Method for the identification of the formation fluid invasion moment

Abstract

The method of the formation fluid invasion moment identification consists in the sinking of an apparatus for the sampling of the fluid mixture into the uncased wellbore; the apparatus consists of the body, standard probe, hydraulic system, sample storage chamber and pumping module. Then the fluid mixture is pumped out and simultaneously the temperature of the fluids being pumped out is measured using at least one temperature transducer positioned in the sampling apparatus hydraulic system. Based on the values obtained the graph of the derivative temperature of the pumped out fluids as function of time is built up and the formation fluid invasion moment is identified.

1 . A method for a formation fluid invasion identification comprising the steps of:
 lowering a fluid mix sampler into an uncased borehole, fluid mix consisting of a drilling mud filtrate and a reservoir fluid, the sampler including an enclosure, a standard probe, a hydraulic system, a chamber for probes storage and a pumping module,   pumping off the fluid mix simultaneously with measuring temperature of the fluids being pumped off using at least one temperature transducer located in the hydraulic system of the sampler,   constructing a graph of the pumped off fluids temperature derivative as a function of the time based on the values obtained, and   determining the formation fluid invasion time.   
     
     
         2 . The method of  claim 1  wherein a borehole is vertical. 
     
     
         3 . The method of  claim 1  wherein a borehole is horizontal. 
     
     
         4 . The method of  claim 1  wherein a standard probe is a double-packer.