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8/16/2019 Kuliah 4 Fluida Komplesi AH
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u au a - -
(2 SKS)
. ,Universitas Trisakti - Jakarta
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Objective/ Objective/SasaranSasaran
Memahami konsep-konsep fluida yang
di unakan untuk Kom lesi sumur dan ker a
ulang sumur Memahami enis- enis fluida en elesaian sumur
Memahami penerapannya di dunia Perminyakan
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Daftar Daftar PustakaPustaka
Allen S.O. and Robert A.P. ”Production Operation”, Vol. I Oil andGas Consultant International Inc.
” “ , ,
2004
Peter E. Clark,”Well Completions : Stimulation and Work Over”.
Pertamina Hulu,” Teknik Produksi”, Jakarta, 2003
H.K. Van Poolen,”Well Completion and Stimulations Program”.
Peter E. Clark ”Well Com letions : Stimulation and Work Over”.
Jonathan Billary,”Well Completions Design”, PetroleumElsevier,2009
Semua buku erihal Kom lesi dan u i Sumur
Semua Jurnal tentang Komplesi dan uji Sumur
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Com letion Fluids
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Completion Fluids: Description & ScopeCompletion Fluids: Description & Scope
Description:
This section of the completions training course coverstopics related to completion fluids and their applications.Important properties of clear completion brines and oil-
ase u s are scusse , as we as ssues re a e oformation damage control and safety and the environment.
Participants will become familiar with the compositions,characteristics and uses of a variety of completion fluid
systems.
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Completion Fluids: ObjectivesCompletion Fluids: Objectives
At the end of this section, you should have areasonable understandin of:
• The composition, properties and uses of completion fluids
completion fluids
• Methods of calculating completion fluid densities undervar ous con t ons
• Special considerations when using completion fluids indeepwater applications
• How to work more effectively with vendors in the selectionand utilization of completion fluids
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Completion Fluids: AgendaCompletion Fluids: Agenda
During the next few hours, we will cover the following:
• Fluid Types and Selection Criteria ..…………………. 35 minutes• Crystallization Point and Other Brine Properties …. 45 minutes
• Wellbore Displacement ………..………………..……... 35 minutes
• Fluid Filtration ……….………………………………….. 40 minutes• Fluid Loss Control …….………………………………… 35 minutes
• Formation Damage & Acidizing ………..…………….. 35 minutes
• Safety and Environmental Concerns ………………... 15 minutes
• Total ……………………………………………………….. 4 hours
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Completion Fluids: PracticesCompletion Fluids: Practices
We will describe preferred practices for:
• Completion fluid selection
• completion fluids
• Methods of filtration and maintenance of fluid quality
• Effective control of completion fluid leak-off
• Formation damage control when completing wells and
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Completion Fluids: Key LearningsCompletion Fluids: Key Learnings
We will describe key learnings and best practices for selecting andusin com letion fluids. Im rovements will be made in our:
• Awareness of the strengths and limitations of variouscompletion fluids
• Knowledge of the important characteristics of completion
fluids under a variety of well conditions• Ability to select completion fluids in a cost-effective manner
• Knowledge of methods to improve the properties of heavy,clear brines
• Knowledge of several practical aspects of handling andmodifying completion fluids
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Completion Fluids: ProblemsCompletion Fluids: Problems
We will work through problems to ensure that you understandthe fundamentals of this technolo area includin :
• Evaluation of factors affecting fluid density
• Calculation of fluid properties required for well control
• Determination of filtration requirements for removing
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Fluid Types and Selection CriteriaFluid Types and Selection Criteria
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Completion Fluids & Their Functions
A completion fluid is any fluid pumped downhole
to conduct post-drilling well operations.
Primary Functions
• Effective control of reservoir pressure while performing well work
• Prevention of permanent formation damage
during completion and workover operations
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The Completion Fluids Family
• –
• Drill-in Fluids – for drilling and completing fluid- sensitive a intervals
• Packer Fluids – for filling annular volume above a
production packer
• Workover Fluids – for remedial operations
• –fluid loss to the formation
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Completion Fluid Types (& Examples)
• Clear BrinesKCl, NaBr, CaCl 2 , CaCl 2 /CaBr 2
ZnBr 2 /CaCl 2 /CaBr 2
• Solids-Laden Fluids
Sized CaCO 3 in NaCl
Organosoluble Resin in KCl
• Brine-in-Oil Emulsions
CaCl 2 Brine in Diesel
• Weighted “All-Oil” Fluids
Hi h Densit Or anics in Diesel
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Important Completion Fluid CharacteristicsImportant Completion Fluid Characteristics
• Easil wei hted or diluted for well control
• Non-damaging to the reservoir and wellbore
• a e a sur ace an own o e con ons
• Easily viscosified for solids transport • Safe to handle and environmentally friendly
• Readil available economical and otentiall
recyclable
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Physical and Chemical Propertiesof Completion & Workover Fluids
• Density
• Viscosity
• Thermal Stability
• Chemical Composition
• Corrosiveness• Additive Compatibility
• Formation Compatibility
• Solids Transport Capability
• Environmental Compatibility
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Uses of Clear Brine Completion Fluids
•
• Perforating
• e ng
• Wellbore Washing • Fishing
• Gravel Packing
• Packer Fluids
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Clear Brine Completion FluidsClear Brine Completion Fluids
Brine Type Common Density Range (ppg) Fluid Cost ($USD/bbl)
NaCl (sodium chloride) 8.4 – 10.0 3.00 – 9.00
KCl (potassium chloride) 8.4 – 9.7 3.00 – 31.00
NH4Cl (ammonium chloride) 8.4 – 8.9 10.00 – 19.00
NaBr (sodium bromide) 10.0 – 12.7 67.00 – 180.00
NaCl/NaBr 10.0 – 12.5 10.00 – 170.00
NaHCO2 (sodium formate) 9.0 – 11.1 35.00 – 165.00
KHCO2 (potassium formate) 10.8 – 13.3 335.00 – 356.00
NaHCO2 / KHCO2 8.4 – 13.1 157.00 – 338.00
CsHCO2 (cesium formate) 13.0 – 19.2 Obtain Quote
CaCl 2 (calcium chloride) 9.0 – 11.8 4.00 – 25.00
CaBr 2 (Calcium bromide) 12.0 – 14.2 30.00 – 191.00
CaCl 2 / CaBr 2 11.7 – 15.1 22.00 – 160.00
ZnBr 2 (zinc bromide) 19.2 – 21.0 538.00 – 671.00
ZnBr 2 / CaBr 2 14.2 – 19.2 30.00 - 538.00
ZnBr 2 / CaBr 2 / CaCl 2 14.2 – 19.2 30.00 – 538.00
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Periodic Table of the Elements
• •
• Alkali metal carbonates and sulfates are soluble
• Alkaline earth metal carbonates are insoluble; calcium sulfate has limited solubility
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Brine Density Ranges
Sodium Formate
Sodium ChloridePotassium Chloride
Potassium Formate
Sodium Bromide
Calcium Chloride
Zinc Bromide
Cesium Formate
Calcium Bromide
8.4 9.4 10.4 11.4 12.4 13.4 14.4 15.4 16.4 17.4 18.4 19.4
Maximum Density (ppg)
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Maximum Solubility of Salt in Water (RT)Maximum Solubility of Salt in Water (RT)
Salt Sol Maximum
Density
Specific
Gravity
lbs/bbl
(ppg)
Sodium Chloride 26 10.0 1.200 109 311
. .
Sodium Bromide 46 12.7 1.525 245 288
Calcium Chloride 40 11.8 1.417 198 298
Calcium Bromide 57 15.3 1.837 366 277
Zinc Bromide 78 21.0 2.521 688 194
Sodium Formate 50 11.1 1.333 231 235
Potassium Formate 78 13.3 1.597 434 125
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Practical Aspects of Common Brines
Brine/Salt Properties & Precautions
•
Potassium
Based
, ,
conditions
• Dissolving dry KCl or KBr in water affords noticeable cooling
(endothermic)
• ,
crystalline salts behind
Calcium and
Zinc Based
• Anhydrous chloride and bromide salts are hygroscopic (will
absorb water from air
• Dissolving bromide and chloride salts in water gives off heat
(exothermic)
• Salts wi ll not crystallize from solution under normal conditions
• Solutions will absorb moisture from the air
• Brines are slippery and cannot be “ wiped” up; spills must beflushed with water
• pH elevation may cause precipitation reactions
• Avoid contact with skin or e es as severe irritation can occur
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Completion Brines and pH
Typical completion brine pH values:
• KCl, NaBr, CaCl 2 (pH = 6 to 8)• ZnBr 2 (19.2 ppg, pH = 1 to 1.5)
• ZnBr 2 /CaBr 2 (17.2 ppg, pH = 3.5)
• Formates (NaHCO 2 , KHCO 2 ), pH >9.5
• pH is a measure of the chemical activity of the H + in solution.
• H = -lo H + or H + = 10 -pH H ran es from 0 to 14
• Due to the ionic strength of high-density completion brines, pHmeasurements provide only an indication of the acidity (orbasicity) of the fluid.
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Brine Availability
• Stock fluids manufactured as clear liquids
- =. .
- 12.5 ppg (SG = 1.50) [45%] NaBr - 14.2 ppg (SG = 1.70) [52%] CaBr 2
- 13.1 ppg (SG = 1.57) [78%] KHCO 2
- 19.2 ppg (SG =2.30) [53%/23%] ZnBr 2 / CaBr 2
• Dr stock salts
- NaCl, NaBr, KCl, NH4Cl, CaCl2, NaHCO2, KHCO2
• Fluids prepared from dry salts
- 3-8% NaCl - 3-8% KCl
- 3-8% NH4Cl
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Important Clear Brine Properties
• Density
• pH
• True crystallization temperature (TCT)• Pressure crystallization temperature (PCT)
• Eutectic point (lowest crystallization temp)
• Brine / formation water compatibility • Brine / crude oil emulsion potential
• Brine / formation mineral compatibility
• Chemical compatibility • Availability
• os s
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Completion Brine Selection GuideCompletion Brine Selection Guide
• Assure Compatibility with Formation Brine
- vo seawa er n orma ons w g a , r or a eve s
- Avoid Ca2+ in formations with high HCO 3- or SO 42- levels- Conduct fluid-fluid compatibility testing in the laboratory
• Assure Compatibility with Formation Minerals
- Protective brines for sandstones typically include- ≥ 1% CaCl2; ≥ 2% KCl; ≥ 3% NH4Cl
- Unocal’s “go-to” fluid remains 6% KCl (8.65 ppg)
- Maintain salinities ≥ that of the formation brine
- High clay formations generally require higher salinities- Review formation mineralogy (XRD, SEM & Thin Section Data)
- Conduct core flow studies for sensitive formations
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Completion Type Log for UIC’s Attaka Field
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Completion Type Log for UIC’s Santan Field
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Completion Type Log for UTL’s Surat Field
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Compatibility Flow ChartCompatibility Flow Chart – – MI SwacoMI Swaco
Spacers v. Mud
Spacers v. Brine
Formation
Crude v. Brine
Formation Water FP/GP Gel v.
FLC Pills v.
Brine
FLC Pills v.Formation
Brine v. Control
Lines
Hydraulic Fluid
Displacem
ent
Perforation FP/GP Remove
Tools
Run
Tubing S acers v. Cement
.
Brine v. Mud & Formation v.
Fluids
FLC Pills v.
.
Inhibitor v.
Brine v. Mud
Mud Filtrate
Brine v.Formation Clays
Pre-Pack Acid
Formation v.FP/GP Gel
Formation
FLC Pills v.Sand Control
Hardware
Tubulars
Brine v.Tubulars
Brine v. ChargeFluids
Brine v.Elastomers
Insulating Fluidv. Tubulars
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Advantages of Formate Brines Advantages of Formate Brines
M +O
O
CH - M + = Na+, K +, Cs+
• Practical alternative to intermediate-density divalent brines
•
• Highest densities among all monovalent brines (up to 13.3 ppg for
potassium formate; 19.2 ppg for cesium formate)• When viscosified with XC polymer, transition temperatures are
retained (i.e., viscosities are maintained at higher temperatures)
•
• Above 8.7 ppg, bacterial growth is inhibited; upon dilution,formates biodegrade
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Completion Brine Additives
• Biocides – to control bacteria, especially sulfate-reducing bacteria
• H Buffers – to maintain o timum H ran e for s ecific fluidsystem
• Sulfide Scavengers – to minimize time effects of sulfide
• Oxygen Scavengers – to retard oxidation
• Corrosion Inhibitors – to protect pipe from chlorides
• Surfactants – to prevent secondary emulsions, improve wellrecovery after workover, minimize fluid retention, etc.
–
the completion fluid
• Polymeric Clay Stabilizers – to further protect against clay
s ur ances
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Oil Based Fluids - Advantages
Oil External Emulsions and “All-Oil” Fluids
• Inhibitive to shales and clays
• Excellent lubricity
•
• Wide range of densities possible
• ompa e w many o -pro uc ng orma ons
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Oil Based Fluids - Limitations
• Disposal. Oil based fluids present significant disposalchallenges; toxic halogenated densifiers in “all-oil” fluidsfurther complicate after-use handling.
• Halogenated Organics. Halogenated densifiers in “all-oil”
high temperatures; halogens can also poison refinerycatalysts.
• ur actants an mu s ons. mu s ers n r ne- n-oemulsions may afford wettability changes and emulsification offormation water; emulsions may block pore throats.
• Low Baseline Density. Oil based fluids require significantamounts of weighting agent to build density from a baselinedensit of 6.5 .
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Packer Fluids
Packer fluids represent a special class ofcompletion fluids designed to provide:
• Weight and pressure on production packers andseals
• Pressure support for the production tubing
• Pressure support for the casing -- to offset formation
forces
• Thermal conduction or insulation for the productiontubing flowing fluids
• n on aga ns corros on an po en a ac c gasseepage from production hardware
• Ease of re-entry and hardware recovery in workoveroperations
Baro
id
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Additional Packer Fluid Issues
• In addition to providing the necessary properties cited previously, packer fluids should be simple to formulate
and economical.
temperature range (e.g., deepwater applications) and fora prolonged period of time.
• Must accommodate a range of additives without showingsigns of incompatibility.
• during a workover operation.
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Packer Fluid Components
Packer Fluid System Typical Additives / Adjustments
-
(Not Recommended)
. .
Sulfide inhibitor
Biocide
Oxygen scavenger
Fresh Water / Salt Water
(including gelled fluids)
Sulfide inhibitor
Biocide
Oxygen scavenger
Oil
(including gelled fluids)
Corrosion inhibitor
Biocide
Oil Based Mud Surfactant stabil izer
(Not Recommended) Biocide
Heavy Brine (CaCl2, CaBr 2, ZnBr 2,
or combinations thereof)
Corrosion inhibitor
Oxygen Scavenger Baro
id
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Other Brine Properties
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Crystallization Point
The Cr stallization Point is the tem erature atwhich crystals begin to fall out of solution, givensufficient time and proper nucleating * conditions.
* Nucleation is the process by which insoluble
crystals can form. Dust, silty particles, andsuspended fines are potential nucleating agents.
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TCT v. PCT
TCT = True Crystallization Temperature
PCT = Pressure Crystallization Temperature
Effects of Crystallization
• Brine densit chan es
• Flow line restrictions can develop
• May cause difficulties in re-establishing desired density
• Physical properties will change (viscosity, etc.)
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Idealized Crystallization Point Curve
FCTA – First-Cr stal-to-A ear u oncooling of completion fluid
TCT – True Crystallization Temperature
LCTD – Last-Crystal-to-Disappearupon re-heating fluid
Cool Heat
r a t u r e
TCT LCTD T e m p
FCTA
Time
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Ocean TemperatureOcean Temperature -- Depth ProfileDepth Profile
(www.windows.ucar.edu)
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Clear Brines – The Eutectic Point
The Eutectic Point is thelowest freezing point of a solution.
• The addition of fresh water to a brine whose density is abovethe Eutectic Point lowers the density and lowers the TCT.
• The addition of fresh water to a brine whose density is belowthe Eutectic Point lowers the density and elevates the TCT.
Eutectic Point
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TCT Curves for Various BrinesTCT Curves for Various Brines
Sodiumchloride
Potassiumchloride
Calcium
Density
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Crystallization Temperature CurveCrystallization Temperature Curve
Pressure Increases
PCT Region
Crystallization
TemperaturePressure DecreasesCrystallization
Hydrate Region
Ice and Brine Salt and Brine
Density
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Effects of Pressure on TCT
• In High Pressure, Low Temperature (HPLT) conditions(e.g., deepwater), higher pressure can elevate TCT.
• Based on SPE 58729 (Freeman, et. al.), PCT (Pressure*
= . ,
* Relationship applies to a variety of calcium chloride,, .
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Clear Brines and Gas Hydrates
What are Gas Hydrates?
• Gas hydrates are solid assemblages of cage
complexes composed of water molecules surroundingsmall hydrocarbon molecules or other light gases.The t icall form when li uid water coexists withnatural gas under high pressures and lowtemperatures (HPLT).
• Gas hydrate formation is a special concern for deep“ ” .may completely block fluid flow.
• Variations in P, T, salinity, free water content and gascomposition present operational challenges forcontrolling and removing gas hydrates.
• Take care to prevent gas hydrate formation in the first place (work with flow assurance specialists and the
http://geology.usgs.g ov/.../
. _ e.htm
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Hydrate Inhibition with CaCl 2 at 40° F
Hydrate Region
9%MEG
Hydrate Free Region
MEG
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Gas Hydrate Curves (CaCl 2 /CaBr 2 )
0.725
10.4 ppg CaCl 2
12.0 ppg CaBr 2
Hydrate Region
Hydrate Free Region
B i D i
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Brine Density
Brine density varies with temperature and pressure:
• As temperature increases, density decreases
• s pressure ncreases, ens y ncreases
Deepwater Gulf of Mexico
Water Depth = 7,100’
Mudline Temp = 38 deg F
MD = 14,000’
SBHP = 6,550 psi
=
Completion Fluid
200 psi Ubal = 9.24 ppg
Th T D it f Cl B i
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The True Density of a Clear Brine
• Temperature Expansion Factor
• Pressure Compression Factor
• Compensated Column Density @ TVD
C id ti f D W t W ll
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Considerations for Deep Water Wells
• Riser Compensated Column Density(inverse function of temperature gradient –surface to mud line)
• Sub-Sea Compensated Column Density
Mud Line
Fluid Cooling Down
Fluid Heating Up
St t C l l t th A Fl id D it
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Steps to Calculate the Average Fluid Density
1. Calculate the average well temperature.
2. Calculate the average temperature increase overthe API standard measurement temperature.
3. Calculate the density loss due to temperature.
4. Calculate the avera e h drostatic ressure.
5. Calculate the density gain due to pressure.
. .
Example Problem:
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Example Problem:
A 12.0 ppg NaBr brine (70 o F) is to be
used as a completion fluid for a wellw per ora ons a , - , . eBHT is 230 o F. What will be the average
wellbore density of the NaBr brine at the perforations?
Solution to Example
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Solution to Example
The following steps are necessary to calculate
1. Calculate the average well temperature (AT).
. a cu a e e average empera ure ncrease overthe API standard measurement temperature (ATI).
. .
4. Calculate the average hydrostatic pressure (AH).
5. Calculate the density gain due to pressure (DG).6. Calculate the average wellbore density (AD).
Solution to Example Step #1
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Solution to Example – Step #1
AT = (BHT + ST)/2
BHT = Bottom Hole Temperature, o F
ST = Surface Tem erature of Fluid, o F
AT = (230 + 70)/2 = 150 ° F
Solution to Example Step #2
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Solution to Example – Step #2
. API standard measurement temperature (ATI):
ATI = AT – 70 F
= ° - ° = °
Solution to Example – Step #3
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Solution to Example – Step #3
3. Calculate the density loss due to temperature (DL):
DL = ATI x Cf
ATI = Average temperature increase over the API standard, ° F
= ° ,
Table 1
Temperature Correction Factors (ppg/o F)
NaCl or KCl 0.0024
CaCl2 0.0027
DL = ATI x Cft
DL = (80 ° F x 0.0033) = 0.264 ppg .
CaBr 2 or CaBr 2 / CaCl2 0.0033
ZnBr 2/ CaBr 2/ CaBr 2 ( . .
Solution to Example – Step #4
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Solution to Example – Step #4
4. Calculate the average hydrostatic pressure (AH):
AH = (SD – DL) x 0.052 x TVD
SD = Surface density at 70 ° F, ppg
DL = Density Loss due to Temperature, ppg
0.052 = Constant = 12 in/ft x 7.48 gal/ft 3 x1 ft 3 /1728 in3, in gal/in2 -ft
TVD = Well depth to mid-perf, ft
AH = (12.0 – 0.264) x 0.052 x 10,000 = 6,102 psi
Solution to Example – Step #5
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Solution to Example – Step #5
5. Calculate the density gain due to Pressure (DG):
= x p
AH = Average hydrostatic pressure, psi
Cf = Pressure correction factor / si
Table 2
Pressure Correction Factors
NaCl or KCl 0.000019
CaCl2 0.000017
DG = AH x Cfp = (6,102 x 0.000021)
= .
CaBr 2 or CaBr 2 / CaCl2 0.000022
ZnBr 2/ CaBr 2/ CaBr 2 (
. .
Solution to Example – Step #6
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Solution to Example Step #6
6. Calculate the average wellbore density (AD):
AD = SD – DL + DG
AD = (12.0 – 0.264 + 0.128) = 11.864 ppg
So, the NaBr brine with a surface density (SD) of 12.0would have an avera e wellbore densit of 11.864
ppg at 10,000 ft (BHT = 230 o F)
JENIS FLUIDA C/WO JENIS FLUIDA C/WO
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--
SolidsSolids--Laden FluidsLaden Fluids
•• Dri ing F ui sDri ing F ui s•• Lease Water or SeawaterLease Water or Seawater
SolidsSolids--Free Brine SystemsFree Brine Systems
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==maupun tinggi)maupun tinggi)
Hi h densit brines meru akan fluida C WO anHi h densit brines meru akan fluida C WO an paling aman (tidak mengakibatkan banyakpaling aman (tidak mengakibatkan banyakkerusakan formasi)kerusakan formasi)
SolidsSolids--Free Brine SystemsFree Brine Systems
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--
Terdapat dua jenis brines: monovalent dan divalentTerdapat dua jenis brines: monovalent dan divalent
-- Monovalent : NaCl, KCl, NaBrMonovalent : NaCl, KCl, NaBr
-- Divalent : CaClDivalent : CaCl22, CaBr, CaBr22
SolidsSolids--Free Brine SystemsFree Brine Systems
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Walaupun ZnClWalaupun ZnCl22 dan ZnBrdan ZnBr22 keduanya secara tekniskeduanya secara teknis--
salt brine akan tetapi tidak praktis dan tidaksalt brine akan tetapi tidak praktis dan tidakekonomisekonomis
ZnClZnCl22 dikenal sangat korosif sedangkan ZnBrdikenal sangat korosif sedangkan ZnBr22 sulitsulitditangani karena sangat hygroscopic.ditangani karena sangat hygroscopic.
SolidsSolids--Free Brine SystemsFree Brine Systems
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NaCl dan KCl brines biasanya dibuat denganme arut an r sta garam er ng engan a r arena
densitas maximum yang dapat dicapai relatif rendah;bila dijual dalam bentuk larutan biaya angkutanmenja i ma a arena a anya tam a an erat air.
NaBr biasanya dibuat dari garam kering atau tersedia
dari su lier dalam bentuk larutan ekat den an densitas sesuai dengan kebutuhan.
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Jika diperlukan, concentrated NaBr diencerkan dilokasi dengan manambah air untuk menurunkan
densitas. Pengenceran pada umumnya dilakukan
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CaCl2 dan CaBr2 brines tersedia dalam bentuklarutan. Pembuatan brines di lapangan dari garam
- bubuk CaCl2 dan CaBr2 merupakan,
- pelarutan bersifat eksotermik dan
atas titik didih air sehingga
dianggap hazardous operation
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Garam kering CaCl2 dan CaBr2 biasanya digunakan
hanya untuk mengatur harga densitas (density.
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Multiple salt brines:
Dibuat dari aram monovalent aram divalent atau campuran dari keduanya
Formulasi yang umum digunakan adalah CaCl2 /CaBr2,CaBr2 /ZnBr2, dan CaCl2 /CaBr2 /ZnBr2
Multiple salt brines dari garam mono-valent secara
,karena tidak ekonomis
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Keuntungan multiple salt brines: dapatormu as an un u memenu persyara an ens y
dan temperatur kristalisasi.
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Pengujian kualitas brines
relatif atau sering disebut nephelometric turbidity.nephelometric turbidity.
Diukur dengan nephelometernephelometer (alat yang mengukurntens tas ca aya yang e o an o o e a anyapadatan dalam suatu larutan). Makin besar intensitasyang dibelokkan berarti fluida makin keruh.
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Pengujian kualitas brines (lanjutan)
voltage dalam suatu photocell dan diberi satuan yangdisebut nephelometric turbidity unit (NTU).
Spesifikasi kejernihan single-salt brines berkisar antara3 – 10 NTU
Nephelometry juga digunakan untuk menentukanefektifitas wellbore clean up dan filtrasi fluida
Formate Formate Brines Brines
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Mulai diperkenalkan di awal 90-an dalam upayamencari high-density brines yang environmentallyfriendly.
Jenis dan SG maximumnya:
NaCOOH (SG 1,33), KCOOH (SG 1,60) dan CeCOOH(SG 2,37).
- maupun low-solids C/WO fluid.
Formate Formate Brines Brines
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Kelebihan formate brines:
Non-hazardous dan biodegradable
Dapat melindungi viscosifyer dan polymer dari degradasi
termal hingga 150oC.
Korosivitas lebih rendah dibandingkan alkali metal halides(klorida dan bromida).
ion sulfat maupun carbonate (mengurangi kemungkinanpresipitasi).
Formate Formate Brines Brines
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Kelebihan formate dari segi teknis dan HSE sangatterasa pada aplikasi sumur dalam yang memerlukandensitas tinggi. Saat ini untuk kasus yang demikian
digunakan C/WO fluid yang mengandung ZnBr2. Namun
korosif dan toxic. Untuk mengatasi hal ini dapatdigunakan caesium formate (SG 2,3) yang non-
2
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SifatSifat--sifat brinessifat brines
DensitasDensitas
Viskositas Viskositas
Densitas Densitas Brines Brines
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Densitas Standard Brines
CaBr2/ZnBr2
ZnBr2
NaBr
CaBr2
a a r
NaCl
CaCl2
KBr
KCl
8 10 12 14 16 18 20 22 24
Density, ppg
DENSITAS SINGLE DENSITAS SINGLE--SALT BRINES SALT BRINES
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Densitas, ppg Densitas, ppg
• Larutan KCl 8.4 - 9.7
• Larutan NaCl 8.4 - 9.8
• Larutan KBr 8.4 - 11.5
2 . - .• Larutan NaBr 8.4 - 12.4
• Larutan CaBr 2 14.2 - 15.5 • Larutan ZnBr 15.0 - 21.5
DENSITAS MULTIPLE DENSITAS MULTIPLE--SALT BRINES SALT BRINES
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Densitas Densitas, , ppg ppg
• KCl/KBr 9.8 - 11.5
• NaCl/CaCl 2 10.1 - 11.1
• NaCl/NaBr 10.1 - 12.5
• CaCl 2 /CaBr
2 11.7 - 15.1
• CaCl 2 /ZnBr 2 /CaBr 2 15.1 - 19.2
• NaBr/ZnBr 12.5 - 20.5
• CaBr 2 /ZnBr2/NaBr 12.5 - 22.5
Efek Efek TT dan dan PP Pada Pada Densitas Densitas
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n s i t a s
60F
1 F14,7 psi
100F10.000
psi
D
V o l u m
14,7
psi
60F
10.000 psi
Perhitungan Perhitungan Densitas Densitas
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⎤⎡ n
⎦⎣
−−
=i
m
1))()(())()(( Dg A Dg B T pi ∆−∆=∆ ρ
= average wellbore density,ppg
m =surface fluid density, ppg
i =incremental density change n = number of intervals
Perhitungan Perhitungan Densitas Densitas
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))()(())()(( Dg A Dg B T pi ∆−∆=∆ ρ
A = thermal expansion coefficient, ppg/oFB = pressure compressibility coeff., ppg/psi∆D =(Di-1- Di) =length of interval, ft
= - =, - ,gT =(Tbh-Tsurf )/D=temperature gradient, oF/ftD=total vertical depth (TVD), ft
A dan B di eroleh dari tabel
ExpansibilityExpansibility dan dan Compressibility Compressibility
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A BBrine ppg
NaCl 9.42 0.24 0.019. . .
NaBr 12.48 0.33 0.021
. . .ZnBr2/CaBr2/CaCl2 16.01 0.36 0.022
. . .
A: from 76 to 198 F at 12000 psi
Perhitungan Perhitungan Densitas Densitas
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Aproksimasi dilakukan berdasarkan hargam po n , m sa nya pa a . apa
digunakan densitas rata-rata yang dihitunger asar an an pa a . .
Men in at efek P tidak be itu besar makaseringkali koreksi dilakukan hanya untuk efek tem eratur.
Perhitungan Perhitungan Densitas Densitas
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• Dasar perhitungan: P hidrostatik
• Operasi dilakukan dengan overbalance:>
terhadap T dan P).
reservoir minyak dan 300 psi untuk
.
Perhitungan Perhitungan Densitas Densitas
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Tentukan P hidrostatik berikut overbalance-nya,misaln a P si ada kedalaman D ft.
Tentukan density, ppg = P/(0.052 D)
Tentukan temperatur rata-rata sumur:= dasar sumur+ permukaan
Koreksi densitas brines berdasarkan temperatur rata-rata
tersebut Konversikan densitas tersebut ke kondisi 60oF (brines
biasanya dijual berdasarkan standar temperatur = 60oF)
Contoh Contoh
S b i t h
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•Sebagai contoh,kalau perlu 10ppg engan s s m
CaCl2 pada 130o
F,
dan ikut garismiring untuk
men apa andensitas pada60oF dida at 10.2
Gb.4.Densitas vs.T ppg.
Untuk Sistim CaCl 2
Gb. 5. Densitas vs. T untuk Sistim CaBr Gb. 5. Densitas vs. T untuk Sistim CaBr 2 2
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Gb.6. Densitas vs. T sistim CaCl Gb.6. Densitas vs. T sistim CaCl 2 2 /CaBr /CaBr 2 2
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Gb. 7. Densitas vs. T Sistim CaCl Gb. 7. Densitas vs. T Sistim CaCl 2 2 /Zn/CaBr /Zn/CaBr 2 2
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Pembuatan Pembuatan C/WO BrinesC/WO Brines di di Lapangan Lapangan
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Dilakukan dengan cara:
Mencampurkan serbuk garam dengan air
MencampurkanMencampurkan larutanlarutan garamgaram dengandengan airair
MencampurkanMencampurkan serbuk serbuk garamgaram dengandengan larutanlarutan garamgaramlainlain
MencampurkanMencampurkan suatusuatu larutanlarutan garamgaram dengandengan larutanlarutangaramgaram lainlain
Pembuatan Pembuatan Lar Lar.. NaBr NaBr dari dari Serbuk Serbuk NaBr NaBr + Air + Air
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Pembuatan Pembuatan Lar Lar. CaCl2/CaBr2. CaCl2/CaBr2 dari dari Serbuk Serbuk CaCl2CaCl2 dan dan CaBr2 + Air CaBr2 + Air
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Pembuatan Pembuatan Lar Lar.. NaBr NaBr dari dari NaBr NaBr 12,512,5 ppg ppg + Air + Air
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Pembuatan Pembuatan Lar Lar. ZnBr2/CaBr2. ZnBr2/CaBr2 dari dari Lar Lar. ZnBr2 19,2. ZnBr2 19,2 ppg ppg dan dan Lar Lar. CaBr2 14,2. CaBr2 14,2 ppg ppg
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Pembuatan Pembuatan Lar Lar. CaCl2/CaBr2/ZnBr2. CaCl2/CaBr2/ZnBr2 dari dari Serbuk Serbuk CaCl2CaCl2 dengan dengan Lar Lar..CaBr2 14,2CaBr2 14,2 ppg ppg dan dan Lar Lar. ZnBr2/CaBr2 19,2. ZnBr2/CaBr2 19,2 ppg ppg
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19.2 ppg ZnBr2/CaBr2
14.2 ppg CaBr2
97% CaCl2 krist
QUESTIONS ? QUESTIONS ?
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1. Sebutkan jenis –jenis fluida komplesi
2. Apa keuntungan dan kerugian fluida komplesi