Sand Injectites: Aature and
Hydrocarbon Implications. Outcrop Analogues From
Scott, Anthony1, Mario
Vigorito1, Andrew Hurst1, Joe Cartwright2 (1)
Aberdeen University, Aberdeen, United Kingdom (2) Cardiff University, Cardiff,
United Kingdom
Sand injectites
have become increasingly important in the oil and gas industry. They have been
identified in oil fields of the
Sand injectite
geometry and petrophysics are extremely variable even
though they may have been initiated by a similar event. The reason for this
variation is due to the influence of the mechanical properties of the host
sediment. Outcrops of Tabarka in
Injectites in Tabarka
suggest that sand injection occurred before significant compaction and lithification of surrounding host sediment. The abrasion and incorporation of mud (>10%) into the injection
results in an irregular geometry with low porosity (<7%) and permeability
(<120mD). In contrast, YBCC sand injection occurred when the host
sediment was compacted or lithified. The contact
margins indicate that the sand was injected into distinct fracture planes. The
reduced mud content (<1%) results in a high porosity (>25%) and
permeability (>2000mD).
Accurate and quantitative description of
sand injectites in the subsurface is essential for
providing models for reservoir simulation. Using sand injectite
outcrop analogues helps to understand the influence of host sediment compaction
and lithification on sand injectite
geometry and petrophysical variation in the
subsurface. This improves the accuracy of predicting fluid flow behaviour in sand injectite
reservoirs.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California