Patent ID: 8596384
Filing Date: 2013-12-03
Classification: E21B

Abstract:
1. A method, comprising: lowering a downhole tool via a pipe into a wellbore drilled through a formation via the pipe; establishing fluid communication between the downhole tool and the formation at a location in the wellbore; extracting a first fluid stream from the formation and passing the first fluid stream through the downhole tool for a first duration; breaking fluid communication between the downhole tool and the formation; moving the pipe in the wellbore; reestablishing fluid communication between the downhole tool and the formation essentially at the location in the wellbore; and extracting a second fluid stream from the formation through the fluid communication and passing the second fluid stream through the downhole tool for a second duration; wherein the steps of establishing fluid communication between the downhole tool and the formation, extracting and passing the first fluid stream through the downhole tool for the first duration, breaking fluid communication between the downhole tool and the formation, reestablishing fluid communication between the downhole tool and the formation essentially at the location, and extracting and passing the second fluid stream through the downhole tool for the second duration, collectively, form at least one of a plurality of pumping phases; and at least one of the plurality of pumping phases comprises measuring a parameter indicative of a fraction of mud filtrate or formation connate fluid in one of the fluid streams; and the number of pumping phases included in the method is determined based on whether a rate of decline of the indicated fraction meets a threshold.