engleski

Laboratory Evaluation of Calcium Carbonate Particle Size Selection for Drill-in fluids

The tehnological developments in horizontal, re-entry and multilateral wells require drilling and completion the reservoir sections of a well inducing as little damage as possible. The trends towards open hole completions places additional emphasis on formation damage avoidance. One of the critical factors in avoiding formation damage during drilling is obtaining surface bridging on the formation face with minimum indepth solids penetration. In case of overbalanced drilling, this can be done by optimizing the particle size distribution of calcium carbonate used as the bridging agent. The paper presents laboratory data from tests carried out on selected fluids which show the extent of the changes that occur in fluid filtration properties (spurt loss, PPT value and static filtration rate) when calcium carbonate with different PSD is used. The Permeability Plugging Tester was used to evaluate the filtration and spurt loss of selected fluids. The ceramic disks with permeabilities 0, 09 &micro ; m2 (90 mD), 0, 13 &micro ; m2 (130 mD) and 0, 4 &micro ; m2 (400 mD) were used as a filter medium.

fluids; formation damage; bridging agent; particle size distribution; filtration

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