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FROZEN HEAT
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As with traditional oil and gas resource development, gas
hydrate development will occur through two linked phases:
exploration and production. In the exploration phase, vari-
ous geological and geophysical tools and concepts are ap-
plied (Riedel
et al.
2010c) to search for the most promising
deposits and to evaluate the resource potential of the fields.
These interpretations are then tested through exploration
drilling, with extensive data collection that includes complex
geophysical well logging and collection and analysis of core
samples (Text Box 2.2). If initial drilling results are positive,
delineation wells might be drilled to refine the extent and na-
ture of the accumulation. Numerical reservoir simulation is
then used to assess the potential recovery and the nature and
potential economics of the full development plan (Moridis
et al.
, 2009; Kurihara
et al.
2010). Only when it is deemed
cost-effective to develop the resources in accordance with re-
quired environmental standards will industry move into the
production phase. (Promising production technologies are
discussed in Volume 2 Chapter 3 of this report.)
Although gas hydrate exploration is still in the research
phase, initial results are positive. Progress toward viable ex-
ploration approaches has been confirmed in both Arctic (Lee
et al.
2011) and deep-water (Shelander
et al.
2010) settings,
where pre-drill, geophysics-based predictions were con-
firmed by later drilling. This approach tailors the petroleum
systems concepts that guide traditional hydrocarbon explo-
ration to the issue of gas hydrates (Fig. 2.3; Text Box 2.2).
Future gas hydrate exploration will search for locations that
combine evidence from seismic surveys and other remote-
sensing data with interpretations of the geologic develop-
ment of the region that suggest the confluence of supplies
of gas, reservoir-quality sediments, and gas hydrate stability
conditions (Collett
et al.
2009).
2.3
GAS HYDRATE
EXPLORATION
Figure 2.3:
Gas hydrate exploration. The method shown here
is a tailored variant of the “petroleum systems” approach that
guides conventional oil and gas exploration. In this example, a
cross-section and map view (insert) from the deep-water setting,
geological and geophysical data from previous drilling and remote
sensing are used to reduce the uncertainty associated with
geophysically-defined prospects (B) by confirming the presence of
gas hydrate stability conditions (A), the occurrence of gas sources
and pathways (C), and the occurrence of potential reservoirs (D).