Sea Water Injection System

In direct to rectify the levigate replacement in an levigate province the insertion of ocean inspire is used to extension the urgency within the reservoir and augment the levigate cemation. The graph consecrated in Figure 1 is a usual oceaninspire insertion classification, precedently the insertion way, inspire must entertain a matter to nearen the indolence scold caused by oceaninspire in pipe lines, manner and downhole insertion equipments. The matter is invetetrounce in a effortnear de-aeration way and chemical scavenger insertion to nearen the tension of oxygen in oceanwater.

Seawater_Inj_Schem

Figure 1. Oceaninspire Insertion Classification

In a ordinary exercise of the oceaninspire insertion classification the predicaments of the way are 150,000 barrels per day, pipe crossing of 8 inches at 25 °C, still in provisions of indolence parameters the certaintys is granted in consideration 1, this consideration shows that the effortnear deaeration way diminish the most measure of Oxygen tension in oceanwater.

Consideration 1. Tension of Oxygen in ordinary exercise

Tension of O2 in unanalogous Aces

PPB

mg/l

mole/m3

Feed Oceanwater

7,000

7

0.22

Succeeding effortnear de-aeration way

100

0.1

0.003

Succeeding scavenger dosage

10

0.01

0.0003

With the certaintys granted, the indolence scold in ordinary exercise predicament is 0.0454mm/year (the vigilance stride by stride including ace intercharge are shown in the postscript) future the indolence scold is remote near than the assemblage accepconsideration compute which is 0.1 mm/year, and it resources that the classification is established correctly.

It has been root that the effortnear de-aeration equipment requires relit, and it procure be quenched of exercise ce betwixt single and three months.

Inspire classification Insertion withquenched a effortnear de-aeration way:

Guarded the word running dullness with the subjoined equation:

Tension of Oxygen singly with the observation of Scavenger dosing = 6.910 ppm

K is the body alienate coefficient and it vigilances and ace intercharges are shown in the postscript.

Guarded the Indolence Scold:

Assuming the ocean rudiment of the pipe Iron govern-this-reason n= 2

M= 55.84 g/mol

Density: 7.87 g/cm3

Now we can parallel the indolence scold of each event and enumescold the implications of easy the classification withquenched the effortnear de-aeration.

Future the indolence scold procure extension 502 seasons withquenched the effortnear de-aeration. Invetetrounce on this conclusion it is open that the most essential way ce oxygen dispersion is the effortnear deareation.

The assemblage entreat the tribute in a technically and economically subject-matter of sentiment three exerciseal explanations during the relit of the effortnear de-aeration equipment.

Ce the consecrated accepconsideration indolence scold near than 0.1 mm/year, a indolence scold compute of 0.09 mm/year was used to trounce the implications of the feasible explanations.

a. Decreasing the Glide Scold

Assuming an accepconsideration indolence Scold of 0.09 mm/year,

From the equation overhead we can thrust the Running dullness:

With running dullness we can thrust body alienate coefficient k:

Now we can thrust the innovating Sh reckon:

With Sh reckon we can achieve Re reckon:

This compute of Reynolds reckon resources that we are in the transition regime betwixt laminar glide and archaic glide.

Now we can thrust the glide scold:

From the technical subject-matter of sentiment and invetetrounce on the concepts of limpids mechanics, decreasing the glide quantity to 260 barrels per day procure genescold a laminar glide (Re near than 3000) on the pipe, in other articulation it resources that the celerity procure referefficacious be in the required optimum rank of 1.5 m/s to 2.5 m/s, according to Streeter. Doing the vigilances the celerity procure thrust a very slack compute of 0.014 m/s in the pipe, which is by remote inferior than the narrowness compute of 1 m/s. Govern-this-reason technically, the abatement of glide scold to thrust an accepconsideration indolence scold is referefficacious a feasible explanation.

In observation, this skin of expressionation of the glide scold (577 seasons inferior than the primordial) would entertain collisions on the levigate polite. Specifically, it would referefficacious be efficacious to oceantain the urgency at the desired roll and govern-this-reason would entertain a proud collision on levigate cemation superfluous to specie detriment.

b. Increasing the quantity of scavenger

Assuming an accepconsideration indolence Scold of 0.09 mm/year

From the equation beneath we can thrust the tension of Oxygen that we want to include in the inspire in direct to entertain an accepconsideration indolence scold

Using Sodium sulfate as scavenger the subjoined reaction procure proceed:

Future cem the stoichiometry of the reaction the agreement betwixt the mixtures procure be 2 ramparts of Scavenger and 1 rampart of Oxygen.

For-this-reason the quantity of scavenger Sodium sulfate wanted is: =>

In an insertion glide scold of 150,000 bbl/day

Invetetrounce on scavenger’s vigilances we want to procure the classification with a noble quantity of scavenger to diminish the oxygen tension that gives an accepconsideration indolence scold, it is up to 1.3 ton per day, it is closely 80 seasons past than quantity of scavenger used in ordinary exercise, which is abquenched 17 kg per day.

On the economically subject-matter of sentiment, if the scavenger procure commute effortnear de-aeration ce a month, the want of scavenger procure be approximately 40 ton per month. By using the interchangeable require of scavenger 0.64 USD/kg (https://www.icis.com), it procure require about 832 USD/day and scaling it to a month it procure require closely 24,960 USD/month.

c. Indolence Inhibitor

Indolence inhibitor mixture procure diminish the indolence scold by neutralizeing twain anodic and cathodic reactions. Anodic inhibitor procure be adsorbed onto metal manner to cem protective film and neutralize metal disexplanation period cathodic inhibitor procure minimize O2 abatement reaction by ceming non-conducting film on metal manner. And in technical provisions it could be the explanation of the equality. Still, from the vigilances, we recognize that indolence scold withquenched the effortnear deareation is 22.5 mm/year and the aid is to nearen the indolence scold beneath 0.1 mm/year. Invetetrounce on the indolence inhibitor miss state that is contemplated by Hedges (2000), if the expected uninhibited indolence scold is graeter than 6 mm/year prohibit is unreasonable to procure parity ce the unmeasured province conduct. Govern-this-reason indolence govern of the classification could referefficacious be efficient with a singly indolence inhibitor owing of the noble expressionation of availability.

Invetetrounce on the conclusions of the three feasible options, on the economically subject-matter of sentiment decreasing the insertion glide scold procure collision in the cemation of levigate, and decreasing the ocean effect (oil) of the diligence it procure entertain tremendous effects in the levigate assemblage. Govern-this-reason in the indolence engineering subject-matter of sentiment the most accurately explanation is to extension the quantity of scavenger (Na2SO3) in direct to thrust a indolence scold of 6 mm/year and then with the observation of indolence inhibitors the indolence scold can be diminish to an accepconsideration compute of near than 0.1 mm/year.

The dosage of O2 scavenger has to be occasional ce 8 hours per week ce the insertion of the biocide. During this season if there was referefficacious the indolence inhibitor, the Indolence scold would be 22.5 mm/yr. still if the Indolence inhibitor prohibit scold is 98.5% (as from 6mm/yr to 0.09mm/yr), the indolence scold would be:

For-this-reason the Indolence scold would be:

The Indolence scold is partially overhead the required command (0.002 mm/yr), still in the cudgel event scenario, 3 months with no deaerator, ascribable to the certainty the Indolence scold with the effortnear deaerator is 0.0454 mm/yr which is 0.0546 mm/year near than the required scale. So, in a year perspective the partially past quantity of Indolence procure be referefficacious telling and the classification procure achievement correctly.

Also, the quantity of Na2SO3 needed to thrust a CR of 6 mm/year is 905 Kg/day and it procure require about 580 USD/day.

Finally, in direct to cull the imaginary indolence inhibitor laboratory tests must be manufactured in the identical oceaninspire that procure be used. In situ tests would acceleration to convince the sort of the conclusions.

  • Streeter, Victor L. “Handbook of limpid mechanics.” McGraw-Hill, ed 1 (1961).
  • Hedges, B. (2000) “The Indolence Inhibitor Availability Model“, NACE International, Paper 00034.
  1. Inspire classification Insertion with a effortnear de-aeration way and Oxygen scavenger observation:

Considering the inspire classification insertion overhead and the subjoined certaintys we can thrust a indolence scold compute in the instant strides.

Facts granted:

  • Pipe Crossing: = 8 inch, govern-this-reason the Area A = 50.26 in2 = 0.032429 m2
  • Quantity Glide Scold: = 150000 bbl/d
  • Initial Oxygen Tension = 7 ppm
  • Tension of Oxygen Succeeding Effortnear De-aeretion = 100 ppb
  • Tension of Oxygen Succeeding Scavenger dosing = 10 ppb
  • Kinematic Viscosity: 1.05 X 10-6 m2/s
  • Schmidt reckon = 505
  1. Vigilance of Re reckon:

  1. Vigilance of Sh Reckon:

  1. In archaic Glide vigilance of Diffusion coefficient:

From Sh reckon we can thrust the body alienate coefficient k:

Now guarded the word running dullness with the subjoined equation:

Tension of Oxygen succeeding effortnear de-aeration and Scavenger dosing = 0.01 ppm

Guarded the Indolence Scold:

Assuming the ocean rudiment of the pipe Iron govern-this-reason:

n= 2

MFe: 55.84 g/mol

ρ: 7.87 g/cm3

Ce 8 hours per week, the O2 scavenger dosing is occasional ce biocide to be injected. So, there is an Availability of :

=>

The Indolence scold at a tension of 0.1ppm of O2 is:

 

  1. Inspire classification Insertion withquenched a effortnear de-aeration way:

Guarded the word running dullness with the subjoined equation:

Tension of Oxygen singly with the observation of Scavenger dosing = 6.910 ppm

Guarded the Indolence Scold:

Assuming the ocean rudiment of the pipe Iron govern-this-reason n= 2

M= 55.84 g/mol

Density: 7.87 g/cm3

Now we can parallel the indolence scold of each event and enumescold the implications of easy the classification withquenched the effortnear de-aeration.

Future the indolence scold procure extension 502 seasons withquenched the effortnear de-aeration.

  1. Evaluation of the subjoined exerciseal explanations:
  1. Lessen the glide scold of inspire:

Assuming an accepconsideration indolence Scold of 0.09 mm/year

From the equation overhead we can thrust the Running dullness:

With running dullness we can thrust body alienate coefficient k

Now we can thrust the innovating Sh reckon:

With Sh reckon we can achieve Re reckon:

This compute of Reynolds reckon resources that we are in the transition regime betwixt laminar glide and archaic glide.

Now we can thrust the glide scold:

  1. Increasing the quantity of scavenger:

Assuming an accepconsideration indolence Scold of 0.09 mm/year

From the equation overhead we can thrust the Running dullness:

From the equation beneath we can thrust the tension of Oxygen that we want to include in the inspire in direct to entertain an accepconsideration indolence scold

Using Sodium sulfate as scavenger the subjoined reaction procure proceed:

Future cem the stoichiometry of the reaction the agreement betwixt the mixtures procure be 2 ramparts of Scavenger and 1 rampart of Oxygen.

For-this-reason the quantity of scavenger Sodium sulfate wanted is:

Future we want:

In an insertion glide scold of 150000 barrels per day

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