The expanded use of sandstone matrix acidizing techniques may have been the most significant trend of the turbulent 1980's. Gulf Coast operators have found that remedial acid treatments cost a fraction of that required for a comparable offshore completion. Improved design and application techniques now provide economic success rates greater than 80% with most treatments paying out in less than 30 days. However, one area that continues to frustrate designers of acid treatments is the unpredictability of crude oil reservoirs. Current testing procedures are inadequate, failing to accurately replicate the interaction between the treating fluid and acid sensitive crudes. Reliance on these procedures can produce catastrophic facility upsets, downhole emulsion blocks, reduced damage removal efficiency or result in a marginal treatment response.

A new simplified laboratory testing procedure was developed which more accurately simulates treatment effects under reservoir conditions. This laboratory test demonstrates the need for less reliance on surfactant non-emulsifiers and an expanded use of mutual solvents. Field data confirms more accurate prediction of add compatibility. In addition, acid treatments designed utilizing this laboratory procedure showed greater initial production response and maintained the incremental increase for a much longer time. Design guidelines are presented which address concerns of mutual solvent/corrosion inhibitor incompatibility, high temperature applications and treating volume requirements.

You can access this article if you purchase or spend a download.