Drilling method and system using foam--foaming composition
AssigneeInstitut Francias du Petrole
InventorsJean-Fran.cedilla.ois Argillier, Annie Audibert-Hayet, Sabine Zeilinger
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Abstract
The invention concerns a method for underground mining comprising the following steps: circulating in a well a foaming composition containing surfactants with cloud point higher than the temperature of the underground formation, heating the composition returning from the bottom to a temperature higher than the cloud point. The invention also concerns a system and a foaming composition based on water for implementing the method. The invention is useful for drilling and oil well completion operations requiring the use of a low-density fluid.
Claims11
A method of circulating a foam in a well, wherein the following stages are carried out:
- forming a foam from an aqueous composition comprising at least one additive whose cloud point temperature and concentration are such that the cloud point temperature of said composition is higher than the temperature of the foam in the well during drilling,
- injecting said foam into the well, said foam circulating from the surface to the well bottom, then from the bottom to the surface,
- heating the foam that has returned to the surface to a temperature at least higher than said cloud point temperature of the composition so as to destabilize the foam.
A system for circulating a foam in a well (1) drilled in the ground, comprising:
- means (9) for forming a foam from an aqueous composition comprising at least one additive whose cloud point temperature and concentration are such that the cloud point temperature of said composition is higher than the temperature of the foam when it is in the well,
- means (10, 2) for injecting said foam into the well, said foam circulating from the surface to the well bottom, then from the bottom to the surface, comprising means (5) for heating the foam that has returned to the surface to a temperature at least higher than said cloud point temperature of the composition so as to destabilize the foam.
Dependencies are inferred from the claim text.