Brittle fracture of cement sheath, induced by perforation and stimulation treatments, can cause cross flow of formation fluid and increase casing damage. A novel agent XL was developed for solving the problem. Experim...Brittle fracture of cement sheath, induced by perforation and stimulation treatments, can cause cross flow of formation fluid and increase casing damage. A novel agent XL was developed for solving the problem. Experimental results showed that the toughness of the set cement containing XL was improved remarkably. The engineering properties of the slurry containing XL, drag reducer USZ （0.2% BWOC）, filtrate loss additive F 17B （1.2% BWOC） and crystalloid expanding agent F17A （3% BWOC） could meet technical requirements of cementing operation. After perforation, good quality cement sheath enhanced with XL was observed by CBL/VDL logs in a deep well.展开更多
文摘针对储气库生产对水泥石韧性的特殊要求,优选了粒径为0.15~0.18 mm经表面改性的橡胶粉作为弹性材料,聚丙烯纤维作为增韧材料,通过实验确定弹性材料和增韧材料的最佳加量分别为3.0%和0.1%,并配合使用PVA胶乳类降失水剂,改善水泥石脆性,提高耐冲击能力及抗折能力,满足水泥环频繁高压注采条件下的长期密封性。综合评价了增韧水泥石的弹性模量、抗折强度、抗压及胶结强度、渗透率及应力条件下水泥环密封性,与净浆水泥石相比,弹性模量降低了43%,抗折强度增加了84.6%,渗透率小于0.05 m D,能够满足35 MPa压力、35℃温差下的水泥环密封性要求,适用于储气库固井。
文摘Brittle fracture of cement sheath, induced by perforation and stimulation treatments, can cause cross flow of formation fluid and increase casing damage. A novel agent XL was developed for solving the problem. Experimental results showed that the toughness of the set cement containing XL was improved remarkably. The engineering properties of the slurry containing XL, drag reducer USZ （0.2% BWOC）, filtrate loss additive F 17B （1.2% BWOC） and crystalloid expanding agent F17A （3% BWOC） could meet technical requirements of cementing operation. After perforation, good quality cement sheath enhanced with XL was observed by CBL/VDL logs in a deep well.
