cm3The plugging agent of (1); the inorganic composite plugging agent comprises G-grade superfine cement as a base and is formed by additives such as a cement retarder, a thickening agent and the like. The preparation method and the injection construction method of the inorganic composite plugging agent are known by the technicians in the field, and the preparation and construction method of the underground operation injection ash is used, and the pressure-sensitive thixotropic agent, the inorganic composite plugging agent and/or the additives such as G-grade superfine cement, cement retarder, thickening agent and the like can be obtained through the market.
In one embodiment of the invention, the intermittent injection method further comprises the steps of closing the well, waiting for setting, testing pressure and pulling out the plugging agent injection string after the plugging agent is injected.
In one embodiment of the invention, the step of closing the well and waiting for setting comprises the steps of pulling out the external thickened oil pipe used in the previous step, installing a simple wellhead, filling the shaft with clean water, closing the well and waiting for setting. In another embodiment of the invention, the shut-in setting waiting step comprises the steps of taking out 13 external thickened oil pipes with the diameter D73mm used in the previous step, installing a simple wellhead, filling the shaft with clean water, and shutting-in setting waiting for 48 hours. The simple well mouth is a common oil field equipment and is available on the market; and those skilled in the art will appreciate that other simple wellhead equipment and methods may be used to perform the set-top job steps.
In one embodiment of the invention, the pressure test comprises a positive pressure; the positive pressurizing comprises positive pressure tests of 3MPa, 5MPa, 8MPa and 10MPa respectively, and the positive pressure test is stabilized for 2 minutes each time; the pressure test construction is well known to those skilled in the art, and in order to detect the solidification effect of the plugging agent, those skilled in the art can adjust the pressure test times and the pressure stabilizing time by combining different oil and gas fields and pipe wells.
In one embodiment of the invention, the well plugging construction is followed by a sand washing and pump-down completion step; in another embodiment of the invention, the sand washing comprises running a sand washing pipe string (such as a D73mm pen point + D73mm external thickened oil pipe) to the sand surface, and then lifting the sand washing pipe string after sand washing to the geological and engineering design depth; and the pump-down well completion comprises the steps of completing the well after the combination of the running pipe columns is arranged according to the engineering design and recovering the production. Among them, the D73mm pen point is a common tool in oil field and is commercially available. The specific methods of said sand washing operations are well known to the person skilled in the art and are not described in detail here.
Compared with the prior art, the invention at least comprises the following beneficial effects:
1) the method for controlling the thickening of the transforming plugging agent is a method for jointly controlling pressure and contact with the stratum, the pressure is increased when the plugging agent is extruded at the last time, so that the plugging agent extruded into the stratum from the casing leakage breaking position simultaneously reaches the pressure threshold and the condition of contact with the stratum, the cement paste can be quickly thickened, the plugging agent entering the stratum is plugged, the control on the thickening time and position of the cement paste is enhanced, and the construction risk is reduced. By controlling the thickening speed, the plugging agent is extruded and injected repeatedly for three times by innovatively using a low-pressure intermittent injection method, so that the plugging agent can penetrate into the stratum more deeply, and the success rate of primary water plugging is improved;
2) the water plugging method for oil well casing damage solves the problem of past dependence on empirical data by using a pressure change accurate control method and solves the problem of water loss time when plugging agent blocks water on the premise of ensuring the plugging effect, thereby achieving the purposes of improving the success rate of primary water plugging and reducing the construction risk. By applying 12 oil wells on site in the subsequent embodiment, the water plugging success rate is 100 percent, and the daily oil increase is 4.7t on average.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to specific embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
The embodiment of the invention provides a water plugging method for oil well casing damage, which comprises the following steps:
s1, determining the damage position of the oil well casing before water plugging construction;
s2, water plugging construction, namely, injecting a plugging agent by an intermittent injection method;
s3 sand washing, well completion and production recovery;
wherein the intermittent injection method for injecting the plugging agent comprises injecting the plugging agent into the damaged position of the oil well casing by pumping for multiple times.
Specifically, in one embodiment of the invention, the water plugging method for oil well casing breakage comprises the following steps:
s1, preparing construction, including determining the damage position of the oil well casing before water plugging construction;
s2, water plugging construction, which comprises injecting plugging agent by the intermittent injection method at the damaged position of the oil well casing;
s3 resumes production, including sand wash completions and resuming production.
Wherein the step of S1 construction preparation comprises:
1) well flushing: 50-60m of oil field deoiled produced water after treatment3Adding 1% HRV-2 viscosity reducer to prepare flushing fluid, heating to 70-75 deg.C, and back flushing by entering from oil sleeve annulus and returning from oil pipeAnd (3) controlling the pump pressure of the well-flushing pump truck within 15.0MPa, controlling the discharge capacity from small to large, and controlling the discharge capacity within 300L/min (a sleeve with the outer diameter of 139.7 mm). And after the well flushing operation is finished, configuring a calcium chloride well killing hydraulic well according to the formation pressure.
The HRV-2 viscosity reducer is produced by Xin Shu chemical industry Co., Ltd, Xin Ji city; the properties of the viscosity reducer for HRV-2 thick oil are described in detail in the section of No. 18, No. 3 of petroleum drilling and production technology 1996 by Poplar and people. The kill method and formulation is well known to those skilled in the art and other conventional kill methods may be selected.
2) Starting a well pipe column: the original production pipe column in the well is pulled out, and comprises a sucker rod column and an oil pipe column.
3) Finding leakage by using a tracer: and (4) finding out the possible damaged position of the casing by using a tracer leakage finding technology.
The tracer leakage finding method can be written by Tantana et al, and is described in detail in 1991, which is published by the Petroleum industry Press as "application of well logging data in oil and gas field development".
4) And (3) well diameter testing: and (4) the deformation condition of the casing is sketched by using a 40-arm logging technology, and the leakage points found by tracer leakage finding are verified. The 40-arm well logging technology is explicitly described in the research on cased-hole well diameter testing technology published by Zhao Qinghai, Chen wen Yan and the like in the first international conference on mechanical engineering academy. The well diameter testing methods described are well known to those skilled in the art and will not be described in detail herein.
5) Well cleaning: selecting a drift gauge (the diameter is D139.9mm sleeve) with the outer diameter of 118mm and a thickened oil pipe with the diameter of D73mm for drifting, flushing with normal-temperature well killing liquid in 2-3 times of the volume of a shaft (1) after the drift exceeds a construction well section, taking out a drift tubular column, checking the drift gauge condition and describing the drift gauge condition. Such well cleanouts are well known to those skilled in the art and will not be described in detail herein.
6) Scraping and washing the well: a GX-140T scraper (a sleeve with the outer diameter of 139.9 mm) + an oil thickening pipe with the diameter of D73mm is selected for scraping; scraping 12-15 times at the well section needing construction, washing the well with medium-normal-temperature well killing fluid with 2-3 times of well shaft volume, taking out the scraping pipe column, checking the scraper and describing the condition of the scraper. The scraper is characterized in that: the model is GX-T140, and the oil field is commonly used for well repairing operation tools which are sold in the market. The GX-T140 scraper is a method for cold recovery of thick oil at the edge of reservoir structure in North China oil field, which is published in the No. 2 petroleum drilling and production process, volume 39, 3.7.2017 and is described in detail. Such scraping and flushing are well known to those skilled in the art and will not be described in detail herein.
7) Setting and testing the sleeve: and (3) inserting a test sleeve string: tubing hanger + external thickened tubing of diameter D73mm + variable buckle + diameter D73mm flat tubing nipple + Y211-114 packer + diameter D73mm external thickened screen + diameter D73mm external thickened tubing + guide cone. Connecting a 1.5m diameter D73mm flat oil pipe nipple on an oil pipe hanger, lifting a pipe string for 1.4m by using oil well operation equipment, slowly lowering, pressurizing by 70KN, setting the oil pipe hanger, and setting a top jackscrew to be qualified. 5MPa pressure stabilization is carried out for 10 minutes from the casing pipe, and the pressure drop is observed; increasing the pressure to 10MPa, stabilizing the pressure for 10 minutes, and observing the pressure drop; and continuously increasing the pressure to 15MPa, stabilizing the pressure for 10 minutes, and observing the pressure drop.
After the test sleeve is qualified, slowly lifting the pipe string for 1-1.5m to unseal, and pulling out the setting test sleeve string.
The oil pipe hanger, the setting oil pipe hanger, the qualified setting of the top jackscrew and the like are recorded in detail in the text of the application of a wellhead integrity technology in the Luimala oil field published in No. 6 unconventional oil and gas of volume 2 of 12 months in 2015. The qualification of setting a tubing hanger and an overhead jackscrew is a method well known to those skilled in the art.
The guide cone is a common accessory in an oil field and is sold in the market; the guide cone is described in detail in the text of 'application discussion of integrated tubular column for pump blowout prevention under perforation' published in 2 nd paper of Jianghan oil workers university at 32 nd volume of 3.2019.
The Y211-114 packer is common equipment in the oil field and is commercially available; the guide cone is recorded in detail in a text of inclined shaft layered oil extraction and sand control combined process technology which is published in No. 4 petroleum field machinery on volume 47 of 8 th month in 2018 of Y211-114 packer.
The diameter D73mm external thickened oil pipe, the diameter D73mm flat oil pipe short section and the diameter D73mm external thickened screen pipe are common equipment in oil fields and are sold in the market.
The variable buckle connected between the external thickened oil pipe with the diameter D73mm and the flat oil pipe nipple with the diameter D73mm is common equipment for oil fields and is sold in the market.
The setting construction and the sleeve testing construction are well known to those skilled in the art and are not described in detail herein.
8) Filling sand: and (3) putting a sand filling pipe string: diameter D73mm outside upset tubing + bell to the job site. And (2) washing the well from the positive circulation of the oil pipe, filling sand to the designed sand surface position according to the geological and engineering design scheme after the oil sleeve is ensured to be unblocked, temporarily plugging the lower sleeve, lifting 6 thickened oil pipes with the diameter D73mm, closing the well, settling sand for 24 hours, then detecting the sand surface, lifting 20 thickened oil pipes after the sand surface is qualified, and completing plugging construction preparation.
The diameter is D73mm external thickening oil pipe and bellmouth for the oil field common equipment, market has.
The sand-pack and sand-face construction is well known to those skilled in the art and will not be described in detail herein.
In another embodiment of the present invention, the step of S2 water shutoff construction includes:
1) and (3) testing the compatibility: and circulating the well by using clean water for one week to replace the well killing fluid. And taking 80ml of well clean water and 200g of plugging agent, fully and uniformly mixing, standing for 90min at normal temperature, and observing the water loss condition.
In the compatibility test, the experimental container should be made of materials such as plastics or glass which do not react with the liquid and the plugging agent in the well, the volume is preferably 200-.
2) Injecting the plugging agent by an intermittent injection method: adjusting the pipe column to the designed depth, pumping at 2-3MPa, discharging at 400L/min, and extruding clean water for 5min to enter the well at 0.26m 3.
Using pressure-sensitive thixotropic agent, inorganic composite plugging agent and clear water which are added according to the depth of a construction well to mix 5-8t of plugging agent with the density of 1.83g/cm3 in a stirring tank, and extruding the plugging agent 4.5-7.5m3 for three times; each time, positive extrusion is carried out for 0.3-4m3, positive extrusion is carried out for clear water for 2.5m3, the pump pressure is controlled within 8MPa in the first two times, and the well is closed for 10min for pressure expansion; the third pump was pumped at 12MPa for 10 min. And ensuring that the pressure fluctuation in the shaft is less than 6MPa in the first two times of plugging agent injection and well closing periods.
And (4) washing the well by using clean water in a reverse circulation manner, washing out the redundant plugging agent in the well until the properties of the inlet and the outlet are consistent.
3 external thickened oil pipes D73mm are added, the well is washed back by clean water 15m3, redundant plugging agents are washed out, the properties of the inlet and outlet are consistent, and the well is qualified.
The inorganic composite plugging agent is based on G-grade superfine cement and is formed by additives such as a cement retarder, a thickening agent and the like. The G-grade superfine cement, the cement retarder and the organic polymer are common petroleum materials and are sold in the market; pressure sensitive mutagens are sold by the medium petrochemical petroleum engineering services, Inc.
The preparation method of the inorganic composite plugging agent and the construction method of the plugging agent are well known to those skilled in the art, and will not be described in detail herein.
3) And (3) waiting coagulation: and (3) taking out 13 external thickened oil pipes with the diameter D73mm, installing a simple wellhead, filling a shaft with clear water, closing the shaft and waiting for setting for 48 hours.
The simple well mouth is a common oil field equipment and is sold in the market.
Setting-candidate construction is well known to those skilled in the art and will not be described in detail herein.
4) And (3) pressure testing: and (5) pressurizing the mixture to 3-5-8-10MPa respectively, and stabilizing the pressure at each point for 2 minutes.
The positive pressure tests are carried out at 3MPa, 5MPa, 8MPa and 10MPa, and the pressure test construction is well known to those skilled in the art and will not be described in detail.
5) And (5) completing plugging construction, and pulling out the cement injection pipe column.
In another embodiment of the present invention, the production and construction of step S3 includes:
1) sand washing: putting a sand washing pipe string: and D73mm pen point + D73mm external thickened oil pipe to sand surface, and sand washing to geological and engineering design depth and then pulling out the sand washing pipe string.
The D73mm nib is a common tool in oil fields and is commercially available.
Sand wash operations are well known to those skilled in the art and will not be described in detail herein.
2) And (3) pump-down well completion: and (5) completing the well after the pipe columns are put into combination according to the engineering design, and recovering production.
The following examples are further illustrative of the practice of the present invention with respect to Zhao 41-4X wells.
[ example 1 ]
The upper sleeve of the Zhao 41-4X well breaks and leaks water, and a lower production layer is pressed, so that the well cannot normally produce; the invention solves the problem that the success rate of one-time water plugging is low due to reverse discharge of a damaged position by using the original water plugging construction method.
Step 1: preparation for construction
(1) Well flushing: 60m of oil field deoiled produced water after treatment3Adding 1% of HRV-2 viscosity reducer to prepare a well washing liquid, heating to 70 ℃, and performing reverse well washing, wherein the pump pressure of a well washing pump truck is controlled within 15.0MPa, the discharge capacity is controlled from small to large, and the discharge capacity is controlled within 300L/min. According to the construction design, the special working procedure of calcium chloride well killing and hydraulic well killing is not needed.
(2) A well pipe column is recovered; and (6) pulling out all original production pipe columns in the well.
(3) Finding leaks using a tracer: breakage was found to occur at 1542.0-1547.83m cannula.
(4) Logging with 40 arms: when the well casing is blocked at 1664.3m, the well casing with 1509.6-1581.5m is deformed and locally damaged, wherein 1547.9-1548.5m is the most serious, the minimum well diameter value at 1548.075m is 116.262mm, and the maximum well diameter value is 131.108 mm.
And (4) finding leakage by using a tracer and logging by using a 40-arm well, and determining that the plugging interval is 1542.0-1547.83 m.
(5) Well cleaning: d118mm drift gauge + D73mm thickened oil pipes are used for drifting to the bottom of a human body, 10m3 clear water is used for backwashing the well, the pump pressure is 2MPa, the discharge capacity is 300L/min, the drift pipe column is lifted out, and the drift gauge is checked to find whether obvious vertical scratches exist.
(6) Scraping and washing the well: scraping is repeated 13 times at 1530 and 1544m positions by using a GX-140T device + D73mm thickened oil pipe pair, the well is back-washed by using 10m3 clear water, the pump pressure is 2MPa, the discharge capacity is 300L/min, and the scraping pipe column is pulled out.
(7) Setting and testing the sleeve: and (3) setting an inspection casing string D73mm bell mouth + D73mm thickened oil pipe + Y211-114 packer + D73mm thickened oil pipe to 1536 +/-1 m, backwashing the well by using 3m3 clean water, and filling the oil sleeve. Lifting the pipe column by 1.4m, slowly lowering the pipe column, pressurizing the pipe column by 70kN, setting a packer, setting a tubing hanger, jacking a jackscrew and installing a wellhead.
And (3) pressurizing the sleeve for 5MPa and stabilizing the pressure for 10min, increasing the pressure to 10MPa and stabilizing the pressure for 10min, then pressurizing to 15MPa and stabilizing the pressure for 10min, wherein the pressure drop is less than 0.2MPa, and the sealing property of the sleeve is qualified.
And after the test sleeve is qualified, slowly lifting the pipe string for 1.2m for deblocking to pull out the setting test sleeve string.
(8) Filling sand: and (3) putting a sand filling pipe string: and the diameter D73mm is increased by the external thickened oil pipe + bell mouth to 1560 m. And (3) washing the well from the positive circulation of the oil pipe, filling 1100L of sand to the position of a designed sand surface after ensuring the smoothness of an oil sleeve, temporarily blocking the lower casing, lifting 6 thickened oil pipes with the diameter D73mm, closing the well, settling sand for 24 hours, then detecting the sand surface, lifting 20 thickened oil pipes after the sand surface is qualified, and completing water plugging construction preparation.
Step 2: water plugging construction
(1) And (3) testing the compatibility: circulating in the well for one week by using clean water. And (3) taking 80mL of clean water in the well and 200g of plugging agent, putting the clean water and the plugging agent into a plastic container of about 250mL, fully and uniformly mixing, standing the mixture for 90min at normal temperature, and obtaining qualified compatibility of the plugging agent without dehydration and solidification.
(2) Injecting a plugging agent: adjusting the pipe column to 1529.6m, pumping pressure of 2MPa, discharge capacity of 400L/min, and trying to squeeze clean water for 5min, wherein the clean water enters the well at 0.26m 3.
2.32t of inorganic composite plugging agent and 4m3 of clean water are used for mixing 7.32t of plugging agent with the density of 1.83g/cm3 in a stirring tank. Pumping for the first time at a pressure of 3.8MPa, extruding a plugging agent to 2m3, closing the well and expanding pressure for 10 min; pumping pressure of 5.1MPa and positive extrusion plugging agent of 1.5m3 for the second time, closing the well and expanding pressure for 10 min; the third pump pressure is 12MPa, the positive extrusion plugging agent is 0.5m3, and the pump pressure of 12MPa is kept for 5 min.
And (4.6 m3 clear water is used for reverse circulation well washing, and redundant plugging agents in the well are washed out until the properties of the inlet and the outlet are consistent.
3 external thickened oil pipes D73mm are added, the well is washed back by clean water 15m3, redundant plugging agents are washed out, the properties of the inlet and outlet are consistent, and the well is washed to be qualified.
(3) And (3) waiting coagulation: and (3) taking out 13 external thickened oil pipes with the diameter D73mm, installing a simple wellhead, filling a shaft with clear water, closing the shaft and waiting for setting for 48 hours.
(4) And (3) pressure testing: and (3) positively pressurizing the shaft after the sand surface is detected, respectively pressurizing to 3-5-8-10MPa, stabilizing the pressure at each point for 2 minutes, and ensuring that the pressure drop is 0 and the plugging is qualified.
(5) And (5) after the water plugging construction is finished, taking out the cement injection pipe column.
And step 3: production and construction
(1) Sand washing: putting a sand washing pipe string: and (3) thickening the oil pipe to 1564m outside the D73mm pen point and D73mm, and lifting the sand washing pipe string after sand washing reaches the bottom of a person.
(2) And (3) pump-down well completion: and (5) completing the well after the pipe columns are put into combination according to the engineering design, and recovering production.
The water plugging effect of the Zhao 41-4X well is good: the daily yield is zero before water plugging, and the crude oil yield is recovered to 6.3 tons every day after water plugging.
The methods of expression of the invention are well known to those skilled in the art. The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A water plugging method for oil well casing damage comprises the following steps:
s1, determining the damage position of the oil well casing before water plugging construction;
s2, water plugging construction, namely, injecting a plugging agent by an intermittent injection method;
s3 sand washing, well completion and production recovery;
wherein the intermittent injection method for injecting the plugging agent comprises injecting the plugging agent into the damaged position of the oil well casing by pumping for multiple times.
2. The method of claim 1, wherein the step of determining the location of the well casing damage prior to the water shut-off operation comprises the steps of determining the location of the casing damage by using a tracer, and verifying the location of the casing damage by a caliper test of the cased well.
3. The method of claim 2, wherein the tracer comprises an isotope tracer method.
4. The method of plugging a casing failure of an oil well according to claim 2, wherein said caliper test comprises verifying a location of the casing failure using a caliper.
5. The method of claim 2, wherein the injection position of the plugging agent by the intermittent injection method comprises a position 10-20 m above the damaged position of the oil well casing.
6. The method of claim 2, further comprising the steps of flushing a well, scraping the well, setting the test casing, pulling out the string of test casings, and sand-packing after determining the location of the well casing damage.
7. The method for plugging damaged oil well casing according to any one of claims 1 to 6, wherein the pump pressure for injecting plugging agent by the intermittent injection method comprises 8MPa to 12 MPa.
8. The method of claim 7, wherein each pumping time for injecting the plugging agent by the intermittent injection method comprises 10 to 30 minutes.
9. The method for plugging damaged oil well casing according to claim 7, wherein the number of times of pumping for injecting the plugging agent by the intermittent injection method comprises 3 to 10 times.
10. The method for plugging damaged oil well casing according to any one of claims 7 to 9, further comprising the steps of flushing a well, closing the well for waiting for setting, testing pressure and tripping out the plugging agent injection string after the plugging agent is injected by the intermittent injection method.
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Application publication date: 20210928 |