METHOD FOR ASSESSING INHIBITING AND REINFORCING PROPERTIES OF DRILLING MUDS FOR WELL AND TEST BENCH FOR ITS IMPLEMENTATION Russian patent published in 2024 - IPC G01N11/02 G01N15/08 

FIELD: mining.

SUBSTANCE: group of inventions relates to drilling of oil and gas wells, in particular to evaluation of properties of drilling mud for unstable rocks. Evaluation of drilling mud is carried out on a test bench with a rock sample prepared for testing. For this purpose, a stressed state is created in the rock sample, which simulates the rock pressure corresponding to the selected depth of the well. Simultaneously, the estimated drilling mud is filtered through the volume of the rock sample. This is done in conditions simulating well conditions. Rock properties of the well are predicted from physical and mechanical properties of a sample of this rock in time depending on its stress state and inhibiting properties, as well as reinforcing properties of the estimated drilling mud. Properties are judged on the bench by the dynamics of variability of physical and mechanical properties of the rock sample, up to its destruction, and the dynamics of filtration of the assessed drilling fluid. Test bench includes a press housing in the form of a vertical cylinder with a blind base, side holes in the local area, a piston placed in the above cylinder and forming a sub-piston space for a rock sample in the area of side holes. Side branch pipe is attached to the housing for supply of drilling mud to the sub-piston space. Piston is made with the possibility of transferring the load to the rock sample, which simulates the rock pressure, and has its stroke sensor. Side branch pipe is made with possibility of supply of tested drilling mud under pressure, which provides filtration of this mud through rock sample. Unit for estimating the dynamics of filtration of the mud in time is provided.

EFFECT: improving reliability of evaluation of inhibiting and reinforcing properties of drilling muds and reducing risks of loss of stability of well walls with application of estimated drilling muds.

21 cl, 2 dwg