| 摘要 |
A method of preventing flow of formation fluid and crude oil into a well bore during an electric resistivity logging operation. A readily flowable liquid gellation composition containing a breaker is of contrasting resistivity to that of the formation water. Fluids in the well bore are displaced by the liquid composition and the composition is allowed to gel. The gel may be of a highly viscous, moderately flowable state, which prevents ingress of formation fluids and crude oil but permits logging equipment to be moved therethrough. Alternatively, the gel in the well bore may be removed while leaving the gel in the adjoining formation in place, and the removed gel replaced with fresh water prior to the logging operation. After effecting the log a breaker in the gel composition causes the gel to revert to a liquid, which is removed from the well bore.
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