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Barium Sulphate Deposits
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Energy (2019) 000–000 879–891 EnergyProcedia Procedia157 00 (2017) www.elsevier.com/locate/procedia Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, 19–21 September 2018, Athens, Greece Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, 19–21 September 2018, Athens, Greece
Barium Sulphate Deposits The 15th International Symposium District Heating and Barium Sulphate Deposits Arbaoui Mohamed Ali a*,on Hacini Messaoud b Cooling
a Ouargla. BP 511 Ouargla 30000, b Algéria production Department,Mohamed Kasdi Merbah University, Arbaoui *, Hacini Assessing the feasibility ofAliusing the Messaoud heat demand-outdoor geology Department, Kasdi Merbah University, Ouargla. BP 511 Ouargla 30000, Algéria production Department,for Kasdi a Merbah University, Ouargla. BP 511 Ouargla 30000, Algéria temperature function long-term district heat demand forecast geology Department, Kasdi Merbah University, Ouargla. BP 511 Ouargla 30000, Algéria a
b
a
b
Abstract
I. Andrića,b,c*, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc
The exploitation of field naturally, leads to decrease the productivity of wells, to continue this exploitation with the best Abstract a IN+ Center for Innovation, Technology and of Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal conditions, it is essential to pass to the stage secondary recovery. b Veolia Recherche & decrease Innovation, 291productivity Avenue 78520 Limay, France exploitation of field naturally, leads to the of Daniel, wells, to continue this there exploitation with the best The injection of water in reservoir is the most used method in theDreyfous recovery of oil; unfortunately, is an incompatibility c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France conditions, is essential to pass to the stage ofwater, secondary between theitinjection water and the reservoir whichrecovery. poses a lot of problems such as training mineral deposits. may alkaline be brought contact with of theoil; wash water which there contains sulfate ions. The reservoir injection waters of water incontain reservoir is theions mostand used method into in the recovery unfortunately, is an incompatibility between the injection water and the reservoir water, which lot ofwells problems such asistraining mineral deposits. The injected water eventually reaches the producing wells poses and inathese the mixture made and the precipitation of barium The reservoir waters contain alkaline then ions stick and be with in thea wash water contains sulfate (BaSO4) takesmay place. The crystals inbrought the wallsinto of contact the tubings, process thatwhich may be similarsulfate to thations. of sodium Abstract chloride, but water this time the problem is more serious because it is in a very deposit insoluble thethe water also in acids. The injected eventually reaches the producing wells and thesecompact wells the mixture is madeinand precipitation of barium sulfate (BaSO4) takes place. The crystals then stick in the walls of the tubings, in a process that may be similar to that of sodium Deposits which formed during production and shipping represent a real calamity against which oil producers have been fighting District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the chloride, but this time the problem is more serious because it is a very compact deposit insoluble in the water also in acids. for several decades, deposits causing irreversible damage particularly dangerous for bottom production facilities such as greenhouse gas emissions from the building sector. These systems require high investments which are returned through surface the heat and sometimes rock itself. Deposits which formed during production and shipping represent a real calamity against oil producers havecould been decrease, fighting sales. Due to for thethe changed climate conditions and building renovation policies, heatwhich demand in the future for several decades, deposits causing irreversible damage particularly dangerous for bottom production facilities such as surface prolonging the investment return period. and sometimes for the rock itself. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand ©forecast. 2018 TheThe Authors. Published by Elsevier Ltd. districtPublished of Alvalade, locatedLtd. in Lisbon (Portugal), was used as a case study. The district is consisted of 665 © 2019 The Authors. by Elsevier This is an open access article under the CC period BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) buildings that vary in both construction and typology. Three weather scenarios (low, medium, high) and three district This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee Technologies andobtained Materials for demand Renewable Energy, renovation wereunder developed (shallow, deep). To of estimate the error, values were Selection andscenarios peer-review responsibility of intermediate, the scientific committee of Technologies and Materialsheat for Renewable Energy, This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Environment and Sustainability, TMREES18. Environment andresults Sustainability, TMREES18. compared with from a dynamic heat demand model, previously developed and validated by the authors. Selection andshowed peer-review underonly responsibility of the is scientific committee of Technologies andbeMaterials forfor Renewable Energy, The results that when weather change considered, the margin of error could acceptable some applications Keywords: water; reservoir; injectionTMREES18. ; barium sulfate; deposits;damage Environment and Sustainability, (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation
scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
Keywords: water; reservoir; injection ; barium sulfate; deposits;damage
* Corresponding author. Tel.: +213660512027; fax: +0-000-000-0000 .
© E-mail 2017 The Authors. Published by Elsevier Ltd. address: [email protected] Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: +213660512027; fax: +0-000-000-0000 . Cooling. E-mail address: [email protected] 1876-6102 © 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Keywords: Heat demand;under Forecast; Climate change Selection peer-review of the scientific 1876-6102and © 2018 The Authors. responsibility Published by Elsevier Ltd. committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. 10.1016/j.egypro.2018.11.254
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Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
1. Introduction The natural exploitation of oil deposits, called natural spontaneous recovery (primary) mainly due to the initial pressure of the deposit, with the lowering of the pressure of the deposit during production, comes the intervention of producers to assist the recovery of hydrocarbons, with the use of several methods to follow, the injection of water, gas lift Even with recovery assistance but it is still mediocre, and the life of a deposit is poor over time, this time depends on recovery rate. The aim of this paper is to study the method of recovery by water injection in the hydrocarbon fields of the Algerian Sahara, and the undesirable effects of this method, especially the barium sulphate deposits that they are created by the incompatibility between the reservoir water and the injection water. Deposits formed during production and shipping represent a real calamity against which oil producers have been struggling for several decades, causing irreversible damage that is particularly dangerous for bottom production facilities such as surface and sometimes for the rock itself. 2. Water in oil fields 2.1. Injection water Injection water used in secondary oil recovery, the injection of water is one of the means of maintaining the tank pressure as well as for the washing of salt wells. The injection may be either of the type distributed in the oil zone or of the peripheral type in an existing aquifer [1] 2.1.1. washing salted wells Some formation waters may contain 350 g / l of sodium chloride and thus be so close to supersaturation that a very small temperature variation or a low water evaporation due to the fall causing a significant precipitation of NaCl on the walls of the tubing until capping and reduction of the section of the tubing which leads to the fall of production. In order to put the wells back into production, we intervene on NaC1 by simply sending a quantity of fresh water. Irrespective of its use, water injection poses serious problems of incompatibility with reservoir water. In fact, the reservoir waters may contain ions of barium, calcium, and strontium, and be brought into contact with the washing water which contains sulphate ions. This results in the formation of deposits in the facilities. [1] 2.1.2. Pressure maintaining water It is used as a means of production when the absolute static pressure at the wellhead decreases rapidly during the exploitation of a deposit and the recovery of oil in place will only reach a very small percentage of the estimated reserves. 2.2. The reservoir water The reservoir water accompanies the crude oil in the producing deposit, this reservoir or formation water can come either from the aquifer which is at the base of the oilfields, or from the store rock itself. This water is generally very rich in salts until saturation; the predominant salt is sodium chloride, but it is always accompanied by varying amounts of calcium salt, potassium, magnesium, carbonates, bicarbonates, chlorides, etc. Indeed, the reservoir water sometimes contains a considerable amount of barium strontium and calcium. [1] Table 1. Average analyzes of Albian water and Cambrian water [3] ALBIN
CAMBRIAN
(mg/l)
(mg/l)
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000 (HCO3)-
170
0
CO32-
0
0
Cl-
420
210 000
(SO4)2-
600
0
Ca2+
210
36 000
Mg2+
70
6 500
Ba2+
0
800
Sr2+
0
970.00
Na+
250
80 000
K+
40
6 000
Fer total
0
5 500
pH
7.0
3.5
Density at 25°C
1.00
1.230
Profounder (m)
1050-1350
3300-3400
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3. Definition, Composition and Structure of Barium Sulfate (BaSO4) 3.1. Definition of barium sulphate (BaSO4) This is the most troublesome salt deposit because the solubility limits are very low and the deposits are hard and compact. In general, the problems of barium sulphate deposits arise from the incompatibility of two waters. The reservoir waters may contain barium (Ba + 2) ions and may come into contact with waters containing sulphate ions (SO4-2). The solubility of barium sulphate (for example) is one hundred percent. less than that of calcium sulphate. However, the solubility of BaSO4 increases with the ionic strength of the water. An excess of sulfate ions tends to coagulate the precipitate while an excess of barium ions tends to disperse it. The level of saturation is an important element that regulates the rate of crystallization for barium sulphate. The higher the level of supersaturation, the faster the precipitation. [11]
Fig.1. Barium sulphate (BaSO4). [3]
3.2. Conditions of formation of deposits An ion exchange in the rock can, among other things, be the cause of the state of saturation of the water. Whatever the case may be, the pressure drop between the deposit and the bottom of the well produces evaporation. partial of this water, which oversaturates and precipitates crystals. Some have proposed an explanation based on electrical charges. The water droplets containing the seed crystals must carry a positive electric charge, and have a larger dielectric constant than that of the crude in which they swim. The rock is negatively charged due to the presence of clays; likewise, the flow currents in the pipes carry it to a negative potential. Hence attraction and fixation on the asperities. Crystals that have their own polarity are electrically and mechanically retained. Their growth is, subsequently, easy to conceive. [11]
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Fig.2. Barium sulphate (BaSO4). [3]
Precipitation of barium sulphate is however not limited to oil reservoirs. Deposits can occur on wells, tubings, surface facilities, or in refinery equipment used for crude oil processing. 3.3. The chemical reaction BaCl2 + SO4-2
(1)
BaSO4 + 2Cl-
4. Comparison between the three deposits By way of comparison, the solubility of BaSO4 in fresh water is 2 mg / l, that is to say 10 times lower than that of CaCO3, 100 times lower than that of SrSO4 and a thousand times less than CaSO4, but its solubility increases with the ionic strength of water and can be found in a reservoir water up to 50 mg / l of dissolved sulphates. [11] On the other hand, the size of the crystals increases as the super saturation of the solution is small. The table below gives a comparison of the solubility of barium sulphate and Calcium sulphate, so this table shows that the first one that is formed is BaSO4 Table 2. Solubility and solubility product of three sulfate deposits. Element
BaSO4
SrSO4
CaSO4
Solubility product Ksp
1 ,1.10-10
2,8.10-7
6,1.10-5
Solubility ‘S’ (mol/l)
1,05.10-5
5,3.10-4
7 ,8.10-
Table 3. Solubility products of some frequent HMD deposits Name of the deposit
Ionic product
Solubility products at 25°C
FeS
[Fe2+]. [S-] 2
3.2 .10-18
BaSO4.
[Ba2+]. [SO24-]
1, 1.10- 10
CaSO4 .2H2O.
[Ca2+]]. [O24-]
6,1.10-5
SrSO4
[Sr2+]. [SO24-]
2,8.10-7
Ba CO3
[Ba2+]. [CO23-]
8,10-9
CaCO3
[Ca2+]. [CO23-]
4,8.10-9
Mg CO3
[Mg2+]. [CO23-]
1,0.10-5
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5. Deposition and treatment of barium sulphates 5.1. The origin of barium sulphates As a result of the interaction of the water contained in the HMD reservoir (Cambrian- deposit water which is loaded with Ba2+ barium), and the injected water (injection water-Albian- which is loaded with sulfate element SO42), it forms the deposition of barium sulfate and gives adverse results on the equipment used during desalting: clogging of wells and corrosion of facilities. These two phenomena have a great influence on the oil extraction process and consequently a decrease in oil production. [9] 6. Characteristics of barium sulphates 6.1. Physico-chemical properties of barium sulphate Barium sulphate has its chemical formula BaSO4. These are colorless or white orthorhombic crystals with a relative molecular weight of 233.4, a relative density of 4.5 (15 ℃), a melting point of 1580 ℃ and a refractive index of 1.637. It is almost insoluble in water with a solubility of 0.00022 to 18 ℃ and 0.0041 to 100 ℃. It is slightly soluble in concentrated sulfuric acid and soluble in an alkali metal carbonate solution in which it is converted into barium is insoluble in other types of acids or bases. In nature, it exists in the mineral form of barite. [9]
Fig.3. white powder of barium sulphate
6.2. Crystal structure of barium sulphate The crystals of BaSO4 as those of SrSO4 are, on the one hand, orthorhombic with very similar mesh, on the other hand, they are porous in nature with a tendency to absorb foreign ions that can co-precipitate. On the other hand, CaSO4 is orthorhombic, monoclinic with very different meshs from those of BaSO4 and SrSO4. Barium sulfate crystallizes in the orthorhombic system (Pmma group). Its mesh parameters vary according to the authors. Miyake (Miyake et al., 1978) obtains: a = 8.88 Å ; b = 5,46 Å ;
c = 7,16 Å
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Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
Fig.4. Crystal structure of barium sulphate
6.3. Solubility of BaSO4 Solubility is the ability of a substance, called a solute, to dissolve in another substance, called a solvent, to form a homogeneous mixture called a solution. In thermodynamics, solubility is a physical quantity denoted S denoting the maximum mass concentration of the solute in the solvent, at a given temperature. The solution thus obtained is then saturated. The solubility is expressed in g / L or in mol / L.BaSO4 is indeed the sulphate salt which has the lowest solubility. At 25 ° C, Rosseinsky 1958 measured by conductimetry a solubility equal to 1.04 ˟ 10-5 mol / l or 2.5 mg / l. The solubility product of BaSO 4 at 25 ° C. is 1.10 × 10 -10. The solubility of BaSO4 in concentrated sulfuric acid (density 1.853) is 15.89 g in 100 g of saturated solution at 25 ° C. The solubility drops rapidly when the sulfuric acid solution is diluted (0.05 g per 100 g of dilute solution containing 83% concentrated acid). The solubility was measured by Kohlrausch, here the results expressed in mg of salt per 100 cm3 of water. Table 4. Solubility of barium sulfate as a function of temperature. T (°C)
0,77
3,33
18
26,75
34
BaSO4 (mg)
0,171
0,207
0,230
0,266
0,291
We have verified that these values do not vary much from one author to another, in particular we can cite the data of Cowan and Weintritt (1976). Table 5.Solubility of barium sulphate as a function of temperature. T (°C)
0°
10°
18°
30°
50°
BaSO4 (mg/100ml)
0.115
0.20
0.226
0.285
0.336
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7. Deposit Analysis 7.1. The chosen deposit
Fig.5. deposit recovered at the ZCINA separator inlet. [7]
7.2. Acid attack 1. Wash, Dry and grind the sample, 2. Take 1g of the sample in 60 ml of aqua regia (40 ml of HCl + 20 ml of HNO3) completely evaporate the solution 3. Add 20 ml of HCl and evaporate to dryness, then 10 ml of distilled water to let it boil for 1 minute, repeat the previous operation by adding 20 ml of boiling water for 10 minutes and finally 100 ml of distilled water and a boiling of 15 minutes, then filter. [5] 7.3. Alkaline attack 1. The insoluble residue is calcined in a muffle furnace at 800 ° C in a platinum crucible. 2. Weigh the contents of the crucible 3. Add 5 to 6 g of sodium carbonate. Melt muffle at 900 ° C for 30 '. 4. Boil about 200 cc of distilled water in a beaker. 5. Insert the crucible into the beaker and let it boil until it comes off. 6. After filtration (the filtrate contains silica and sodium sulfate and filters the barium carbonate), dissolve the contents of the filter with conc. HCl, a 250 ml beaker. Spread with distilled water and boil the next reaction 8. After boiling, add 10 N H 2 SO 4. A white precipitate forms, indicating the presence of barium sulphate. Let stand overnight then filter, wash, dry, and calcine in the oven at 800 ° C. [7]
BaCO3 + H2SO4
BaSO4 + H2O + CO2
Let P 2 be the weight of the precipitate obtained:
(2)
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% BaSO4 = P2 x 100 % SiSO2 = (P1 - P2) x 100 P crucible + 1g of deposit before calcination = 39.134g P crucible + 1g of deposit after calcination = 38.3383g P1 = 39.134 - 38.3383 = 0.8g So there is 80% (BaSo4 + silicas) P2 = 0.69g so % BaSO4 = 0.69 x 100 = 69% % SiSO2 = (0.8 - 0.69) x 100 = 11% 7.4. NaCl content 1. Weigh 1g of the sample (dried and crushed) 2. Dissolve in a volume of water with heating 3. Filter the solution and make up to 100 ml of distilled water 4. Collect 5ml and assay with AgNO3 (0.1 N or 0.01 N) in the presence of K2CrO4 indicator Let v be the volume to spend AgNO3. % Nacl = 58.45.N.V.10 / 5 % Nacl = 58.45 x 0.1 x 0.85 x 10/5 % Nacl = 9.9365%
Fig.6. AgNO3 dosing solution [7]
7.5. Calcium Dosage 1. Take a test portion of the sample 2. Add 5ml of 1N NaOH (ph = 13) + murexide, the solution becomes pink 3. Titrate with EDTA 0.1M until the turn purple, V1 volume poured.
� 𝐶𝐶𝐶𝐶�� � � ��.��. �. ����. �� . 𝐷𝐷𝐷𝐷𝐷�
40.08 g: Molar mass of calcium M: Molarity of EDTA V1: the volume of EDTA elapsed Pe: Test sample D: dilution factor [Ca ++] = is expressed in mg / l
(3)
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[Ca++] = 40, 08 x 0, 01 x 1000 x 1, 4/ (20 x 4) =7,014mg/l Y=23.8245mg X= 2,38245mg, so [CaSo4] =2, 38245%
Fig.7. EDTA dosing solution [7]
7.6. Magnesium dosage 1. Take a test portion of the sample 2. Add 5ml ammonia buffer (ph = 10) + black euriochrome T, the solution becomes red-wine 3. Titrate with EDTA 0.1M until blue turn, V2 the volume poured. [7]
� 𝑀𝑀𝑀𝑀�� � � ����� 𝑀𝑀� ����� ��� � �� �� ����
24.3: molar mass of magnesium M: Molarity of EDTA V: EDTA volume elapsed Pe: test portion (20ml) D: Dilution factor = 1/4 [Mg ++] is expressed in mg / l [Mg ++] = 24.3 x 0.01 x 1000 x 3 x 1 / (20 x 4) = 9.41625mg / l Y = 9.41625 x 120 / 24.3 = 46.5mg X = 4.65mg so [MgSo4] = 4.65% 7.7. total iron dosage Before dosing the iron, make sure of its presence 1. Add 2 drops of HCl conc to the sample 2. Spread with distilled water and add 2 to 3 drops of potassium ferrocyanide 3. K4Fe (CN) 6, the blue colour indicates the presence of iron. 4. Take 25ml of the filtrate in a 250ml beaker
(4)
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Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
5. Oxide the middle with hot HNO3 6. Allow to cool, raise the pH with NaOH and then add the diluted acetic acid and sodium acetate to bring the pH between 3 and 3.5
Fig.8. PH meter. [7]
7. Then add 5 ml of indicator (Sulfosalicylic acid) 8. Titrate with 0.1M or 0.01M EDTA depending on iron concentration up to purple to yellowish turn.
� Fer� � �� �� ����������� ����
(5)
55.85 g: Molar mass of iron V: the volume of EDTA Pe: Test sample D: Dilution factor [Iron] is expressed in mg / l [Iron] = 0.01.4.5. 55.85.1000 / (4.50) [Iron] = 12.56 mg / l Y = 12, 56.116 / 55.85 = 26.1mg X = 2.61mg therefore [FeCO3] = 2.61% 8. Treatment of barium sulphate deposition 8.1. The subtractive process By elimination of the deposit-forming ions; example removal of the sulfate ions S4-2 contained in the injection water, precipitating them with BaCl 2 according to the following reaction: 𝑆𝑆𝑆𝑆42− + 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵2 →𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵4 + 2𝐶𝐶𝐶𝐶−
(6)
8.2. Inhibitor AD32 Inhibitor AD32 is a deposition inhibitor used for the treatment of water circuits in order to avoid the precipitation of calcium, strontium, barium, iron and other cations in combination with sulphates, carbonates and oxides. The AD32 inhibitor is particularly recommended for crude oil lines and for water injection circuits to control the trimming of tubing, pumps, pipes, etc. [10]
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
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Fig.9. the deposit inhibitor AD32
8.3. AD32 Inhibitor Instructions for Use Injected directly into the system to be inhibited, pure or diluted in water, preferably by continuous injection using a metering pump. [10] Table 6.The physical-chemical properties of AD32 inhibitor. Nature
Phosphonate
appearance
Liquid
Solidification temperature
‐5 °C
PH
6 – 8
Active matter
25%
Flash point
100°C (NF T 60‐103)
Density
1230‐1280 Kg/m3
Viscosity
10 m Pa/s
9. Case of Well ONIZ432 9.1. Gauging test The main purpose of the test is to measure the production flow, the pressure at the top, the pipe and the separator. All the same, this test allowed us to obtain other parameters such as the GOR, the oil temperature. The results of ONIZ432 well gauging tests are shown in Table 7 Table 7. Results of ONIZ432 well gauging tests. Date of measurement
18/09/2016
D Duse
Q oil
GOR
(mm)
(m3/h)
(sm3/sm3)
15
3.05
1162
pressure (Kg/cm2)
T ° oil
Head
Pipe
Sép
26.49
17.73
17.19
(°c) 22
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890 12 22/12/2016
15.08
0.25
41221
24.1
21.1
_
_
21/02/2017
15.08
2.13
1360
33.4
17.6
_
_
11/04/2017
15.08
0.95
2288
25.75
15.92
16.38
21
07/07/2017
15.08
0.15
5218
32
18
5.3
34
18/07/2017
15.08
1.39
530.27
381
26.1
13.6
34
31/07/2017
15.08
0.16
9953
17.4
12.13
14.29
36
26/08/2017
15.08
0.63
2024
23.3
9.19
_
27
03/09/2017
15.08
0.83
1187
18.2
10.1
_
33
There was a potential drop in the ONIZ432 well from 31/07/2017. Using laboratory analysis results, BaSO4, Silica, salts (NaCl) and CaSO4 were confirmed in the tubing and around the well. It is suspected because of the incompatibility of the injected water (contains sulfate) and the formation water (contains barium) creates a deposit of BaSO4. Table 8. Analysis results of a well sample ONIZ432. WELL
Location sampling (cote)
Date of Sampling
Results 3,7%Sels (NaCl) ,8 %
ONIZ432
3099 m
16/03/2017
CaSO4 47% BaSO4 41,2 % silice, Rest of treatment products
From the results of the Gauging test, it can be concluded that: ➢ the disruption of the production flow during the period (18/09/2016 until 18/07/2017). ➢ the decrease in flow from 1.39 m3 / h to 0.16 m3 / h corresponds to a fall of 1.23m3 / h during (18/07/2017 to 31/07/2017) because of the precipitation of sulphate deposition from barium. ➢ the variation of the GOR values is directly proportional to the values of the production flow. Before connecting the well to the ONI skid (before treatment with the AD32 inhibitor): Table 9. Results of gauging tests before the operation Date of measurement 31/07/2017
D Duse
Q oil
GOR
pressure (Kg/cm2)
T ° oil
(mm)
(m3/h)
(sm3/sm3)
head
Pipe
Sep
(°c)
15.08
0.16
9953
17.4
12.13
14.29
36
After connecting the well to the ONI skid (after treatment with the inhibitor AD32): Table 10. Results of gauging tests before the operation
D Duse
Q Oil
GOR
Pressure (Kg/cm2)
T oil
Date of measurement
(mm)
(m3/h)
(sm3/sm3)
Tête
Pipe
Sep
(°c)
26/08/2017
15.08
0.63
2024
23.3
9.19
_
27
03/09/2017
15.08
0.83
1187
18.2
10.1
_
33
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
891 13
9.2. Results interpretation The increase in production flow from 26/08 / 2017and and stabilization at a good flow rate for a month, this increase is justified by the elimination of the damage caused by barium sulfate, so our well is stimulated. 9.3. Treatment Efficiency The determination of the treatment efficiency is done by the following relation: ܧൌ ሺ ୟ୲ୣ୰ െ ୠୣ୭୰ୣ ሻȀ ୠୣ୭୰ୣ
(7)
E: treatment efficiency. Q after: flow after treatment. Q before: flow before treatment. The calculation of the treatment efficiency is: E = (0.63 - 0.16) /0.16 = 3.9375 Therefor the treatment efficiency is: E = 393.75% References
[1] LAMBARKI A., L'impact des dépôts sur la production, mémoire de fin de formation IAP. [2] KIEFFER R., Contribution contacteurs à membrane pour la précipitation du sulfate de baryum; simulation numérique ET résultats expérimentaux, thèse de doctorat, Université Claude Bernard- Lyon, 2006. [3] KACI Y., ScaleBlaster and Tube Clean Reformat treatment through 2"7/8 CCE OMM32 (zone 1A- Complexe), stimulation program, September 2016, EP HASSI MESSAOUD. [4] ALIA K., CHENGUEL R., Optimisation des paramètres d'inhibition des sels insolubles au niveau des installations industriels ET des puits pétroliers de la région Ourhoud, mémoire master, université d'El Oued, 2014 [5] HARCHECHE Sara «Suivi de la séparation de brut émulsionné au niveau de la region TFT», Rapport de fin de formation, SONATRACH TFT, 2017. [6] R. VILLATTE, « Étude des mécanismes de libération d’actifs Nano disperses Application au traitement de puits », thèse de doctorat, Université Bordeaux I école doctorale des sciences chimiques, [7] laboratoire de salinité base IRARA. [8] Jones.F, Jones, P, Ogden M.I, Richmond W.R, Rohl, A.L, Saunders M.The interaction of EDTA With barium sulphate. Journal of colloid and interface science 316, 553-561. [9] Yu T , Yang X, Yuan J. Guo L, Wu X, and Wang H., Preparation and Performance Evaluation of a Highly Effective Barium Sulfate Descaling System Based on Ammonium Carboxy Chelating Agent DTPA, Russian Journal of Applied Chemistry, Vol. 89, No. 7, pp. 1145−1157. [10] Mavredaki E, Neville A, Sorbie KSm Initial stages of barium sulfate formation at surfaces in the presence of inhibitors, Cryst Growth. [11] Jones F, Stanley A, Oliveira A, Rohl A.L, Reyhani M.M, Parkinson G.M. And Ogden M.I., The role of phosphonate speciation on the inhibition of barium sulfate precipitation, J. Cryst. Growth, 249 (2003) 584-593.
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Energy (2019) 000–000 879–891 EnergyProcedia Procedia157 00 (2017) www.elsevier.com/locate/procedia Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, 19–21 September 2018, Athens, Greece Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, 19–21 September 2018, Athens, Greece
Barium Sulphate Deposits The 15th International Symposium District Heating and Barium Sulphate Deposits Arbaoui Mohamed Ali a*,on Hacini Messaoud b Cooling
a Ouargla. BP 511 Ouargla 30000, b Algéria production Department,Mohamed Kasdi Merbah University, Arbaoui *, Hacini Assessing the feasibility ofAliusing the Messaoud heat demand-outdoor geology Department, Kasdi Merbah University, Ouargla. BP 511 Ouargla 30000, Algéria production Department,for Kasdi a Merbah University, Ouargla. BP 511 Ouargla 30000, Algéria temperature function long-term district heat demand forecast geology Department, Kasdi Merbah University, Ouargla. BP 511 Ouargla 30000, Algéria a
b
a
b
Abstract
I. Andrića,b,c*, A. Pinaa, P. Ferrãoa, J. Fournierb., B. Lacarrièrec, O. Le Correc
The exploitation of field naturally, leads to decrease the productivity of wells, to continue this exploitation with the best Abstract a IN+ Center for Innovation, Technology and of Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal conditions, it is essential to pass to the stage secondary recovery. b Veolia Recherche & decrease Innovation, 291productivity Avenue 78520 Limay, France exploitation of field naturally, leads to the of Daniel, wells, to continue this there exploitation with the best The injection of water in reservoir is the most used method in theDreyfous recovery of oil; unfortunately, is an incompatibility c Département Systèmes Énergétiques et Environnement - IMT Atlantique, 4 rue Alfred Kastler, 44300 Nantes, France conditions, is essential to pass to the stage ofwater, secondary between theitinjection water and the reservoir whichrecovery. poses a lot of problems such as training mineral deposits. may alkaline be brought contact with of theoil; wash water which there contains sulfate ions. The reservoir injection waters of water incontain reservoir is theions mostand used method into in the recovery unfortunately, is an incompatibility between the injection water and the reservoir water, which lot ofwells problems such asistraining mineral deposits. The injected water eventually reaches the producing wells poses and inathese the mixture made and the precipitation of barium The reservoir waters contain alkaline then ions stick and be with in thea wash water contains sulfate (BaSO4) takesmay place. The crystals inbrought the wallsinto of contact the tubings, process thatwhich may be similarsulfate to thations. of sodium Abstract chloride, but water this time the problem is more serious because it is in a very deposit insoluble thethe water also in acids. The injected eventually reaches the producing wells and thesecompact wells the mixture is madeinand precipitation of barium sulfate (BaSO4) takes place. The crystals then stick in the walls of the tubings, in a process that may be similar to that of sodium Deposits which formed during production and shipping represent a real calamity against which oil producers have been fighting District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the chloride, but this time the problem is more serious because it is a very compact deposit insoluble in the water also in acids. for several decades, deposits causing irreversible damage particularly dangerous for bottom production facilities such as greenhouse gas emissions from the building sector. These systems require high investments which are returned through surface the heat and sometimes rock itself. Deposits which formed during production and shipping represent a real calamity against oil producers havecould been decrease, fighting sales. Due to for thethe changed climate conditions and building renovation policies, heatwhich demand in the future for several decades, deposits causing irreversible damage particularly dangerous for bottom production facilities such as surface prolonging the investment return period. and sometimes for the rock itself. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand ©forecast. 2018 TheThe Authors. Published by Elsevier Ltd. districtPublished of Alvalade, locatedLtd. in Lisbon (Portugal), was used as a case study. The district is consisted of 665 © 2019 The Authors. by Elsevier This is an open access article under the CC period BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) buildings that vary in both construction and typology. Three weather scenarios (low, medium, high) and three district This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) © 2018 The Authors. Published by Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee Technologies andobtained Materials for demand Renewable Energy, renovation wereunder developed (shallow, deep). To of estimate the error, values were Selection andscenarios peer-review responsibility of intermediate, the scientific committee of Technologies and Materialsheat for Renewable Energy, This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Environment and Sustainability, TMREES18. Environment andresults Sustainability, TMREES18. compared with from a dynamic heat demand model, previously developed and validated by the authors. Selection andshowed peer-review underonly responsibility of the is scientific committee of Technologies andbeMaterials forfor Renewable Energy, The results that when weather change considered, the margin of error could acceptable some applications Keywords: water; reservoir; injectionTMREES18. ; barium sulfate; deposits;damage Environment and Sustainability, (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation
scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
Keywords: water; reservoir; injection ; barium sulfate; deposits;damage
* Corresponding author. Tel.: +213660512027; fax: +0-000-000-0000 .
© E-mail 2017 The Authors. Published by Elsevier Ltd. address: [email protected] Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and * Corresponding author. Tel.: +213660512027; fax: +0-000-000-0000 . Cooling. E-mail address: [email protected] 1876-6102 © 2018 The Authors. Published by Elsevier Ltd.
This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Keywords: Heat demand;under Forecast; Climate change Selection peer-review of the scientific 1876-6102and © 2018 The Authors. responsibility Published by Elsevier Ltd. committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. 1876-6102 © 2017 The Authors. Published by Elsevier Ltd. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. 10.1016/j.egypro.2018.11.254
880 2
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
1. Introduction The natural exploitation of oil deposits, called natural spontaneous recovery (primary) mainly due to the initial pressure of the deposit, with the lowering of the pressure of the deposit during production, comes the intervention of producers to assist the recovery of hydrocarbons, with the use of several methods to follow, the injection of water, gas lift Even with recovery assistance but it is still mediocre, and the life of a deposit is poor over time, this time depends on recovery rate. The aim of this paper is to study the method of recovery by water injection in the hydrocarbon fields of the Algerian Sahara, and the undesirable effects of this method, especially the barium sulphate deposits that they are created by the incompatibility between the reservoir water and the injection water. Deposits formed during production and shipping represent a real calamity against which oil producers have been struggling for several decades, causing irreversible damage that is particularly dangerous for bottom production facilities such as surface and sometimes for the rock itself. 2. Water in oil fields 2.1. Injection water Injection water used in secondary oil recovery, the injection of water is one of the means of maintaining the tank pressure as well as for the washing of salt wells. The injection may be either of the type distributed in the oil zone or of the peripheral type in an existing aquifer [1] 2.1.1. washing salted wells Some formation waters may contain 350 g / l of sodium chloride and thus be so close to supersaturation that a very small temperature variation or a low water evaporation due to the fall causing a significant precipitation of NaCl on the walls of the tubing until capping and reduction of the section of the tubing which leads to the fall of production. In order to put the wells back into production, we intervene on NaC1 by simply sending a quantity of fresh water. Irrespective of its use, water injection poses serious problems of incompatibility with reservoir water. In fact, the reservoir waters may contain ions of barium, calcium, and strontium, and be brought into contact with the washing water which contains sulphate ions. This results in the formation of deposits in the facilities. [1] 2.1.2. Pressure maintaining water It is used as a means of production when the absolute static pressure at the wellhead decreases rapidly during the exploitation of a deposit and the recovery of oil in place will only reach a very small percentage of the estimated reserves. 2.2. The reservoir water The reservoir water accompanies the crude oil in the producing deposit, this reservoir or formation water can come either from the aquifer which is at the base of the oilfields, or from the store rock itself. This water is generally very rich in salts until saturation; the predominant salt is sodium chloride, but it is always accompanied by varying amounts of calcium salt, potassium, magnesium, carbonates, bicarbonates, chlorides, etc. Indeed, the reservoir water sometimes contains a considerable amount of barium strontium and calcium. [1] Table 1. Average analyzes of Albian water and Cambrian water [3] ALBIN
CAMBRIAN
(mg/l)
(mg/l)
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000 (HCO3)-
170
0
CO32-
0
0
Cl-
420
210 000
(SO4)2-
600
0
Ca2+
210
36 000
Mg2+
70
6 500
Ba2+
0
800
Sr2+
0
970.00
Na+
250
80 000
K+
40
6 000
Fer total
0
5 500
pH
7.0
3.5
Density at 25°C
1.00
1.230
Profounder (m)
1050-1350
3300-3400
881 3
3. Definition, Composition and Structure of Barium Sulfate (BaSO4) 3.1. Definition of barium sulphate (BaSO4) This is the most troublesome salt deposit because the solubility limits are very low and the deposits are hard and compact. In general, the problems of barium sulphate deposits arise from the incompatibility of two waters. The reservoir waters may contain barium (Ba + 2) ions and may come into contact with waters containing sulphate ions (SO4-2). The solubility of barium sulphate (for example) is one hundred percent. less than that of calcium sulphate. However, the solubility of BaSO4 increases with the ionic strength of the water. An excess of sulfate ions tends to coagulate the precipitate while an excess of barium ions tends to disperse it. The level of saturation is an important element that regulates the rate of crystallization for barium sulphate. The higher the level of supersaturation, the faster the precipitation. [11]
Fig.1. Barium sulphate (BaSO4). [3]
3.2. Conditions of formation of deposits An ion exchange in the rock can, among other things, be the cause of the state of saturation of the water. Whatever the case may be, the pressure drop between the deposit and the bottom of the well produces evaporation. partial of this water, which oversaturates and precipitates crystals. Some have proposed an explanation based on electrical charges. The water droplets containing the seed crystals must carry a positive electric charge, and have a larger dielectric constant than that of the crude in which they swim. The rock is negatively charged due to the presence of clays; likewise, the flow currents in the pipes carry it to a negative potential. Hence attraction and fixation on the asperities. Crystals that have their own polarity are electrically and mechanically retained. Their growth is, subsequently, easy to conceive. [11]
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882 4
Fig.2. Barium sulphate (BaSO4). [3]
Precipitation of barium sulphate is however not limited to oil reservoirs. Deposits can occur on wells, tubings, surface facilities, or in refinery equipment used for crude oil processing. 3.3. The chemical reaction BaCl2 + SO4-2
(1)
BaSO4 + 2Cl-
4. Comparison between the three deposits By way of comparison, the solubility of BaSO4 in fresh water is 2 mg / l, that is to say 10 times lower than that of CaCO3, 100 times lower than that of SrSO4 and a thousand times less than CaSO4, but its solubility increases with the ionic strength of water and can be found in a reservoir water up to 50 mg / l of dissolved sulphates. [11] On the other hand, the size of the crystals increases as the super saturation of the solution is small. The table below gives a comparison of the solubility of barium sulphate and Calcium sulphate, so this table shows that the first one that is formed is BaSO4 Table 2. Solubility and solubility product of three sulfate deposits. Element
BaSO4
SrSO4
CaSO4
Solubility product Ksp
1 ,1.10-10
2,8.10-7
6,1.10-5
Solubility ‘S’ (mol/l)
1,05.10-5
5,3.10-4
7 ,8.10-
Table 3. Solubility products of some frequent HMD deposits Name of the deposit
Ionic product
Solubility products at 25°C
FeS
[Fe2+]. [S-] 2
3.2 .10-18
BaSO4.
[Ba2+]. [SO24-]
1, 1.10- 10
CaSO4 .2H2O.
[Ca2+]]. [O24-]
6,1.10-5
SrSO4
[Sr2+]. [SO24-]
2,8.10-7
Ba CO3
[Ba2+]. [CO23-]
8,10-9
CaCO3
[Ca2+]. [CO23-]
4,8.10-9
Mg CO3
[Mg2+]. [CO23-]
1,0.10-5
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5. Deposition and treatment of barium sulphates 5.1. The origin of barium sulphates As a result of the interaction of the water contained in the HMD reservoir (Cambrian- deposit water which is loaded with Ba2+ barium), and the injected water (injection water-Albian- which is loaded with sulfate element SO42), it forms the deposition of barium sulfate and gives adverse results on the equipment used during desalting: clogging of wells and corrosion of facilities. These two phenomena have a great influence on the oil extraction process and consequently a decrease in oil production. [9] 6. Characteristics of barium sulphates 6.1. Physico-chemical properties of barium sulphate Barium sulphate has its chemical formula BaSO4. These are colorless or white orthorhombic crystals with a relative molecular weight of 233.4, a relative density of 4.5 (15 ℃), a melting point of 1580 ℃ and a refractive index of 1.637. It is almost insoluble in water with a solubility of 0.00022 to 18 ℃ and 0.0041 to 100 ℃. It is slightly soluble in concentrated sulfuric acid and soluble in an alkali metal carbonate solution in which it is converted into barium is insoluble in other types of acids or bases. In nature, it exists in the mineral form of barite. [9]
Fig.3. white powder of barium sulphate
6.2. Crystal structure of barium sulphate The crystals of BaSO4 as those of SrSO4 are, on the one hand, orthorhombic with very similar mesh, on the other hand, they are porous in nature with a tendency to absorb foreign ions that can co-precipitate. On the other hand, CaSO4 is orthorhombic, monoclinic with very different meshs from those of BaSO4 and SrSO4. Barium sulfate crystallizes in the orthorhombic system (Pmma group). Its mesh parameters vary according to the authors. Miyake (Miyake et al., 1978) obtains: a = 8.88 Å ; b = 5,46 Å ;
c = 7,16 Å
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Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
Fig.4. Crystal structure of barium sulphate
6.3. Solubility of BaSO4 Solubility is the ability of a substance, called a solute, to dissolve in another substance, called a solvent, to form a homogeneous mixture called a solution. In thermodynamics, solubility is a physical quantity denoted S denoting the maximum mass concentration of the solute in the solvent, at a given temperature. The solution thus obtained is then saturated. The solubility is expressed in g / L or in mol / L.BaSO4 is indeed the sulphate salt which has the lowest solubility. At 25 ° C, Rosseinsky 1958 measured by conductimetry a solubility equal to 1.04 ˟ 10-5 mol / l or 2.5 mg / l. The solubility product of BaSO 4 at 25 ° C. is 1.10 × 10 -10. The solubility of BaSO4 in concentrated sulfuric acid (density 1.853) is 15.89 g in 100 g of saturated solution at 25 ° C. The solubility drops rapidly when the sulfuric acid solution is diluted (0.05 g per 100 g of dilute solution containing 83% concentrated acid). The solubility was measured by Kohlrausch, here the results expressed in mg of salt per 100 cm3 of water. Table 4. Solubility of barium sulfate as a function of temperature. T (°C)
0,77
3,33
18
26,75
34
BaSO4 (mg)
0,171
0,207
0,230
0,266
0,291
We have verified that these values do not vary much from one author to another, in particular we can cite the data of Cowan and Weintritt (1976). Table 5.Solubility of barium sulphate as a function of temperature. T (°C)
0°
10°
18°
30°
50°
BaSO4 (mg/100ml)
0.115
0.20
0.226
0.285
0.336
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885 7
7. Deposit Analysis 7.1. The chosen deposit
Fig.5. deposit recovered at the ZCINA separator inlet. [7]
7.2. Acid attack 1. Wash, Dry and grind the sample, 2. Take 1g of the sample in 60 ml of aqua regia (40 ml of HCl + 20 ml of HNO3) completely evaporate the solution 3. Add 20 ml of HCl and evaporate to dryness, then 10 ml of distilled water to let it boil for 1 minute, repeat the previous operation by adding 20 ml of boiling water for 10 minutes and finally 100 ml of distilled water and a boiling of 15 minutes, then filter. [5] 7.3. Alkaline attack 1. The insoluble residue is calcined in a muffle furnace at 800 ° C in a platinum crucible. 2. Weigh the contents of the crucible 3. Add 5 to 6 g of sodium carbonate. Melt muffle at 900 ° C for 30 '. 4. Boil about 200 cc of distilled water in a beaker. 5. Insert the crucible into the beaker and let it boil until it comes off. 6. After filtration (the filtrate contains silica and sodium sulfate and filters the barium carbonate), dissolve the contents of the filter with conc. HCl, a 250 ml beaker. Spread with distilled water and boil the next reaction 8. After boiling, add 10 N H 2 SO 4. A white precipitate forms, indicating the presence of barium sulphate. Let stand overnight then filter, wash, dry, and calcine in the oven at 800 ° C. [7]
BaCO3 + H2SO4
BaSO4 + H2O + CO2
Let P 2 be the weight of the precipitate obtained:
(2)
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Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
% BaSO4 = P2 x 100 % SiSO2 = (P1 - P2) x 100 P crucible + 1g of deposit before calcination = 39.134g P crucible + 1g of deposit after calcination = 38.3383g P1 = 39.134 - 38.3383 = 0.8g So there is 80% (BaSo4 + silicas) P2 = 0.69g so % BaSO4 = 0.69 x 100 = 69% % SiSO2 = (0.8 - 0.69) x 100 = 11% 7.4. NaCl content 1. Weigh 1g of the sample (dried and crushed) 2. Dissolve in a volume of water with heating 3. Filter the solution and make up to 100 ml of distilled water 4. Collect 5ml and assay with AgNO3 (0.1 N or 0.01 N) in the presence of K2CrO4 indicator Let v be the volume to spend AgNO3. % Nacl = 58.45.N.V.10 / 5 % Nacl = 58.45 x 0.1 x 0.85 x 10/5 % Nacl = 9.9365%
Fig.6. AgNO3 dosing solution [7]
7.5. Calcium Dosage 1. Take a test portion of the sample 2. Add 5ml of 1N NaOH (ph = 13) + murexide, the solution becomes pink 3. Titrate with EDTA 0.1M until the turn purple, V1 volume poured.
� 𝐶𝐶𝐶𝐶�� � � ��.��. �. ����. �� . 𝐷𝐷𝐷𝐷𝐷�
40.08 g: Molar mass of calcium M: Molarity of EDTA V1: the volume of EDTA elapsed Pe: Test sample D: dilution factor [Ca ++] = is expressed in mg / l
(3)
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
887 9
[Ca++] = 40, 08 x 0, 01 x 1000 x 1, 4/ (20 x 4) =7,014mg/l Y=23.8245mg X= 2,38245mg, so [CaSo4] =2, 38245%
Fig.7. EDTA dosing solution [7]
7.6. Magnesium dosage 1. Take a test portion of the sample 2. Add 5ml ammonia buffer (ph = 10) + black euriochrome T, the solution becomes red-wine 3. Titrate with EDTA 0.1M until blue turn, V2 the volume poured. [7]
� 𝑀𝑀𝑀𝑀�� � � ����� 𝑀𝑀� ����� ��� � �� �� ����
24.3: molar mass of magnesium M: Molarity of EDTA V: EDTA volume elapsed Pe: test portion (20ml) D: Dilution factor = 1/4 [Mg ++] is expressed in mg / l [Mg ++] = 24.3 x 0.01 x 1000 x 3 x 1 / (20 x 4) = 9.41625mg / l Y = 9.41625 x 120 / 24.3 = 46.5mg X = 4.65mg so [MgSo4] = 4.65% 7.7. total iron dosage Before dosing the iron, make sure of its presence 1. Add 2 drops of HCl conc to the sample 2. Spread with distilled water and add 2 to 3 drops of potassium ferrocyanide 3. K4Fe (CN) 6, the blue colour indicates the presence of iron. 4. Take 25ml of the filtrate in a 250ml beaker
(4)
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Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
5. Oxide the middle with hot HNO3 6. Allow to cool, raise the pH with NaOH and then add the diluted acetic acid and sodium acetate to bring the pH between 3 and 3.5
Fig.8. PH meter. [7]
7. Then add 5 ml of indicator (Sulfosalicylic acid) 8. Titrate with 0.1M or 0.01M EDTA depending on iron concentration up to purple to yellowish turn.
� Fer� � �� �� ����������� ����
(5)
55.85 g: Molar mass of iron V: the volume of EDTA Pe: Test sample D: Dilution factor [Iron] is expressed in mg / l [Iron] = 0.01.4.5. 55.85.1000 / (4.50) [Iron] = 12.56 mg / l Y = 12, 56.116 / 55.85 = 26.1mg X = 2.61mg therefore [FeCO3] = 2.61% 8. Treatment of barium sulphate deposition 8.1. The subtractive process By elimination of the deposit-forming ions; example removal of the sulfate ions S4-2 contained in the injection water, precipitating them with BaCl 2 according to the following reaction: 𝑆𝑆𝑆𝑆42− + 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵2 →𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵4 + 2𝐶𝐶𝐶𝐶−
(6)
8.2. Inhibitor AD32 Inhibitor AD32 is a deposition inhibitor used for the treatment of water circuits in order to avoid the precipitation of calcium, strontium, barium, iron and other cations in combination with sulphates, carbonates and oxides. The AD32 inhibitor is particularly recommended for crude oil lines and for water injection circuits to control the trimming of tubing, pumps, pipes, etc. [10]
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
889 11
Fig.9. the deposit inhibitor AD32
8.3. AD32 Inhibitor Instructions for Use Injected directly into the system to be inhibited, pure or diluted in water, preferably by continuous injection using a metering pump. [10] Table 6.The physical-chemical properties of AD32 inhibitor. Nature
Phosphonate
appearance
Liquid
Solidification temperature
‐5 °C
PH
6 – 8
Active matter
25%
Flash point
100°C (NF T 60‐103)
Density
1230‐1280 Kg/m3
Viscosity
10 m Pa/s
9. Case of Well ONIZ432 9.1. Gauging test The main purpose of the test is to measure the production flow, the pressure at the top, the pipe and the separator. All the same, this test allowed us to obtain other parameters such as the GOR, the oil temperature. The results of ONIZ432 well gauging tests are shown in Table 7 Table 7. Results of ONIZ432 well gauging tests. Date of measurement
18/09/2016
D Duse
Q oil
GOR
(mm)
(m3/h)
(sm3/sm3)
15
3.05
1162
pressure (Kg/cm2)
T ° oil
Head
Pipe
Sép
26.49
17.73
17.19
(°c) 22
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890 12 22/12/2016
15.08
0.25
41221
24.1
21.1
_
_
21/02/2017
15.08
2.13
1360
33.4
17.6
_
_
11/04/2017
15.08
0.95
2288
25.75
15.92
16.38
21
07/07/2017
15.08
0.15
5218
32
18
5.3
34
18/07/2017
15.08
1.39
530.27
381
26.1
13.6
34
31/07/2017
15.08
0.16
9953
17.4
12.13
14.29
36
26/08/2017
15.08
0.63
2024
23.3
9.19
_
27
03/09/2017
15.08
0.83
1187
18.2
10.1
_
33
There was a potential drop in the ONIZ432 well from 31/07/2017. Using laboratory analysis results, BaSO4, Silica, salts (NaCl) and CaSO4 were confirmed in the tubing and around the well. It is suspected because of the incompatibility of the injected water (contains sulfate) and the formation water (contains barium) creates a deposit of BaSO4. Table 8. Analysis results of a well sample ONIZ432. WELL
Location sampling (cote)
Date of Sampling
Results 3,7%Sels (NaCl) ,8 %
ONIZ432
3099 m
16/03/2017
CaSO4 47% BaSO4 41,2 % silice, Rest of treatment products
From the results of the Gauging test, it can be concluded that: ➢ the disruption of the production flow during the period (18/09/2016 until 18/07/2017). ➢ the decrease in flow from 1.39 m3 / h to 0.16 m3 / h corresponds to a fall of 1.23m3 / h during (18/07/2017 to 31/07/2017) because of the precipitation of sulphate deposition from barium. ➢ the variation of the GOR values is directly proportional to the values of the production flow. Before connecting the well to the ONI skid (before treatment with the AD32 inhibitor): Table 9. Results of gauging tests before the operation Date of measurement 31/07/2017
D Duse
Q oil
GOR
pressure (Kg/cm2)
T ° oil
(mm)
(m3/h)
(sm3/sm3)
head
Pipe
Sep
(°c)
15.08
0.16
9953
17.4
12.13
14.29
36
After connecting the well to the ONI skid (after treatment with the inhibitor AD32): Table 10. Results of gauging tests before the operation
D Duse
Q Oil
GOR
Pressure (Kg/cm2)
T oil
Date of measurement
(mm)
(m3/h)
(sm3/sm3)
Tête
Pipe
Sep
(°c)
26/08/2017
15.08
0.63
2024
23.3
9.19
_
27
03/09/2017
15.08
0.83
1187
18.2
10.1
_
33
Arbaoui Mohamed Ali et al. / Energy Procedia 157 (2019) 879–891 ARBAOUI mohamed ali / Energy Procedia 00 (2018) 000–000
891 13
9.2. Results interpretation The increase in production flow from 26/08 / 2017and and stabilization at a good flow rate for a month, this increase is justified by the elimination of the damage caused by barium sulfate, so our well is stimulated. 9.3. Treatment Efficiency The determination of the treatment efficiency is done by the following relation: ܧൌ ሺ ୟ୲ୣ୰ െ ୠୣ୭୰ୣ ሻȀ ୠୣ୭୰ୣ
(7)
E: treatment efficiency. Q after: flow after treatment. Q before: flow before treatment. The calculation of the treatment efficiency is: E = (0.63 - 0.16) /0.16 = 3.9375 Therefor the treatment efficiency is: E = 393.75% References
[1] LAMBARKI A., L'impact des dépôts sur la production, mémoire de fin de formation IAP. [2] KIEFFER R., Contribution contacteurs à membrane pour la précipitation du sulfate de baryum; simulation numérique ET résultats expérimentaux, thèse de doctorat, Université Claude Bernard- Lyon, 2006. [3] KACI Y., ScaleBlaster and Tube Clean Reformat treatment through 2"7/8 CCE OMM32 (zone 1A- Complexe), stimulation program, September 2016, EP HASSI MESSAOUD. [4] ALIA K., CHENGUEL R., Optimisation des paramètres d'inhibition des sels insolubles au niveau des installations industriels ET des puits pétroliers de la région Ourhoud, mémoire master, université d'El Oued, 2014 [5] HARCHECHE Sara «Suivi de la séparation de brut émulsionné au niveau de la region TFT», Rapport de fin de formation, SONATRACH TFT, 2017. [6] R. VILLATTE, « Étude des mécanismes de libération d’actifs Nano disperses Application au traitement de puits », thèse de doctorat, Université Bordeaux I école doctorale des sciences chimiques, [7] laboratoire de salinité base IRARA. [8] Jones.F, Jones, P, Ogden M.I, Richmond W.R, Rohl, A.L, Saunders M.The interaction of EDTA With barium sulphate. Journal of colloid and interface science 316, 553-561. [9] Yu T , Yang X, Yuan J. Guo L, Wu X, and Wang H., Preparation and Performance Evaluation of a Highly Effective Barium Sulfate Descaling System Based on Ammonium Carboxy Chelating Agent DTPA, Russian Journal of Applied Chemistry, Vol. 89, No. 7, pp. 1145−1157. [10] Mavredaki E, Neville A, Sorbie KSm Initial stages of barium sulfate formation at surfaces in the presence of inhibitors, Cryst Growth. [11] Jones F, Stanley A, Oliveira A, Rohl A.L, Reyhani M.M, Parkinson G.M. And Ogden M.I., The role of phosphonate speciation on the inhibition of barium sulfate precipitation, J. Cryst. Growth, 249 (2003) 584-593.