II. ENVIRONMENTAL IMPACTS AND RISKS EVALUATION OF OFFSHORE DRILLING
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65
0.00E+00
5.00E+04
1.00E+05
1.50E+05
2.00E+05
2.50E+05
3.00E+05
3.50E+05
4.00E+05
4.50E+05
5.00E+05
PDF*m2*yr
0.00E+00
1.00E+06
2.00E+06
3.00E+06
4.00E+06
5.00E+06
6.00E+06
PDF*m2*yr
Section 17 1/2" 2.32E+05 1.33E+05 3.59E+04 5.78E+03 1.61E+03 4.92E+02 1.84E+03 3.64E+02 4.73E+02 1.83E+02 6.24E+01 1.41E+02 4.12E+05 4.38E+05
Section 8 1/2" 1.42E+05 2.41E+04 6.16E+04 2.55E+04 4.09E+03 9.56E+02 3.62E+03 9.25E+02 9.52E+02 4.64E+02 1.58E+02 2.44E+02 2.65E+05 2.99E+05
Section 36"
4.76E+06 1.69E+05 1.03E+04 8.28E+03 2.79E+03 1.89E+03 1.34E+03 6.32E+02 3.89E+02 3.17E+02 1.07E+02 4.40E+01 4.95E+06 4.98E+06
Section 26"
4.81E+04 9.66E+05 2.88E+04 9.63E+03 9.80E+02 1.52E+02 1.38E+03 2.21E+02 3.48E+02 1.11E+02 3.79E+01 1.13E+02 1.06E+06 1.09E+06
Section 12 1/4" 1.23E+05 1.21E+05 5.08E+04 5.17E+03 1.02E+03 5.30E+02 2.16E+03 2.29E+02 5.31E+02 1.15E+02 3.93E+01 1.98E+02 3.05E+05 3.30E+05
Ba
As
PAH
Barite
V
Zn
Ni
Se
Cu
Co
Mo
Cd
TEW
TEC
Figure 27: Marine ecotoxicity scores of toxic emissions from well sections
II.3.8 Calculation of impact and damage scores related to offshore drilling waste
treatments
Drilling waste is largely composed of cuttings resulting from rocks broken by the mechanical
tool which crosses the geological formations all along the sections of the well until the
hydrocarbons arrive at the reservoir. There is also in this waste, the residual fluids coming from
the sections of the well especially those drilled with oil-based muds (OBM). Three discharge
management methods were simulated, including transport from the offshore platform and three
treatment processes for these discharges heavily polluted by hydrocarbons and chemical
additives. These treatment processes are: (i) physical separation of fluids and oils by a series of
sieving and centrifugation (ii) stabilization-solidification which consists of stabilization or
inerting of pollutants and their solidification in a cemented solid matrix (iii) thermal desorption
where the cuttings soaked in fluids are subjected to an indirect high temperature (~1000°C)
making it possible to recover the oil for recycling. These three treatment processes are already
applied to drilling waste onshore at Hassi Messaoud.
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65
0.00E+00
5.00E+04
1.00E+05
1.50E+05
2.00E+05
2.50E+05
3.00E+05
3.50E+05
4.00E+05
4.50E+05
5.00E+05
PDF*m2*yr
0.00E+00
1.00E+06
2.00E+06
3.00E+06
4.00E+06
5.00E+06
6.00E+06
PDF*m2*yr
Section 17 1/2" 2.32E+05 1.33E+05 3.59E+04 5.78E+03 1.61E+03 4.92E+02 1.84E+03 3.64E+02 4.73E+02 1.83E+02 6.24E+01 1.41E+02 4.12E+05 4.38E+05
Section 8 1/2" 1.42E+05 2.41E+04 6.16E+04 2.55E+04 4.09E+03 9.56E+02 3.62E+03 9.25E+02 9.52E+02 4.64E+02 1.58E+02 2.44E+02 2.65E+05 2.99E+05
Section 36"
4.76E+06 1.69E+05 1.03E+04 8.28E+03 2.79E+03 1.89E+03 1.34E+03 6.32E+02 3.89E+02 3.17E+02 1.07E+02 4.40E+01 4.95E+06 4.98E+06
Section 26"
4.81E+04 9.66E+05 2.88E+04 9.63E+03 9.80E+02 1.52E+02 1.38E+03 2.21E+02 3.48E+02 1.11E+02 3.79E+01 1.13E+02 1.06E+06 1.09E+06
Section 12 1/4" 1.23E+05 1.21E+05 5.08E+04 5.17E+03 1.02E+03 5.30E+02 2.16E+03 2.29E+02 5.31E+02 1.15E+02 3.93E+01 1.98E+02 3.05E+05 3.30E+05
Ba
As
PAH
Barite
V
Zn
Ni
Se
Cu
Co
Mo
Cd
TEW
TEC
Figure 27: Marine ecotoxicity scores of toxic emissions from well sections
II.3.8 Calculation of impact and damage scores related to offshore drilling waste
treatments
Drilling waste is largely composed of cuttings resulting from rocks broken by the mechanical
tool which crosses the geological formations all along the sections of the well until the
hydrocarbons arrive at the reservoir. There is also in this waste, the residual fluids coming from
the sections of the well especially those drilled with oil-based muds (OBM). Three discharge
management methods were simulated, including transport from the offshore platform and three
treatment processes for these discharges heavily polluted by hydrocarbons and chemical
additives. These treatment processes are: (i) physical separation of fluids and oils by a series of
sieving and centrifugation (ii) stabilization-solidification which consists of stabilization or
inerting of pollutants and their solidification in a cemented solid matrix (iii) thermal desorption
where the cuttings soaked in fluids are subjected to an indirect high temperature (~1000°C)
making it possible to recover the oil for recycling. These three treatment processes are already
applied to drilling waste onshore at Hassi Messaoud.