|Title||Chapter 13: Application of mineral provenance studies to petroleum exploration: case study of the Scotian Basin|
|Author||Pe-Piper, G; Piper, D J W|
|Source||Quantitative mineralogy and microanalysis of sediments and sedimentary rocks; by Sylvester, P (ed.); Mineralogical Association of Canada, Short Course Series vol. 42, 2012 p. 249-264|
|Alt Series||Earth Sciences Sector, Contribution Series 20110416|
|Publisher||Mineralogical Association of Canada (MAC)|
|Province||Eastern offshore region|
|Subjects||sedimentology; marine geology; geochronology; geochemistry; provenance; basin analysis; exploration methods; petroleum exploration; analytical methods; diagenesis; tectonic evolution; basin evolution;
dispersal patterns; reservoir rocks; zircon dates; monazite; muscovite; heavy minerals; geochemical analyses; quartz; isotopes; sedimentation; Tertiary; Cretaceous; Jurassic; Triassic; Mesozoic|
|Abstract||Mineral provenance studies are an important component of sedimentary basin analysis in support of petroleum exploration and production. The compositions of particular minerals are an important indicator
of their source (Nisbet & Pearce 1977, Henry & Guidotti 1985) and detrital mineral studies can provide evidence for the nature and age of source terranes (Cliff et al. 1991). Provenance studies can thus constrain models for the tectonic evolution of
the hinterland and the availability of source rocks that supplied abundant sands for potential reservoirs (Morton 1985). The sources and dispersal patterns of fluvial, deltaic and turbidite sediment can be tracked, providing critical information
regarding the petrographic characteristics and extent of reservoir quality sands. Changes in provenance are important in stratigraphic correlation and in basin modeling (Hurst & Morton 1988).|
We present here a case study illustrating the role that
provenance studies have played in
exploration and development of Upper Jurassic and Lower Cretaceous sandstone reservoirs in the Scotian Basin (Wade & MacLean 1990), which produce natural gas from the Sable Project and hosted a small oil pool in
the Panuke-Cohasset field. Information from this provenance study was used in the play fairway analysis sponsored by the Nova Scotia Department of Energy through the Offshore Energy Technical Research Association (OETR) and principally delivered by
two groups of petroleum consultants, RPS Energy and BeicipFranlab (OETR 2011). Detailed accounts of aspects of this provenance study have been published elsewhere or are under consideration for publication, and details of the analytical methods used
are presented in the appropriate primary sources.
Provenance studies can assist in resolving the following groups of questions relating to petroleum exploration and development in the Scotian Basin:
1. Provenance and dispersal patterns:
location of reservoir sands.Where were the fluvial entry points for sediment to the basin? How did the interplay of hinterland tectonics and fluvial dispersal through time influence the distribution of reservoir sands? How were sediments dispersed
from source rocks that weathered to provide good reservoir sands? Can mineralogical composition or chemostratigraphic techniques be used to refine stratigraphic correlations that are limited by poor biostratigraphic control and lack of seismic
continuity across growth faults?
2. Impact of provenance on diagenesis and reservoir quality. Does detrital sediment composition influence reservoir quality?
3. The tectonic and thermal evolution of the basin. What was the general history of
the unroofing of the hinterland and fluvial supply to the basin, and how does this contribute to regional stratigraphic and maturation models such as those in the play fairway analysis of the Scotian Basin (OETR 2011)?
More generally, this study
of the Scotian Basin addresses issues of general significance to provenance analysis and “source to sink” studies (e.g., Martinsen et al. 2010), including the challenge of distinguishing sources where hinterland terranes parallel the basin margin,
and where much of the detritus is polycyclic. We also demonstrate how bulk geochemistry (some of which can be measured by logging tools or by bulk chemical analysis of cuttings samples) and radiogenic isotopes can be used to quantify sediment supply
from different sources.