Development And Performance Evaluation Of Cationic Emulsified Asphalt

In the drilling industry, generally as inhibitor and filtrate reducer, cationic emulsified asphalt can improve the quality of mud cake, and penetrate into formation combining with clay to inhibit hydration swelling of clay. Cationic asphalt treatment agent has been shown to reduce the formation pollution in the lab, and has been applicated in Xinjiang, Jilin and other places. Currently, the development of emulsified asphalt mainly focused on roads construction,etc., but was seldomly developed for drilling. Emulsified asphalt typically are made by colloid mill which is high energy consumption, high investment. In this thesis, the phase transition is used to develop the cationic emulsified asphalt and figure out the cationic emulsified asphalt which average particle size is 4μm or smaller and uniformly distributed.And we tested this kind of cationic emulsified asphalt performance.In this thesis, we did a large number of verification experiment which aimed at optimizing asphalt emulsification process, surfactant complex programs and optimization of emulsified asphalt. And get the conclusions:1.Under the laboratory conditions, 90℃ is the best emulsification temperature for the asphalt we used. 2.The emulsification ability of complex surfactant is better than single surfactant. 3.For the asphalt used in the experiments,emulsification will be best when complex surfactant HLB is about 12.325. 4.When the proportion of asphalt and water is 2:25, the size distribution and stability of the emulsified asphalt are better than the 1:50 one. 5.Inversed phase emulsification is a simple process, low energy consumption method to emulsify asphalt, which can develop the cationic emulsified asphalt of which 50% particle size is smaller than 4μm. 6.By putting the emulsified asphalt into drilling fluid, nonionic emulsified asphalt can not reduce the drilling fluid loss and inhibit swelling of clay. 7.By the method of putting cationic surfactant into nonionic emulsified asphalt, we can develop cationic emulsified asphalt. And cationic emulsified asphalt has better ability than nonionic emulsified asphalt in reducing the drilling fluid filtration loss and improving the inhibition. Integrated the effect of emulsification, stability and the actual effect of the drilling fluid, we optimize a kind of cationic emulsified asphalt of which oil/solvent ratio is 1:1, oil/water ratio is 2:25, Span80:Tween80:OP-10=1:2:1, and which is transformed to positive by CTAB. It’s proved that such cationic emulsified asphalt affected drilling fluid rheology very little, and can still reduce drilling fluid filtration loss and play a good role in inhibiting clay swelling.