Characterising Subsurface Reservoirs
A wide range of rock types act as subsurface reservoirs for fluids and gases, be they hosts for petroelum, carbon dioxide or water etc. Each with their own characteristics and problems. It is therefore important to have experts in reservoir characterisation in order that the best decisions are made during each stage of development.
Clastic (sandstone) reservoirs are considered the prototype for analysis and software is often biased towards these but even here there is a huge amount of variability. Mineralogy, both primary and secondary, and diagenesis all affect reservoir properties and types while connectivity can be unpredictable and require other inputs to define it from seismic, rock physics and petrophysics.
Other reservoirs include carbonates, which hold vast quantities of the world’s hydrocarbons but can be highly complex. Carbonates can contain abrupt facies variations reflecting changes in the initial depositional environment, which are vital to understand for drilling and field development purposes.
Some of the most challenging reservoirs occur in plays where igneous and volcaniclastic sequences prevail including in and around the Atlantic Margin where an understanding of their productivity might unlock a frontier province.
Other rocks that can form reservoirs include ‘basement’ metamorphic rocks. Often Palaeozoic in age or older, and with little natural porosity, they are commonly intensely fractured, something that allows them to act as reservoirs. Basement rocks can have highly complex fracture patterns and require expert analysis to understand them and determine the best development plan.
Experts in these areas would integrate with those in similar research groups at Heriot-Watt University and the BGS in the Lyell Centre research facility.