Apparatus and method for measurement of hole pressure - differentials and swelling pressure - differentials in non-newtonian liquids (9) to or similar

摘要

The hole pressure differential is measured by providing at least one hole in a wall along which the liquid is caused to flow. The wall may constitute a portion of a passage, reaction vessel or the like. A pressure transducer or sensor is recessed into the hole to measure the hole pressure therein. At least one non-hole pressure transducer is also provided to measure the non-hole pressure along the wall. The hole pressure and the non-hole pressure, as measured, are combined subtractively, or otherwise, so as to derive the difference between the non-hole pressure and the hole pressure at a particular location along the wall. The non-hole pressure sensor may be located opposite the hole at a point where the non-hole pressure is the same as it would be at the location of the hole. In another arrangement, two non-hole pressure sensors are provided upstream and downstream at intervals from the hole, in which case the hole pressure may be combined subtractively with the average of the non-hole pressures. Similarly, two holes and hole pressure sensors may be spaced upstream and downstream at intervals from the non-hole pressure sensor so that the non-hole pressure may be combined subtractively with the average of the hole pressures. Other arrangements may utilize a sequence of two non-hole pressure sensors and one hole pressure sensor with subtractive combining means to derive the differential hole pressure. Alternatively, two hole pressure sensors and one non-hole pressure sensor may be arranged in sequence. Similar arrangements may be employed to measure the protuberance or negative-hole pressure differentials, by replacing the holes and hole pressure transducers with protuberances and protuberance pressure transducers.