Abstract

KCl-Polymer-Polyol mud system is being increasingly used for reactive shale stabilisation and enhanced drilling performance. Though this mud system improves drilling performance, the polyol contaminated sediments create problem in geochemical analysis as polyol interferes with Programmed Pyrolysis (Rock Eval) peaks of volatile hydrocarbons (S1) as well as of pyrolysable hydrocarbons (S2) and damages the instrument. It is not possible to carry out geochemical pay zone evaluation in the wells where polyol activated mud system has been used as both hydrocarbons and polyol contribute to S1 peak.