CN101787269A - Low-injury sandstone acid used for acidification technology of oil well - Google Patents
Low-injury sandstone acid used for acidification technology of oil well Download PDFInfo
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Abstract
The invention relates to a low-injury sandstone acid used for the acidification technology of an oil well. The low-injury sandstone acid comprises the compositions according to the mass percentage: 2-15% of hydrochloric acid, 0-10% of ammonium bifluoride, 0-10% of hydrogen nitrate, 0-8% of acetic acid, 8-18% of composite phosphonic acid, 0.5-5% of citric acid, 5-15% of acidulate corrosion inhibitor and 70-84% of water or additive water solution, wherein the additive water solution comprises the compositions according to the weight percentage: 0.5-5% of mutual solvent, 0.1-5% of demulsifying agent, 0-30% of clay stabilizer and 60-99.4% of water. The sandstone acid has the characteristics that the permeability of the oil well can be improved, the speed of reaction is slow and uniform, and the corrosion of the sandstone acid to the area near the oil well is nearly the same as that of the clean water.
Description
Technical field
The present invention relates to a kind of oil layer unblocking and improve recovery ratio preparation, particularly a kind of low-injury sandstone acid used for acidification technology of oil well.
Background technology
Oil well sandstone reservoir acidification is used hydrochloric acid and hydrofluoric acid mixing acid, i.e. mud acid usually.Conventional mud acid is ratio preparation in 12: 3% in HCI: HF, also fluoram can be dissolved in usually preparing HF among the HCI, as the NH of 15%HCI and 5%
4HF
2Produce HF mud acid blockages relieving fluid.But nearest studies show that, reduce potential fluoride salt precipitation, and this ratio should be 6: 1 at least, preferably 9: 1.External BJ Service Co. develops a kind of new HF mixture, is to replace HCI hydrolysis fluoride salt with the chelated acid complex compound, and this acid has 5 hydrogen ions, is called " HV acid ", HV acid and hydrofluorination ammonium (NH
4HF
2) produce complexing ammonium salt and hydrogen fluoride, be referred to as " sandstone acid ".Normally quartzy hundreds of times even thousands of times of the surface-area of clay; Most of acid solutions will consume with the reaction of clay in, rather than consume with the reaction of quartz particles in, the active penetration depth of acid solution is less, so reduce speed of response, making it to relax evenly is current conventional acidifying problem.There is the corrodibility problems of too to the immediate vicinity of wellbore in the common acidifying of current routine.
Summary of the invention
In order to overcome the defective of above-mentioned prior art, the object of the present invention is to provide a kind of low-injury sandstone acid used for acidification technology of oil well, have and can improve the oil well rate of permeation, speed of response relaxes evenly, to the corrosion of the immediate vicinity of wellbore characteristics near clear water.
In order to achieve the above object, technical scheme of the present invention is achieved in that
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 2～15% of gross weight, ammonium bifluoride accounts for 0～10%, nitric acid accounts for 0～10%, acetate accounts for 0～8%, and compound phosphonic acids accounts for 8～18%, and citric acid accounts for 0.5～5%, acidification corrosion inhibitor accounts for 5～15%, and the water or the additive aqueous solution account for 70～84%.
Described additive aqueous composition is: mutual solvent accounts for 0.5～5% of additive aqueous composition weight, emulsion splitter accounts for 0.1～5% of additive aqueous composition weight, clay stabilizer accounts for 0～30% of additive aqueous composition weight, and water accounts for 60～99.4% of additive aqueous composition weight.
Sandstone acid system of the present invention is to add compound phosphonic acids and villiaumite reaction generation HF with a kind of organic acid, and this NEW TYPE OF COMPOSITE acid contains a plurality of hydrogen ions.Can under different chemical metering condition, decompose.The general structure of sandstone acid is as follows:
Wherein: R, R1, R2, R3 are hydrogen, alkyl, aryl, phosphonates, phosphoric acid fat, acyl group, amine, hydroxyl or oh group.
R4, R5 are made up of hydrogen, sodium, potassium, ammonium or organic group.
The slow mechanism of sandstone acid is as follows:
Physical adsorption: the easier surface of clay that is adsorbed on of sandstone acid.This is because at sandstone reservoir, the specific surface area maximum of clay.
Chemisorption: chemisorption also is easy to act on calcic, iron, the aluminium component higher clay and weighting material.Sandstone acid and clay are reflected at " thin layer " that surface of clay generates aluminium silicon phosphonate.
More than the adsorption that produces of the two kinds of reactions speed of response that can slow down acid solution and clay.
Find that by test in place sandstone acid and polynite reaction have formed " thin layer " on the surface of clay, slow down the speed of response of acid fluid system to clay mineral.
Sandstone acid suppresses PRECIPITATION MECHANISM
(1) sandstone acid complex ability that polyvalent metal ion in the solution is had, under very low concentration with Ca
2+, Al
3+, Fe
2+, Fe
3+In solution, keep solution state Deng polyvalent metal ion " chelating " thereby make some generate sedimentary metal ion easily.
(2) sandstone acid is to Ca
2+, Na
+, K
+, NH4
+And so on ion very strong adsorptive power is arranged.Therefore, in the solution environmental that has sandstone acid to exist, Ca
2+, Na
+, K
+, NH
4 +And so on ion just be difficult to have an opportunity and F
-, SiF
6 2-Form villiaumite precipitation and silicofluoride precipitation.
Low-injury sandstone acid has been compared following outstanding advantage with existing other souring agents:
(1) is applied in the acidization, quickens after the acidifying acid solution effectively and discharge, prevent that acid solution and crude oil from producing acid sludge formation and causing reservoir damage; Also produce the effect of good anti-swollen steady sand after the de-plugging;
(2) can guarantee effectively that acid enters oil and water well well depths, little to formation damage, overcome acidifying in the past and easily form acid sludge, need anti-row, steam circle is little, and validity period is short, on-the-spot dangerous big problem;
(3) can improve the oil well rate of permeation by a larger margin;
(4) in the process of de-plugging, new infringement is not caused on the stratum, do not produce secondary sedimentation, have long-time deposition scale effect;
(5) because the process of its de-plugging is slow, core is not caused fierce injury because of skeleton, avoid occurring the regular mud acid acidifying after, easily the skeleton injury is caused on the stratum, formation collapse shakes out easily, the problem that the de-plugging validity period is short;
(6) corrosion of immediate vicinity of wellbore is near clear water.
Embodiment
Elaborate below by embodiment.
Embodiment one
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 2% of gross weight, and compound phosphonic acids accounts for 8%, and citric acid accounts for 1%, and acidification corrosion inhibitor accounts for 5%, and water accounts for 84%.
Embodiment two
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 8% of gross weight, and compound phosphonic acids accounts for 12%, and citric acid accounts for 0.5%, and acidification corrosion inhibitor accounts for 5%, and the additive aqueous solution accounts for 74.5%.
Described additive aqueous composition is: mutual solvent accounts for 0.5% of additive aqueous composition weight, and emulsion splitter accounts for 0.1% of additive aqueous composition weight, and water accounts for 99.4% of additive aqueous composition weight.
Embodiment three
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 11% of gross weight, and ammonium bifluoride accounts for 3%, and compound phosphonic acids accounts for 9%, and citric acid accounts for 2%, and acidification corrosion inhibitor accounts for 5%, and the additive aqueous solution accounts for 70%.
Described additive aqueous composition is: mutual solvent accounts for 5% of additive aqueous composition weight, emulsion splitter accounts for 5% of additive aqueous composition weight, clay stabilizer accounts for 30% of additive aqueous composition weight, and water accounts for 60% of additive aqueous composition weight.
Embodiment four
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 3% of gross weight, and nitric acid accounts for 5%, and compound phosphonic acids accounts for 10%, and citric acid accounts for 5%, and acidification corrosion inhibitor accounts for 7%, and water accounts for 70%.
Embodiment five
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 5% of gross weight, and ammonium bifluoride accounts for 4%, acetate accounts for 2%, and compound phosphonic acids accounts for 8%, and citric acid accounts for 1%, acidification corrosion inhibitor accounts for 10%, and the water or the additive aqueous solution account for 70%.
Described additive aqueous composition is: mutual solvent accounts for 2% of additive aqueous composition weight, emulsion splitter accounts for 2% of additive aqueous composition weight, clay stabilizer accounts for 10% of additive aqueous composition weight, and water accounts for 86% of additive aqueous composition weight.
Embodiment six
A kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 2% of gross weight, and ammonium bifluoride accounts for 1%, nitric acid accounts for 1%, and acetate accounts for 1%, and compound phosphonic acids accounts for 8%, citric acid accounts for 3%, and acidification corrosion inhibitor accounts for 14%, and the water or the additive aqueous solution account for 70%.
Described additive aqueous composition is: mutual solvent accounts for 3% of additive aqueous composition weight, emulsion splitter accounts for 4% of additive aqueous composition weight, clay stabilizer accounts for 20% of additive aqueous composition weight, and water accounts for 73% of additive aqueous composition weight.
According to the present invention the component of sandstone acid as can be seen, the negatively charged ion of fluorochemical is to be provided by the dissolved ionic fluoride saltization, 1 HF molecule is to be combined into by 1 oxonium ion and 1 fluoride anion.Owing to the reason of the pH value of this mixture causes oxonium ion and active HF concentration all very low, so the shock absorption of weak acid and salt of weak acid forms balance.When this acid and stratum reacted, the balance of this system was destroyed, activates said process once more, and up to rebuliding balance, as long as the concentration of solute is abundant, the acidification reaction speed of this solvent is very stable.During the preparation sandstone acid, have only 3 hydrogen ion hydrolysis the strongest to produce HF, remaining is not had an effect, because of they need hydrolysis under the condition of pH＞4.The strongest saloid acid of hydrionic property class, and the most weak hydrogen ion property class is like carbonic acid, sort buffer effect make the speed of response of acid and clay and carbonate slow down several times, are equivalent to retarded acid.And speed of response can substitute some sandstone acids by other acid and change, and for example hydrochloric acid is faster than the speed that organic acid forms HF.
In addition, also have following synergistic effect when acidifying strata: 1) when beginning to react with the stratum, because chemisorption forms layer of aluminum-silicate-phosphate layer around clay, its thick book is less than 1 μ m, solubleness is very low in weak acid and water, but can be dissolved fast by HCl.This layer film has blocked clay and has further reacted, thereby can prevent the basement rock fragmentation.2) sandstone acid has anti-absorption and water-wet characteristic, promotes HF and quartzy reaction, although speed of response is slower than mud acid, the quartz dissolution degree is higher.3) sandstone acid is a kind of good dispersant and scale inhibitor, therefore can postpone and suppress precipitation in the immediate vicinity of wellbore and form.
Low-injury sandstone acid of the present invention has been compared following outstanding advantages with other acidulants:
(1) is applied in the acidization, effectively accelerates after the acidifying acid solution and discharge, prevent that acid solution and crude oil from producing acid sludge formation and causing reservoir damage; Also produce the effect of good anti-swollen steady sand after the de-plugging.
(2) can guarantee effectively that acid enters oil-water well well depths, little to formation damage, overcome in the past acidifying and easily form acid sludge, need anti-row, operating radius is little, and the term of validity is short, on-the-spot dangerous big problem.
(3) can improve by a larger margin the oil well permeability.
(4) in the process of de-plugging, new infringement is not caused on the stratum, do not produce secondary precipitation, have long-time deposition scale effect.
(5) because the process of its de-plugging is slow, core is not caused fierce injury because of skeleton, avoid occurring the regular mud acid acidifying after, easily the skeleton injury is caused on the stratum, formation collapse shakes out easily, the problem that the de-plugging term of validity is short.
(6) corrosion of near wellbore zone is near clear water.
Because sandstone acid system of the present invention is the acid fluid system that is added compound phosphonic acids and villiaumite reaction production hydrofluoric acid by a kind of organic acid, has following features:
(1) sandstone acid contains a plurality of hydrogen ions, can be under different pH value conditions, and slowly ionization goes out hydrogen ion, provides sufficient hydrogen ion and villiaumite reaction to produce hydrofluoric acid. Sandstone acid can keep the hydrogen ion concentration of solution in higher level in the rock forming mineral course of reaction, is conducive to stop the generation of various precipitations.
(2) the sandstone acid acid fluid system has higher corrosion rate to quartz, and in the identical situation of hydrofluoric acid concentration, the corrosion rate of sandstone acid system is higher than mud acid to the corrosion rate of quartz. Simultaneously, sandstone acid can suppress acid solution and reaction speed as the clay of sandstone's cementation matter, reduces clay solubility, and has prevented that stratum matrix from being dismembered.
(3) sandstone acid has complexing power to polyvalent metal ion in the solution, and all polycations are had very strong adsorption capacity. The threshold effect of sandstone acid and be exactly the mechanism that sandstone acid suppresses the sandstone acidizing secondary precipitation to the characterization of adsorption of ion.
(4) the sandstone acid acid fluid system is specially adapted to that cement is loose, the sandstone reservoir of short texture. Because sandstone acid can avoid hydrofluoric acid to react with clay too quickly, thereby avoids acid solution to the corrosion as the rock cement, can not cause the loose of rock and collapse. Simultaneously, the sandstone acid acid fluid system has higher corrosion ability to quartz, can not affect the whole corrosion rate to rock.
(5) novel sandstone acid system is used in the oil well acidation of Bohai Bay Oil is processed, and obtains significant effect of increasing production. Succeeding in developing of this novel acid solution is for the acidification to dispel block of sandstone reservoir provides a kind of new Acidizing Process Technique.
Claims (7)
1. low-injury sandstone acid used for acidification technology of oil well, it is characterized in that, its component comprises by mass ratio: hydrochloric acid accounts for 2～15% of gross weight, ammonium bifluoride accounts for 0～10%, nitric acid accounts for 0～10%, acetate accounts for 0～8%, compound phosphonic acids accounts for 8～18%, citric acid accounts for 0.5～5%, and acidification corrosion inhibitor accounts for 5～15%, and the water or the additive aqueous solution account for 70～84%, described additive aqueous composition is: mutual solvent accounts for 0.5～5% of additive aqueous composition weight, emulsion splitter accounts for 0.1～5% of additive aqueous composition weight, and clay stabilizer accounts for 0～30% of additive aqueous composition weight, and water accounts for 60～99.4% of additive aqueous composition weight.
2. sandstone acid according to claim 1 is characterized in that, its component comprises by mass ratio: hydrochloric acid accounts for 2% of gross weight, and compound phosphonic acids accounts for 8%, and citric acid accounts for 1%, and acidification corrosion inhibitor accounts for 5%, and water accounts for 84%.
3. sandstone acid according to claim 1, it is characterized in that, its component comprises by mass ratio: hydrochloric acid accounts for 8% of gross weight, compound phosphonic acids accounts for 12%, and citric acid accounts for 0.5%, and acidification corrosion inhibitor accounts for 5%, the additive aqueous solution accounts for 74.5%, described additive aqueous composition is: mutual solvent accounts for 0.5% of additive aqueous composition weight, and emulsion splitter accounts for 0.1% of additive aqueous composition weight, and water accounts for 99.4% of additive aqueous composition weight.
4. sandstone acid according to claim 1, it is characterized in that, its component comprises by mass ratio: hydrochloric acid accounts for 11% of gross weight, ammonium bifluoride accounts for 3%, compound phosphonic acids accounts for 9%, citric acid accounts for 2%, acidification corrosion inhibitor accounts for 5%, the additive aqueous solution accounts for 70%, described additive aqueous composition is: mutual solvent accounts for 5% of additive aqueous composition weight, emulsion splitter accounts for 5% of additive aqueous composition weight, and clay stabilizer accounts for 30% of additive aqueous composition weight, and water accounts for 60% of additive aqueous composition weight.
5. sandstone acid according to claim 1, it is characterized in that, its component comprises by mass ratio: a kind of low-injury sandstone acid used for acidification technology of oil well, its component comprises by mass ratio: hydrochloric acid accounts for 3% of gross weight, nitric acid accounts for 5%, and compound phosphonic acids accounts for 10%, and citric acid accounts for 5%, acidification corrosion inhibitor accounts for 7%, and water accounts for 70%.
6. sandstone acid according to claim 1, it is characterized in that, its component comprises by mass ratio: hydrochloric acid accounts for 5% of gross weight, ammonium bifluoride accounts for 4%, acetate accounts for 2%, compound phosphonic acids accounts for 8%, citric acid accounts for 1%, acidification corrosion inhibitor accounts for 10%, the water or the additive aqueous solution account for 70%, and described additive aqueous composition is: mutual solvent accounts for 2% of additive aqueous composition weight, and emulsion splitter accounts for 2% of additive aqueous composition weight, clay stabilizer accounts for 10% of additive aqueous composition weight, and water accounts for 86% of additive aqueous composition weight.
7. sandstone acid according to claim 1, it is characterized in that, its component comprises by mass ratio: hydrochloric acid accounts for 2% of gross weight, ammonium bifluoride accounts for 1%, nitric acid accounts for 1%, acetate accounts for 1%, compound phosphonic acids accounts for 8%, citric acid accounts for 3%, and acidification corrosion inhibitor accounts for 14%, and the water or the additive aqueous solution account for 70%, described additive aqueous composition is: mutual solvent accounts for 3% of additive aqueous composition weight, emulsion splitter accounts for 4% of additive aqueous composition weight, and clay stabilizer accounts for 20% of additive aqueous composition weight, and water accounts for 73% of additive aqueous composition weight.
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Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102120930A (en) * | 2010-11-29 | 2011-07-13 | 尚伟 | Oil reservoir modification acid liquor and oil production method by using same |
| CN102536166A (en) * | 2012-02-14 | 2012-07-04 | 中国石油天然气股份有限公司 | Method for deep treatment of oil layer through self-generation foam acidification |
| CN103045227A (en) * | 2011-10-17 | 2013-04-17 | 中国石油天然气股份有限公司 | Multi-component retarded acid for acidizing sandstone reservoir |
| CN103484088A (en) * | 2013-09-06 | 2014-01-01 | 廊坊中石油科学技术研究院 | Blocking remover suitable for acidification of complex lithologic reservoirs and acidification blocking removing method |
| CN104946232A (en) * | 2014-03-27 | 2015-09-30 | 中国石油化工股份有限公司 | Mixed alcohol-acid liquid system for compact sandstone reservoir |
| CN107892912A (en) * | 2017-11-02 | 2018-04-10 | 中国石油集团渤海钻探工程有限公司 | A kind of antiacid slag agent of acidifying suitable for a variety of acid fluid systems |
| CN109777389A (en) * | 2019-03-04 | 2019-05-21 | 北京国海能源技术研究院 | A kind of MH acid system and preparation method thereof suitable for reservoir blockages relieving acidification |
| CN112646562A (en) * | 2020-12-16 | 2021-04-13 | 陕西科技大学 | Application of binary acid system reagent in reducing core fracture pressure |
| CN113122221A (en) * | 2021-04-06 | 2021-07-16 | 西安石油大油气科技有限公司 | Acid liquor system for online acidification of water injection well for oil exploitation and preparation process thereof |
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| CN101089118A (en) * | 2006-06-16 | 2007-12-19 | 长江大学 | Acidifying agent composition |
| CN101161762A (en) * | 2007-11-27 | 2008-04-16 | 西安石油大学 | Acid for corroding sandstone |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101089118A (en) * | 2006-06-16 | 2007-12-19 | 长江大学 | Acidifying agent composition |
| CN101161762A (en) * | 2007-11-27 | 2008-04-16 | 西安石油大学 | Acid for corroding sandstone |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102120930A (en) * | 2010-11-29 | 2011-07-13 | 尚伟 | Oil reservoir modification acid liquor and oil production method by using same |
| CN103045227A (en) * | 2011-10-17 | 2013-04-17 | 中国石油天然气股份有限公司 | Multi-component retarded acid for acidizing sandstone reservoir |
| CN103045227B (en) * | 2011-10-17 | 2015-05-13 | 中国石油天然气股份有限公司 | Multi-component retarded acid for acidizing sandstone reservoir |
| CN102536166A (en) * | 2012-02-14 | 2012-07-04 | 中国石油天然气股份有限公司 | Method for deep treatment of oil layer through self-generation foam acidification |
| CN102536166B (en) * | 2012-02-14 | 2015-01-21 | 中国石油天然气股份有限公司 | Method for deep treatment of oil layer through self-generation foam acidification |
| CN103484088A (en) * | 2013-09-06 | 2014-01-01 | 廊坊中石油科学技术研究院 | Blocking remover suitable for acidification of complex lithologic reservoirs and acidification blocking removing method |
| CN103484088B (en) * | 2013-09-06 | 2016-02-03 | 廊坊中石油科学技术研究院 | A kind of unblocking agent and acidification to dispel block method being applicable to complex lithology reservoir acidifying |
| CN104946232A (en) * | 2014-03-27 | 2015-09-30 | 中国石油化工股份有限公司 | Mixed alcohol-acid liquid system for compact sandstone reservoir |
| CN107892912A (en) * | 2017-11-02 | 2018-04-10 | 中国石油集团渤海钻探工程有限公司 | A kind of antiacid slag agent of acidifying suitable for a variety of acid fluid systems |
| CN109777389A (en) * | 2019-03-04 | 2019-05-21 | 北京国海能源技术研究院 | A kind of MH acid system and preparation method thereof suitable for reservoir blockages relieving acidification |
| CN112646562A (en) * | 2020-12-16 | 2021-04-13 | 陕西科技大学 | Application of binary acid system reagent in reducing core fracture pressure |
| CN113122221A (en) * | 2021-04-06 | 2021-07-16 | 西安石油大油气科技有限公司 | Acid liquor system for online acidification of water injection well for oil exploitation and preparation process thereof |
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Application publication date: 20100728 |