Schlumberger Technology Corporation

Hisayo Tauchi

Christopher Del Campo

Ricardo Vasques

Jonathan Webster Brown

Mark Milkovisch

Raymond V Nold, Iii

Noriyuki Matsumoto

Vassilis Varveropoulos

Kenneth L Havlinek

Fanping Bu

Ken-Vidar Ditlefsen

A head wireline tension control system may determine a head tension based on a speed of the tool driving equipment and a cable speed of the cable as a function of an operation of the winch. A head tension regulation error may be determined based on a comparison of the head tension and a target head tension, and the head tension control system may operate the winch or the tool driving equipment according to an operating zone that includes the head tension regulation error. The operating zone may be defined by a first range of values for a difference between the speed of the tool driving equipment and the cable speed, and a first range of values for a difference between the head tension and the target head tension.

Systems and methods for controlling head tension

Techniques for reduced contamination formation evaluation are provided. The techniques relate to drawing fluid into a downhole tool positionable in a wellbore penetrating a subterranean formation having a virgin fluid and a contaminated fluid therein. Fluid is drawn into at least two inlets for receiving the fluids from the formation. At least one evaluation flowline is fluidly connected to at least one of the inlets for passage of the virgin fluid into the downhole tool. At least one cleanup flowline is fluidly connected to the inlets for passage of the contaminated fluid into the downhole tool. At least one fluid circuit is fluidly connected to the evaluation flowline and/or cleanup flowlines for selectively drawing fluid therein. At least one fluid connector is provided for selectively establishing a fluid connection between the flowlines. At least one sensor is provided for measuring downhole parameters in one of the flowlines. Fluid may be selectively pumped through the flowlines to reduce the contamination in the evaluation flowline.

Apparatus and method for formation evaluation

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Sugar Land, TX, United States of America

Hisayo Tauchi