engleski

Effect to Selected of Lubricants on Drilling Fluids Properties

The lubricity of drilling fluid is a property of special importance in drilling directional wells. Friction between drill string and borehole is always expected when drilling a hole off-vertical. In the horizontal and highly deviated sections of a horizontal well, the torque and drag were usually large enough to cause an unacceptable loss of power, and differential sticking was particularly liable to occur. In such situations crude oil or certain lubricating agents should be used. Good lubricating properties of the mud can greatly improve the drilling operation efficiency. A drilling fluid lubricant is used to reduce torque and drag between the drill string and wall of a wellbore, to prevent sidewall sticking and to prolong bit bearing life. Desirable characteristics of a lubricant for this purpose, aside from the obvious requirements of performing well as a lubricant, are that it is non-toxic and biodegradable. The paper describes laboratory tests and their results showing the performances of a vegetable oil based lubricant (domestic product) for reducing torque and pipe drag when using three different water based drilling fluids. Testing was conducted under controlled laboratory conditions simulating actual drilling conditions. In order to evaluate performances of the lubricant, the lubricating properties were compared with results that were obtained under same conditions with two commercially available lubricants.

lubricants; drilling fluids; horizontal drilling

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