A kind of offshore drilling fluid system and preparation method thereof
Technical field
The present invention relates to a kind of drilling fluid system, particularly a kind of offshore drilling fluid system and preparation method thereof.
Background technology
The be known as blood of drilling well of drilling fluid, good drilling liquid technology be guarantee drilling well production operation safety, high-quality, efficiently, one of fast important guarantee measure, must use drilling well/well finishing liquid in the oil-field development operation.In drilling process and after the drilling well end, drilling well/well finishing liquid and waste thereof can enter surrounding environment.Increasingly stringent along with the day by day strong and Law on Environmental Protection Laws ﹠ Regulations of Environmental awareness in the world wide; drilling well/well finishing liquid and waste thereof have caused home and abroad environment protection circle, petroleum industrial circle and many public's common concern to the impact of environment, and this problem at sea oil field seems particularly outstanding.
In the Process of Oil Well Drilling, often use polymer drilling fluid and the oil base drilling fluids such as sulphonated polymer mud at sea, comprise the oil-containing drilling fluid additive.
These drilling fluids have satisfied the needs of offshore drilling engineering preferably, but also brought problem of environmental pollution to ocean environment after using, be mainly manifested in: (1) oil-containing rejected well drilling liquid discharge into sea, oils will be separated from rejected well drilling liquid, the floating oil slick that forms across the sea.Oil slick can cause a series of harm to ocean environment: 1. oils swims in the seawater water surface and forms oil film, affects the exchange of seawater and atmosphere, reduces dissolved oxygen of seawater, causes the massive losses of marine organisms or sea fisheries; 2. oil film drifts about with sea wind, usually to the bay and Scenic Spots drift, affects color and the smell of seawater, thereby affects strand fisheries, tourism and industrial and agricultural production and domestic water, causes huge financial loss or abominable social influence; 3. in oils and its degradation production, exist multiple toxic substance (such as benzene, polycyclic aromatic hydrocarbons etc.), by hydrobiont absorption, enrichment, then the effect by food chain enters human body to these materials, is detrimental to health in seawater; 4. large-area ocean oil slick also can affect atmospheric circulation, and the harm Marine ecosystems cause the long term environmental effect that is difficult to estimate.(2) oils of not separating from rejected well drilling liquid can sink to the seabed with rejected well drilling liquid, and under the condition of hypoxgia, the biological degradation of oils is very slow, can remain in for a long time the seabed in the seabed.Oils can cause long-term effect and harm to ocean environment at the extended residual in seabed, as affects the vegeto-animal growth and breeding in seabed.In addition, the oils that sinks in the rejected well drilling liquid in seabed can progressively discharge, and affects halobiontic growth and breeding, or forms oil slick and cause multiple harm.
The marine eco-environment is the same with land ecotope; it is the important component part of China's ecotope; nineteen eighty-two; State Bureau of Environmental Protection, National Bureau of Oceanography promulgate the laws and regulations such as " People's Republic of China's law of marine environmental protection ", " offshore oil drilling open loop border protection method " in succession; offshore drilling waste discharge rules are quite strict; for this reason, research environment-friendly type offshore drilling fluid system, the environmental issue of paying close attention to drilling fluid from the source has become one of emphasis of offshore oil exploration exploitation efforts at environmental protection.
Summary of the invention
The object of the present invention is to provide a kind of offshore drilling fluid system and preparation method thereof.This offshore drilling fluid system has protection hydrocarbon zone and protection of the environment dual-use function, and the system main treating agent is natural substance modified thing, and the rejected well drilling liquid after the use can realize that the sea arranges on the spot the sea or shed acute biological toxicity EC with turning
50Value is high, and is biodegradable.It has overcome the existing following problem of offshore drilling liquid: the discarded oil-containing drilling fluid that (1) arranges the sea on the spot can cause oil pollution to ocean environment; (2) the partial polymer heavy metal content exceeds standard in the drilling fluid system, simultaneously than difficult for biological degradation, causes potential, long-term pollution of the sea; (3) drilling fluid system such as oil base drilling fluid or sulphonated polymer mud acute biological toxicity EC
50Be worth lowlyer, be little poison or poisoning, can impact marine organisms, and by food chain remote effect human lives with healthy.
A kind of offshore drilling fluid system among the present invention comprises the component (benchmark is the drilling fluid system gross weight) of following weight percent:
0.5%-1.0% environment-friendly type coating agent coater-10,
The weak gel tackifier SDL-30 of 2.0%-3.0%,
1.5%-2.5% environment-friendly type fluid loss agent CMS-L,
2.0%-3.0% environment-friendly type anti-sloughing agent SDE-1,
2.0%-4.0% high temperature resistance anti-sloughing agent SDA-25,
Surplus is seawater.
In the such scheme:
Environment-friendly type coating agent coater-10 is white powder, and its preparation method is:
(1) preparation initiator (oxidized form and reduced form) solution: in 93.5mL water, add respectively 6.5g ammonium persulphate and 6.5g S-WAT, stir, to be triggered dose fully the dissolving after, namely obtaining ammonium persulfate solution and concentration that concentration is 6.5% (wt) is the sodium sulfite solution of 6.5% (wt).
(2) add 25mL water in beaker, Xiang Shuizhong adds the 11.0g Methacrylamide, stirs and fully dissolving;
(3) add the 3.0g Sumstar 190, continue to stir, allow it fully dissolve;
(4) add the 7.0g sodium acrylate, continue fully to stir;
(5) add 5.0g pH value conditioning agent ammoniacal liquor, fully stir;
(6) add initiator: add first the 2.0mL ammonium persulfate solution, after fully stirring, add again the 2.0mL sodium sulfite solution, fully stir;
(7) continue to stir, begin heating after 5 minutes and be aggregated under the 40-50 ℃ of condition, reaction 2-4h gets the finished product coater-10.
Weak gel tackifier SDL-30 is white powder, and its preparation method is:
(1) add 7.5g Surfactant OP-10 in the 150ml tap water, preparation obtains 5% Surfactant OP-10 aqueous solution;
(2) Surfactant OP-10 aqueous solution with 150g 5% joins in the reactor, adds while stirring the 100g xanthan gum, under 80-90 ℃ of temperature, and priming reaction 7h;
(3) product gets intermediates after the activation after 105 ℃ of oven dry, pulverizing and crossing 200 mesh sieves.
(4) get intermediates 50.0g, carry out compoundly with 40.0g HV-CMC and 10.0g potassium formiate, obtain the weak gel tackifier SDL-30 of 100.0g.
Environment-friendly type fluid loss agent CMS-L is white powder, and its composition is carboxymethyl cellulose CMS.
Environment-friendly type anti-sloughing agent SDE-1 is orange thick liquid, and its preparation method is:
(1) in 200mL water, add 20.0g ethylene glycol, stir, it is fully dissolved;
(2) add the 10.0g polyoxyethylene glycol, continue to stir, it is fully dissolved;
(3) add 6.0g Repone K, continue to stir, it is fully dissolved;
(4) add the 2.0g trolamine, continue to stir, all medicaments are fully mixed, obtain environment-friendly type anti-sloughing agent SDE-1.
High temperature resistance anti-sloughing agent SDA-25 is pale yellow powder, and its preparation method is:
With 40.0g polyacrylonitrile sylvite, the 20.0g sulfonated phenol formaldehyde resin, the 25.0g oil-soluble resin, the 15.0g calcium carbonate superfine powder after evenly mixing, obtains 100.0g high temperature resistance anti-sloughing agent SDA-25.
The preparation method of a kind of offshore drilling fluid system among the present invention comprises the steps:
(1) get quantitative seawater and join in the jar, turn on agitator stirs;
(2) add the environment-friendly type coating agent coater-10 that accounts for drilling fluid system gross weight 0.5%-1.0%, continue to stir, coating agent is fully dissolved;
(3) adding accounts for the weak gel tackifier SDL-30 of drilling fluid system gross weight 2.0%-3.0%, continues to stir, and allows it fully dissolve;
(4) adding accounts for drilling fluid system gross weight 1.5%-2.5% environment-friendly type fluid loss agent CMS-L, continues to stir to make dissolving evenly;
(5) adding accounts for drilling fluid system gross weight 2.0%-3.0% environment-friendly type anti-sloughing agent SDE-1, continues to stir;
(6) adding accounts for drilling fluid system gross weight 2.0%-4.0% high temperature resistance anti-sloughing agent SDA-25, continues to stir;
(7) after above drilling fluid additive dissolving evenly, obtain the finished product environment-friendly type offshore drilling fluid system.
In the such scheme:
Environment-friendly type coating agent coater-10 is white powder, and its preparation method is:
(1) preparation initiator (oxidized form and reduced form) solution: in 93.5mL water, add respectively 6.5g ammonium persulphate and 6.5g S-WAT, stir, to be triggered dose fully the dissolving after, namely obtaining ammonium persulfate solution and concentration that concentration is 6.5% (wt) is the sodium sulfite solution of 6.5% (wt).
(2) add 25mL water in beaker, Xiang Shuizhong adds the 11.0g Methacrylamide, stirs and fully dissolving;
(3) add the 3.0g Sumstar 190, continue to stir, allow it fully dissolve;
(4) add the 7.0g sodium acrylate, continue fully to stir;
(5) add 5.0g pH value conditioning agent ammoniacal liquor, fully stir;
(6) add initiator: add first the 2.0mL ammonium persulfate solution, after fully stirring, add again the 2.0mL sodium sulfite solution, fully stir;
(7) continue to stir, begin heating after 5 minutes and be aggregated under the 40-50 ℃ of condition, reaction 2-4h gets the finished product coater-10.
Weak gel tackifier SDL-30 is white powder, and its preparation method is:
(1) add 7.5g Surfactant OP-10 in the 150ml tap water, preparation obtains 5% Surfactant OP-10 aqueous solution;
(2) Surfactant OP-10 aqueous solution with 150g 5% joins in the reactor, adds while stirring the 100g xanthan gum, under 80-90 ℃ of temperature, and priming reaction 7h;
(3) product gets intermediates after the activation after 105 ℃ of oven dry, pulverizing and crossing 200 mesh sieves.
(4) get intermediates 50.0g, carry out compoundly with 40.0g HV-CMC and 10.0g potassium formiate, obtain the weak gel tackifier SDL-30 of 100.0g.
Environment-friendly type fluid loss agent CMS-L is white powder, and its composition is carboxymethyl cellulose CMS.
Environment-friendly type anti-sloughing agent SDE-1 is orange thick liquid, and its preparation method is:
(5) in 200mL water, add 20.0g ethylene glycol, stir, it is fully dissolved;
(6) add the 10.0g polyoxyethylene glycol, continue to stir, it is fully dissolved;
(7) add 6.0g Repone K, continue to stir, it is fully dissolved;
(8) add the 2.0g trolamine, continue to stir, all medicaments are fully mixed, obtain environment-friendly type anti-sloughing agent SDE-1.
High temperature resistance anti-sloughing agent SDA-25 is pale yellow powder, and its preparation method is:
With 40.0g polyacrylonitrile sylvite, the 20.0g sulfonated phenol formaldehyde resin, the 25.0g oil-soluble resin, the 15.0g calcium carbonate superfine powder after evenly mixing, obtains 100.0g high temperature resistance anti-sloughing agent SDA-25.
Use this offshore drilling fluid system, have following advantage: satisfy the offshore drilling engine request, field maintemance is simple; The environment-friendly type offshore drilling fluid system has good rheological, fluid loss is little, has satisfied preferably marine to Different Strata drilling well requirement; Simultaneously, system master's additive only has 5 kinds, and on-the-spot drilling fluid is safeguarded simple.Protect the marine environment; the environment-friendly type offshore drilling fluid system prepares drilling fluid additive take natural biological copolymer as raw material; the heavy metal content of system and acute biological toxicity all satisfy GB 4914-2008 " offshore oil exploration and exploitation Pollutant emission concentration limit value " requirement, and biodegradable is good.The protection hydrocarbon zone, the permeability resume figure of environment-friendly type offshore drilling fluid system can reach more than 90%, and the permeability resume figure behind the excision infringement end face has good reservoir protection effect more than 92%.
Embodiment
The preparation method of a kind of environment-friendly type offshore drilling fluid system in according to the present invention comprises the steps:
(1) get quantitative seawater and join in the jar, turn on agitator stirs;
(2) add the environment-friendly type coating agent coater-10 that accounts for drilling fluid system gross weight 0.5%-1.0%, continue to stir, coating agent is fully dissolved;
(3) adding accounts for the weak gel tackifier SDL-30 of drilling fluid system gross weight 2.0%-3.0%, continues to stir, and allows it fully dissolve;
(4) adding accounts for drilling fluid system gross weight 1.5%-2.5% environment-friendly type fluid loss agent CMS-L, continues to stir to make dissolving evenly;
(5) adding accounts for drilling fluid system gross weight 2.0%-3.0% environment-friendly type anti-sloughing agent SDE-1, continues to stir;
(6) adding accounts for drilling fluid system gross weight 2.0%-4.0% high temperature resistance anti-sloughing agent SDA-25, continues to stir;
(7) after above drilling fluid additive dissolving evenly, obtain the finished product offshore drilling fluid system.
Component percentages among the embodiment 1-3 all is to be the weight percent of benchmark with wellbore fluid.
Embodiment 1:
(1) get the 400mL seawater and join in the jar, turn on agitator stirs;
(2) add 0.5% environment-friendly type coating agent coater-10, continue to stir, coating agent is fully dissolved;
(3) add 2.0% weak gel tackifier, continue to stir, allow it fully dissolve;
(4) add 1.5% environment-friendly type fluid loss agent CMS-L, continue to stir to make and dissolve evenly;
(5) add 2.0% environment-friendly type anti-sloughing agent SDE-1, continue to stir;
(6) add 2.0% high temperature resistance anti-sloughing agent SDA-25, continue to stir;
(7) after above drilling fluid additive dissolving evenly, obtain the finished product offshore drilling fluid system.
Embodiment 2:
(1) get the 400mL seawater and join in the jar, turn on agitator stirs;
(2) add 0.8% environment-friendly type coating agent coater-10, continue to stir, coating agent is fully dissolved;
(3) add 2.5% weak gel tackifier, continue to stir, allow it fully dissolve;
(4) add 2.0% environment-friendly type fluid loss agent CMS-L, continue to stir to make and dissolve evenly;
(5) add 2.5% environment-friendly type anti-sloughing agent SDE-1, continue to stir;
(6) add 3.0% high temperature resistance anti-sloughing agent SDA-25, continue to stir;
(7) after above drilling fluid additive dissolving evenly, obtain the finished product offshore drilling fluid system.
Embodiment 3:
(1) get the 400mL seawater and join in the jar, turn on agitator stirs;
(2) add 1.0% environment-friendly type coating agent coater-10, continue to stir, coating agent is fully dissolved;
(3) add 3.0% weak gel tackifier, continue to stir, allow it fully dissolve;
(4) add 2.5% environment-friendly type fluid loss agent CMS-L, continue to stir to make and dissolve evenly;
(5) add 3.0% environment-friendly type anti-sloughing agent SDE-1, continue to stir;
(6) add 4.0% high temperature resistance anti-sloughing agent SDA-25, continue to stir;
(7) after above drilling fluid additive dissolving evenly, obtain the finished product offshore drilling fluid system.
The embodiment method of evaluating performance
1, rheological property evaluation
Get the environment-friendly type offshore drilling fluid system among the embodiment 1-3 for preparing, behind the stirring at low speed 5min, according to the φ that measures drilling fluid on the six fast rotational viscosimeters that is defined in of GB/T16783.1-2006
600, φ
300, φ
200, φ
100, φ
6, φ
3Viscosity, yield value, middle pressure API dehydration, HTHP (150 ℃, the 3.5Mpa) gel strength of dehydration and 10s, 10min.
Calculate:
PV=φ
600-φ
300........................(1)
YP=0.51×(φ
300-PV)...................(2)
G
10S(or G
10min)=φ
3/ 2.................. (3)
In the formula: PV---plastic viscosity, mPa.s;
YP---yield value, Pa;
φ
600, φ
300, φ
3---600r/min, 300r/min, the stable value of reading during 3r/min, mPa.s; G
10S, G
10min---the gel strength of 10s or 10min, Pa
φ
3---the 3r/min maximum value of reading when static 10s or 10min, mPa.s;
2, heat-resisting property evaluation
Get the environment-friendly type offshore drilling fluid system among the embodiment 1-3 for preparing, behind the high-speed stirring 20min, the digestion tank of packing into, put into roller furnace, under 150 ℃, after constant temperature rolled 16 hours, take out and be cooled to room temperature, again high stir 5min after, by the φ that is defined in working sample solution on the six fast rotational viscosimeters of GB/T16783.1-2006
600, φ
300, φ
200, φ
100, φ
6, φ
3Viscosity, yield value, fluid loss and 10s, the gel strength of 10min.
3, caving-preventing characteristic evaluation
(1) the mud shale rate of recovery is estimated
Get a certain amount of drilling cuttings, the order number is between the 6-10 order, and 105 ℃ lower dry; In digestion tank, add drilling fluid and the dried drilling cuttings of 50.0g among the 350mL embodiment 1-3, aging 120 ℃ * 16h; Solution after aging is crossed 40 mesh sieves, and uses the tap water natural flushing; Drilling cuttings after the flushing is weighed 105 ℃ of lower dryings, calculates the mud shale rate of recovery.
(2) the mud shale linear expansion is estimated
Get dried landwaste, obtain the landwaste powder after the pulverizing, core block (under the 4MPa pressure, pressing 5min) is estimated in preparation; Open instrument, install the evaluation core block, pour into after the zeroing among the embodiment 1-3; Begin test, record the polar expansion amount (mm) behind every 0.5h; With the blank solution contrast, calculate polar expansion amount reduced rate.
4, heavy metal evaluation
According to GB 5084.3-1996 " Hazardous wastes judging standard leaching characteristic identification ", after drilling fluid hydrochloric acid or the molten pre-treatment of nitric acid acid, the lysate for preparing adopts atomic fluorescence detector, plasma mass spectrograph etc. to measure by corresponding heavy metal element determination method.
5, biodegradable evaluation
With BOD
5(biological oxygen demand (BOD))/COD (chemical oxygen demand) measures respectively first the BOD of embodiment product as evaluation index
5And COD, then calculate the two ratio.
6, acute biological toxicity EC
50Estimate
In the centrifuge tube of whizzer, add 20mL embodiment drilling fluid, speed with 1000r/min is carried out centrifugal, get centrifugal after liquid at the middle and upper levels, measure the acute biological toxicity EC of embodiment drilling fluid according to GB/T 15441-1995 " the mensuration photogenic bacterium method of acute toxicity of water quality "
50Value.
Table 1 embodiment marine drilling liquid rheological property comparative evaluation (room temperature)
Table 2 embodiment drilling fluid heat-resisting property comparative evaluation (150 ℃, 16h)
Table 3 embodiment marine drilling liquid caving-preventing characteristic comparative evaluation
Table 4 embodiment
Drilling fluid heavy metal content comparative evaluation (unit: mg/kg)
Table 5 embodiment drilling fluid acute biological toxicity EC
50The comparative evaluation
Table 6 embodiment drilling fluid biodegradable comparative evaluation
Table 7 embodiment drilling fluid reservoir protection performance comparison is estimated (* cuts end face 1cm)