MULTI-VARIABLE OPERATIONS

摘要

Operation of a multi-variable drilling-rig is carried out within an envelope defined by convex hulls (TC,BC) that are derived from sets of historical values for the variables accumulated in a store (3) from previous operations. A display unit (5) shows the real-time values (Q01-Q10) of the variables on parallel axes (X01­X10) together with upper and lower limits (Up01-Up10, Lp01-Lp10) of the viable ranges for each variable to remain within the envelope, taking into account the current value of each other variable. The adjustment of the value of a variable (Q03) required to correct for a variable (Q08) found to be outside its viable range, is determined tentatively before implementation, by bring about re­in viable ranges adjusting that value in the display to calculation and display of the changes that would result from such adjustment.