【摘要】 针对巴彦-河套盆地井深6000 m以上的膏盐层，井底循环温度180℃左右，常规的高温高密度水泥浆存在流变性和稳定性差，失水量大，稠化时间难以调控、早期强度发育缓慢等技术难题，急需研发出密度为2.30～2.50 g/cm~3的耐盐高温高密度韧性水泥浆体系。针对水泥浆外加剂以“无机纳米颗粒+聚合物弱交联”结构设计制备出降失水剂（LHF）、“强吸附阳离子单体+阴离子单体”制备出缓凝剂（LHR）和“温敏缔合+微交联”结构设计制备出悬浮稳定剂（LHX）分别调控水泥浆的失水量，稠化时间，沉降稳定性；依靠紧密堆积理论，采用Dinger与Funk对Andrease方程进行修正的MAA模型，以铁矿粉为主，GM-1为辅作为加重剂构建密度为2.30、2.40和2.50 g/cm~3的高密度水泥浆体系，颗粒之间以滚珠形式相接触，降低摩阻；针对早期水泥石力学性能发展缓慢，分别引入增强剂和增韧剂，从纳米尺度、微米尺度两方面增加水泥石的力学性能：一部分填充孔隙，另一部分充当骨架结构，形成类似于“钢筋混泥土”构型，降低了水泥石的脆性。最终形成密度为2.30、2.40和2.50 g/cm~3的水泥浆体系，该体系流变性好，稳定性高，失水量小于50 mL，稠化时间可调。更多还原

【Abstract】 For the gypsum salt layer encountered in wells deeper than 6,000 meters in the Bayan-Hetao Basin, where the bottom hole circulating temperature is around 180℃, conventional high-temperature and high-density cement slurries present several technical challenges, including poor rheological performance and stability, high fluid loss, difficult control of thickening time, and slow early strength development. There is an urgent need to develop a salt-resistant, high-temperature, and high-density resilient cement slurry system with a density range of 2.30 to 2.50 g/cm~3. In view of the cement slurry admixture, the fluid loss agent(LHF) was prepared by the structure design of ’inorganic nanoparticles + polymer weak crosslinking’, the retarder(LHR) was prepared by the structure design of ’strong adsorption cationic monomer + anionic monomer’, and the suspension stabilizer(LHX) was prepared by the structure design of ’temperature sensitive association + micro crosslinking’. The fluid loss, thickening time and sedimentation stability of cement slurry were controlled respectively. Relying on the theory of close packing, and adopting a modified MAA model by correcting the Andrease equation with Dinger and Funk’s approach, a high-density cement slurry system with densities of2.30 g/cm3, 2.40 g/cm~3, and 2.50 g/cm3 is constructed using iron ore powder as the primary weighting agent and GM-1 as a supplementary weighting agent. The particles interact in a ball-bearing manner to reduce friction. To address the issue of slow early development of the mechanical properties of the cement stone, both strength enhancers and toughness improvers are introduced.These additives work at both the nanoscale and microscale to improve the mechanical properties of the cement stone: some fill the pores, while others act as a skeletal structure, forming a configuration similar to "reinforced concrete," which reduces the brittleness of the cement stone. The final cement slurry systems formed with densities of 2.30, 2.40, and 2.50 g/cm~3 exhibit good rheological properties, high stability, fluid loss of less than 50 mL, and adjustable thickening times.更多还原