酸溶性水泥浆体系的研究

委内瑞拉东部的Anaco地区气层发育显著,地层压力高,而且易塌易漏,同时对生产井完井时产层的保护要求极为苛刻,在有效封固地层的同时不能对产层和可能的产油通道污染和破坏。因此,在此区块的固井作业中,需要在支撑套管封固地层的同时有效地防止气窜、地层污染和地层坍塌。以常规水泥水化和遇酸溶解的原理为基础,通过对比实验对Ca CO3含量、盐酸用量、养护时间、酸液的种类和浓度、水泥的种类等逐一分析,得出影响酸溶性水泥浆体系的重要因素和规律,为酸溶性水泥浆体系的技术研发提供重要参考,并依此进行酸溶性防气窜水泥浆的生产调整和固井作业。

Mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions

To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.