Click for a larger image
|
Click for a larger image |
The simulator allows to calculate pressure losses in borehole during
drilling and cementing. Approximation of rheological characteristic measured
by viscosimeter with two-power and polynomial model of non-Newtonian liquid,
provides best precision among similar methods of pressure computation, because
the polynomial model in computations uses full information received from
multivelocity viscosimeters. Z-criterion, usually used for a non-Neutonian
liquid power model is used in the simulator for determining the flow type.
After the borehole circulating system channel is presented as the tube sections
of round and annular profile with a constant area, their flow type is determined.
Then simulator computes pressure losses for two-power and polynomial models
of liquid flow. Precision benefits from using polynomial model are most
significant for high viscosity muds with complicated rheology. |