CN114854386B - Offshore oilfield anti-emulsifying workover fluid and preparation method and application method thereof - Google Patents
Offshore oilfield anti-emulsifying workover fluid and preparation method and application method thereof Download PDFInfo
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- YDEXUEFDPVHGHE-GGMCWBHBSA-L disodium;(2r)-3-(2-hydroxy-3-methoxyphenyl)-2-[2-methoxy-4-(3-sulfonatopropyl)phenoxy]propane-1-sulfonate Chemical compound [Na+].[Na+].COC1=CC=CC(C[C@H](CS([O-])(=O)=O)OC=2C(=CC(CCCS([O-])(=O)=O)=CC=2)OC)=C1O YDEXUEFDPVHGHE-GGMCWBHBSA-L 0.000 claims description 10
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 claims description 10
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/52—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
- C09K8/524—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning organic depositions, e.g. paraffins or asphaltenes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/52—Compositions for preventing, limiting or eliminating depositions, e.g. for cleaning
Abstract
The invention relates to an offshore oilfield anti-emulsifying workover fluid, and a preparation method and a use method thereof. The offshore oilfield anti-emulsifying well repair liquid comprises 0.5-1.5% of drainage-assisting cleaning agent, 0.1-0.5% of demulsifier and the balance of water in percentage by mass; the water is selected from production sewage and/or source well water; adding water into a stirring tank, heating to above 50 ℃, adding other raw materials, and stirring uniformly; controlling the well entering temperature of the offshore oilfield anti-emulsifying well repair liquid to be more than 50 ℃. The technical problem solved is how to provide the offshore oilfield anti-emulsifying well workover fluid, so that the damage to a reservoir is reduced, the recovery effect of the oil well yield after well workover is improved, the treatment capacity of the well workover flowback fluid in oil-water separation of an offshore platform is reduced, and the offshore oilfield anti-emulsifying well workover fluid is more suitable for practical use.
Description
Technical Field
The invention relates to the technical field of oilfield chemistry, in particular to an offshore oilfield anti-emulsifying workover fluid, a preparation method and a use method thereof.
Background
The offshore oil field has the characteristics of high single well yield, most horizontal well development, loose sandstone heavy oil reservoirs and the like, and because of the special environment of an offshore platform, the liquid preparation water source of the well repair working solution is complex, including production sewage, water source well water, seawater and the like. It has mainly the following disadvantages:
the first is a horizontal well which is produced for a long time and high strength, and various temporary plugging liquid systems which are commonly used are not ideal in the leakage control effect in the operation process of the offshore oilfield horizontal well due to the reasons of low formation pressure coefficient, long horizontal well section and the like, and a large amount of external working liquid is leaked, so that serious crude oil emulsification, organic matter deposition and other injuries are easily caused after the liquid enters a reservoir.
Secondly, in order to prevent reservoir damage in the well repair process, a large amount of surfactant is added into the well repair liquid, and stable emulsion is easily formed after the surfactant is mixed with crude oil. The offshore platform space is limited, the treatment capacity of the ground oil-water separation device is limited, and a large amount of oil-water emulsion in the well repair flowback fluid can cause serious impact on the ground oil-water treatment process, so that the normal production of the offshore platform is affected.
Disclosure of Invention
The invention mainly aims to provide an offshore oilfield anti-emulsifying workover fluid, a preparation method and a use method thereof, and aims to solve the technical problem of how to provide the offshore oilfield anti-emulsifying workover fluid, reduce damage to a reservoir, improve the recovery effect of the oil well yield after workover, and reduce the treatment capacity of the workover flowback fluid in oil-water separation of an offshore platform, so that the workover fluid is more practical.
The aim and the technical problems of the invention are realized by adopting the following technical proposal. The invention provides an offshore oilfield anti-emulsifying well workover fluid, which comprises the following components in percentage by mass: 0.5 to 1.5 percent of drainage assisting cleaning agent and 0.1 to 0.5 percent of demulsifier, and the balance is complemented by water; the water is selected from production sewage and/or source well water.
The aim and the technical problems of the invention can be further realized by adopting the following technical measures.
Preferably, the offshore oilfield anti-emulsifying well repair fluid is characterized in that the water meets the water quality standard specified in Q/HS2042-2014 offshore clastic rock reservoir water injection quality index and analysis method.
Preferably, the above-mentioned offshore oilfield anti-emulsifying workover fluid, wherein the drainage assisting cleaning agent is a mixed aqueous solution comprising sodium dodecyl benzene sulfonate, octadecyl hydroxypropyl sulfobetaine, sodium lignin sulfonate and glycerol.
Preferably, in the above-mentioned offshore oilfield anti-emulsifying workover fluid, in the mixed aqueous solution, the effective content of sodium dodecyl benzene sulfonate is not less than 15%, the effective content of octadecyl hydroxypropyl sulfobetaine is not less than 15%, the effective content of sodium lignin sulfonate is not less than 10%, and the effective content of glycerol is not less than 10%.
Preferably, the above-mentioned offshore oil field emulsification-preventing workover fluid, wherein the demulsifier is selected from an aqueous solution of at least one of bisphenol a-based phenolic resin-based polyether and nonylphenol-based polyether.
Preferably, in the offshore oilfield anti-emulsifying workover fluid, the sum of the effective contents of the bisphenol A type phenolic resin-based polyether and the nonylphenol resin-based polyether in the aqueous solution is more than or equal to 30%.
Preferably, the above-mentioned offshore oilfield anti-emulsifying workover fluid comprises the following components in percentage by mass: 1.5% of drainage assisting cleaning agent and 0.4% of demulsifier.
The aim of the invention and the technical problems are also achieved by adopting the following technical proposal. The invention provides a preparation method of an offshore oilfield anti-emulsifying well workover fluid, which comprises the following steps:
1) Pretreating production sewage and/or source well water to obtain water; the water meets the water quality standard of Q/HS2042-2014 offshore clastic rock oil reservoir water injection water quality index and analysis method;
2) Adding the water into a stirring tank for heating to enable the temperature of the water to be more than 50 ℃;
3) Adding 0.5-1.5% of drainage-assisting cleaning agent and 0.1-0.5% of demulsifier into the mixture according to the mass percentage, and uniformly stirring to obtain the offshore oilfield anti-emulsifying well repair liquid, wherein the total amount of the offshore oilfield anti-emulsifying well repair liquid is 100%.
The aim and the technical problems of the invention can be further realized by adopting the following technical measures.
Preferably, in the preparation method, the stirring tank in the step 2) is a constant temperature stirring tank.
The aim of the invention and the technical problems are also achieved by adopting the following technical proposal. According to the application method of the offshore oilfield anti-emulsifying well repair liquid provided by the invention, the well entering temperature of the offshore oilfield anti-emulsifying well repair liquid is controlled to be more than 50 ℃.
By means of the technical scheme, the offshore oilfield anti-emulsifying workover fluid provided by the invention has the following advantages:
1. according to the offshore oilfield anti-emulsifying well workover fluid, the drainage-assisting cleaning agent is added into the well workover fluid, and the drainage-assisting cleaning agent contains various surfactants, so that the surface tension and the interfacial tension can be reduced, wettability change caused by water phase saturation rise is prevented, and flowback capacity of working fluid leaking into a reservoir is enhanced; meanwhile, the device can strip and disperse and dissolve aged oil stains, organic matter precipitates and the like which are retained in the underground pipe column and the near wellbore zone, clean the oil stains, organic matter deposits and the like which are retained in the underground pipe column and the near wellbore zone, play a role in enhancing the flowback performance and cleaning efficiency of the workover fluid, and further improve the productivity recovery effect after the oil well operation; by adding the demulsifier, the stable emulsion generated between the workover fluid and the underground crude oil can be effectively prevented, the problems that the demulsification and dehydration of the workover flowback fluid are difficult and the impact on the productivity of the on-site oil-water treatment process is reduced can be solved; by the technical scheme that the demulsifier is added in advance in the formula of the offshore oilfield anti-emulsifying well repair liquid, the offshore oilfield anti-emulsifying well repair liquid is low-injury well repair liquid, and by using the low-injury well repair liquid to repair wells, the damage of well-entering working liquid to a reservoir during well repair operation can be reduced, and the impact of well repair flowback liquid to the oil-water separation productivity of the offshore platform ground treatment process can be reduced; furthermore, through the comprehensive use of the technical means, the surface tension, interfacial tension, oil sand washing efficiency, oil pipe steel washing efficiency and other properties of the well workover fluid are balanced well, and the comprehensive performance is shown as good permeability recovery index (more than 84.9%), so that good reservoir protection performance is obtained.
2. The invention provides an offshore oilfield anti-emulsifying well repair liquid, a preparation method and a use method thereof, wherein the offshore oilfield anti-emulsifying well repair liquid is prepared at the temperature of more than 50 ℃ and the temperature of the offshore oilfield anti-emulsifying well repair liquid is kept at the temperature of more than 50 ℃ continuously when the offshore oilfield anti-emulsifying well repair liquid is put into a well, so that cold damage to a reservoir layer caused by low-temperature well repair liquid can be avoided.
3. The invention provides an offshore oilfield anti-emulsifying workover fluid, which is prepared by adding a demulsifier into the workover fluid, namely the demulsifier is added in advance before the workover fluid and crude oil are mixed and emulsified; the demulsifier and the workover fluid can not interfere with each other, so that serious emulsification of the workover fluid and crude oil after mixing due to adding a large amount of drainage aids, clay stabilizers and other agents into the workover fluid can be prevented, the subsequent demulsification and dehydration after entering oil-water separation equipment can be ensured, the problem that oil-water separation is difficult to perform after flowback fluid is emulsified is solved, the problem that the flowback fluid is incompatible with oil-water separation capacity designed by offshore flow is solved, and the method is particularly suitable for offshore oil fields.
The foregoing description is only an overview of the present invention, and is intended to provide a more thorough understanding of the present invention, and is to be accorded the full scope of the present invention.
Detailed Description
In order to further describe the technical means and effects adopted by the invention to achieve the preset aim, the following is a detailed description of specific implementation, structure, characteristics and effects of the offshore oilfield anti-emulsifying workover fluid, the preparation method and the use method thereof according to the invention in combination with the preferred embodiment.
The invention provides an offshore oilfield anti-emulsifying well workover fluid, which comprises the following components in percentage by mass: 0.5 to 1.5 percent of drainage assisting cleaning agent and 0.1 to 0.5 percent of demulsifier, and the balance is complemented by water; the water is selected from on-site production sewage and/or source well water.
The water is pretreated before use, so that the water meets the water quality standard specified in Q/HS2042-2014 offshore clastic rock oil reservoir water injection quality index and analysis method.
The drainage-assisting cleaning agent is a mixed aqueous solution comprising sodium dodecyl benzene sulfonate, octadecyl hydroxypropyl sulfobetaine, sodium lignin sulfonate and glycerol; the effective content of sodium dodecyl benzene sulfonate is more than or equal to 15 percent, the effective content of octadecyl hydroxypropyl sulfobetaine is more than or equal to 15 percent, the effective content of sodium lignin sulfonate is more than or equal to 10 percent, and the effective content of glycerol is more than or equal to 10 percent. The drainage-assisting cleaning agent consists of a plurality of surfactants, can reduce surface tension and interfacial tension, strip and disperse and dissolve aged greasy dirt, organic matter sediment and the like remained in underground pipe columns and near-wellbore zones, plays a role in enhancing the drainage performance and cleaning efficiency of workover fluid, and is beneficial to improving the productivity recovery effect after workover.
The demulsifier is selected from an aqueous solution of at least one of bisphenol A type phenolic resin-based polyether and nonylphenol resin-based polyether; the sum of the effective contents of the bisphenol A type phenolic resin-based polyether and the nonylphenol-based polyether is more than or equal to 30 percent. The demulsifier can effectively prevent the workover fluid and the underground crude oil from generating stable emulsion.
Preferably, the invention provides an offshore oilfield anti-emulsifying well repair liquid, which comprises the following components in percentage by mass: 0.5 to 1.5 percent of drainage assisting cleaning agent and 0.1 to 0.5 percent of demulsifier, and the balance is complemented by water; the water is selected from on-site production sewage and/or source well water. The drainage-assisting cleaning agent is a mixed aqueous solution comprising sodium dodecyl benzene sulfonate, octadecyl hydroxypropyl sulfobetaine, sodium lignin sulfonate and glycerol; the effective content of sodium dodecyl benzene sulfonate is more than or equal to 15 percent, the effective content of octadecyl hydroxypropyl sulfobetaine is more than or equal to 15 percent, the effective content of sodium lignin sulfonate is more than or equal to 10 percent, and the effective content of glycerol is more than or equal to 10 percent. The demulsifier is an aqueous solution of bisphenol A type phenolic resin-based polyether, and the effective content of the demulsifier is more than or equal to 30%.
The invention also provides a preparation method of the offshore oilfield anti-emulsifying well workover fluid, which comprises the following steps: 1) Pretreating production sewage and/or source well water to obtain water; the water meets the water quality standard of Q/HS2042-2014 offshore clastic rock oil reservoir water injection water quality index and analysis method; 2) Adding the water into a constant temperature stirring tank for heating to enable the temperature of the water to be more than 50 ℃; 3) Adding 0.5-1.5% of drainage-assisting cleaning agent and 0.1-0.5% of demulsifier into the mixture according to the mass percentage, and uniformly stirring to obtain the offshore oilfield anti-emulsifying well repair liquid, wherein the total amount of the offshore oilfield anti-emulsifying well repair liquid is 100%.
The invention also provides a use method of the offshore oilfield anti-emulsifying well repair liquid, and the well entering temperature of the offshore oilfield anti-emulsifying well repair liquid is controlled to be more than 50 ℃. By controlling the well-repairing liquid well-entering temperature to be above 50 ℃, the cold damage of the reservoir layer caused by the low-temperature well-entering liquid can be avoided.
The technical scheme of the invention is further described by the more specific examples. The used reagents are all purchased in the market; the water used is at least one of production sewage, source well water and seawater in a production field, and is pretreated to meet the water quality standard specified in Q/HS2042-2014 water quality index of water injection of offshore clastic rock reservoir and analysis method.
The testing method comprises the following steps:
1. surface tension and interfacial tension measurement: the measurement was performed by reference to SY/T5370-2018 surface and interfacial tension measurement method (measurement was performed at 50℃and 5000 rpm using a TX-500C series rotary drop surface interfacial tension meter).
2. Oil washing efficiency determination
(1) Oil sand wash efficiency determination
Step 1: oil sand preparation
Weighing a certain mass of oil sample of the Bohai sea A oil field, adding a certain amount of petroleum ether into a beaker, fully dissolving the oil sample, adding quartz sand with mass of M1 into the solution, heating and stirring for more than 0.5h, fully mixing the sand and oil stains, and obtaining the oil sand after petroleum ether is completely evaporated, wherein the mass of the oil sand is M2.
Step 2: oil wash rate determination
Adding the workover fluid into the prepared oil sand, placing the oil sand in a constant-temperature water bath at 50 ℃, taking out and gently shaking for 10 times every 15min, enabling the workover fluid to fully contact the oil sand, and taking out after placing for 1 h. Washing the reacted oil sand and the well repairing liquid with distilled water until the eluate is transparent, drying the oil sand, and weighing until the weight is unchanged to M3.
The oil sand wash rate X1 is calculated according to the formula (1):
(2) Oil pipe steel oil washing efficiency measurement
Step 1: preparation of experimental hanging piece
Polishing the N80 steel sheet to be bright, cleaning the polished test piece with filter paper, cleaning with deionized water, cleaning with absolute ethyl alcohol and acetone respectively, drying with cold air, and placing in a dryer for standby. Immersing the test piece in the crude oil of the oil field of Bohai sea A (the oil temperature is raised to 60 ℃ in advance), taking out and hanging the test piece on a test piece frame until no oil drops.
Step 2: oil wash rate determination
The treated N80 steel sheet was fastened with glass wool, hung with a hook, dried in a constant temperature oven controlled at 40℃for 30 minutes, taken out, cooled to room temperature in a dryer, and weighed (W0).
Immersing the test piece in the crude oil sample of the Bohai A oilfield heated to 60 ℃ to fully coat the crude oil, taking out the test piece, hanging the test piece on a test piece frame until oil is not dropped, weighing (Wl), respectively immersing and cleaning the test piece in the well repairing liquid which has been kept at the constant temperature of 50 ℃ for 1h, taking out the test piece, flushing the test piece under tap water for 3min, putting the test piece and the hanger into a baking oven at 40 ℃ for drying for 1h, taking out the test piece and cooling the test piece to room temperature, and weighing (W2).
The oil pipe steel oil washing efficiency X2 is calculated according to the formula (2):
3. permeability recovery measurement
The permeability recovery rate is an important index for judging the damage degree of the workover fluid to the core, and is the ratio between the permeability of the core after the workover fluid is displaced and the permeability of the core before the workover fluid is displaced, and the higher the permeability recovery rate is, the lower the damage of the workover fluid to the core is indicated.
Step 1: sample preparation
The core used in the test is a natural core of the Bohai sea A oil field, and the test water is stratum water. And (3) drying the natural rock core of the Bohai sea A oil field with the air permeability measured, measuring the length and weighing, vacuumizing the rock core, saturating the stratum water, weighing again, and estimating the pore volume occupied by the saturated stratum water of the rock core through the weight difference and the stratum water density, and marking as PV.
Step 2: permeability recovery measurement
According to the industrial standard SY/T6540-2002 drilling fluid completion fluid damage reservoir indoor evaluation method, testing the initial permeability K0 of the core after saturated stratum water at the constant temperature of the stratum temperature of 50 ℃, then reversely displacing the workover fluid 2PV, stopping displacing, fully reacting for more than 12 hours, positively displacing the stratum water again for more than 20PV, and measuring the K1 after the well workover fluid is displaced after the well workover fluid is stabilized. Permeability recovery η= (K1/K0) ×100%.
4. Evaluation of Effect on demulsification and dehydration of crude oil
The influence of the well servicing fluid on the demulsification and dehydration of the crude oil in the Bohai sea A oil field is evaluated by referring to the method in the industry standard SY/T5280-2018 crude oil demulsifier general technical condition. The demulsification and dehydration properties of the workover fluid and the corresponding blank sample of the 50% crude oil obtained from the wellhead of the Bohai sea A oilfield are respectively tested. The blank is the residual formula system after the demulsifier is removed from the workover fluid formula in each embodiment. After the workover fluid and the crude oil sample are uniformly mixed, the respective dehydration amounts after 2min, 5min, 10min, 20min, 30min, 40min, 50min, 60min and 80min are respectively measured at 60 ℃.
Example 1
Adding water into a constant temperature stirring tank for heating to ensure that the water temperature is more than 50 ℃; adding 1.5% of drainage-assisting cleaning agent and 0.4% of demulsifier into the mixture according to the mass percentage, and uniformly stirring the mixture, wherein the total amount is 100%. Wherein the drainage-assisting cleaning agent is a mixed aqueous solution comprising sodium dodecyl benzene sulfonate, octadecyl hydroxypropyl sulfobetaine, sodium lignin sulfonate and glycerol, wherein the effective content of the sodium dodecyl benzene sulfonate is more than or equal to 15%, the effective content of the octadecyl hydroxypropyl sulfobetaine is more than or equal to 15%, the effective content of the sodium lignin sulfonate is more than or equal to 10%, and the effective content of the glycerol is more than or equal to 10%. The demulsifier is an aqueous solution of bisphenol A type phenolic resin-based polyether, and the effective content of the demulsifier is more than or equal to 30%.
The results of evaluating the performance of the workover fluid of this example are shown in tables 1 to 4 below.
Example 2
The raw materials in the same way as in example 1 are as follows: 1.0 percent of drainage assisting cleaning agent and 0.5 percent of demulsifier.
Example 3
The raw materials in the same way as in example 1 are as follows: 0.5% of drainage assisting cleaning agent and 0.1% of demulsifier.
Example 4
The raw materials in the same way as in example 1 are as follows: 0.5% of drainage assisting cleaning agent and 0.5% of demulsifier.
Table 1 surface tension and interfacial tension of the workover fluids of the various examples
| Surface tension mN/m | Interfacial tension (Bohai sea A oil field oil sample) mN/m | |
| Example 1 | 24.27 | 0.248 |
| Example 2 | 26.5 | 0.578 |
| Example 3 | 29.45 | 0.863 |
| Example 4 | 30.15 | 0.995 |
As can be seen from the test results in Table 1, the surface tension of the well repairing liquid in the embodiment of the invention is between 24.27 and 30.15mN/m, and the interfacial tension of the well repairing liquid to the oil sample of the oil field of Bohai sea A is between 0.248 and 0.995 mN/m. As can be seen from the test data of the above embodiments 1 to 4, the well servicing fluid of the present invention has a remarkable effect of reducing surface tension and interfacial tension, and can enhance flowback performance of the well servicing fluid, and avoid serious reservoir damage caused by long-term retention of the well servicing fluid in the reservoir; further, as can be seen from the above test data, with the increase of the addition amount of the drainage assisting cleaning agent in the well repairing liquid, the test data of the surface tension and the interfacial tension show a decreasing trend, but the increase of the addition amount of the drainage assisting cleaning agent may be related to the increase of the manufacturing cost on one hand, and may affect the comprehensive performance of the well repairing liquid on the other hand, for example, the addition amount of the drainage assisting cleaning agent may form stable emulsion with crude oil to increase the productivity pressure and the economic cost of the post-treatment process, and the addition amount is preferably 0.5-1.5%; further, as can be seen from the above test data, the addition amount of the demulsifier has a certain influence on the surface tension and the interfacial tension of the product, and when the drainage-assisting cleaning agent with equal content is added, the addition amount of the demulsifier can be reduced, so that the surface tension and the interfacial tension of the product can be reduced.
Table 2 oil washing efficiency of various examples on oil sands and tubing steels
As can be seen from the test results in Table 2, the oil-washing efficiency of the well servicing fluid in the above embodiment of the present invention on oil sand and oil pipe steel is more than 81%. As can be seen from the test data of the above embodiments 1 to 4, the addition of the drainage-assisting cleaning agent in the well servicing fluid has obvious dissolution and dispersion effects on the oil stains and organic plugs in the underground pipe string and the near wellbore zone, and can improve the well servicing efficiency and the productivity recovery effect after well servicing; and the oil washing efficiency is improved along with the improvement of the addition amount of the drainage-assisting cleaning agent.
Table 3 results of permeability recovery measurements of various example workover fluids on cores
| Core gas permeability mD | K 0 mD | K 1 mD | Permeability recovery% | |
| Example 1 | 2024.5 | 555.7 | 505.6 | 91.0 |
| Example 2 | 1998.7 | 499.6 | 448.1 | 89.7 |
| Example 3 | 2155.3 | 500.5 | 431.9 | 86.3 |
| Example 4 | 2107.4 | 518.1 | 439.8 | 84.9 |
As can be seen from the test results in Table 3, the permeability recovery rate of the workover fluid in the above embodiment of the present invention to the natural core of the Bohai A oilfield is 84.9% -91%. As can be seen from the test data of the above examples 1 to 4, the damage of the workover fluid to the permeability of the reservoir is small, and the protection performance of the reservoir is good; and the permeability recovery rate of the product is also improved along with the improvement of the addition amount of the drainage-assisting cleaning agent in the well repairing liquid; considering the manufacturing cost of the well repairing liquid, the productivity pressure of the post-treatment process and the post-treatment cost comprehensively, the addition amount of the preferable drainage assisting cleaning agent is preferably 0.5-1.5% and the addition amount of the preferable demulsifier is preferably 0.1-0.5%.
Table 4 evaluation results of demulsification and dehydration properties of well servicing fluid and corresponding blank samples in units of ml
As can be seen from the test results in table 4, for the workover fluid, the dewatering amount of the workover fluid after mixing with the crude oil of the oil field of the Bohai sea a in the same time is significantly greater than that of the blank sample without the demulsifier, and the demulsification and dewatering speed is significantly faster than that of the blank sample. This means that the emulsion formed by mixing the workover fluid and crude oil can be greatly reduced after the demulsifier is added in front of the workover fluid, the influence of the emulsion on the demulsification and dehydration productivity of the offshore platform can be reduced, and the cost of the subsequent treatment process can be reduced.
The technical features of the claims and/or the description of the present invention may be combined in a manner not limited to the combination of the claims by the relation of reference. The technical scheme obtained by combining the technical features in the claims and/or the specification is also the protection scope of the invention.
Claims (6)
1. The anti-emulsifying well repair liquid for the offshore oil field is characterized by comprising the following components in percentage by mass: 0.5-1.5% of drainage-assisting cleaning agent and 0.1-0.5% of demulsifier, and the balance is complemented by water; the water is selected from production sewage and/or source well water;
the drainage-assisting cleaning agent is a mixed aqueous solution comprising sodium dodecyl benzene sulfonate, octadecyl hydroxypropyl sulfobetaine, sodium lignin sulfonate and glycerol;
in the mixed aqueous solution, the effective content of sodium dodecyl benzene sulfonate is more than or equal to 15 percent, the effective content of octadecyl hydroxypropyl sulfobetaine is more than or equal to 15 percent, the effective content of sodium lignin sulfonate is more than or equal to 10 percent, and the effective content of glycerol is more than or equal to 10 percent;
the demulsifier is selected from an aqueous solution of at least one of bisphenol A type phenolic resin-based polyether and nonylphenol resin-based polyether;
in the aqueous solution, the sum of the effective contents of the bisphenol A type phenolic resin-based polyether and the nonylphenol-based polyether is more than or equal to 30 percent.
2. The offshore oilfield anti-emulsifying well servicing fluid of claim 1, wherein the water meets water quality standards specified in Q/HS2042-2014 offshore clastic rock reservoir water injection quality index and analysis method.
3. The offshore oilfield anti-emulsifying well servicing fluid according to claim 1 or 2, comprising, in mass percent: 1.5% of drainage assisting cleaning agent and 0.4% of demulsifier.
4. A method for preparing the offshore oilfield anti-emulsifying well servicing fluid as defined in claim 1, comprising the steps of:
1) Pretreating production sewage and/or source well water to obtain water; the water meets the water quality standard of Q/HS2042-2014 offshore clastic rock oil reservoir water injection water quality index and analysis method;
2) Adding the water into a stirring tank for heating to enable the temperature of the water to be more than 50 ℃;
3) And adding 0.5-1.5% of drainage-assisting cleaning agent and 0.1-0.5% of demulsifier into the mixture according to the mass percentage, and uniformly stirring to obtain the offshore oilfield anti-emulsifying well repair liquid, wherein the total amount of the offshore oilfield anti-emulsifying well repair liquid is 100%.
5. The method according to claim 4, wherein the stirring tank in the step 2) is a constant temperature stirring tank.
6. A method of using an offshore oilfield anti-emulsion well servicing fluid as defined in any one of claims 1 to 3, wherein the offshore oilfield anti-emulsion well servicing fluid is controlled to have a well entry temperature of > 50 ℃.
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| US5110487A (en) * | 1989-04-03 | 1992-05-05 | Chevron Corporation | Enhanced oil recovery method using surfactant compositions for improved oil mobility |
| CN109705832A (en) * | 2019-01-29 | 2019-05-03 | 中国海洋石油集团有限公司 | A kind of anti-newborn synergist of high temperature and its preparation and application |
| CN113956856A (en) * | 2021-10-26 | 2022-01-21 | 九江蓝卓新材料科技有限公司 | Nano multifunctional cleanup additive for oil field drilling fluid and preparation method thereof |
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| US20110071056A1 (en) * | 2009-09-24 | 2011-03-24 | Rajesh K Saini | Degradable Surfactants, Including Degradable Gemini Surfactants, and Associated Methods |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5110487A (en) * | 1989-04-03 | 1992-05-05 | Chevron Corporation | Enhanced oil recovery method using surfactant compositions for improved oil mobility |
| CN109705832A (en) * | 2019-01-29 | 2019-05-03 | 中国海洋石油集团有限公司 | A kind of anti-newborn synergist of high temperature and its preparation and application |
| CN113956856A (en) * | 2021-10-26 | 2022-01-21 | 九江蓝卓新材料科技有限公司 | Nano multifunctional cleanup additive for oil field drilling fluid and preparation method thereof |
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| 聚醚型原油破乳剂结构与破乳性能关系的研究;蔡奇峰;周继柱;付增华;冷传志;时武龙;王国瑞;;应用化工(01);摘要、第1.2节 * |
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