Methods and systems for characterizing lcm particle plugging and rheology in real time

Abstract

Methods and systems for characterizing drilling fluids laden with LCM (Lost Circulation Material) and other solid materials are disclosed. A test cell for analyzing a fluid is provided with a first conical inner portion and an axial positioning device positioned along an axis of the test cell. A first conical plug is coupled to the axial positioning device and is movable in and out of the first conical inner portion along the axis of the test cell. A fluid inlet is positioned at a first location on the test cell and a fluid outlet at a second location.

1 .- 11 . (canceled) 
     
     
         12 . A method of measuring the rheology of a first fluid comprising:
 passing the first fluid through a gap formed between a conical plug and a conical portion of a test cell;   measuring a pressure drop along the gap;   using the pressure drop measurement to determine a shear stress;   measuring the flow rate of the first fluid through the gap;   using the flow rate measurement and flow geometry to determine an average shear rate; and   predicting rheological model parameters of the first fluid using the shear stress and the average shear rate.   
     
     
         13 . The method of  claim 12 , wherein the rheological model parameters are selected from the group consisting of: plastic viscosity, Bingham model yield point and Herschel-Bulkley model parameters. 
     
     
         14 . The method of  claim 12 , further comprising:
 passing a second fluid through a gap formed between a conical plug and a conical portion of a test cell;   measuring a pressure drop along the gap;   using the pressure drop measurement to determine a shear stress;   measuring the flow rate of the second fluid through the gap;   using the flow rate measurement to determine an average shear rate;   predicting a rheological model of the second fluid using the shear stress and the average shear rate; and   comparing the rheological model of the first fluid and the second fluid.   
     
     
         15 . The method of  claim 14 , wherein the first fluid is a LCM laden fluid and the second fluid is a LCM particle free fluid. 
     
     
         16 .- 21 . (canceled)