Identifying Pore Structure and Clay Content from Seismic Data within an Argillaceous Sandstone Reservoir

Robert Schelstrate
Texas A&M University, Department of Geology & Geophysics, College Station, Texas, United States of America
[email protected]

Sandstone facies are ideal reservoirs for the accumulation of hydrocarbons in conventional exploration due to high porosity and permeability. Interbedded sandstone and shale, however, often occur in a depositional sequence. The amount of shale becomes a limiting factor in the quality of the reservoir by creating baffles to fluid flow. Previous studies have developed rock physics models of identifying critical clay content from experimental and well log data in a shaly sandstone reservoir. This study is to correlate a rock physics-based petrophysical parameter with seismic attributes in order to map and predict the location of fluid baffles. The project will involve calculating the critical clay content within the target reservoir, by applying the model proposed by Adesokan (2012) to wells logs within the Norne field, offshore Norway. Once the petrophysical analysis is completed, a deterministic seismic inversion will be conducted, using the well log data to build an inverse model of reservoir interval to identify how clay content varies within the reservoir. Seismic inversion will generate a most likely case reservoir model, predicting zones of increased clay content within the argillaceous sandstone reservoir. Utilizing the results of the seismic inversion, a volumetric assessment will be conducted to estimate original oil in place, which will then be compared to production data to gauge the accuracy of the method.

AAPG Search and Discovery Article #90183©2013 AAPG Foundation 2013 Grants-in-Aid Projects