Methods for determining the existence of an event control shaft and to control the pressure of the formation during drilling of a drill hole through a training subterru00e1nea

摘要

Method determines whether there is in the control shaft of an event and the drilling process of control pressure and bores a hole, by forming a subterr á nea. A kind of drilling fluid of control strata pressure in drilling process, including a pump by the drilling for the drill string that drills at one, in the annular space of drill string. Drilling fluid is discharged from the annular space near the surface of the earth. Flow measurement outside the drill-hole annulus of the flow of at least one drilling fluid and an inner hole. The investigation of the pressure and the bottom hole near the earth of fluid in the annular space of the pressure lower surface of fluid is measured. The investigation of bottom hole is arrived under the pressure of fluid, estimation is in flow measurement, the density of annular pressure and drilling fluid, a caution signal, if the pressure of difference estimation and measurement between the pressure generated is more than selected threshold value.