Flowback-sample analysis

Analysis of flowback samples is important for observation of sludge, emulsion, solids production, and related problems. Compositional analysis of spent add (see chapter 16) can shed light on problems, espedally precipitation of add reaction products, and can be used to optimize future treatment design. 

Unbroken gel plugging may occur in carbonate acidizing procedures in which gelled acid is used. Monitoring and analysis of posttreatment flowback fluid samples may indicate unbroken gel, which will restrict flow of formation fluids. Gel breaking should be defined and controlled through pretreatment laboratory testing by the service company, at expected downhole temperature and residence time conditions. 

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