Estimating break-down pressure of upper marine sediments using soil boring data

This paper illustrates how soil boring data is used to determine the formation break-down pressure for the Green Canyon area of the Gulf of Mexico. Example soil boring data is integrated with deeper well log data to accurately estimate overburden stress. Values for the horizontal to vertical effective stress ratios are confirmed by measuring the actual in situ formation break-down pressure while collecting the soil samples. This study shows that upper marine clays for the Green Canyon Area example have horizontal to vertical effective stress ratios of about 1.0 rather than the extrapolated value of 0.33 often used for sands. rrent objective of soil-boring geotechnical studies is to aid in the design of platform foundations. This study recommends that oil-boring geotechnical studies be extended to include obtaining data for designing shallow-gas well control systems.