胜科1井ф244.5 mm×ф250.8 mm复合尾管固井技术

Composite Liner(ф244.5-ф250.8mm) Cementing Technique in Well Shengke-1

胜科1井三开固井存在的盐膏层蠕变和软泥岩膨胀造成的井眼缩径、钻井液密度高(2.26 kg/L)、井径不规则、井底温度高(168℃)等问题及水泥封固段上下温差大(90℃)等技术难点,采取了优化钻井液性能、确定套管安全下入时间、选用高抗挤套管复合管柱和附件,采用抗高温抗盐抗污染高密度(2.30 kg/L)水泥浆和其他配套技术措施。在实际固井时,在下完套管发生井漏不返的情况下,采取先尾管注水泥后高压挤水泥的补救措施,固井质量合格,在四开钻穿孔1段下部及孔2段巨厚裂缝发育的泥岩地层、超长裸眼段、钻开多套压力共存地层和井下温度超高的情况下,没有出现244.5 mm×250.8 mm复合尾管被挤扁现象,安全钻至井深7 026 m。

According to the challenges in Well Shengke-1 of wellbore shrinkage due to gypsum formation creep,high drilling fluid density（2.26kg/L）,irregular wellbore diameter,high bottom hole temperature（168℃）,and high temperature differences（90℃） between the upper and the lower cementing sections,a series of technical measurements were used,including optimized drilling fluid in cementing,determination of safety casing setting time,using high anti-collapse casing and spares,and using the high density cement slurry（2.30kg/L）with properties of anti-high-temperature,anti-salt and anti-pollution.During in-situ cementing operation,circulating lost happened after running casing strings and remedial cementing was conducted by displacement liner strings followed by high pressure squeeze cementing,therefore a qualified cementing job was achieved.The collapse of the composite liner（φ244.5mm×φ250.8mm） did not occur considering the lower Kong-1 to the Kong-2 in fourth section,a ultra-long open hole in the mudstone with thick fracture development,ultra-long open hole,and multiple pressure system and high formation temperature,the completed well depth is 7026m.