Detecting overpressure using the Eaton and Equivalent Depth methods in Offshore Nova Scotia, Canada

41st HAGI Annual Convention and Exhibition 2016

Ernanda^1 ; Primasty, A.Q.T.^1 ; Akbar, K.A.^1

Geophysics Sub-Department, Faculty of Mathematical and Science, Universitas Gadjah Mada, Indonesia^1

关键词: Abnormal pressure;    Equivalent depth;    Hydrocarbon generation;    Overpressure;    Pressure evaluation;    Subsurface pressure;    Trend analysis;    Vertical stress;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/132/1/012016/pdf
DOI  :  10.1088/1755-1315/132/1/012016

来源: IOP

【 摘 要 】

Overpressure is an abnormal high subsurface pressure of any fluids which exceeds the hydrostatic pressure of column of water or formation brine. In Offshore Nova Scotia Canada, the values and depth of overpressure zone are determined using the eaton and equivalent depth method, based on well data and the normal compaction trend analysis. Since equivalent depth method is using effective vertical stress principle and Eaton method considers physical property ratio (velocity). In this research, pressure evaluation only applicable on Penobscot L-30 well. An abnormal pressure is detected at depth 11804 feet as possibly overpressure zone, based on pressure gradient curve and calculation between the Eaton method (7241.3 psi) and Equivalent Depth method (6619.4 psi). Shales within Abenaki formation especially Baccaro Member is estimated as possible overpressure zone due to hydrocarbon generation mechanism.