油井水泥纤维增韧材料的研究与应用

Study and application of toughness-enhancing fiber material for the cement used for well-cementing

为了解决国内油田薄油层井、小间隙井和侧钻井固井后射孔及后续增产措施造成的水泥环脆裂(即二次窜流)问题,研制开发了油井水泥纤维增韧材料(增韧剂F17F).对增韧水泥石的各种力学性能(抗折强度、抗冲击功、弹性模量和应力/应变关系等)及纤维增韧水泥浆体系的工程性能进行了测试.结果表明,增韧水泥石的弹性模量降低了16.9%～48.0%,抗冲击功提高了27.0%～68.0%,抗折强度提高了15.9%～33.0%;增韧水泥的流动性得到改善,其失水量和析水率显著降低.此外,还进行了聚能射孔试验、地面打灰试验、1口井的现场打水泥塞试验和2口井的现场固井试验.室内实验和现场试验结果表明:增韧水泥的强度、抗冲击能力及其综合工程性能均能满足固井施工的要求.

In order to solve the problem of the brittle fracture of cement sheath caused by perforation and other production-enhancing measures after the well cementing of thin oil reservoir wells, small-borehole wells and laterally-drilling wells, a fiber toughness-enhancing material for well-cementing cement is developed. The mechanical properties (including bending strength, impact work,, elastic module and stress-strain relationship etc.) of the high-toughness fiber cement and the engineering properties of the high-toughness fiber cement slurry are measured. It is shown that, the elastic module of the fiber cement is decreased by 16.9%～48.0%, its impact work is increased by 27.0%～68.0%, bending strength is increased by 15.9%～33.0%; the flowability of the cement slurry is improved, its water loss and water-liberating rate are reduced. Besides, jet perforating simulation test, surface compounding test, field cement plug test of one well and field well-cementing tests of two wells are carried out. The results show that, the strength, impact resistance and the comprehensive engineering performance of the fiber cement can all meet the requirements of well-cementing technology to it.