Applicability of magnetic susceptibility techniques and novel templates for improved hydrocarbon reservoir characterization

Abstract

The work presented in this thesis is an effort to help petrophysicists and reservoir engineers in improving reservoir characterization. Magnetic susceptibility techniques were used for prediction of important reservoir parameters in hydrocarbon sedimentary sequences. For the first time ever I have shown that the grain lining hematite cement surrounding quartz grains has significant control on permeability in hydrocarbon bearing reservoir rock samples. This work also shows that it is not only the dispersed hematite and clay minerals in a reservoir rock matrix that control permeability, but also that the grain lining hematite has additional and dominant control on permeability. In addition, for the first time ever, magnetic susceptibility techniques have been applied on core samples from relatively tight gas sandstone reservoirs. Such techniques were previously known to have been used in only conventional clastic reservoirs. Magnetic hysteresis measurements were used to show that the permeability is dependent on hematite content and independent of hematite particle size. Identifying and Evaluating faults and fluid contact in hydrocarbon bearing reservoir rocks are challenging tasks. The work presented in this thesis has shown for the first time that raw magnetic susceptibility measurements performed on drill cuttings can be used to detect faults and fluid contacts in sedimentary sequences. Such measurements can be performed at well site, thereby enabling companies to make important field development decisions quickly.Additionally, a series of novel crossplots have been developed between magnetic susceptibility and various wireline log data for determination of mineralogy, mixture porosity and mineral quantification. These crossplots are similar in format to standard industry charts, which provide a further tool for improved petrophysical characterization using rapid, non-destructive magnetic susceptibility measurements.