摘要
目前油气井固井缺乏成熟的触变水泥浆体系,已有体系常存在触变性不够强、对温度敏感以及综合性能欠佳等问题,限制了其应用。针对以上问题,通过合成两性聚合物与无机纳米材料相结合的方式开发了一种触变剂N-1,合成的聚合物分子量较大(6.0×106左右)且分布较宽,在常温下高分子量组分会溶解很慢,随着温度升高溶解会逐渐加快,为材料较高温度发挥触变作用提供了保障。选用的无机纳米材料为纤维状物质,在水中可以通过吸附和缠结形成网络结构从而体现出触变性。对其微观结构进行了表征,并以其为主剂制备出了一套新型触变水泥浆体系。室内评价实验表明,该水泥浆触变性强,并具有一定的堵漏作用,不加压时几乎不发生漏失,在50℃、2.1 MPa下加量从1.0%升到1.5%时,漏失量从380 m L降为0,其触变性随温度升高不但没变弱反而有所增强,且其失水量低(40 m L)、强度高(62℃下的24 h强度为31.6 MPa)。该体系克服了常见触变水泥浆体系存在的不足,综合性能良好,可满足施工要求。
Mature thixotropic cement slurries are seldom seen in China presently. Slurries commonly used in oilfelds are of weak thixotropy, temperature sensitive, and have poor overall properties. To solve these problems, a thixotropic agent, N-1, has recently been developed by combining a synthesized amphoteric polymer and an inorganic nano material. The amphoteric polymer has high widely distributed molecular weight （MW, about 6.0×106）. At room temperatures, the high MW polymer molecules dissolve very slowly, and the dissolution becomes fast as temperature rises. This feature ensures the amphoteric polymer. The inorganic nano material selected is a fbrous material, which forms a network in water through adsorption and entanglement. N-1 was characterized for its microstructure, and was used as main additive to formulate a novel thixotropic cement slurry. Laboratory evaluation indicated that the cement slurry had strong thixotropy and did not lose without the action of pressure. At a pressure of 2.1 MPa, a cement slurry treated with 1.0%N-1 to 1.5%N-1 had volume of loss from 380 mL down to 0 mL. At elevated temperatures, the thixotropy of the N-1 treated cement was enhanced, instead of weakened, and had low flter loss （40 mL） and high strength （aged at 62℃ for 24 hours, the strength was 31.6 MPa.） Compared with conventional cement slurries, this cement slurry has strong thixotropy and good overall properties, and can satisfy the needs of well cementing.
出处
《钻井液与完井液》
CAS
北大核心
2016年第6期73-78,共6页
Drilling Fluid & Completion Fluid
关键词
固井
触变剂
触变水泥浆
合成聚合物
纳米材料
综合性能
Thixotropy
Thixotropic cement slurry
Synthesized polymer
Nano material
Overall property
