초록 ▼

Apparatus and method for detecting the level of gases entrained within a circulating drilling fluid used in subterranean well operations are disclosed. Detection of incipient gas kicks during drilling operations is accomplished by detecting the level of entrained gases. A gas-air sample is gathered

Apparatus and method for detecting the level of gases entrained within a circulating drilling fluid used in subterranean well operations are disclosed. Detection of incipient gas kicks during drilling operations is accomplished by detecting the level of entrained gases. A gas-air sample is gathered at the surface of the well, and a gas-air sample having a constant relative humidity is delivered at a constant volumetric flow rate to gas sensors. Dilution air is automatically added to the sample when the gas concentration exceeds a known limit. Automatic periodic calibration of the sensors is provided. Stable signals from the gas sensor are obtained at two distinct flow rates.

대표청구항 ▼

An apparatus for detecting the presence of a gas entrained in an aqueous fluid circulated through a subterranean well bore, comprising: a gas gathering means for gathering gas liberated from the circulating fluid for delivery to a sample gas flow line; a sample flow controller in said flow line comp

An apparatus for detecting the presence of a gas entrained in an aqueous fluid circulated through a subterranean well bore, comprising: a gas gathering means for gathering gas liberated from the circulating fluid for delivery to a sample gas flow line; a sample flow controller in said flow line comprising means for establishing a constant rate of sample gas flow; means for regulating the relative humidity of the constant rate sample gas flow to a fixed value less than 100%; sensor means for detecting the presence of gas in a gas sample flow; means for directing the fixed relative humidity, constant rate sample gas flow to the sensor means; a dilution flow line communicating with the gas flow line between the sample flow controller and the sensor means for reducing the concentration of the gas supplied to the sensor means and including valve means selectively communicating said dilution flow line with the gas flow line; and control means in communication with said sensor means and said valve means for establishing communication between the sample gas flow line and the dilution flow line when the concentration of gas in the circulating fluid exceeds a predetermined concentration, whereby the concentration of gas thereafter exposed to the sensor means is less than the predetermined concentration.