Skip to Main Content
Skip Nav Destination


When formations are unconsolidated and/or mud conditions prevent running a conventional drill stem test, pressure information and formation fluid samples can be obtained by using a wireline test tool called a repeat formation tester. This tool offers the capability of taking any number of pressure-depth measurements with a single logging run. At each setting depth, a “pretest” is made in which small samples of fluid are withdrawn from the formation. The formation pressures are recorded at the surface. The “pretest” fluids are not retained. However, a larger fluid sample can be retrieved by using either or both of two larger sample chambers, 2-3/4 and 1 gallon. This capacity permits fluid samples to be obtained from two separate intervals with one logging run.

The fluid samples provide a qualitative indication of formation productivity. For example, a Yegua formation that recovered 35 cubic feet of gas and 2000 cc of mud filtrate was completed producing 1 MMCFPD with 1250 psi FTP and no water. However, because of the small volume of fluid removed from the reservoir, quantitative values for productivity are very questionable.

You do not currently have access to this chapter.

Figures & Tables





Citing Books via

Close Modal

or Create an Account

Close Modal
Close Modal