|dc.contributor.advisor||van Dijke, Rink||
|dc.contributor.author||Harland, Sophie Rebekah||
|dc.description.abstract||Micropores can constitute up to 100% of the total porosity within carbonate
hosted hydrocarbon reservoirs, usually existing within micritic fabrics. There
is, however, only a rudimentary understanding of the contribution that these
pores make to reservoir performance and hydrocarbon recovery. To further our
understanding, a flexible, object-based algorithm has been developed to produce
3D computational representations of end-point micritic fabrics. By methodically
altering model parameters, the state-space of microporous carbonates is explored.
Flow properties are quantified using lattice-Boltzmann and network modelling
In purely micritic fabrics, it has been observed that average pore radius has
a positive correlation with single-phase permeability and results in decreasing
residual oil saturations under both water-wet and 50% fractionally oil-wet states.
Similarly, permeability increases by an order of magnitude (from 0.6md to 7.5md)
within fabrics of varying total matrix porosity (from 18% to 35%) due to increasing
pore size, but this has minimal effect on multi-phase flow. Increased pore size
due to micrite rounding notably increases permeability in comparison to original
rhombic fabrics with the same porosity, but again, multi-phase flow properties
are unaffected. The wetting state of these fabrics, however, can strongly influence
multi-phase flow; residual oil saturations vary from 30% for a water-wet state and
up to 50% for an 80% oil wet fraction.
flow when directly connected.
Otherwise, micropores control single-phase permeability magnitude. Importantly
in these fabrics, recovery is dependent on both wetting scenario and
pore-network homogeneity; under water-wet imbibition, increasing proportions of
microporosity yield lower residual oil saturations.
Finally, in grain-based fabrics where mesopores form an independently connected
pore network, micropores do not affect permeability, even when they constitute
up to 50% of the total porosity.
Through examination of these three styles of microporous carbonates, it is
apparent that micropores can have a significant impact on flow and sweep characteristics in such fabrics.||en
|dc.publisher||The University of Edinburgh||en
|dc.relation.hasversion||Kallel, W., van Dijke, M., Sorbie, K., Jiang, Z., Wood, R. & Harland, S. (2014). Modelling wettability alteration in microporous carbonate rocks. In: AAPG Annual Conference, Houston, Texas, Abstract Number 41428.||en
|dc.title||Quantifying the role of microporosity in fluid flow within carbonate reservoirs||en
|dc.type||Thesis or Dissertation||en
|dc.type.qualificationname||PhD Doctor of Philosophy||en