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深井超深井常会遇到长封固段大温差固井水泥浆施工困难，固井质量难以保证等问题。本文在总结国内外研究现状的基础上，分析了长封固段大温差固井水泥浆技术研究不足主要在于：(1)缓凝剂的跨温区使用易造成水泥浆超缓凝，目前研究没有从本质上解决该问题，且缓凝剂加量大抗盐性有待提高；(2)聚合物类外加剂在高温下的粘度急剧降低易造成水泥浆稳定性变差；(3)低密度水泥浆环空封隔性能较差；(4)高密度水泥浆在高温高压条件下稳定性较差等。针对上述难点，提出了长封固段大温差固井水泥浆技术对策，包括：(1)合理设计缓凝剂分子结构，研发加量少、抗盐性强的低温敏感缓凝剂；(2)探索AMPS类共聚物引起“鼓包”现象的本质；(3)选择并修正适用于固井水泥浆的紧密堆积模型，以提高高密度、低密度水泥浆应用性能；(4)积极开展高温悬浮稳定剂的合成与生产。

In recent years, due to the exploration and development of oil and gas continue to develop in deep formation, the number of the cementing for long sealing section and large temperature difference also increases rapidly. It was pointed out that the shortage of cementing slurry for long sealing section and large temperature difference mainly lie in:(1) The use of retarder in different temperature range leading to ultra-retarding of cement slurry and the present research do not solve the problem in essence, the amount of retarder is large and has the poor salt resistance; ( 2 ) The sharp drop in viscosity of polymer additives at high temperature causing the stability deteriorates of cement slurry; ( 3 ) The difficulties in sealing annular space using low density cement; ( 4 ) The stability of cement slurry with high density is poor under the condition of high temperature and high pressure, based on summarizing the domestic and foreign research statuses. Considering these difficulties, the technical countermeasures of cementing slurry for long sealing section and large temperature difference were proposed, including: ( 1 ) The molecular structure of retarder is designed reasonable and the low temperature sensitive retarder researched has the advantage of strong salt-resistant and add a little;(2) Explore the essence of"bulge"phenomenon caused by AMPS copolymer; ( 3 ) Select and modify the closely packed model combined with the characteristics of well cementing engineering, to improve the application performance of high density and low density cement slurry; ( 4 ) Carry out the synthesis and production of high temperature suspension stabilizer.