复合空心微珠低密度水泥浆的研究与应用

低压易漏地层在固井过程中易发生漏失,因此固井时要求降低水泥浆密度。以漂珠和空心玻璃微珠复合作为密度减轻材料,根据颗粒级配紧密堆积理论,以水泥、稳定剂DZW以及其他各种外加剂进行合理配比,设计出一种密度为1.28 g/cm3的低密度水泥浆。性能评价结果表明:该体系满足沉降稳定性要求,流动性好,65℃下滤失量小于50 m L,24 h抗压强度大于14 MPa。现场应用结果表明,复合空心微珠低密度水泥浆体系能够有效解决低压易漏地层固井漏失问题。

Research and application of composite hollow microbead low density cement slurry

Lost circulation may easily occur in low pressure leaking-prone formation during cementing, so cement slurry density needs to be reduced while cementing. Using floating beads and hollow glass microbeads jointly as density lightening material and properly matching cement, stabilizer DZW and various other additives according to theory of close packing of grain composition, a low density cement slurry was designed – with a density of 1.28 g/cm3. The result of performance evaluation shows that this system can meet the requirement of settling stability, has good flowability and its filtration at 65 ℃ is less than 50 mL and its 24 h compression strength is greater than 14 MPa. Results of field application show that this composite hollow micro-bead low density cement slurry system can effectively address the problem of lost circulation in low pressure leaking-prone formation during cementing.