MEASUREMENT PRETEST DRAWDOWN METHODS AND APPARATUS

摘要

Methods of and apparatus to perform a drawdown of a formation fluid in a downhole environment are disclosed. An example method includes contacting a borehole wall with a fluid communication device of a formation testing tool and performing a first type of drawdown to draw fluid into the fluid communication device. The method also includes detecting a breach of a mudcake on the borehole wall during performance of the first type of drawdown and performing a second type of drawdown to draw fluid into the sample probe in response to detecting the breach of the mudcake. The second type of drawdown is different than the first type of drawdown. Furthermore, the example method includes confirming the breach of the mudcake on the borehole wall during performance of the second type of drawdown.