抗高温固井用悬浮稳定型降失水剂的制备与应用  

Preparation and Application of a High Temperature Suspension Stabilizing Filter Loss Reducer for Cement Slurries

作　　者：杜宇斌 刘子帅 吕斌 赵维超 周崇峰 樊荣华 DU Yubin;LIU Zishuai;LYU Bin;ZHAO Weichao;ZHOU Chongfeng;FAN Ronghua(Oil&Gas Technology Research Institute of Qinghai Oilfield Company,CNPC,Dunhuang,Gansu 736202;CNPC Engineering Technology R&D Company Limited,Beijing,102206)

机构地区：[1]中国石油青海油田公司油气工艺研究院,甘肃敦煌736202 [2]中国石油集团工程技术研究院有限公司,北京102206

出　　处：《钻井液与完井液》2025年第1期102-109,共8页Drilling Fluid & Completion Fluid

基　　金：青海油田公司科技项目“柴达木盆地复杂深井安全钻完井配套技术研究”(2023KJ0701)。

摘　　要：青海油田柴达木盆地地温梯度高且多处于地层超压带或邻近区带,深井超深井固井过程中,对高密度水泥浆高温高压工况下的失水、流变以及热冲击后的沉降稳定性、力学性能等提出了更高的要求。通过接枝聚合制备了含有温敏基团和支链结构的悬浮稳定型降失水剂DFS-200,并对其综合性能进行了评价。结果表明,DFS-200可将2.10~2.30 g/cm^(3)水泥浆体系高温工况下的API失水量控制在50 mL以内,游离液为0、密度差小于0.03 g/cm^(3),流变和稠化性能良好,浆体“低温不增稠、高温不稀释”;水泥石强度发育快,静胶凝强度过渡时间短,200℃下48 h抗压强度大于30 MPa、无衰减。应用DFS-200在柴达木盆地目的层尾管固井中进行了多次现场试验,效果良好,为改善青海油田深井超深井封固质量、保障井筒完整性提供了技术支撑。High formation temperature gradients prevail in the Qinghai Oilfield(Tsaidam Basin).High bottom hole temperatures in deep and ultra-deep wells plus high formation pressures from the over-pressurized formation belts impose rigorous requirements on cement slurries as to their high temperature high pressure(HTHP)filter losses and rheology,the settling stability and mechanical performance after experiencing heat impact.To deal with these situations,a suspension stabilizing filter loss reducer DFS-200 containing temperature-sensitive groups and branched chain structures was developed.Evaluation of the general performance of DFS-200 shows that it can reduce the high temperature filter loss of a cement slurry(with density between 2.10 g/cm^(3) and 2.30 g/cm^(3))to less than 50 mL,and the cement slurry still has zero free water,small density difference between the top cement and the bottom cement of less than 0.03 g/cm^(3),as well as good rheology and thickening performance.The DFS-200 treated cement slurry does not viscosify at low temperatures and does not thin at elevated temperatures.The strength of the set cement develops quickly,the transition time of the static gel strength of the cement slurry is short.The 200℃×48 h compressive strength of the set cement is greater than 30 MPa and does not decline.DFS-200 has been used many times in liner cementing operations in Tsaidam Basin and has gained good results,it has provided a technical support to improving the job quality of cementing the deep and ultra-deep wells in Qinghai Oilfield and also to ensuring the borehole integrity.

关 键 词：降失水剂 支链结构 沉降稳定性 水泥浆 高温 深井 

分 类 号：TE256.6[石油与天然气工程—油气井工程]