CN118065824A - Method for removing blockage of shaft and near-well zone in gas well - Google Patents
Method for removing blockage of shaft and near-well zone in gas well Download PDFInfo
- Publication number
- CN118065824A CN118065824A CN202211469515.7A CN202211469515A CN118065824A CN 118065824 A CN118065824 A CN 118065824A CN 202211469515 A CN202211469515 A CN 202211469515A CN 118065824 A CN118065824 A CN 118065824A
- Authority
- CN
- China
- Prior art keywords
- unblocking
- blocking
- liquid
- atomization
- well
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 50
- 230000000903 blocking effect Effects 0.000 claims abstract description 188
- 238000000889 atomisation Methods 0.000 claims abstract description 42
- 239000007791 liquid phase Substances 0.000 claims abstract description 30
- 239000012530 fluid Substances 0.000 claims abstract description 26
- 239000007787 solid Substances 0.000 claims abstract description 16
- 238000011010 flushing procedure Methods 0.000 claims abstract description 10
- 239000007788 liquid Substances 0.000 claims description 91
- 239000007789 gas Substances 0.000 claims description 80
- 239000003795 chemical substances by application Substances 0.000 claims description 42
- 238000002347 injection Methods 0.000 claims description 41
- 239000007924 injection Substances 0.000 claims description 41
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 18
- 230000015572 biosynthetic process Effects 0.000 claims description 12
- 239000003345 natural gas Substances 0.000 claims description 9
- 229910052757 nitrogen Inorganic materials 0.000 claims description 8
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen(.) Chemical compound [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 8
- 239000011148 porous material Substances 0.000 claims description 8
- 239000002253 acid Substances 0.000 abstract description 26
- 230000020477 pH reduction Effects 0.000 abstract description 4
- 238000004519 manufacturing process Methods 0.000 description 24
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 230000007797 corrosion Effects 0.000 description 12
- 238000005260 corrosion Methods 0.000 description 12
- 239000003112 inhibitor Substances 0.000 description 10
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 7
- 238000002791 soaking Methods 0.000 description 7
- 239000003381 stabilizer Substances 0.000 description 7
- 238000006243 chemical reaction Methods 0.000 description 6
- -1 iron ion Chemical class 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 230000007935 neutral effect Effects 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 3
- 230000033558 biomineral tissue development Effects 0.000 description 3
- 239000011737 fluorine Substances 0.000 description 3
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000035699 permeability Effects 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 2
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 2
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229920000926 Galactomannan Polymers 0.000 description 2
- BQTOJCOSKKLTAB-UHFFFAOYSA-L [Na+].O1P(OC1CO)(=O)OP(=O)([O-])[O-].[Na+] Chemical compound [Na+].O1P(OC1CO)(=O)OP(=O)([O-])[O-].[Na+] BQTOJCOSKKLTAB-UHFFFAOYSA-L 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 238000004061 bleaching Methods 0.000 description 2
- 239000003638 chemical reducing agent Substances 0.000 description 2
- 239000002734 clay mineral Substances 0.000 description 2
- 239000008139 complexing agent Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910001447 ferric ion Inorganic materials 0.000 description 2
- 239000000706 filtrate Substances 0.000 description 2
- 239000008398 formation water Substances 0.000 description 2
- USHAGKDGDHPEEY-UHFFFAOYSA-L potassium persulfate Chemical compound [K+].[K+].[O-]S(=O)(=O)OOS([O-])(=O)=O USHAGKDGDHPEEY-UHFFFAOYSA-L 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000008961 swelling Effects 0.000 description 2
- UEUXEKPTXMALOB-UHFFFAOYSA-J tetrasodium;2-[2-[bis(carboxylatomethyl)amino]ethyl-(carboxylatomethyl)amino]acetate Chemical compound [Na+].[Na+].[Na+].[Na+].[O-]C(=O)CN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O UEUXEKPTXMALOB-UHFFFAOYSA-J 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 229940079593 drug Drugs 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 229920003063 hydroxymethyl cellulose Polymers 0.000 description 1
- 229940031574 hydroxymethyl cellulose Drugs 0.000 description 1
- 239000003595 mist Substances 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 125000005010 perfluoroalkyl group Chemical group 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B37/00—Methods or apparatus for cleaning boreholes or wells
- E21B37/06—Methods or apparatus for cleaning boreholes or wells using chemical means for preventing or limiting, e.g. eliminating, the deposition of paraffins or like substances
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Gas Separation By Absorption (AREA)
Abstract
The invention relates to a blocking removing method for a shaft and a near-wellbore zone in a gas well, which comprises the following steps: blocking removal of a wellbore and/or blocking removal of a near wellbore zone; the shaft unblocking comprises a first atomization unblocking, a first liquid phase unblocking, a first well stewing and a first emptying flowback which are sequentially carried out; the well shaft unblocking is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the first emptying flowback fluid is less than or equal to 10mg/L; the near wellbore zone unblocking comprises a second liquid phase unblocking, a second well-flushing, a second emptying flowback, a second atomization unblocking, a third well-flushing and a third emptying flowback which are sequentially carried out; and the blocking removal of the near wellbore zone is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the third emptying flowback fluid is less than or equal to 30mg/L. The unblocking method provided by the invention can adjust the integral acidification section of the gas reservoir, so that the acid wave and the volume are increased, meanwhile, the unblocking method can enter the remote zone of the gas reservoir, and can communicate discontinuous hole seams, thereby realizing deep unblocking of the gas reservoir.
Description
Technical Field
The invention relates to the technical field of oil and gas extraction, in particular to a blocking removing method for a shaft and a near-shaft zone in a gas well.
Background
At present, in the exploitation process of a gas well, the water-gas well containing H 2S、CO2 and high mineralization stratum has the combined action of corrosive media in well entering fluid, natural gas and stratum water, corrosion products of a pipe column, crystallization products of the stratum water and heavy components in corrosion inhibitors along with the production time, and part of pipe columns of the gas well have serious corrosion and scaling phenomena, and organic or inorganic plugs are formed near a near-wellbore zone, so that the gas well cannot normally produce, and the production process has the characteristics of rapid yield dip or drop speed, increased oil sleeve pressure difference, low stratum pressure recovery speed and the like, so that the gas well is in a low-yield low-efficiency production state for a long time until the gas well is forced to be shut in, and the single-well energy exertion of the gas well is seriously influenced.
At present, an acidizing chemical method is generally used for unblocking a shaft and a near-wellbore zone, a liquid acid is injected into the shaft by a pump truck at a pressure smaller than the stratum pressure, scale in the shaft is eroded and cleaned, then nitrogen or natural gas is used for lifting and discharging, and the injected acid and cleaned scale are discharged back into a surface combustion tank.
After removing the scale in the shaft, injecting the liquid stratum blocking remover into the near-wellbore zone at a pressure higher than the stratum pressure and lower than the stratum fracture pressure by using a pump truck, and then injecting nitrogen or natural gas for displacement, and completely displacing the liquid stratum blocking remover into the stratum for blocking removal of the near-wellbore zone.
The method comprises determining a blocking point in an operation pipe closest to an air outlet end of the operation pipe, and recording as a blocking metering point; calculating to obtain the dosage of the blocking removal acid liquor according to the blocking metering point, wherein the volume quantity of the blocking removal acid liquor is recorded as V; pressure control emptying the operation pipe; injecting V volume of the unblocking acid liquor into the operation pipe, so that attachments are soaked in the unblocking acid liquor; closing the operation pipe to enable the blocking removing liquid to react with attachments for a preset time; the method can determine the optimal amount of the blocking removal acid solution for the acidic attachments, and prevent the situations of excessive blocking removal acid solution or incomplete attachments reaction.
CN113462372a discloses an unblocking acid solution for unblocking a wellbore of a high-temperature high-pressure gas well, which comprises the following components based on the mass of the unblocking acid solution: 5-10wt% of hydrochloric acid, 0-2.0wt% of hydrofluoric acid, 1-3wt% of clay stabilizer, 3.0-6.0wt% of corrosion inhibitor, 1-3wt% of cleanup additive, 1-3wt% of iron ion stabilizer, 5-20wt% of waterproof locking agent, 1-3wt% of demulsifier, and the balance of water. The unblocking acid liquor can be used for effectively unblocking a high-temperature high-pressure well barrel on the premise of basically not corroding the well barrel oil pipe and having less damage to stratum.
However, in the process of plugging removal operation of the well shaft and the near-wellbore zone, the liquid plugging removal agent flows down the well shaft in the well shaft too fast, the plugging removal agent flows to the bottom of the well very fast, the residual plugging removal agent content of the upper oil pipe is small, meanwhile, as the plugging removal agent does not flow down the whole oil pipe, part of the oil pipe cannot contact with the plugging removal agent, thus the plugging removal of the upper oil pipe scale is insufficient, in the process of plugging removal of the near-wellbore zone, the liquid stratum plugging removal agent is likely to generate a finger-in phenomenon along a hypertonic channel, heterogeneous propulsion is caused, discontinuous hole seams cannot be communicated, the wave and volume of the liquid stratum plugging removal agent are limited, and thus the ideal plugging removal effect is not achieved.
Disclosure of Invention
In view of the problems existing in the prior art, the invention aims to provide a blocking removal method for a well bore and a near-well zone in a gas well, so as to solve the problems that in the prior art, the liquid blocking remover flows down along the well bore too quickly, the blocking removal dosage of the residual blocking remover of an upper oil pipe is too small due to insufficient contact between the well bore and the blocking remover, or the blocking removal is not ideal due to insufficient contact between part of the oil pipe and the blocking remover, and the blocking removal agent of the liquid stratum is limited in wave and volume due to fingering phenomenon of the blocking remover of the liquid stratum along a hypertonic channel.
To achieve the purpose, the invention adopts the following technical scheme:
the invention provides a blocking removing method for a well bore and a near-well zone in a gas well, which comprises the following steps: blocking removal of a wellbore and/or blocking removal of a near wellbore zone;
The shaft unblocking comprises a first atomization unblocking, a first liquid phase unblocking, a first well stewing and a first emptying flowback which are sequentially carried out; the well shaft unblocking is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the first emptying flowback fluid is less than or equal to 10mg/L;
The near wellbore zone unblocking comprises a second liquid phase unblocking, a second well-flushing, a second emptying flowback, a second atomization unblocking, a third well-flushing and a third emptying flowback which are sequentially carried out; and the blocking removal of the near wellbore zone is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the third emptying flowback fluid is less than or equal to 30mg/L.
According to the blocking removing method provided by the invention, in the blocking removing stage of a shaft, an atomized blocking removing agent fills the whole shaft, the whole shaft is blocked, the liquid blocking removing agent is soaked to remove the blocking of a low position with serious shaft scaling, meanwhile, in the blocking removing process of a near-well zone, the liquid stratum blocking removing agent is firstly used for removing the seriously blocked position of the near-well zone, then atomized acid is used for deep blocking removing, compared with liquid acid, the atomized acid can enter the upper part and the position with lower permeability, the integral acidification section of a gas reservoir can be adjusted, so that the acid wave and the volume are increased, meanwhile, the acid can enter the far-well zone of the gas reservoir, and discontinuous hole seams are communicated, so that the blocking removing of the deep part of the gas reservoir is realized.
In the invention, when both the well shaft unblocking and the near well zone unblocking are implemented, the well shaft unblocking is firstly carried out, and then the near well zone unblocking is carried out.
In the invention, when the blockage removal of the shaft is carried out for a plurality of times, the solid content of the flowback fluid obtained by the first emptying flowback fluid is detected every time, and when the solid content is less than or equal to 10mg/L, the subsequent operation is carried out, and the specific solid content can be 10mg/L, 9mg/L, 8mg/L, 7mg/L, 6mg/L or 5mg/L, etc., but the invention is not limited to the listed values, and other non-listed values in the range are applicable.
In the invention, when the blockage removal is carried out for a plurality of times in a near wellbore zone, the solid content of the flowback fluid obtained by the third emptying flowback fluid is detected every time, and when the solid content is less than or equal to 30mg/L, the subsequent operation is carried out, and the specific solid content can be 30mg/L, 25mg/L, 20mg/L, 15mg/L, 10mg/L or 5mg/L, etc., but the invention is not limited to the listed numerical values, and other non-listed numerical values in the range are applicable.
In the invention, after the liquid blocking remover and the atomized blocking remover are injected in the blocking removing of the near wellbore zone, the gas medium is needed to be adopted to push the agent into the near wellbore zone.
In the invention, the operation end point of the well shaft blocking removal also needs to control the oil sleeve pressure difference to be less than 2MPa.
According to the preferred technical scheme, the first atomization blocking removal is to atomize a liquid shaft blocking removal agent by adopting a gas medium and then inject the atomized liquid shaft blocking removal agent into a shaft for treatment.
Preferably, the injection speed of the gaseous medium used in the first atomization unblocking is 1000-1200dm 3/h, such as 1000dm3/h、1010dm3/h、1020dm3/h、1030dm3/h、1040dm3/h、1050dm3/h、1060dm3/h、1070dm3/h、1080dm3/h、1090dm3/h、1100dm3/h、1110dm3/h、1120dm3/h、1130dm3/h、1140dm3/h、1150dm3/h、1160dm3/h、1170dm3/h、1180dm3/h、1190dm3/h or 1200dm 3/h, but not limited to the recited values, and other non-recited values within this range are equally applicable.
Preferably, the volume ratio of the gas medium and the liquid wellbore plugging agent used in the first atomization plugging is (2000-2400): 1, for example, 2000:1、2105:1、2310:1、2315:1、2320:1、2325:1、2330:1、2335:1、2340:1、2345:1、2350:1、2355:1、2360:1、2365:1、2370:1、2375:1、2380:1、2385:1、2390:1、2395:1 or 2400:1, etc., but is not limited to the recited values, and other values not recited in the range are equally applicable.
In the invention, the injection amount of the liquid shaft plugging removing agent in the first atomization plugging removing is based on that the atomized plugging removing agent fills the whole shaft after the shaft pressure is converted, and the method comprises the following specific steps:
Wherein: v Injection quantity -ground standard state atomized gas injection quantity (nitrogen or natural gas), m 3;V well bore -well bore volume, m 3;T Standard of -ground standard state temperature, K; p well bore -average pressure in wellbore, MPa; z well bore -gas deviation coefficient under the conditions of average pressure and average temperature of the shaft; t well bore -average temperature in the wellbore, K; p Standard of -pressure in ground standard state, MPa.
As a preferable technical scheme of the invention, the first liquid phase blocking removal is to inject a liquid shaft blocking remover into a shaft for treatment.
As a preferable technical scheme of the invention, the injection amount of the liquid shaft blocking remover in the first liquid phase blocking remover is less than or equal to the volume of 100m of the height of the shaft. The injection amount of the liquid blocking remover at the moment is ensured to meet the requirement that the liquid level is less than or equal to 100m. Specifically, if the well bore blocking removal is performed for at least 2 times, the injection amount of the first liquid blocking remover satisfies 80-100m, the pumping speed is less than 0.01m 3/min, and from the second time, the injection amount of the liquid blocking remover also needs to ensure that the liquid level is less than or equal to 60m. The specific liquid level may be 100m, 95m, 90m, 85m, 80m, 75m, 70m, 65m, 60m, 55m, 50m, 45m, 40m, 35m or 30m, etc., but is not limited to the recited values, and other non-recited values within this range are equally applicable.
According to the invention, the well-soaking time of the first well-soaking is selected according to the time required by the reaction of the well-shaft blocking remover and the well-shaft scale, and the well-soaking time is 16 hours after the well-shaft blocking remover is injected, wherein the mass concentration of the well-shaft blocking remover is 15% HCl+1.5% corrosion inhibitor+1.0% gel breaker+1.0% iron ion stabilizer+8%.
As a preferable technical scheme of the invention, the second liquid phase blocking removal is to inject the liquid stratum blocking remover into the near wellbore zone for treatment.
As a preferable technical scheme of the invention, the injection amount of the liquid stratum blocking remover in the second liquid phase blocking remover is 2.0m of reservoir radius pore volume. The specific process is as follows:
Wherein: v-injection amount of plugging removing agent in near wellbore zone, m 3; r is the radius of injection, m; h Layer(s) 1 —horizon 1 thickness, m; h Layer(s) 2 —horizon 2 thickness, m; phi Layer(s) 1 -horizon 1 porosity; phi Layer(s) 2 -horizon 2 porosity.
Preferably, the injection speed of the liquid stratum blocking remover in the second liquid phase blocking remover is 0.3-0.5m 3/min, for example, 0.3m3/min、0.31m3/min、0.32m3/min、0.33m3/min、0.34m3/min、0.35m3/min、0.36m3/min、0.37m3/min、0.38m3/min、0.39m3/min、0.4m3/min、0.41m3/min、0.42m3/min、0.43m3/min、0.44m3/min、0.45m3/min、0.46m3/min、0.47m3/min、0.48m3/min、0.49m3/min or 0.5m 3/min, etc., but the injection speed is not limited to the recited values, and other non-recited values in the range are equally applicable.
According to the invention, the well-soaking time of the second well-soaking is selected according to the time required by the reaction of the stratum blocking remover and stratum scales, and the time required by the reaction of the stratum blocking remover is 24 hours after the injection of the stratum blocking remover, wherein the mass concentration of the stratum blocking remover is 20% HCl+0.5% corrosion inhibitor+1.0% gel breaker+1.0% iron ion stabilizer+8% neutral blocking remover+0.5% fluorine surfactant+1.0% filtrate reducer.
As a preferable technical scheme of the invention, in the second atomization blocking remover, a gas medium is adopted to atomize the liquid stratum blocking remover and then the atomized liquid stratum blocking remover is injected into a near-wellbore zone for treatment.
As a preferable technical scheme of the invention, the injection speed of the gas medium used in the second atomization blocking removal is 1000-1200dm 3/h, for example, 1000dm3/h、1010dm3/h、1020dm3/h、1030dm3/h、1040dm3/h、1050dm3/h、1060dm3/h、1070dm3/h、1080dm3/h、1090dm3/h、1100dm3/h、1110dm3/h、1120dm3/h、1130dm3/h、1140dm3/h、1150dm3/h、1160dm3/h、1170dm3/h、1180dm3/h、1190dm3/h or 1200dm 3/h and the like, but the invention is not limited to the listed values, and other non-listed values in the range are applicable.
Preferably, the volume ratio of the gas medium and the liquid stratum blocking remover used in the second atomization blocking remover is (1000-1200): 1, for example, 1000:1、1010:1、1020:1、1030:1、1040:1、1050:1、1060:1、1070:1、1080:1、1090:1、1100:1、1110:1、1120:1、1130:1、1140:1、1150:1、1160:1、1170:1、1180:1、1190:1 or 1200:1, etc., but is not limited to the recited values, and other non-recited values in the range are equally applicable.
Preferably, the injection amount of the liquid stratum blocking remover in the second atomization blocking remover after atomization is the reservoir pore volume of which the stratum pressure is converted into the stratum radius of 2m to 5 m. The specific calculation process is as follows:
Wherein: v Injection quantity -the amount of atomized gas injection (nitrogen or natural gas) in ground standard state, m 3;T Standard of -the temperature in ground standard state, K; p Stratum layer -average formation pressure in near wellbore zone, MPa; z Stratum layer -the gas deviation coefficient under the conditions of average formation pressure and average formation temperature in near wellbore zone; t Stratum layer -average formation temperature in near wellbore zone, K; p Standard of -pressure in ground standard state, MPa; r 1 -5 m of injection radius, m; r 2 -2 m is the radius of drug injection, m; h Layer(s) 1 —horizon 1 thickness, m; h Layer(s) 2 —horizon 2 thickness, m; phi Layer(s) 1 -horizon 1 porosity; phi Layer(s) 2 -horizon 2 porosity.
According to the invention, the well-soaking time of the third well-soaking is selected according to the time required by the reaction of the stratum blocking remover and stratum scales, and the time required by the reaction of the stratum blocking remover is 24 hours after the injection of the stratum blocking remover, wherein the mass concentration of the stratum blocking remover is 20% HCl+0.5% corrosion inhibitor+1.0% gel breaker+1.0% iron ion stabilizer+8% neutral blocking remover+0.5% fluorine surfactant+1.0% filtrate reducer.
As a preferable technical scheme of the invention, the gas medium used in the unblocking method comprises nitrogen and/or natural gas.
As a preferable technical scheme of the invention, the blocking removing method comprises the following steps: blocking removal of a wellbore and/or blocking removal of a near wellbore zone;
The shaft unblocking comprises a first atomization unblocking, a first liquid phase unblocking, a first well stewing and a first emptying flowback which are sequentially carried out; the well shaft unblocking is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the first emptying flowback fluid is less than or equal to 10mg/L; the first atomization blocking removal is to atomize a liquid shaft blocking remover by adopting a gas medium and then inject the atomized liquid shaft blocking remover into a shaft for treatment; the injection speed of the gas medium used in the first atomization unblocking is 1000-1200dm 3/h; the volume ratio of the gas medium and the liquid shaft blocking remover used in the first atomization blocking remover is (2000-2400): 1; the first liquid phase blocking removal is to inject a liquid shaft blocking remover into a shaft for treatment; the injection amount of the liquid shaft blocking remover in the first liquid phase blocking remover is less than or equal to the volume of 100m of the shaft height;
The near wellbore zone unblocking comprises a second liquid phase unblocking, a second well-flushing, a second emptying flowback, a second atomization unblocking, a third well-flushing and a third emptying flowback which are sequentially carried out; the blocking removal of the near wellbore zone is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the third emptying flowback fluid is less than or equal to 30mg/L; the second liquid phase unblocking is to inject a liquid stratum unblocking agent into a near wellbore zone for treatment; the injection amount of the liquid stratum blocking remover in the second liquid phase blocking remover is 2.0m of reservoir radius pore volume; the injection speed of the liquid stratum blocking remover in the second liquid phase blocking remover is 0.3-0.5m 3/min; in the second atomization blocking removal process, a gas medium is adopted to atomize a liquid stratum blocking removal agent and then the atomized liquid stratum blocking removal agent is injected into a near-wellbore zone for treatment; the injection speed of the gas medium used in the second atomization unblocking is 1000-1200dm 3/h; the volume ratio of the gas medium and the liquid stratum blocking remover used in the second atomization blocking remover is (1000-1200) 1; the injection amount of the liquid stratum blocking remover in the second atomization blocking remover after atomization is the reservoir pore volume of which the stratum pressure is converted into the stratum radius of 2m to 5 m;
The gaseous medium used in the unblocking method comprises nitrogen and/or natural gas.
In the invention, in the process of back drainage, if the oil pressure is quickly reduced to 0 when the liquid is discharged, the flame is small and the liquid is not discharged, the liquid is immediately converted into gas lift liquid, and when the oil jacket pressure is basically balanced and the water is not discharged any more, the end of the stage of the back drainage is regarded as the end of the stage of the back drainage when the oil jacket pressure is basically balanced.
In the invention, the selection of the types of the well bore blocking remover and the stratum blocking remover only needs to ensure no matter what is needed, and the specific types do not influence the blocking removing effect brought by the blocking removing process. The wellbore blocking remover and the stratum blocking remover can be prepared by referring to the existing blocking remover in the prior art, specifically can be prepared by referring to the formula disclosed in the prior art, and can also be treated by adopting the commercial blocking remover which can be atomized.
Compared with the prior art, the invention has the following beneficial effects:
According to the method for removing the blockage, disclosed by the invention, an atomized blockage removing liquid treatment process is introduced at a specific stage, and the atomized acid can enter the upper part and the part with lower permeability compared with the liquid acid, so that the integral acidification section of the gas reservoir can be adjusted, the acid wave and the volume are increased, meanwhile, the gas reservoir can enter a remote zone of the gas reservoir, discontinuous hole seams are communicated, the deep blockage removal of the gas reservoir is realized, and the problem that the blockage removing agent of the liquid stratum has limited wave and volume due to the fact that the blockage removing agent of the liquid stratum is introduced along a hypertonic channel only by using the liquid blockage removing agent is avoided.
Drawings
FIG. 1 is a schematic diagram of a unblocking method according to an embodiment of the present invention;
FIG. 2 is a graph of gas production before and after unblocking a CJ26-6 gas well in example 1 of the present invention.
In the figure, a section A is a gas production curve of a gas well in the previous month of unblocking; the interval B is a gas well gas production curve during the blocking removal period, and gas production data are not counted because the gas well is frequently switched on and off during the blocking removal period; interval C is the gas production curve of the gas well three months after unblocking;
a-jacket pressure curve, b-oil pressure curve, c-daily gas production curve and d-daily water production curve.
The present invention will be described in further detail below. The following examples are merely illustrative of the present invention and are not intended to represent or limit the scope of the invention as defined in the claims.
Detailed Description
For a better illustration of the present invention, which is convenient for understanding the technical solution of the present invention, exemplary but non-limiting examples of the present invention are as follows:
The invention provides a method for removing the blockage of a well bore and a near-wellbore zone in a gas well, which is shown in figure 1, and comprises the steps of firstly injecting an atomized blockage removing agent after the well bore is drained, then injecting a liquid blockage removing agent for treatment, and then carrying out reciprocating circulation through a stewing well and a flowback, wherein when the flowback fluid is clear and transparent, the blockage removal of the well bore is finished, and the blockage removal of the near-wellbore zone is started;
In the blocking removal of the near wellbore zone, firstly, liquid blocking remover is filled, pushed into the near wellbore zone through a gas medium, then, the well is closed, and flowback is carried out, then, atomized blocking remover is added, blocking removal is carried out (pushed into the near wellbore zone through the gas medium), the state of flowback liquid during emptying flowback is confirmed during each time of cyclic reciprocation through the well closing and emptying flowback, and the blocking removal of the near wellbore zone is finished when the flowback liquid is clear and transparent.
The specific implementation process is as follows:
Example 1
The embodiment is used for carrying out blocking removal treatment on an actual gas well, and the details are as follows:
The normal production oil sleeve pressure difference of CJ26-6 wells of the CJ gas field is about 1.5MPa, daily gas production rate is about 2.5X10 4m3/d, CO 2 in produced gas is 3.670%, H 2 S is 409.38mg/m 3, corrosion inhibitor 5400L is added before production and unblocking, the total mineralization of the produced water quality is 14785mg/L, chloride content is 9718mg/L, and water type CaCl 2. Along with the extension of the production time, the pressure difference of the oil jacket is increased to about 5.3MPa, the daily gas yield is reduced to about 0.35 multiplied by 10 4m3/d, the well is cleared for multiple times, and the analysis proves that the main reason for reducing the gas well yield is as follows:
① The heavy component organic attachments of the corrosion inhibitor, the water crystal products produced by the stratum and the like cause scale formation of a shaft;
②CO2 CO 3 2- ions are formed in water and Ca 2+ in formation water form CaCO 3 scale deposits and reservoir clay minerals are transported by water swelling to cause blockage in near-wellbore zones.
According to the method for unblocking the pipe according to the present invention,
Using a well bore blocking remover (15 percent HCl+1.5 percent corrosion inhibitor (disodium hydroxyethylidene diphosphate) +1.0 percent gel breaker (potassium persulfate) +1.0 percent ferric ion stabilizer (ethylene diamine tetraacetic acid tetrasodium salt) +8 percent neutral blocking remover (EDTA is a complexing agent, carboxyethyl galactomannan is a solubilizer, pancreatic bleaching T is a penetrating agent, and acrylic acid-methyl acrylate copolymer is a dispersing agent compound)), the near wellbore zone blocking remover (20% HCl+0.5% corrosion inhibitor (disodium hydroxyethylidene diphosphate) +1.0% gel breaker (potassium persulfate) +1.0% ferric ion stabilizer (ethylene diamine tetraacetic acid tetrasodium salt) +8% neutral blocking remover (EDTA is complexing agent, carboxyethyl galactomannan is solubilizer, pancreatic bleaching T is penetrant, acrylic acid-methyl acrylate copolymer is dispersant compound) +0.5% fluorine surfactant (perfluoroalkyl acid) +1.0% fluid loss agent (hydroxymethyl cellulose)) is used for carrying out blocking removal operation, wherein the wellbore blocking removal stage is carried out by co-injecting the blocking remover 8m 3, ten times of adding, namely, the wellbore blocking removal is carried out by 10 times, each time of liquid blocking remover is 0.3m 3, the mist blocking remover is 0.5m 3, and the next time of adding after the well is braised and flowback;
And (3) co-injecting stratum blocking remover 23m 3 in the near-wellbore zone blocking removing stage, wherein the liquid stratum blocking remover 8m 3, the atomized stratum blocking remover 15m 3 and the well-logging flowbacks are respectively carried out.
The production dynamics of the gas well after unblocking is observed three months after the test is shown in figure 2, the pressure difference of the wellhead oil sleeve is reduced from 5.3MPa to 1.43MPa, the yield is increased from 0.35 multiplied by 10 4m3/d to 2.62 multiplied by 10 4m3/d, and the normal production level is recovered, so that the successful unblocking of the fog in the shaft and the near-well zone is indicated.
Example 2
This example serves as a comparative example to example 1, where the production of the gas well is about the same as that of example 1, using conventional chemical deblocking methods, as follows:
The normal production oil sleeve pressure difference of CJ26-9 wells of the CJ gas field is about 1.4MPa, daily gas production rate is about 2.5X10 4m3/d, CO 2 in produced gas is 3.662%, H 2 S is 400.31mg/m 3, corrosion inhibitor is added 4900L before production and unblocking, the total mineralization of the produced water quality is 14231mg/L, chloride content is 9610mg/L, and water type CaCl 2. Along with the extension of the production time, the pressure difference of the oil jacket is increased to about 5MPa, the daily gas production is reduced to about 0.33 multiplied by 10 4m3/d, the well is cleared for multiple times, and the analysis proves that the main reason for reducing the gas well yield is as follows:
① The formation produces water crystallization products and the like to cause scale formation of a shaft;
②CO2 CO 3 2- ions are formed in water and Ca 2+ in formation water form CaCO 3 scale deposits and reservoir clay minerals are transported by water swelling to cause blockage in near-wellbore zones.
The liquid well shaft blocking remover and the near wellbore zone blocking remover in the embodiment 1 are adopted for carrying out blocking removing operation, wherein the liquid well shaft blocking remover is injected into the well shaft at the stage of blocking removing the well shaft for 8m 3, 10 times of injection are carried out, namely, the well shaft blocking removing is carried out ten times, the liquid well shaft blocking remover is 0.8m 3 in each time, and the next time of injection is carried out after the well is braised and the flowback of the well is carried out;
And (3) co-injecting stratum blocking remover 23m 3 at the near-wellbore zone blocking removing stage, wherein all the stratum blocking remover are liquid blocking remover, and respectively carrying out well logging and flowback. The production dynamics of the gas well after the plugging removal is observed three months after the test, the pressure difference of the wellhead oil jacket is reduced from 5MPa to 2.9MPa, the yield is increased from 0.33 multiplied by 10 4m3/d to 0.76 multiplied by 10 4m3/d, the conventional plugging removal is successful, but compared with the embodiment 1, the pressure difference of the oil jacket is still larger, the plugging removal of the shaft is not thorough, the daily gas production after the measure is still larger than the pressure recovery level compared with the embodiment 1, and the plugging removal of the near-wellbore zone is not thorough.
According to the method for removing the blocking, disclosed by the embodiment of the invention, in a shaft blocking removing stage, an atomized blocking removing agent fills the whole shaft, the whole shaft is removed, the liquid blocking removing agent is soaked to remove the blocking of the low position with serious scale formation of the shaft, meanwhile, in the blocking removing process of a near-well zone, the liquid stratum blocking removing agent is firstly used for removing the seriously blocked position of the near-well zone, then atomized acid is used for removing the blocking of the deep layer, compared with liquid acid, the atomized acid can enter the upper part and the position with lower permeability, the integral acidification section of the gas reservoir can be adjusted, the acid wave volume is increased, meanwhile, the acid can enter the far-well zone of the gas reservoir, and discontinuous hole seams are communicated, so that the deep blocking removing of the gas reservoir is realized.
It is stated that the detailed structural features of the present invention are described by the above embodiments, but the present invention is not limited to the above detailed structural features, i.e., it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be apparent to those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope of the present invention and the scope of the disclosure.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the scope of the technical concept of the present invention, and all the simple modifications belong to the protection scope of the present invention.
In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.
Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.
Claims (10)
1. A method of unblocking a wellbore and a near wellbore zone in a gas well, the method comprising: blocking removal of a wellbore and/or blocking removal of a near wellbore zone;
The shaft unblocking comprises a first atomization unblocking, a first liquid phase unblocking, a first well stewing and a first emptying flowback which are sequentially carried out; the well shaft unblocking is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the first emptying flowback fluid is less than or equal to 10mg/L;
The near wellbore zone unblocking comprises a second liquid phase unblocking, a second well-flushing, a second emptying flowback, a second atomization unblocking, a third well-flushing and a third emptying flowback which are sequentially carried out; and the blocking removal of the near wellbore zone is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the third emptying flowback fluid is less than or equal to 30mg/L.
2. The unblocking method of claim 1, wherein the first atomizing unblocking is a process of injecting a liquid wellbore unblocking agent into a wellbore after atomizing the liquid wellbore unblocking agent with a gaseous medium;
Preferably, the injection speed of the gas medium used in the first atomization unblocking is 1000-1200dm 3/h;
Preferably, the volume ratio of the gas medium and the liquid shaft plugging agent used in the first atomization plugging is (2000-2400): 1.
3. The method of unblocking according to claim 1 or 2, wherein the first liquid phase unblocking is a treatment by injecting a liquid wellbore unblocking agent into a wellbore.
4. A method of plugging according to any one of claims 1 to 3 wherein the injection amount of liquid wellbore plugging agent in the first liquid phase plugging is less than or equal to the volume of 100m of wellbore height.
5. The method of any of claims 1-4, wherein the second liquid phase de-plugging is a treatment of injecting a liquid formation de-plugging agent into a near wellbore zone.
6. The method of plugging removal of any one of claims 1-5, wherein the injection amount of liquid formation plugging removal agent in the second liquid phase plugging removal is 2.0m reservoir radius pore volume;
preferably, the injection speed of the liquid stratum blocking remover in the second liquid phase blocking remover is 0.3-0.5m 3/min.
7. The method of any one of claims 1-6, wherein the second atomization deblocking is performed by injecting a liquid formation blocking remover into a near wellbore zone after atomizing the liquid formation blocking remover with a gaseous medium.
8. The unblocking method according to any one of claims 1 to 7, wherein an injection rate of the gaseous medium used in the second atomization unblocking is 1000 to 1200dm 3/h;
Preferably, the volume ratio of the gas medium used in the second atomization blocking remover to the liquid stratum blocking remover is (1000-1200): 1;
Preferably, the injection amount of the liquid stratum blocking remover in the second atomization blocking remover after atomization is the reservoir pore volume of which the stratum pressure is converted into the stratum radius of 2m to 5 m.
9. The unblocking method according to any one of claims 1 to 8, wherein the gaseous medium used in the unblocking method comprises nitrogen and/or natural gas.
10. The unblocking method according to any one of claims 1-9, wherein the unblocking method comprises: blocking removal of a wellbore and/or blocking removal of a near wellbore zone;
The shaft unblocking comprises a first atomization unblocking, a first liquid phase unblocking, a first well stewing and a first emptying flowback which are sequentially carried out; the well shaft unblocking is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the first emptying flowback fluid is less than or equal to 10mg/L; the first atomization blocking removal is to atomize a liquid shaft blocking remover by adopting a gas medium and then inject the atomized liquid shaft blocking remover into a shaft for treatment; the injection speed of the gas medium used in the first atomization unblocking is 1000-1200dm 3/h; the volume ratio of the gas medium and the liquid shaft blocking remover used in the first atomization blocking remover is (2000-2400): 1; the first liquid phase blocking removal is to inject a liquid shaft blocking remover into a shaft for treatment; the injection amount of the liquid shaft blocking remover in the first liquid phase blocking remover is less than or equal to the volume of 100m of the shaft height;
The near wellbore zone unblocking comprises a second liquid phase unblocking, a second well-flushing, a second emptying flowback, a second atomization unblocking, a third well-flushing and a third emptying flowback which are sequentially carried out; the blocking removal of the near wellbore zone is carried out for at least 1 time, and the end point of the operation is that the solid content of the flowback fluid obtained by the third emptying flowback fluid is less than or equal to 30mg/L; the second liquid phase unblocking is to inject a liquid stratum unblocking agent into a near wellbore zone for treatment; the injection amount of the liquid stratum blocking remover in the second liquid phase blocking remover is 2.0m of reservoir radius pore volume; the injection speed of the liquid stratum blocking remover in the second liquid phase blocking remover is 0.3-0.5m 3/min; in the second atomization blocking removal process, a gas medium is adopted to atomize a liquid stratum blocking removal agent and then the atomized liquid stratum blocking removal agent is injected into a near-wellbore zone for treatment; the injection speed of the gas medium used in the second atomization unblocking is 1000-1200dm 3/h; the volume ratio of the gas medium and the liquid stratum blocking remover used in the second atomization blocking remover is (1000-1200) 1; the injection amount of the liquid stratum blocking remover in the second atomization blocking remover after atomization is the reservoir pore volume of which the stratum pressure is converted into the stratum radius of 2m to 5 m;
The gaseous medium used in the unblocking method comprises nitrogen and/or natural gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211469515.7A CN118065824A (en) | 2022-11-22 | 2022-11-22 | Method for removing blockage of shaft and near-well zone in gas well |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211469515.7A CN118065824A (en) | 2022-11-22 | 2022-11-22 | Method for removing blockage of shaft and near-well zone in gas well |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN118065824A true CN118065824A (en) | 2024-05-24 |
Family
ID=91102723
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211469515.7A Pending CN118065824A (en) | 2022-11-22 | 2022-11-22 | Method for removing blockage of shaft and near-well zone in gas well |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN118065824A (en) |
-
2022
- 2022-11-22 CN CN202211469515.7A patent/CN118065824A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102828734B (en) | Offshore oilfield water injection well online one-step-process acidification technology | |
| CN105505360B (en) | A kind of fluoboric acid de-plugging agent and acidification method for removing blockage | |
| CN104109528B (en) | Acidifying liquid capable of sand stabilization and plug removal, and preparation method thereof | |
| CN108756817B (en) | Method for judging scaling risk of shaft of water-producing gas well and determining injection time of antiscaling agent | |
| CN102536166B (en) | Advanced treatment method for oil layer by self-generated foam acidification | |
| CN108049855A (en) | A kind of MH acid construction technology suitable for sandstone reservoir transformation | |
| CN104232041B (en) | A kind of oil-water well strong corrosion acidifying unblocking liquid of low leak-off and preparation method thereof | |
| CN111621276A (en) | Solid acid plugging agent and method for removing stratum plugging by using same | |
| CN110748324A (en) | Composite blockage removal process for high-salinity oil reservoir | |
| CN101691838B (en) | Ultralow permeability oil filed water injection well multicomponent chemical microemulsion pressure reduction and injection gain method | |
| CN115703962B (en) | Blocking remover and construction method thereof | |
| CN104213885A (en) | Acidification profile control integrated method | |
| US9284828B2 (en) | Method for increasing hydrocarbon extraction and for ensuring the continuous operation of wells | |
| CN104481475A (en) | Oil well carbon dioxide carbonated water throughput production increasing method | |
| CN118065824A (en) | Method for removing blockage of shaft and near-well zone in gas well | |
| CN111396019B (en) | Method for optimizing online acidizing acid liquid consumption of water injection well | |
| CN116875296A (en) | Solid acid precursor for reservoir reformation | |
| RU2004116889A (en) | METHOD FOR TREATING A BOREHOLE BOTTOM ZONE | |
| RU2490437C1 (en) | Procedure for development of hydrocarbon deposit | |
| CN113250653A (en) | Acidification method of water injection well | |
| CN104179488A (en) | Method for improving low-permeability carbonate rock heavy oil reservoir development effect | |
| US9453401B2 (en) | Chelating fluid for enhanced oil recovery in carbonate reservoirs and method of using the same | |
| RU2528803C1 (en) | Processing of bottomhole of low-cemented terrigenous bed at abnormally low bed pressure | |
| US8863841B2 (en) | Alkanesulfonic acid microcapsules and use thereof in deep wells | |
| CN117683524A (en) | Oilfield blocking remover and blocking removing method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |