Factors influencing production in the toronto limestone, (Shawnee Group, Upper Pennsylvanian) Snake Creek Field, Clark County, Kansas

Autor: P. G. Sutterlin, J. M. Linehan
Rok vydání: 1986
Předmět:
Zdroj: Carbonates and Evaporites. 1:44-60
ISSN: 1878-5212
0891-2556
DOI: 10.1007/bf03174402
Popis: Commercial quantities of hydrocarbons in the Toronto Member of the Oread Formation (Shawnee Group, Upper Pennsylvanian) were discovered in November, 1980. The field subsequently was developed to include 33 Toronto wells which produce on pump assisted by a dissolved gas drive. Estimated ultimate recovery is 1,500,000 bbls of oil, based on a recovery efficiency of 35%. Cumulative primary production to January, 1986 is 91,180 stock tank barrels (STB) of 40° API gravity oil. Initial reservoir pressure was 1,700 psi, with a maximum production rate of 1,080 barrels of oil/day (BOPD). Since then, reservoir pressure has fallen to 250 psi and production has declined to 185 BOPD. Detailed core studies show that the Toronto Limestone consists of seven lithofacies and represents a transgressive-regressive cycle within the Oread “megacyclothem”. An algal “bioherm” was formed during the regressive phase of Toronto deposition, and it is in the algar-plate and algal-intraclast facies of this carbonate buildup that the reservior is developed. Three distinct pore networks are present in the reservior. The most effective of these from the standpoint of recovery efficiency is formed by stylolites and fractures, and is the reason why production has declined so rapidly. An Enhanced Oil Recovery (EOR) waterflood program has been designed, and is to be implemented in the near future. This seems to be the only economically feasible EOR method at this time. However, because of the nature of the pore networks, it is suggested that a polymer or CO2 flood could be more effective.
Databáze: OpenAIRE
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