313 results about "Critical condition" patented technology

Method and system for drilling control comprising a plurality of controllers adapted to control performance process parameters, on the basis of driller controls from a driller that provides this as instructions to said controllers, wherein the system further comprises sensors and means for obtaining process values, such as downhole pressure, temperature and torque, wherein the system is adapted to, continuously and / or repeatedly, calculate safeguard envelopes for performance process parameters on the basis of process values and drilling process models and that it is adapted to restrain said controllers from applying performance process parameters outside said safeguard envelopes as a result of driller instructions, and—a method and system for automatically triggering a remedying action in case of an evolving or existing critical situation, comprising calculation of process parameter boundaries which represent a critical condition for the well by using calibrated drilling process models, comprising (i) triggering an emergency action if a parameter exceeds said boundaries, said emergency action being intended to minimize the effect of said critical situation, (ii) then further analyzing the well in order to determine which remedying action to then be applied, the remedying action being intended to remedy the cause of said effect; (iii) if said remedying action is not capable of remedying the cause of said effect, then applying predetermined safe process parameters or shutting down.

Provided is an improved pressure-type flow rate control apparatus. The empirical formula for the compressible fluid under non-critical conditions (sub-sonic) is expressed as Qc=KP2(P1-P2) and the flow rate of fluid passing through orifice (4) is calculated by: Qc=KP2(P1-P2) (K is a proportional constant; and m and n are constants) so that the flow rate of fluid passing through the orifice can be controlled to the target flow rate with high precision at a high speed. Also provided is an improved pressure-type flow rate control apparatus in which a pressure ratio P2 / P1=r, obtained from an upstream pressure (P1) and a downstream pressure (P2) is constantly compared with a critical value (rc), and under critical conditions (r<=rc), the flow rate is calculated by: Qc=KP1. Under non-critical conditions (r>rc), the flow rate is calculated by Qc=KP2(P1-P2), so that the flow rate is controlled to the target flow rate with accuracy at a high speed depending upon the conditions of fluid.