Stabilisation/solidification of synthetic drill cuttings - PowerPoint PPT Presentation

International conference on Stabilisation/Solidification Treatment and Remediation, Cambridge 12-13 April 2005 Stabilisation/solidification of synthetic drill cuttings Stabilisation/solidification of synthetic drill cuttings representing Ras Shukier oil field in Egypt representing Ras Shukier oil field in Egypt UNIVERSITY OF M. S. Al- -Ansary Ansary & A & A. . Al Al- -Tabbaa Tabbaa M. S. Al CAMBRIDGE

Outline Outline I. I. Oil Drill Cuttings Oil Drill Cuttings II. II. Ras Shukier Case Study Ras Shukier Case Study III. III. Experimental Work Experimental Work IV. IV. Ongoing programme Ongoing programme V. V. Conclusion Conclusion

Drill cuttings are heterogeneous wastes Drill cuttings are heterogeneous wastes that are generated from petroleum drilling industry that are generated from petroleum drilling industry � Cla � Cla

fluid Recycled fluid Recycled Drill Cuttings + fluid fluid Drill Cuttings + Drill Cuttings Drill Cuttings contaminated with contaminated with chemicals from chemicals from fluid & oil & oil fluid Drill fluid Circulation System Drill fluid Circulation System

Treatment methods for drill cuttings Treatment methods for drill cuttings � Leave in place Leave in place- - disturbed disturbed � Crawler retrieval Crawler retrieval � � � Leave in place Leave in place- - undisturbed undisturbed � Re Re- -injection injection � � � Entombment Entombment � Re Re- -spreading spreading � � � Capping Capping � Mechanical separation Mechanical separation � � � Gravel Dumping Gravel Dumping � Distillation Distillation � � � Bioremediation in situ Bioremediation in situ � Stabilisation Stabilisation � � � Bio Bio- -reactor reactor � Combustion Combustion � � � Land Farming Land Farming � Supercritical extraction Supercritical extraction � � � Mechanical Dredging Mechanical Dredging � Thermal Thermal Desorption Desorption � �

II. Ras Shukier Drill Cuttings Ras Shukier Drill Cuttings II. Ras Shukier is an offshore oil production site located in the Gulf of Suez, Red Sea, Egypt. This site generates approximately 2,740 tonnes of cuttings per year. Ras Shukier consists of nine complex platforms.

Offshore Onshore Drilling Rig Manifest by Toolpusher Cutting Manifest by Box Load Master Approved disposal by Environment Transportation Service boat Waste Disposal Area Drill Cuttings

Physical and Chemical Characteristics Physical and Chemical Characteristics • Brownish black, sticky with a clayey texture soil. • Distinctive crude odour. • Density ranges between 1.2 and 2.0 g/cm 3 . (w/w) Hydrocarbon% Cr% Zn% Ba% % Pb% % Cl% % (w/w) Hydrocarbon% Cr% Zn% Ba Pb Cl Average 0.1 0.2 0.2 0.1 2.1 Average 11.0 Max 11.8 0.4 0.6 1.2 0.3 9.2 Max

III. Experimental Work Experimental Work III. Synthetic drill cuttings and their properties Synthetic drill cuttings and their properties Soil composition % Sand content 10 Silt (rock flour) content 50 Clay 1 (kaolin) 20 Clay 2 (bentonite) 20 Property Value Water content 20% Cutting composition % pH 9 Sodium Chloride 3.5 Plastic Limit 25% Paraffin oil (of dry soil) 11 Liquid Limit 51%

Binder System Binder System B. Novel Binders A. Conventional Binders B. Novel Binders A. Conventional Binders � MgO MgO cement cement � � Portland Cement (PC) Portland Cement (PC) � � Zeolite Zeolite � � Lime Lime � � Microsilica Microsilica (silica fume) (silica fume) � � Pulverised Fuel Ash (PFA) Pulverised Fuel Ash (PFA) � � Cement Kiln Dust (CKD Cement Kiln Dust (CKD � � Blastfurnace Blastfurnace Slag (BFS Slag (BFS ) ) � � Compost Compost �

Sample Preparation Sample Preparation Water : Dry binder: 0.6 : 1 0.6 : 1 Water : Dry binder: Dry binder content by weight : 10%, 20% and 30% 10%, 20% and 30% Dry binder content by weight : either PC only or 1:1 PC:other binder Binders: either PC only or 1:1 PC:other binder Binders: Sample size : 50 x 100 mm 50 x 100 mm Sample size :

Testing Program Testing Program Tests at 28 days of curing Tests at 28 days of curing Unconfined compressive strength (UCS) 1. Unconfined compressive strength (UCS) 1. Leachability (Chloride and Oil) (Chloride and Oil) 2. Leachability 2. Leachate pH pH 3. Leachate 3. Microstructure analysis 4. 4. Microstructure analysis

1. Unconfined Compressive Strength (UCS) Unconfined Compressive Strength (UCS) 1. 3 0 % 20% 4 5 0 0 4 0 0 0 3 5 0 0 UCS (kPa) 3 0 0 0 10% 2 5 0 0 2 0 0 0 1 5 0 0 1 0 0 0 5 0 0 0 Microsilica-PC PC BFS-PC Zeolite-PC PFA-PC MgO-Cement 2 CKD-PC Lime-PC Compost-PC MgO-Cement 1

Chloride leachate conc. (mg/L) 2. 2. 1250 1550 1850 950 Chloride Leachability Chloride 10% PC 20% Leachability PFA- PC 30% CKD- PC Compost- PC Lime- PC Zeolite- PC BFS- PC Microsilica- PC MgOcement 2 MgOcement 1

Paraffin oil leachate conc. (mg/L) 2. 2. 10000 1000 100 Oil Leachability Oil 10 Leachability PC 10% PFA- PC 20% CKD- PC 30% Compost- PC Lime- PC Zeolite- PC BFS- PC Microsilica- PC MgOcement 2 MgOcement 1

3. Leachate Leachate pH pH 3. Binder content Binder System 10% 20% 30% PC 12.0 12.4 12.6 BFS - PC 12.0 12.2 12.4 Microsilica - PC 10.5 10.4 10.6 Lime - PC 12.1 12.5 12.4 Compost - PC 11.6 12.1 12.2 PFA - PC 12.0 12.1 12.1 MgO cement1 9.9 11.0 11.0 MgO cement2 10.9 12.0 12.0 Zeolite - PC 11.6 11.9 11.7 CKD- PC 12.0 12.3 12.4

4. Microstructural Analysis Microstructural Analysis 4. SEM at 28 days PC Microsilica - PC Lime - PC Zeolite - PC Compost - PC MgO cement 2

IV. Ongoing Programme Ongoing Programme IV. North Sea Case Study � North Sea Case Study � Best S/S systems selected for more detailed study � � Best S/S systems selected for more detailed study Next mixes to include heavy metals � Next mixes to include heavy metals � For chloride, possibility of a low pH cement � � For chloride, possibility of a low pH cement Pelletisation of thermally treated drill cuttings � Pelletisation of thermally treated drill cuttings �

V. Conclusion Conclusion V. Drill cutting is a big problem that the petroleum � industry is keen to find solutions The utilisation of S/S techniques to treat drill cuttings � by using conventional as well as novel binders indicated the following: - UCS of the drill cuttings UCS of the drill cuttings- -binder mixes at 28 days binder mixes at 28 days - covered a wide range of feasible applications. covered a wide range of feasible applications.

V. Conclusion (contd.) Conclusion (contd.) V. - Chloride leachate concentrations showed a change from Chloride leachate concentrations showed a change from - hazardous to non- -reactive hazardous waste. reactive hazardous waste. hazardous to non - Oil leaching concentrations decreased as the dry binder Oil leaching concentrations decreased as the dry binder - content increased. content increased. - The The leachate leachate pH values indicated the use of lower pH binders. pH values indicated the use of lower pH binders. - - The The microstructural analysis suggested an advanced level of microstructural analysis suggested an advanced level of - hydration. hydration. Future work will give more detailed information on the � relative performance of different binders.

Thank You Thank You Thank You Thank You Marwa at Ras Shukier oil field May 2003 at Ras Shukier oil field May 2003 Marwa