Compatibility Study of Treated Effluent from KNPC- MAB Refinery - PowerPoint PPT Presentation

Compatibility Study of Treated Effluent from KNPC- MAB Refinery with Brackish Water, PIC Water and GC’s Formation Water Imad Al-Maheimid, Ahmad Kh. Al-Jasmi Research & Technology Group - KOC Surface Team www.kockw.com

Introduction  Kuwait oil company extracts brackish groundwater from the Abdaliyah water field which is the single source of brackish water supplying West, SEK Oil Fields and Ahmadi residence areas . m Demand of Source Water (based on last year data) (Unit : BWPD) Summer Winter Normal ge source Water required at STF/NTF = 135,000 85,000 105,000 ge source Water required at WK GCs = 35,000 25,000 30,000 ge source Water required at Camel Point + Irrigation = 25,000 10,000 15,000 al Demand of Source Water at KOC 195,000 120,000 150,000 www.kockw.com www.kockw.com

Introduction  KOC is proposing to increase oil production, accordingly, the use of ground water will increase, overexploitation of ground water will lower the water table in Abdaliyah Brackish field this will allow the intrusion of the saline water and it my lead to brackish water deterioration.  To avoid this phenomenon and to secure KOC low salinity water future demand, suitability of KNPC, PIC effluent treated from MAB & MAA Refineries have been explored to be utilized in KOC for industrial applications. www.kockw.com

Introduction  KNPC effluent treated water may will mixed with Abdaliyah brackish water, this water mixture will be utilized for desalting wet crude at each of 14 Gathering Centers, GC's desalters which located downstream of separator. A scaling / precipitation may occur when the formation waters from each GC which containing high levels of calcium, magnesium, strontium and barium are mixed with wash water with high level of sulphate ion. www.kockw.com

Introduction  In order to establish the suitability of treated effluent from both sources (KNPC + PIC) for KOC daily operational activities, a comprehensive compatibility study of the mentioned treated effluent with KOC brackish water and formation water from each GC was executed. Also full analysis of KNPC treated effluent water were conducted to explore the suitability of this water for irrigation purposes, bacteria analysis were carried out in order to design the most suitable bacteria inhibitor (biocide) with its optimal dosing rate to control bacteria growth within the water distribution system. www.kockw.com

Objectives  To analyze and characterize the mixing waters  To perform computer scale compatibility study to predict type and masses of scale that could be generated at recommended temperature and pressure conditions  To predict scaling tendency and mass of individual waters at defined temperature and pressure conditions  To check compatibility of these waters using Laboratory Jar Tests www.kockw.com

Deliverables  Executive summary  Introduction and background  Sampling and analysis techniques  Results of the static and computer scale prediction  Interpretation and discussion  Conclusions and recommendations www.kockw.com

BACKGROUND www.kockw.com

Common Oilfield Scales Name Chemical formula Calcium carbonate (calcite) CaCO 3 Calcium Sulphate Gypsum CaSO 4 .2H 2 O Hemi – Hydrate CaSO 4 .1/2 H 2 O Anhydrite CaSO 4 Barium Sulphate BaSO 4 Strontium Sulphate SrSO 4 Iron Compounds Ferrous Carbonate FeCO 3 Ferrous Sulfide FeS Ferrous Hydroxide Fe(OH) 2 Ferric Hydroxide Fe(OH) 3 Ferrous Carbonate Fe 2 CO 3 www.kockw.com

COMPATIBILITY STUDY EXPERIMENTS www.kockw.com

Schematic Diagram – Mixing of Water GC -A GC -A ABDALLIYAH GC -B GC -B GC -C GC -C GC -D GC -D Brackish Water GC -E GC -E GC - F GC - F GC -G GC -G GC -H GC -H GC -I GC -I KNPC-MAB TREATED SOUTH GC -J GC -J EFFLUENT TANK FARM WATER GC - K GC - K GC -L GC -L GC -M GC -M GC- GATHERING CENTER GC -N GC -N KNPC - Kuwait National Petroleum PIC TREATED Company EFFLUENT PIC - Petrochemical Industries Company WATER www.kockw.com

Mixing Water in De-salter  At desalter we’ll have  Wash Water  Formation Water  Crude in contact with the formation Water  Gas phase in equilibrium H2S and CO2 www.kockw.com

Mixing Scenarios www.kockw.com

METHODOLOGY www.kockw.com

Methodology Computer Scale Predictability  Balancing the ionic composition of water analysis  Predicting the self scaling potential of individual water  Compatibility of two waters at various temp and pressure  Study the worst case mixing scenario www.kockw.com

Methodology Static Jar Test  Mixing water samples at various ratios  Incubation at 65 °C for 72 hours  Mixture – cool down to room temperature  Filtration through 0.45 micron membrane filter  Weighing filtrate in mg per liter  SEM / EDS analysis of the membrane www.kockw.com

Methodology Full Ionic Composition of Water  Anions -1 SO 4 -2 ,Cl -1 ,S -2 ) -2 , HCO 3 (CO 3  Cations (Ca +2 ,Mg +2 ,Sr +2 ,Ba +2 ,Na +1 ,K +1 , Fe +2 , Fe +3 )  Dissolved gases (O 2 and H 2 S)  Specific Gravity  Total Dissolved Solids www.kockw.com

Analytical Parameters Physical Parameters of PIC, KNPC and Brackish water . Parameters Unit Brackish KNPC PIC Conductivity mS/cm 4.64 2.00 0.02 pH 7.63 7.83 5.97 Density gm/cm 3 1.0000 0.9980 0.9970 www.kockw.com

Analytical Parameters Compositional Analysis of PIC, KNPC and Brackish water. Elements Unit Brackish KNPC PIC Sodium mg/l 534 551 5 Calcium mg/l 387 30 2 Magnesium mg/l 146 19 0.38 Potassium mg/l 41 32 1.41 Strontium mg/l 14 6 2 0.02 0.17 0.19 Barium mg/l Iron mg/l 0.11 0.05 0.06 Lithium mg/l 0.06 0.01 0.002 Silicon mg/l 8.92 0.75 0.08 Boron mg/l 1.20 0.04 0.24 Aluminum mg/l 0.10 0.00 0.00 Chloride mg/l 872 664 8 Bicarbonate mg/l 140.79 214 6 1288 177 1.3 Sulfate mg/l Phosphate mg/l 0.05 1.18 0.01 Ammonia Nitrogen mg/l 0.01 3.1 0.8 Nitrite mg/l 0.02 0.7 0.08 Nitrate mg/l 1.1 4.3 0.02 3.43 1.69 0.03 Total Dissolved Solid gm/l www.kockw.com

Analytical Parameters ELEMENTS Unit GC- A GC -B GC -C GC -D Sodium mg/l 51293 56670 45875 43094 Calcium mg/l 10726 11892 9416 9372 Magnesium mg/l 2462 2684 2238 2147 Potassium mg/l 3261 2780 2654 2504 Strontium mg/l 295 327 228 283 3.46 3.12 2.04 2.50 Barium mg/l 16.46 Iron mg/l 5.67 0.68 1.40 Lithium mg/l 4.17 4.25 3.97 4.60 Silicon mg/l 7.20 4.44 3.65 3.30 Boron mg/l 32.85 44.10 29.32 38.40 Aluminum mg/l 0.04 4.04 0.85 0.10 Chloride mg/l 103971 114796 92381 86398 Bicarbonate mg/l 231.07 247.42 189.59 141 589.1 579.6 411.1 524 Sulfate mg/l Phosphate mg/l 1.417 1.727 6.803 2.4 Conductivity mS/cm 144.8 143 170.7 129 pH 6.46 6.36 6.38 6.66 Density gm/cm 3 1.1080 1.1060 1.1020 1.0970 Dissolved H 2 S ppm <0.1 <0.1 1 <0.1 172882 190053 Total Dissolved Solid mg/l 153433 144513 www.kockw.com

Analytical Parameters ELEMENTS Unit GC -E GC-F GC -G GC -H Sodium mg/l 49169 45470 47079 49505 Calcium mg/l 10343 9457 9725 10450 Magnesium mg/l 2480 2420 2347 2278 Potassium mg/l 2950 1917 2645 2416 Strontium mg/l 190 300 293 273 1.70 2.30 2.10 3.22 Barium mg/l Iron mg/l 0.80 4.20 2.30 1.66 Lithium mg/l 4.31 7.53 7.01 3.66 Silicon mg/l 4.60 5.00 7.20 5.41 Boron mg/l 25.80 35.20 35.30 40.09 Aluminum mg/l 0.00 0.10 0.10 0.10 Chloride mg/l 98455 99111 94383 100044 Bicarbonate mg/l 247 249 259 305.24 537 211 523 769.1 Sulfate mg/l Phosphate mg/l 0.35 1.06 2.15 0.008 Conductivity mS/cm 103 133 143 178.7 pH 6.40 6 6 6.35 Density gm/cm 3 1.1060 1.1010 1.1080 1.1100 Dissolved H 2 S ppm 1.5 1 <0.1 <0.1 Total Dissolved Solid mg/l 164408 159189 157308 166094 www.kockw.com

FINAL CONCLUSION & RECOMMENDATION www.kockw.com

Conclusion  All waters were found to be self scaling except PIC water.  PIC acts as a diluent for all mixing calculations.  GC waters showed comparatively higher scaling tendency than wash waters.  In most of the mixing cases, total scale mass increases with increasing GCs formation water. www.kockw.com

Conclusion  Scale predicted are: calcite, barite, anhydrite, celestine.  Barite (BaSO 4 )  Celestine (SrSO 4 )  Calcite (CaCO 3 ) Worst Case Combination: 20% KNPC and 80% GC formation water www.kockw.com

Recommendation  Scale Inhibitor Application of suitable scale inhibitor will be possibly best scale controlling method. Chemical should be compatible with other chemicals used and with the waters. Laboratory trial is necessary for selection of most suitable chemical. www.kockw.com

Recommendation  PIC water can be used as diluent for minimizing scaling mass.  Worst case combinations should be avoided.  Dissolved gases like H 2 S and O 2 should be removed completely.  Scaling occurring at STF (if any) should not carry over to the desalter. www.kockw.com