(19)
(11) EP 0 126 680 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.06.1986 Bulletin 1986/23

(43) Date of publication A2:
28.11.1984 Bulletin 1984/48

(21) Application number: 84400946

(22) Date of filing: 09.05.1984
(84) Designated Contracting States:
DE FR GB IT NL

(30) Priority: 16.05.1983 US 495283

(71) Applicants:
  • SCHLUMBERGER LIMITED
     ()
  • SOCIETE DE PROSPECTION ELECTRIQUE SCHLUMBERGER
     ()

(72) Inventor:
  • Ciccarelli, Armann Ostilio
     ()

   


(54) Formation sampling apparatus


(57) An apparatus and method for taking fluid samples from earth formations surrounding a borehole while minimizing the erosion of the formations which occurs during such sample-taking, in which a specialized tool is brought into communication with the desired formation and the fluid pressure which exists within the formation prior to taking a sample is used to restricttheflow of fluids into the tool. This restriction is however opposed with a pre-determined biasing force in combination with the dynamic fluid pressure during the sample-taking process. These opposing forces control the rate of flow of formation fluids into the tool in a manner diminishing the erosion which occurs.






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