Formation fracturing with stable foam
AssigneesThe Dow Chemical Company, Minerals Management, Inc.
InventorsRoland E. Blauer, Clarence J. Durborow
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Abstract
Stable foam within specified quality range is used as a fracturing fluid or to extend fractures in subterranean formations.
Claims20
A method of extending an initially fractured subterranean formation penetrated by a well bore with a stable foam, said foam comprising a mixed dispersion of a liquid base, a surfactant, a propping agent and a gas such that the Mitchell quality of said foam at the temperature and fracture extension pressure of the formation, as derived from the formula:
- ##EQU3## where .GAMMA. tp = the Mitchell derived quality
- V.sub.sg = the volume of saturated gas (excluding gas in solution if any)
- V.sub.f = the volume of foam
- is between the range of 0.5236 to 0.9999;
- injecting said foam into said well bore and increasing the pressure of said foam against said formation to reopen and/or extend said initial fracture of said formation.
A stable foam composition for fracturing subterranean hydrocarbon bearing formation comprising, a mixed dispersion of a liquid base, a surfactant, a propping agent and a gas such that the Mitchell quality of said foam at the temperatures and break-down pressures of the formation as derived from the formula:
- ##EQU4## where .GAMMA. tp = the Mitchell derived quality
- V.sub.sg = the volume of saturated gas (excluding gas in solution if any)
- V.sub.f = the volume of foam
- is between the range of 0.5236 to 0.9999.
A method of initially fracturing a subterranean formation penetrated by a well bore within a stable foam, said foam comprising a mixed dispersion of a liquid base, a surfactant, a propping agent and a gas such that the Mitchell quality of said foam at the temperature and pressures of the formation at the time of treatment as derived from the formula:
- ##EQU5## where .GAMMA. tp = the Mitchell derived quality
- V.sub.sg = the volume of saturated gas (excluding gas in solution if any)
- V.sub.f = the volume of foam
- is between the range of 0.5236 to 0.9999;
- injecting said foam into said well bore and increasing the pressure of said foam against said formation until break-down and fracture of said formation.
Dependencies are inferred from the claim text.