Because we recognize a passive transformation, are shown , we know there's an agent lurking nearby. The original sentence is in passive voice, suggesting that an agent got suppressed during the transformation. Disembedding for Clarity Our revised sentence may still be less than perfectly clear. That's because of complicated embeddings in the technical jargon. A means is waterflood.
Crude oil is unprecipitated.
This list suggests why people who aren't petroleum engineers or geologists may still be bemused by the restructured sentence. An editor or reviewer, by analyzing a sentence thus, could hazard an educated guess about the knowledge the sentence assumes. The asphaltene causes some of the oil to settle to the bottom of the formation. This oil can be forced out by waterflooding, a mechanism for displacing it. But the sentence suggests that precipitation by asphaltene may not be necessary, since the displacement mechanisms for the precipitated and the unprecipitated crude are similar.