Schlumberger

Technical Paper: An Integrated Regional Model in the Gulf of Mexico: A Versatile Tool for Rapid Pre-Drill Assessments, While-Drilling Updates, and Prospect Grading

Society: AADE
Paper Number: 09-ntce-13-05
Presentation Date: 2009
 

Abstract

An integrated regional model of the entire northern Gulf of Mexico (GoM) is aimed at reducing the risk associated with drilling difficult wells, especially in deeper water or in known High-Temperature High-Pressure (HTHP) areas. Quantitative pre-drill predictions of formation pore pressure are essential for safe, cost-effective drilling in overpressured areas. In order to respond more rapidly to the short lead times associated with such projects, an integrated 3D geomechanical model comprised of temperature, velocity, density, vertical stress, effective stress and pore pressure has been constructed for the entire northern region of the GoM. These models are constructed entirely from publicly available well data, including checkshot surveys, bottomhole measurements and log data from the Mineral Management Services (MMS). The volumes derived from this integrated modeling effort have been successfully employed for numerous projects, where time constraints, economics, and/or lack of data precluded the use of 3D seismic velocities. A regional pre-drill pore-pressure model can be updated while drilling, as new well data are acquired, allowing the velocity-to-pore pressure transform to be recalibrated on-the-fly. By applying the revised transform to the regional velocity model, uncertainty ahead of the bit is thus reduced.