摘要：Oilfield drilling often encounters heterogeneous, high-viscosity active bituminous formations. Bituminous formations have plastic and creep properties, and their adhesion is strong, so it is easy to cause drilling accidents, such as viscose vibrating screen, drill pipe sticking, lost circulation, and well abandon. The current drilling fluid technologies cannot effectively avoid or solve these problems. Therefore, anti-bitumen drilling fluid technology optimization for bituminous formation is necessary to be proposed. In this paper, based on the four components and elemental analysis of formation bitumen, formation bitumen sample 2# exhibits high viscosity, high temperature-sensitivity, strong adhesion, and was chosen for continuous experiments. Through the experiments, the following three aspects were studied: (1) technical methods for improving anti-bitumen properties of drilling fluid based on viscosity reduction mechanism by emulsification; (2) technical methods for effectively reducing bitumen adhesion and contamination degree of drilling fluid based on bituminization mechanism; (3) technical measures for effectively delaying the bitumen invading into the wellbore by thickening plugging the bituminous formation. Finally, special drilling fluid treatment agents for preventing formation bitumen contamination were proposed and recommended, including emulsified viscosity reducer EMF-1, formation bitumen curing agent GHJ-1 and bituminous formation thickening plugging formulas.
关键词：Bituminous formation;drill pipe sticking;emulsification;bitumen solidification;plugging by thickening;drilling fluid
