1. Impairment Control Historically Abrams et al 1/3 –1/7 rule
external bridging versus internal cake
concentration aspects: 5% solids
poor match with pore size and
permeability
no understanding of spurt loss

2. Impairment Control New Insights: Sharma et al
invasion of particles impact pore structure
adequate description of change in pore properties
flow back of particles modeled
relative perm effects modeled
polymers described as solids

3. Impairment Control Work done so far:
extensive coreflush testing for measuring factors controlling filtration process
validation of impairment prediction models
matching model results with field data
development of practical field tool

6. Particle Sizes in Drilling Fluids
Initial Design

7. PSD of Drilled Solids in Mud
At TD after 2 days of drilling

9. Available Software Op-ti Bridge (through MI via BP) Sharma’s Model
DIF design (bridging agent)
Acid Wash program