Carbonates make up about half of the sedimentary rock in the
Western Canada Sedimentary Basin (WCSB), ranging from
Cambrian to early Jurassic in geologic age, in which large oil and
gas reserves exist in the Devonian and Early Carboniferous
formations. Middle and Upper Devonian carbonate rocks alone
have a known reserve of about 15 billion barrel of oil and 35 tril-
lion cubic feet of natural gas. A variety of carbonate reservoirs
exist in the WCSB, mostly reef and platform types. These reser-
voirs are formed by porous limestones or platforms that were
dolomitized prior to basin-wide hydrocarbon maturation and
migration. Fractured reservoirs were formed by natural fractures
due to regional or local stress regimes or by local overpressure.