CN117345207B - Oil-gas well plugging method based on shaft and lifting nipple integrity detection analysis - Google Patents
Oil-gas well plugging method based on shaft and lifting nipple integrity detection analysis Download PDFInfo
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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
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- G06Q50/00—Systems or methods specially adapted for specific business sectors, e.g. utilities or tourism
- G06Q50/02—Agriculture; Fishing; Mining
Abstract
The embodiment of the invention discloses an oil and gas well plugging method based on integrity detection and analysis of a shaft and a lifting nipple, which comprises the following steps of detecting and analyzing the integrity of the shaft of a target oil and gas well; carrying out integrity detection analysis on the raised nipple of the target oil-gas well; and marking the target oil and gas well as to-be-plugged or normal in performance according to the well shaft integrity detection and analysis result of the oil and gas well and the integrity detection and analysis result of the lifting nipple. The method can provide a reliable scheme for plugging the oil and gas well, and can accurately plug the abandoned well in the later period.
Description
Technical Field
The invention relates to the technical field of wellbore risk evaluation, in particular to an oil and gas well plugging method, a chip and a storage medium based on wellbore and lifting nipple integrity detection analysis.
Background
In the later period of oil field development, partial oil and gas wells have the conditions of casing damage, down-hole junk and the like, and the well is forced to stop for a long time to become abandoned wells. For these abandoned wells, the previous engineering may cause damage to the sealing structure, mainly the damage to the well bore and the lifting nipple, the well bore damage will generate the channel of oil-gas channeling, the lifting nipple damage will not bear the bottom hole gas pressure, thus the wellhead of the oil-gas well with the structural damage needs to be plugged in time, otherwise the development of oil-gas safety and environmental protection will be seriously affected.
However, the early oil and gas wells are shallow in depth, the plugging materials are not durable and the disposal standards are ambiguous, and the technology has not been greatly developed. Therefore, a plugging method for oil and gas wells is needed, and a scientific basis is provided for the later development of oil and gas fields to the waste plugging.
Disclosure of Invention
Based on the method, the chip and the storage medium, the invention provides an oil and gas well plugging method based on shaft and lifting nipple integrity detection analysis, and solves the problem that no reliable scheme for plugging the oil and gas well exists in the prior art.
In a first aspect, an oil and gas well plugging method based on wellbore and lift nipple integrity detection analysis is provided, including:
carrying out integrity detection analysis on a shaft of a target oil-gas well;
carrying out integrity detection analysis on the raised nipple of the target oil-gas well;
and marking the target oil and gas well as to-be-plugged or normal in performance according to the well shaft integrity detection and analysis result of the oil and gas well and the integrity detection and analysis result of the lifting nipple.
Optionally, performing an integrity check analysis of the wellbore of the target oil and gas well, comprising:
obtaining a cement stone sample based on target cement sheath sampling of a target oil-gas well, and obtaining historical construction information of the target cement sheath;
Carrying out cement sheath state mechanism analysis based on the cement sheath sample and the historical construction information, wherein the analysis comprises contact analysis of drilling fluid, cement slurry and a drilling fluid treating agent, corrosion analysis of a cement sheath of a sulfur-containing gas well, analysis of triaxial stress mechanical properties of the cement sheath, and analysis of mechanical integrity of the cement sheath;
the contact analysis of the drilling fluid, the cement slurry and the drilling fluid treating agent is used for analyzing the contact pollution of the drilling fluid and the cement slurry, the influence of the drilling fluid treating agent on the rheological property of the cement slurry and the influence of the cement slurry on the drilling fluid property; the sulfur-containing gas well cementing cement ring corrosion analysis is carried out, and the analysis of the acid medium corrosion rule and corrosion mechanism is carried out on the cement stone sample through integral corrosion and interface corrosion; the triaxial stress mechanical property analysis of the cement sheath simulates the triaxial stress, the formation pressure and the temperature born by a cement sheath sample in a stratum to obtain a triaxial stress-strain curve; the cement sheath mechanical integrity elastoplasticity analysis is carried out by analyzing the mechanical integrity of the cement sheath through a sleeve-cement sheath-stratum combination elastoplasticity model;
based on a cement sheath state mechanism analysis result, carrying out mass analysis on a target cement sheath to obtain the current state of the target cement sheath;
And if the current state of the target cement sheath indicates that the target cement sheath is damaged, marking the target oil and gas well as incomplete well shaft.
Optionally, the analysis of the corrosion rule and the corrosion mechanism of the acid medium is carried out on the cement sample through integral corrosion, which comprises the following steps:
placing a cement stone sample into a high-temperature high-pressure corrosion instrument, corroding for a preset time in an acid gas corrosion environment, and carrying out a first corrosion test on the basis of two water types of calcium chloride and distilled water;
and obtaining first corrosion depth data according to the first corrosion experiment, and carrying out comprehensive evaluation based on the first corrosion depth data to obtain a first analysis result.
Optionally, the analysis of the corrosion rule and the corrosion mechanism of the acid medium is carried out on the cement sample through interface corrosion, which comprises the following steps:
filling a cement stone sample into a corrosion-resistant mold, sealing the non-contact part of the cement stone and the mold by using epoxy resin, and polishing the end face of the cement stone to obtain a treated cement stone sample;
placing the treated cement stone sample into a high-temperature high-pressure corrosion instrument for a second corrosion experiment;
and obtaining second corrosion depth data according to the second corrosion experiment, and carrying out comprehensive evaluation based on the second corrosion depth data to obtain a second analysis result.
Optionally, the analysis of triaxial stress mechanical properties of the cement sheath simulates the triaxial stress, the formation pressure and the temperature born by the cement sheath sample in the stratum, and after obtaining the triaxial stress-strain curve, the analysis comprises:
and calculating Young modulus, poisson's ratio, yield strength, yield strain, ultimate strength and ultimate strain of the cement stone sample according to the triaxial stress-strain curve.
Optionally, the analysis of the elasto-mechanical properties of the well-cementing set may comprise, before simulating the three-dimensional stress, the formation pressure and the temperature to which the set cement sample is subjected in the formation:
setting a preset loading rate, a preset temperature and a preset confining pressure.
Optionally, the analyzing the mechanical integrity of the cement sheath by using the elastic plastic model of the sleeve-cement sheath-stratum combination comprises:
based on the elastic-plastic model of the sleeve-cement sheath-stratum combination, a stratum-cement sheath-sleeve two-dimensional finite element model is established, and the stress of the cement sheath is compared with the limit stress to obtain the mechanical integrity of the cement sheath.
Optionally, performing an integrity detection analysis of the raised nipple of the target oil and gas well, comprising:
detecting an elevated nipple of a target oil-gas well through a directional thickness gauge to obtain a defect image, and carrying out data analysis based on the defect image to obtain defect information;
Detecting the main stress and the direction of the lifting nipple of the target oil-gas well through a strain measuring device, and carrying out load distribution calculation analysis;
and when the defect information and the load distribution calculation analysis result show that the target oil-gas well is damaged, marking the target oil-gas well as an incomplete lifting nipple.
In a second aspect, a chip is provided, comprising a first processor for recalling and running a computer program from a first memory, so that a device on which the chip is mounted performs the steps of the well plugging method based on wellbore and lift sub integrity detection analysis as claimed in any one of claims 1 to 8.
In a third aspect, a terminal is provided, comprising a second memory, a second processor and a computer program stored in the second memory and executable on the second processor, the second processor implementing the steps of the wellbore and lift sub integrity detection analysis based hydrocarbon well plugging method as described above when executing the computer program.
According to the oil and gas well plugging method, device, chip and storage medium based on the shaft and lifting nipple integrity detection analysis, whether the sealing structure performance of the target oil and gas well is damaged or not is judged according to the oil and gas well shaft integrity detection analysis result and the lifting nipple integrity detection analysis result, plugging marks or marks with normal performance are further carried out, a reliable scheme for plugging the oil and gas well is provided, and the later-stage abandoned well is accurately plugged.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a basic flow of an oil and gas well plugging method based on wellbore and lift sub integrity detection analysis in accordance with an embodiment of the present invention;
FIG. 2 is a schematic diagram of a basic flow of an integrity test analysis of a wellbore according to an embodiment of the invention;
FIG. 3 is a schematic diagram of an elastoplastic mechanical coupling model of a casing-cement sheath-borehole wall surrounding rock in an embodiment of the invention;
FIG. 4 is a schematic view of a two-dimensional finite element model of a formation-cement sheath-casing according to an embodiment of the present invention;
FIG. 5 is a schematic illustration of a basic flow of an integrity check analysis of an elevated nipple in accordance with an embodiment of the present invention;
fig. 6 is a basic structural block diagram of a terminal according to an embodiment of the present invention.
Detailed Description
In order to enable those skilled in the art to better understand the present invention, the following description will make clear and complete descriptions of the technical solutions according to the embodiments of the present invention with reference to the accompanying drawings.
In some of the flows described in the specification and claims of the present invention and in the foregoing figures, a plurality of operations occurring in a particular order are included, but it should be understood that the operations may be performed out of order or performed in parallel, with the order of operations such as 101, 102, etc., being merely used to distinguish between the various operations, the order of the operations themselves not representing any order of execution. In addition, the flows may include more or fewer operations, and the operations may be performed sequentially or in parallel. It should be noted that, the descriptions of "first" and "second" herein are used to distinguish different messages, devices, modules, etc., and do not represent a sequence, and are not limited to the "first" and the "second" being different types.
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by a person skilled in the art without any inventive effort, are intended to be within the scope of the present invention based on the embodiments of the present invention.
The embodiment of the application can acquire and process the related data based on the artificial intelligence technology. Among them, artificial intelligence (AI: artificial Intelligence) is a theory, method, technique and application system that simulates, extends and expands human intelligence using a digital computer or a machine controlled by a digital computer, perceives the environment, acquires knowledge and uses the knowledge to obtain the best result.
Artificial intelligence infrastructure technologies generally include technologies such as sensors, dedicated artificial intelligence chips, cloud computing, distributed storage, big data processing technologies, operation/interaction systems, mechatronics, and the like. The artificial intelligence software technology mainly comprises a computer vision technology, a robot technology, a biological recognition technology, a voice processing technology, a natural language processing technology, machine learning/deep learning and other directions.
Referring specifically to fig. 1, fig. 1 is a schematic flow chart of an oil and gas well plugging method based on detection and analysis of integrity of a well bore and a raised nipple according to the present embodiment.
As shown in fig. 1, an oil and gas well plugging method based on integrity detection and analysis of a well bore and a raised nipple comprises:
s11, carrying out integrity detection analysis on a shaft of a target oil-gas well;
S12, carrying out integrity detection analysis on the raised nipple of the target oil-gas well;
s13, marking the target oil and gas well as to-be-plugged or normal in performance according to the well shaft integrity detection and analysis result of the oil and gas well and the integrity detection and analysis result of the lifting nipple.
In the embodiment of the invention, the step S11 marks the target oil and gas well with incomplete cement sheath according to the well shaft integrity detection analysis result, the step S12 marks the target oil and gas well with incomplete lifting nipple according to the integrity detection analysis result, and then the step S13 marks any mark, namely the oil and gas well with incomplete shaft and/or incomplete lifting nipple is finally marked as to-be-plugged, and the oil and gas well without any mark is finally marked as normal based on the steps S11 and S12.
For the step S11, the well bore belongs to the bottom structure of the oil and gas well, the quality of which mainly depends on the quality of the cement sheath, once the cement sheath no longer has the sealing property, the well bore no longer has the integrity, and the oil and gas well needs to be sealed. Thus, the embodiment of the invention realizes the integrity detection analysis of the well bore of the target oil and gas well through cement sheath packer evaluation, as shown in fig. 2, and comprises the following steps:
S111, sampling the target cement sheath to obtain a cement paste sample, and obtaining historical construction information of the target cement sheath.
In the step S111, the preparation and acquisition modes of the cement stone sample are exemplified as follows: and (3) preparing and curing the on-site sampling cement slurry according to the specifications of an API (American Petroleum Institute), and after the high-temperature high-pressure curing is finished, taking a core to obtain a cement sample. The historical build information for the target cement sheath includes, but is not limited to: the highest environmental temperature, the highest confining pressure, the type of drilling fluid treatment agent, the cement slurry density, the type of oil well cement admixture, the drilling fluid concentration, the oil well cement admixture and the like.
S112, carrying out cement sheath state mechanism analysis based on the cement sheath sample and the historical construction information, wherein the analysis comprises drilling fluid, cement slurry, contact analysis of a drilling fluid treating agent, corrosion analysis of a cement sheath of a sulfur-containing gas well, triaxial stress mechanical property analysis of the cement sheath and elastoplastic analysis of mechanical integrity of the cement sheath.
In the embodiment of the present invention, the step S112 is a state mechanism analysis of the target cement sheath, and the contact analysis of the drilling fluid, the cement slurry, and the drilling fluid treatment agent analyzes the contact pollution of the drilling fluid and the cement slurry, the influence of the drilling fluid treatment agent on the rheological property of the cement slurry, and the influence of the cement slurry on the drilling fluid property; the sulfur-containing gas well cementing cement ring corrosion analysis is carried out, and the analysis of the acid medium corrosion rule and corrosion mechanism is carried out on the cement stone sample through integral corrosion and interface corrosion; the triaxial stress mechanical property analysis of the cement sheath simulates the triaxial stress, the formation pressure and the temperature born by a cement sheath sample in a stratum to obtain a triaxial stress-strain curve; and analyzing the mechanical integrity of the cement sheath by using a sheath-cement sheath-stratum combination elastoplastic model.
In practical application, even if a good cement slurry system and a displacement design are designed before well cementation, once the drilling fluid and the cement slurry are in contact pollution in the underground, the interval sealing between the well cementation layers is easy to lose efficacy, so in the embodiment of the invention, whether the target cement sheath is the drilling fluid and the cement sheath mixed by the annulus mixed fluid after the annulus is solidified is judged through the contact analysis of the drilling fluid, the cement slurry and the treatment agent of the drilling fluid, and the evaluation of the interval sealing failure degree between the well cementation layers is further completed.
In the embodiment of the invention, the cement stones with different densities have different acid medium corrosion rules and corrosion mechanisms, the acid medium corrosion rules and corrosion mechanisms of the cement stones with different densities are determined by the corrosion analysis of the sulfur-containing gas well cementing cement rings, and the overall corrosion and the interface corrosion are suitable for the practical situations of sulfur-containing gas wells in different areas, such as the corrosion of the sulfur-containing gas well underground cement rings of the Chuan gas field in all directions at the same time, and only the interface of a gas layer and the cement rings is subjected to continuous acid corrosion, so that the analysis of the acid medium corrosion rules and the corrosion mechanisms is realized by using the interface corrosion test method for the sulfur-containing gas wells such as the Chuan gas field.
In practical application, the mechanical integrity damage of cement rings in deep wells, ultra-deep wells and gas wells is a main factor for causing underground accidents such as ring air channeling and the like. In the well completion and production increasing operation, the pressure in the well can change to a certain extent, if the pressure born by the casing and the cement sheath exceeds the bearing capacity of the casing and the cement sheath, the casing and the cement sheath are damaged, and the mechanical integrity of the cement sheath is lost. In the field of research on mechanical integrity of a wellbore, safety of a completion string and casing is mainly focused, and mechanical integrity of a 'wellbore first barrier' -cement sheath is ignored. According to the theoretical research method for continuing mathematical modeling, a multifunctional rock mechanical tester of American MTS company 815 is adopted to simulate conditions of three-dimensional stress, formation pressure, temperature and the like born by a rock core in a stratum, rock mechanical experiments such as strength characteristics, deformation characteristics and the like of the rock core under the triaxial condition are carried out according to relevant experimental standards, three-dimensional stress, formation pressure and temperature born by a cement sample in the stratum are simulated, a triaxial stress-strain curve is obtained, and the evaluation of the mechanical integrity of a downhole cement sheath is completed.
In specific applications, the mechanical integrity of the cement sheath also comprises elastoplasticity, so that the mechanical integrity of the cement sheath is analyzed through a sleeve-cement sheath-wall surrounding rock elastoplasticity coupling model.
S113, based on the analysis result of the cement sheath state mechanism, carrying out mass analysis on the target cement sheath to obtain the current state of the target cement sheath.
The step S112 truly simulates the environment and the stress process of the actual cement sheath under the service condition, analyzes the mechanical integrity of the cement sheath from two aspects of stress and elastoplasticity, verifies the mechanical damage degree of the cement sheath, simulates the cement sheath to complete the evaluation of the interval packing failure degree of the cement sheath, and simultaneously realizes the analysis of the corrosion rule and the corrosion mechanism of the acid medium through integral corrosion and interface corrosion to complete the evaluation of the corrosion degree, thereby the analysis result of the cement sheath state mechanism based on the step S113 comprises the evaluation of the mechanical damage degree of the cement sheath and the interval packing failure degree of the cement sheath and the evaluation of the corrosion degree.
In one embodiment, the current state of the target cement sheath may be represented by a score.
And S114, if the current state of the target cement sheath indicates that the target cement sheath is damaged, marking the target oil and gas well as incomplete well shaft.
The embodiment of the present invention further describes in step S112 a contact analysis of the drilling fluid, cement slurry, and drilling fluid treatment agent, where the contact analysis includes: the contact pollution of the drilling fluid and the cement slurry, the influence of the drilling fluid treating agent on the rheological property of the cement slurry and the influence of the cement slurry on the performance of the drilling fluid.
The cement paste, that is, cement sheath raw material, the cement paste density described in the examples of the present invention is obtained based on the state before thickening and hardening.
The method mainly analyzes the interference phenomenon of the drilling fluid and the cement slurry. In practical application, the drilling fluid and the cement slurry are two working fluids with different physical and chemical properties and purposes, and the two fluids have different components and different physical and chemical characteristics, so that different degrees of physical and chemical reactions occur after the two fluids are mutually contacted and mixed, and chemical interference phenomenon is generated. The conventional drilling fluid is displaced with cement slurry, the drilling fluid and the cement slurry form a slurry mixture in an annulus, the displacement efficiency is low, the slurry mixture flowing capability is poor, so the slurry mixture is almost immobile, annulus mixed fluid is formed, the drilling fluid and the cement slurry formed after the annulus is solidified are mixed with a cement slurry ring, and the cement ring has small strength. Once such cement sheath is formed, it is prone to failure of the interval seal between cementing layers even if a good cement slurry system and displacement design is designed prior to cementing.
Exemplary methods for analyzing interference phenomena of drilling fluid and cement slurry are mainly based on SY/T5546-92 "oil well cement application Performance test method", GB 10238-2005 "oil well Cement", GB/T19139-2005 "oil well Cement test method", GB/T16783.1-2006 "first portion of drilling fluid field test: the performances of cement paste, drilling fluid and mixing paste are tested according to the corresponding regulations of water-based drilling fluid, GB/T5005-2010 drilling fluid material Specification, API RP 10B recommended practice for oil well cement test and conventional pollution test methods for deep well cementation compatibility in Chongqing area.
Wherein, the influence of drilling fluid treating agents on cement slurry rheological property is exemplified, 14 types of drilling fluid treating agents are selected in the embodiment of the invention, as shown in the following table 1, according to the single drilling fluid treating agent evaluation step, the drilling fluid treating agents are used for well cementation retarder conventional density cement slurry of a casing of 177.8mm of a dragon 002-4 well, and the influence rule of the 14 types of drilling fluid treating agents on conventional density, high density cement slurry flow rheological property and thickening time is practiced.
The normal flow fluidity of the conventional density cement slurry is 25cm, the high flow fluidity is 22cm, and the thickening time is 300min. The constant flow fluidity of the high-density cement paste is 20cm, the high flow fluidity is 19cm, and the thickening time is 320min. Thus, the experimental conditions for the high flow experiment were specified as: the cement paste is preset for 2 hours at 90 ℃ of the normal pressure thickening instrument, and the fluidity value of the cement paste is tested.
TABLE 1
Conclusion based on conventional density cement slurries: among the 14 drilling fluid treatment agents, the drilling fluid treatment agents which have no effect or little effect on the rheological property of the conventional density cement paste comprise HPS, SHR, JN-A, MG-1, LS-2, KR102 and RLC-101; the drilling fluid treating agents with great influence on the rheological property of the conventional density cement slurry comprise SMP-1 and KHM, KPAM, YH-S, and the proportion of the SMP-1 and KHM, KPAM, YH-S in the cement slurry is controlled within 1%, 0% and 1% respectively; the drilling fluid treating agent with certain influence on rheological property of conventional density cement slurry includes SMT, SMC and biological tackifier, and the proportion of the treating agent in cement slurry is controlled within 1.2%, 2% and 0.5% separately.
Conclusion based on high density cement paste: compared with the conventional density, the influence rule of the drilling fluid treating agent on the rheological property of the high-density cement slurry is less in change; the high-density cement slurry is the same as the oil well cement and the oil well cement admixture used by the conventional density cement slurry, and the difference is mainly that the solid phase content of the high-density cement slurry is high, the liquid-solid ratio is low, and the cement slurry fluidity is poor. The research on the influence rule of the drilling fluid treating agent on the fluidity of the high-density cement slurry is more important.
Conclusion based on the thickening time effect: on the basis of an early-stage rheological property experiment, various drilling fluid treatment agents are added into cement paste to carry out a high-temperature high-pressure pollution thickening experiment, and the influence rule of the drilling fluid treatment agents on the thickening time of conventional density cement paste is examined. The experimental condition of the single drilling fluid treating agent for thickening cement paste is 105 ℃ multiplied by 60MPa multiplied by 50min.
For conventional density cement paste, SMC, KHM, HPS, SHR, MG-1, LS-2 and YH-S, RLC-101 can prolong the thickening time of the cement paste within a certain addition range, and have no adverse effect on fluidity; KPAM and biological tackifier can drastically shorten the thickening time of cement paste, and the influence is uncontrollable; SMT, SMP-1, JN-A can shorten cement paste thickening time, but the influence is controllable. The addition amount is controlled within 0.5%, 0.3% and 0.3%. The influence rule of the drilling fluid treating agent on the thickening time of the high-density cement paste is less changed compared with the conventional density.
The above conclusion is that the application of the cement paste density, the type of the drilling fluid treatment agent and the dosage of the drilling fluid treatment agent in the embodiment of the invention is exemplified, the interval packing failure degree of the well cementation layer is taken as a result, a corresponding function or a score table is constructed, and when the history construction information indicates that the cement paste density of the target cement sheath is the conventional density and the type of the drilling fluid treatment agent is the drilling fluid treatment agent with great influence on the rheological property, the numerical value of the interval packing failure degree of the well cementation layer is adjusted according to the type and the dosage of the drilling fluid treatment agent.
Wherein, cement paste influences the performance of drilling fluid, exemplary, the embodiment of the invention selects 6 oil well cement admixtures, including SD18, SD12, SDP-1, SD10, SD32, SD21, etc.; and carrying out research on the influence of the oil well cement additive on the performance of the drilling fluid according to the single oil well cement additive evaluation step. The drilling fluid densities are respectively 1.85g/cm3 and 2.26g/cm3, the high-flow experimental conditions are preset for 20min at 90 ℃ of the normal-pressure thickening instrument, and the rheological properties of the drilling fluid densities are tested.
Conclusion based on drilling fluid density 1.85g/cm 3: SD18 has a larger influence on rheological property of drilling fluid, and the influence of SD18 should be considered in the process of analyzing pollution reasons; SDP-1, SD10, SD32, SD12, SD21 and the like have no obvious negative effect on rheological properties of drilling fluid.
Conclusion based on drilling fluid density 2.26g/cm 3: SD18 and SD12 have larger influence on rheological property of high-density drilling fluid, and the influence of SD18 and SD12 is mainly examined when pollution cause analysis is carried out; SDP-1, SD10, SD32 and the like have no obvious negative effect on rheological properties of drilling fluid.
Conclusion on the impact of thickening time: SD18 and SD12 have great influence on the initial thickening of the mixed fluid, and when pollution cause analysis is carried out, the influence of SD18 and SD12 is mainly examined; SDP-1, SD10, SD32, SD21 and the like have no obvious negative effects on the initial thickening time and the like of the mixed fluid.
The above conclusion is that the application of the oil well cement admixture in the embodiment of the present invention is exemplified by taking the well cement admixture as a variable, taking the drilling fluid rheological property as a second variable, taking the interval packing failure degree of the well cementation layer as a result, constructing a corresponding function or score table, adjusting the value of the second variable when the history construction information indicates that the well cement admixture is SD18 or SD12, and adjusting the value of the interval packing failure degree of the well cementation layer according to the adjusted value of the second variable.
The embodiment of the invention also provides a detailed description of the corrosion analysis of the cement sheath of the sulfur-containing gas well in the step S112, firstly, in the underground system of stratum (gas layer) -cement sheath-casing, the cement sheath of the cement sheath is used for preventing H 2 S、CO 2 A first barrier to corrosion by acidic media. Therefore, the corrosion-proof cement slurry system must be studied to clarify the corrosion essence of the cement stone in the acid environment, and corresponding corrosion-proof measures are adopted in a targeted manner, so that the well cementation quality of the acid gas well is fundamentally improved. The cement sheath is subjected to CO by adopting two modes of integral corrosion by completely soaking cement paste and interfacial corrosion by partially soaking cement paste 2 、H 2 The mechanism of acid gas corrosion such as S is deeply analyzed.
In the analysis of the corrosion of the cement sheath of the sulfur-containing gas well, the analysis of the corrosion rule and the corrosion mechanism of the acid medium is carried out on a cement sample through integral corrosion, and the analysis comprises the following steps:
placing a cement stone sample into a high-temperature high-pressure corrosion instrument, corroding for a preset time in an acid gas corrosion environment, and carrying out a first corrosion test on the basis of two water types of calcium chloride and distilled water;
and obtaining first corrosion depth data according to the first corrosion experiment, and carrying out comprehensive evaluation based on the first corrosion depth data to obtain a first analysis result.
In the embodiment of the invention, the acid gas corrosion environment provided by the integral corrosion comprises single CO 2 Single H 2 S and CO 2 、H 2 S is compounded with three environments of acid gas.
In addition, the cement paste system formula is as follows: grade G+high temperature stabilizer+silica fume+3% SDP-1+1.5% SD66+2.7% FS-31L+5% SD10, water-cement ratio of 0.44 and density of 1.88G/cm3. In order to meet the requirements of conventional performance test, porosity permeability test and corrosion maintenance, cement sheath samples are of two sizes, namely the core size phi 25mm multiplied by 25mm and the core size phi 25mm multiplied by 50mm.
Illustratively, 7 sets of experiments were performed for the corrosion tests described above, with the experimental design parameters as set forth in Table 2 below.
TABLE 2
Exemplary, the first corrosion depth data includes H 2 S partial pressure, CO 2 Partial pressure, total pressure, temperature, depth of penetration, based on which a first analysis result is obtained:
a. in a single H 2 S、CO 2 And H 2 S/CO 2 In the mixed corrosion environment, the strength of the cement stone is reduced along with the increase of the partial pressure of the corrosion gas, and the corrosion depth is increased; because the compact corrosion layer is formed on the surface of the cement stone, the permeability and the porosity of the cement stone are not increased and reduced after corrosion.
b. In a single CO 2 In corrosive environment, the corrosion product of the cement stone adopts SiO 2 (amorphous) CaCO 3 Mainly comprises; in a single H 2 S-shaped beancurdIn the etching environment, the corrosion product of the cement stone adopts SiO 2 (amorphous), caSO 4 ·2H 2 O, aft is the main component; at H 2 S/CO 2 In a mixed corrosion environment, the corrosion product of the cement stone adopts SiO 2 (amorphous) CaCO 3 、CaSO 4 ·2H 2 O, aft is the dominant.
In the presence of H 2 Under corrosive environment of S gas, table 3 below.
TABLE 3 Table 3
In the analysis of the corrosion of the cement sheath of the sulfur-containing gas well, the interface corrosion indicates that only the interface between the gas layer and the cement sheath is continuously subjected to acid corrosion, and in the embodiment of the invention, the analysis of the corrosion rule and the corrosion mechanism of the acid medium is carried out on the cement sheath sample through the interface corrosion, and the analysis comprises the following steps:
filling a cement stone sample into a corrosion-resistant mold, sealing the non-contact part of the cement stone and the mold by using epoxy resin, and polishing the end face of the cement stone to obtain a treated cement stone sample;
placing the treated cement stone sample into a high-temperature high-pressure corrosion instrument for a second corrosion experiment;
and obtaining second corrosion depth data according to the second corrosion experiment, and carrying out comprehensive evaluation based on the second corrosion depth data to obtain a second analysis result.
The core-taking size of the cement stone sample is phi 25mm multiplied by 50mm, the inner diameter of the corrosion-resistant die is 26mm, the length of the corrosion-resistant die is 52mm, and the non-contact part of the cement stone and the die is sealed by using epoxy resin and is used for guaranteeing the tightness between the cement stone and the die, so that the cementing of the stratum and the cement sheath interface is simulated.
Illustratively, the second corrosion depth data includes depth of penetration of the corrosive component into the set, penetration and porosity of the set after corrosion, microstructure of the set after corrosion, composition of the set after corrosion, and the like, based on which a second analysis result is obtained:
a. under the high-temperature high-pressure acid gas corrosion condition, the corrosion depth of various cement interfaces increases along with the increase of the maintenance temperature and time, but the increase amplitude tends to decrease along with the increase of time; the compressive strength value is in a decreasing trend; porosity and permeability tend to decrease. Under the environment of normal pressure stratum water soaking corrosion, the strength of various cement stones slightly increases along with the increase of curing time, but the increasing amplitude tends to be weakened, and analysis may be that the curing effect of stratum water on the cement stones occupies a main position and the corrosion effect occupies a secondary position within 7 days and 14 days.
b. The corrosion depth of various cement interfaces increases with the increase of the partial pressure and the total pressure of hydrogen sulfide; compressive strength, porosity and permeability tend to decrease with increasing hydrogen sulfide partial pressure and total pressure. The partial pressure of the corrosive medium is a major factor affecting the corrosion rate of the set cement, and the total pressure of the corrosive environment is a minor factor.
c. In an acidic corrosion environment, the corrosion products of the cement stones of the three systems are expressed as SiO 2 (amorphous) CaCO 3 、CaSO 4 ·2H 2 O, aft is mainly.
d. Under an acidic environment, due to the difference of internal structures of the set cement of the three systems, the corrosion resistance of the set cement is obtained by sequentially: high density set cement > conventional density set cement > low density set cement.
By utilizing two methods of integral corrosion and interface corrosion, the analysis of the corrosion rule and corrosion mechanism of the acid medium is carried out on cement stones with different densities, and the application of the method in the embodiment of the invention is as follows: downhole in acid gas well, H 2 S、CO 2 And (3) etching the cement sheath in the transverse direction from the interface of the production layer and the cement sheath to the cement sheath and in the longitudinal direction from the interface of the production layer and the cement sheath to the upper part of the gas well. The contact surface of the cement sheath and the air layer is completely corroded, and the compactness of the cement sheath is broken due to the chemical reaction of the acid gas and the cement sheathThe cement sheath is damaged, so that the porosity and permeability of the corroded surface of the cement sheath are increased. Over time, the acidic corrosive medium continues to act inside the cement sheath, its corrosive product SiO 2 AFt, C-S-H gel, caCO 3 、CaSO 4 ·2H 2 O, caS and the like utilize the pores in the cement sheath surface full corrosion zone to migrate to the surface, gradually forming a uniform dense transition zone. The dense transition zone blocks the pore canal due to the enrichment of a large amount of corrosion products, so that the porosity and permeability of the dense transition zone are not increased and reduced, and H is finally led to be 2 S、CO 2 It is difficult for the acidic corrosive medium to continue to develop corrosion to the cement sheath in both the lateral and longitudinal directions. Therefore, if the current area is suitable for the whole corrosion, the corrosion degree of the cement sheath is higher, the negative influence on the integrity of the cement sheath is higher, and if the current area is suitable for the interface corrosion, the corrosion degree of the cement sheath is lower, and the negative influence on the integrity of the cement sheath is lower. Accordingly, in practical application, the practical value can be obtained by establishing a relation model of cement paste density, corrosion time and cement sheath corrosion degree.
In one embodiment, in the analysis of triaxial stress mechanical properties of the cement sheath, the method further comprises the steps of:
and calculating Young modulus, poisson's ratio, yield strength, yield strain, ultimate strength and ultimate strain of the cement stone sample according to the triaxial stress-strain curve.
The data such as Young's modulus, poisson's ratio, yield strength, yield strain, ultimate strength and ultimate strain of the cement paste sample are used for evaluating annular variables of cement and recovering deformation capability.
In practical application, the loading rate, temperature and confining pressure will affect the analysis result of the triaxial stress mechanical properties of the cement sheath, so in one embodiment, the analysis of the elastic mechanical properties of the cement sheath for well cementation, before simulating the triaxial stress, formation pressure and temperature to which the cement sheath sample is subjected in the formation, includes:
Setting a preset loading rate, a preset temperature and a preset confining pressure.
It should be noted that, after the preset loading rate, the preset temperature, and the preset confining pressure are set according to the control variables, that is, after different preset loading rates are set, the same preset temperature and preset confining pressure are set, and after different preset temperatures are set, the same loading rate and preset confining pressure are set. Wherein the temperature has a greater influence on the ultimate stress; the influence of confining pressure on limit strain is larger, and the influence of confining pressure on elastic modulus is smaller; the yield stage of the cement stone is obvious under the conditions of higher confining pressure and higher temperature. The influence of temperature on limit strain is larger; the confining pressure has a larger influence on the limit stress and the limit strain; the yield stage of the cement stone is obvious at higher confining pressure and lower temperature.
In one embodiment, at a higher loading rate, the cement stone stress-strain curve is smooth, the yield phase is more obvious, and the comparison of different cement stone data rules can be carried out by using the calculated yield strength value for the highest load of alternating load. Namely, under alternating load, the higher loading rate can truly reflect the yield strain behavior of the cement stone, so that the preset loading rate is the higher loading rate under the alternating load, for example, 5.0kN/min under the alternating load is the higher loading rate, and 1.6kN/min under the alternating load is the lower loading rate.
The application of the content in the embodiment of the invention is exemplified by that the analysis of the triaxial stress mechanical properties of the cement sheath is carried out at a higher loading rate under alternating load, the temperature and confining pressure are used as variables, a stress-strain curve of the cement sheath is obtained, and the obtained yield strength value is calculated; and obtaining the highest temperature and the highest confining pressure in the historical construction information, and analyzing whether the highest yield strength value in the analysis of the triaxial stress mechanical properties of the cement sheath is reached or not, thereby completing the judgment of the mechanical integrity of the cement sheath based on the stress.
The embodiment of the invention also uses the measurement of the variable loading rate of 3 parallel cement paste samples of a certain well 2 to explain the triaxial stress mechanical property analysis process of the cement sheath. Curing conditions of 3 parallel cement stone samples are set to 58 ℃ multiplied by 20.7MPa for 7 days, experimental conditions are set to 58 ℃ multiplied by 20.7MPa, loading rate is 1.6kN/min under alternating load, unloading rate is 3.2kN/min, and calculated experimental data are shown in the following table 4.
TABLE 4 Table 4
The experimental data described above involved two methods for calculating the young's modulus, one of which was calculated at 50% point and the other was calculated at tangential slope.
The embodiment of the present invention further describes in detail the mechanical integrity of the cement sheath by analyzing the elastic-plastic model of the sheath-cement sheath-formation assembly in step S112, which includes:
based on the elastic-plastic model of the sleeve-cement sheath-stratum combination, a stratum-cement sheath-sleeve two-dimensional finite element model is established, and the stress of the cement sheath is compared with the limit stress to obtain the mechanical integrity of the cement sheath.
Firstly, an elastoplastic model of a sleeve-cement sheath-stratum combination is described, in the elastoplastic model of the sleeve-cement sheath-stratum combination, in order to conveniently study the elastoplastic mechanical coupling condition of a downhole sleeve-cement sheath-well wall surrounding rock combination, the following assumption conditions are provided:
1. the well bore is a vertical well bore and is in a regular round shape;
2. the sleeve is infinitely long and is ideally centered, and cement slurry completely fills the annular space in the well cementation process;
3. the casing, the cement sheath and the well wall surrounding rock are all made of homogeneous, continuous and isotropic ideal elastoplastic materials;
4. the sleeve has no defect, and the cement sheath is complete and has uniform thickness.
5. The interfaces of the combination body are tightly connected without sliding;
6. the ground stress is a uniform stress.
A schematic diagram of the elastic-plastic mechanical coupling model of the sleeve, the cement ring and the wall surrounding rock is shown in figure 3, wherein a broken line in the figure is an elastic region boundary line, and r p1 、r p2 、r p3 The plastic yield radius of the casing, the cement ring and the well wall surrounding rock are respectively shown, the internal pressure and the external pressure born by the coupling body are represented by p, and the acting force between interfaces is represented by q.
q 1 To q 5 The following relationship is provided:
f 1 ·q 1 -f 2 ·q 2 ＝f 3 ·q 3 -f 4 ·q 4
f 5 ·q 3 -f 6 ·q 4 ＝f 7 ·q 5 -f 8 ·p 0
the relevant coefficients in the formula are:
/>
based on the elastic-plastic mechanical coupling model of the casing-cement sheath-wall surrounding rock shown in fig. 3, the cement sheath mechanical damage judgment criteria are divided into: the mechanical damage of the cement sheath is judged through the strain generated by the stress of the cement sheath, or the mechanical damage of the cement sheath is judged through the stress condition of the cement sheath.
Wherein, the mechanical damage of the cement sheath is judged through the strain generated by the stress of the cement sheath: on the one hand, the distribution of circumferential stress and radial stress on the cement sheath under the action of pressure in the well and formation stress is analyzed, and whether positive circumferential stress or radial stress occurs or not. Positive stress is tensile stress or tensile stress, and negative stress is compressive stress, as defined by the stress direction. If positive circumferential stress appears on the cement sheath, the circumferential tensile stress is very small, and the tensile strength or the tensile strength of the cement sheath is very small, so that the cement sheath can easily crack in the radial direction by the circumferential tensile stress, and the mechanical integrity of the cement sheath is damaged; if positive radial stress occurs, the cementing strength of the first cementing surface and the second cementing surface of the cement sheath is smaller than the tensile strength of the cement sheath, and the radial tensile stress easily causes the axial fracture and the damage of the first cementing surface and the second cementing surface of the cement sheath, so that the mechanical integrity of the cement sheath is damaged. On the other hand, the maximum Tresca stress when the cement sheath fails to yield plastically, or the plastic yield range when the cement sheath has yielded plastically, is analyzed.
Wherein, the mechanical damage of the cement sheath is judged according to the stress condition of the cement sheath: the two-dimensional finite element model of the stratum-cement sheath-casing shown in fig. 4 is established based on the elastoplastic coupling model of the sheath-cement sheath-well wall surrounding rock, the model material is set to be an elastoplastic model, and a maximum shear stress judgment criterion based on a third strength theory can be adopted, wherein the judgment criterion considers that the damage of an object is caused by a shearing force and is suitable for a material with plastic deformation. The compressive strength and the yield strength obtained by the cement sheath laboratory mechanical test are the test results aiming at a certain confining pressure and geometric shape, and the stress distribution of the sleeve, the cement sheath and the stratum is analyzed, the strain of the cement sheath after being stressed is calculated, and the strain is compared with the limit strain obtained by the laboratory, so that whether the cement sheath is subjected to plastic deformation and mechanical damage is judged.
In practical application, the mechanical integrity of the well cementation cement paste under the working conditions of well killing, pressure testing, acidification, well closing, well opening and the like is calculated by using an elastic-plastic model of the sleeve-cement ring-stratum combination body, and the analysis result shows that the cement ring at 6000m can keep the mechanical integrity under different working conditions. The finite element model of the sleeve-cement sheath-stratum combination is utilized to explore the mechanical integrity of the well cementation cement stones under the working conditions of well killing, hollowing, pressure test, acidification and the like, and the well killing (clean water, 1.27 g/cm) 3 ) Under the working condition of 35MPa of emptying and pressure test, the cement sheath at 6000m can maintain mechanical integrity, and acidizing is carried outUnder the working condition of (wellhead pressure 70 MPa), the cement sheath at 6000m is completely broken, but the casing above the packer and the cement sheath are not directly subjected to high pressure (mainly subjected to a well completion string) during acidification, so that the mechanical integrity of the cement sheath above the packer can be maintained during acidification.
The application of the above in embodiments of the invention is exemplified by the fact that a maximum shear stress criterion based on a third strength theory may be employed, which is suitable for materials where plastic deformation exists. The compressive strength and the yield strength obtained by the cement sheath laboratory mechanical test are the test results aiming at a certain confining pressure and geometric shape, the stress distribution of the sleeve, the cement sheath and the stratum is analyzed, the strain of the cement sheath after being stressed is calculated, and the strain is compared with the limit strain obtained by the laboratory, so that whether the cement sheath is subjected to plastic deformation and mechanical damage is judged, and the judgment of the mechanical integrity of the cement sheath based on elastoplasticity is completed.
The two mechanical integrity judgment results are that the cement sheath transmits plastic deformation or mechanical damage, the current state of the cement sheath is a damaged state, and the state of the cement sheath needs to be further judged according to the evaluation results, wherein the evaluation is different from the evaluation of the fracture degree and the evaluation of the corrosion degree of the interval packing between the cementing layers.
Step S111 to step S114 are performed through analysis of a cement sheath state mechanism, namely, the mechanical damage degree of the cement sheath is verified from the aspects of stress and elastoplasticity through the mechanical integrity of the cement sheath; simulating the cement sheath forming process to finish evaluation of the interval packing failure degree of the well cementation layer; meanwhile, analysis of an acid medium corrosion rule and an acid medium corrosion mechanism is realized through integral corrosion and interface corrosion, the environment and stress of the target cement sheath under the actual service working condition are fully reduced, evaluation of corrosion degree is completed, and then the current state of the target cement sheath is judged according to the analysis result of the cement sheath state mechanism, so that the integrity of a shaft is judged.
For the step S12, the raising nipple belongs to an oil and gas well wellhead structure, where the bottom hole pressure and gas are accumulated, so that the embodiment of the invention realizes the integrity detection analysis of the raising nipple of the target oil and gas well through defect detection and stress-based load distribution calculation analysis, as shown in fig. 5, including but not limited to the following steps:
s121, detecting an ascending nipple of a target oil-gas well through a directional thickness gauge to obtain a defect image, and carrying out data analysis based on the defect image to obtain defect information;
S122, detecting the size and the direction of main stress at the rising nipple of the target oil-gas well through a strain measuring device, and carrying out load distribution calculation analysis;
and S123, marking the target oil-gas well as an incomplete raising nipple when the defect information and the load distribution calculation analysis result show that the target oil-gas well is damaged.
In the step S121, the defect image can be obtained by detecting the orientation thickness gauge, the defect image is a two-dimensional image, the imaging is visual, the defect display is clear, and meanwhile, the data analysis is performed based on the defect image to obtain the comprehensive defect information such as the size, the position, the damage degree of the part and the like.
In the step S122, the strain measurement device includes a strain gauge, an acquisition instrument, and measurement analysis software, the magnitude and direction of the main stress at the raised nipple are calculated by load distribution, and the maximum comprehensive stress of the raised nipple is calculated.
In order to solve the technical problem, an embodiment of the present invention further provides an oil and gas well plugging wellbore detection device, including:
the shaft detection module is used for detecting and analyzing the integrity of the shaft of the target oil-gas well;
The lifting nipple detection module is used for carrying out integrity detection analysis on the lifting nipple of the target oil-gas well;
and the plugging marking module is used for marking the target oil and gas well as to-be-plugged or normal in performance according to the well shaft integrity detection and analysis result of the oil and gas well and the integrity detection and analysis result of the lifting nipple.
In order to solve the above technical problems, the embodiment of the present invention further provides a chip, where the chip may be a general-purpose processor or a special-purpose processor. The chip comprises a processor, and the processor is used for supporting the terminal to execute the related steps, such as calling and running a computer program from a memory, so that equipment provided with the chip executes the related steps to realize the oil and gas well plugging method based on the well shaft and the lift nipple integrity detection analysis in the various embodiments.
Optionally, in some examples, the chip further includes a transceiver, where the transceiver is controlled by the processor, and is configured to support the terminal to perform the related steps to implement the method for plugging an oil and gas well based on the wellbore and the lift sub integrity detection analysis in the foregoing embodiments.
Optionally, the chip may further comprise a storage medium.
It should be noted that the chip may be implemented using the following circuits or devices: one or more field programmable gate arrays (field programmable gate array, FPGA), programmable logic devices (programmablelogic device, PLD), controllers, state machines, gate logic, discrete hardware components, any other suitable circuit or combination of circuits capable of performing the various functions described throughout this application.
The invention also provides a terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the well plugging method based on the detection and analysis of the integrity of the well bore and the raised nipple as defined in any one of claims 1 to 8 when the computer program is executed by the processor.
Referring specifically to fig. 6, fig. 6 is a basic block diagram illustrating a terminal including a processor, a nonvolatile storage medium, a memory, and a network interface connected by a system bus. The nonvolatile storage medium of the terminal stores an operating system, a database and a computer readable instruction, the database can store a control information sequence, and when the computer readable instruction is executed by a processor, the processor can realize an oil and gas well plugging method based on shaft and raising nipple integrity detection analysis. The processor of the terminal is operative to provide computing and control capabilities supporting the operation of the entire terminal. The memory of the terminal may store computer readable instructions that, when executed by the processor, cause the processor to perform an oil and gas well plugging method based on wellbore and lift sub integrity detection analysis. The network interface of the terminal is used for connecting and communicating with the terminal. It will be appreciated by those skilled in the art that the structures shown in the drawings are block diagrams of only some of the structures associated with the aspects of the present application and are not intended to limit the terminals to which the aspects of the present application may be applied, and that a particular terminal may include more or less components than those shown, or may combine some of the components, or have a different arrangement of components.
The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (8)
1. An oil and gas well plugging method based on detection and analysis of integrity of a shaft and a lifting nipple is characterized by comprising the following steps:
carrying out integrity detection analysis on a shaft of a target oil-gas well;
carrying out integrity detection analysis on the raised nipple of the target oil-gas well;
marking the target oil and gas well as to-be-plugged or normal in performance according to the well shaft integrity detection and analysis result and the raised nipple integrity detection and analysis result;
performing an integrity check analysis of a wellbore of a target oil and gas well, comprising:
obtaining a cement stone sample based on target cement sheath sampling of a target oil-gas well, and obtaining historical construction information of the target cement sheath;
carrying out cement sheath state mechanism analysis based on the cement sheath sample and the historical construction information, wherein the analysis comprises contact analysis of drilling fluid, cement slurry and a drilling fluid treating agent, corrosion analysis of a cement sheath of a sulfur-containing gas well, analysis of triaxial stress mechanical properties of the cement sheath, and analysis of mechanical integrity of the cement sheath;
The contact analysis of the drilling fluid, the cement slurry and the drilling fluid treating agent is used for analyzing the contact pollution of the drilling fluid and the cement slurry, the influence of the drilling fluid treating agent on the rheological property of the cement slurry and the influence of the cement slurry on the drilling fluid property; the sulfur-containing gas well cementing cement ring corrosion analysis is carried out, and the analysis of the acid medium corrosion rule and corrosion mechanism is carried out on the cement stone sample through integral corrosion and interface corrosion; the triaxial stress mechanical property analysis of the cement sheath simulates the triaxial stress, the formation pressure and the temperature born by a cement sheath sample in a stratum to obtain a triaxial stress-strain curve; the cement sheath mechanical integrity elastoplasticity analysis is carried out by analyzing the mechanical integrity of the cement sheath through a sleeve-cement sheath-stratum combination elastoplasticity model;
based on a cement sheath state mechanism analysis result, carrying out mass analysis on a target cement sheath to obtain the current state of the target cement sheath;
if the current state of the target cement sheath indicates that the target cement sheath is damaged, marking the target oil and gas well as incomplete well shaft;
performing an integrity detection analysis on the raised nipple of the target oil and gas well, comprising:
detecting an elevated nipple of a target oil-gas well through a directional thickness gauge to obtain a defect image, and carrying out data analysis based on the defect image to obtain defect information;
Detecting the main stress and the direction of the lifting nipple of the target oil-gas well through a strain measuring device, and carrying out load distribution calculation analysis;
and when the defect information and the load distribution calculation analysis result show that the target oil-gas well is damaged, marking the target oil-gas well as an incomplete lifting nipple.
2. The oil-gas well plugging method based on the detection and analysis of the integrity of a well bore and a raised nipple according to claim 1, wherein the analysis of the corrosion law and the corrosion mechanism of the acid medium on the cement sample by the integral corrosion comprises the following steps:
placing a cement stone sample into a high-temperature high-pressure corrosion instrument, corroding for a preset time in an acid gas corrosion environment, and carrying out a first corrosion experiment based on two types of water, namely calcium chloride and distilled water;
and obtaining first corrosion depth data according to the first corrosion experiment, and carrying out comprehensive evaluation based on the first corrosion depth data to obtain a first analysis result.
3. The oil-gas well plugging method based on the detection and analysis of the integrity of a well bore and a raised nipple according to claim 1, wherein the analysis of the corrosion law and the corrosion mechanism of the acid medium on the cement sample through the interface corrosion comprises the following steps:
Filling a cement stone sample into a corrosion-resistant mold, sealing the non-contact part of the cement stone and the mold by using epoxy resin, and polishing the end face of the cement stone to obtain a treated cement stone sample;
placing the treated cement stone sample into a high-temperature high-pressure corrosion instrument for a second corrosion experiment;
and obtaining second corrosion depth data according to the second corrosion experiment, and carrying out comprehensive evaluation based on the second corrosion depth data to obtain a second analysis result.
4. The oil-gas well plugging method based on the detection and analysis of the integrity of a well bore and a raised nipple of claim 1, wherein the analysis of the triaxial stress mechanical properties of the cement sheath simulates the triaxial stress, the formation pressure and the temperature of a cement sheath sample in a stratum, and after obtaining a triaxial stress-strain curve, the method comprises the following steps:
and calculating Young modulus, poisson's ratio, yield strength, yield strain, ultimate strength and ultimate strain of the cement stone sample according to the triaxial stress-strain curve.
5. The oil-gas well plugging method based on the detection and analysis of the integrity of a well bore and a raised nipple of claim 4, wherein the analysis of the triaxial stress mechanical properties of the cement sheath simulates the three-dimensional stress, the formation pressure and the temperature of a cement sheath sample in the formation, and the method comprises:
Setting a preset loading rate, a preset temperature and a preset confining pressure.
6. The method for plugging an oil and gas well based on detection and analysis of integrity of a wellbore and a raised nipple of claim 1, wherein the analysis of mechanical integrity of a cement sheath by means of an elastoplastic model of a sheath-cement sheath-formation assembly comprises:
based on the elastic-plastic model of the sleeve-cement sheath-stratum combination, a stratum-cement sheath-sleeve two-dimensional finite element model is established, and the stress of the cement sheath is compared with the limit stress to obtain the mechanical integrity of the cement sheath.
7. A chip, comprising: a first processor for recalling and running a computer program from the first memory, causing an apparatus on which the chip is mounted to perform the respective steps of the wellbore and lift sub integrity detection analysis-based oil and gas well plugging method as set forth in any one of claims 1 to 6.
8. A terminal comprising a second memory, a second processor and a computer program stored in and executable on the second memory, wherein the second processor, when executing the computer program, performs the steps of the wellbore and lift sub integrity detection analysis-based oil and gas well plugging method according to any one of claims 1 to 6.
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| US7753117B2 (en) * | 2008-04-04 | 2010-07-13 | Schlumberger Technology Corporation | Tool and method for evaluating fluid dynamic properties of a cement annulus surrounding a casing |
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