Effect of curing environment on compressive strength of low density set cement mixed with floating potential and microsilica

Application of floating potential and microsilica typed low-density cement system is one of the major solutions for cementing low-pressure lost circulation sections and long well intervals.Its strength development under high temperature and high pressure,however,has not been well systematically analyzed and experimentally evaluated.Based on the analysis of particle size distribution and the optimization of low density cement system formulation using laser grain size test and related compatibility experiments,the effect of different curing environment on the strength of cement samples is analyzed by conducting the compressive strength test.Meanwhile,experimental results are compared with the high-temperature strength of base slurry of Jiahua class-G cement.Finally,experimental results are discussed from the perspectives of chemical composition,particle size distribution and agitation method.Resultsshow that the effect of curing environment on the compressive strength of low density system is apparently different with that of base slurry.The cement system with floating potential and microsilica has favorable durothermic properties to inhibit the decline of high-temperature strength.The close packing effect allows less influence of curing pressure on the compressive strength of set cement.