![]() ![]() Marsh H: "Properties and Treatment of Rotary Mud," Petroleum Development and Technology, Transactions of the AIME (1931): 234-251. Marsh was quoted by someone who knew him as saying (paraphrased), "Of all the things I have done in mud technology, I am remembered for inventing this d*** funnel." As a matter of fact, it is one of the most complicated, technical, important and interesting subjects in connection with rotary drilling." ![]() Marsh was a forward thinking mud technologist in his day, as can be seen from the following words from his 1931 AIME paper: "The subject of mud sounds so simple, uninteresting and unimportant that it has failed to receive the attention that it deserves, at least as applied to the drilling of oil wells. One quart of water should flow through a Marsh Funnel in 26 ±. This viscosity measurement is used to periodically report mud consistency. diameter tube at the bottom of the Marsh Funnel. For water at 21C it was found to have a quart discharge time of 25.9 seconds (standard deviation 0.18 seconds) compared with the API specification of 26.0. Centipoise (cP) is commonly used to describe dynamic viscosity because water at a. Marsh Funnel viscosity is the time required (seconds) for a quart of mud to flow through a 2-in. Marsh of Los Angeles published the design and use of his funnel viscometer in 1931, and it is worth the time to read the detailed, often humorous, discussion that followed. Pascals can be combined with time (seconds) to define dynamic viscosity. Simple, quick and fool-proof, it still serves as a useful indicator of change in the mud by comparing mud-in and mud-out sample funnel viscosities. This test was one of the earliest mud measurements for field use. Water exits the funnel in about 26 seconds. Not only has this cup been improved with respect to earlier produced cups and designed to comply to the requirements of ASTM D4212 but, in addition, each EZ Viscosity Dip Cup is furnished with a table which permits conversion between efflux time in seconds to the nearest tenth of a second to viscosity in centistokes. Funnel viscosity is reported in seconds (for a quart). In the test standardized by API for evaluating water-base and oil-base muds, the funnel viscosity measurement is the time (in seconds) required for one quart of mud to flow out of a Marsh funnel into a graduated mud cup. Different quantities of bentonite, barite and other additives which have been used to prepare many samples. A screen over the top removes large particles that might plug the tube. It is determined by measuring the time in seconds, required for a fixed volume of fluid to flow a known distance by gravity through a capillary within a calibrated viscometer at a closely controlled temperature. The calculator below can be used to calculate the liquid water dynamic or kinematic viscosity at given temperatures. A conical-shaped funnel, fitted with a small-bore tube on the bottom end through which mud flows under a gravity head. Kinematic viscosity is a measure of a fluids internal resistance to flow under gravitational forces. So for example, the viscosity of water at room temperature is 1.002 cP, or 0.001002 Pa.s the density of water is about 1000 kg.m-3, which gives a kinematic. ![]()
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