海洋深水用双充填低温低密度水泥浆体系研究

LTLD Double-Filling Cement Slurry System for Use in Deepwater Well Cementing

题示低温低密度水泥浆用于海洋油藏深水井固井，填充的惰性气体气泡用物理和化学方法共同产生，所用外加剂大部分是专门研制的。对该体系的组成及原理作了一般性的说明。详细说明了该体系的室内制备方法。报道了水泥和主要外加剂的筛选结果。所选水泥为葛洲坝水泥厂生产的低温高强水泥T5，水泥石7℃抗压、抗折强度为28．7、4．8MPa。化学发泡剂INS和TNL反应产生氮气使水泥浆发泡。促凝剂ACL使水泥浆在-5℃凝固，缓凝剂RD可调节5℃稠化时间为4～8小时，35℃时也可调。加入6％～8％降滤失剂JPO使水泥浆滤失量〈20mL。加入5％增强剂GCO使密度1．35g／cm^3的泡沫水泥抗压强度由8．14MPa增至10．41MPa。密度可调范围为0．8～1．5g／cm^3，在8MPa下仍可达1．48g／cm^3。给出了水泥装的配方：T5＋90％海水＋7％JPO＋1％FLY（分散剂）＋0．8％ACL＋1．5％RD＋35％LGT、（减轻剂）＋5％GCO＋1％SB（泡沫分散剂4）＋2％INS＋1％INL。图3表3参8。

The titled LTLD cement slurry is developed for cementing deepwater wells at offshore oil/gas reservoirs and characterized by combinational physical/chemical way of foaming by N2, that is , double gas filling and the majority of additives used is synthesized specially. The composition and the principle of this slurry system are outlined. The laboratory procedure of preparing the slurry is described in some detail. The cement selected is Gezhouba＇s low-temperature, high-strength grade T5 and the set cement has compression and flexual strength at 7℃ of 28.7 and 4.8 MPa, Two-component frothing agent INS＋ INL reacts and foams the slurry. Using promotor ACL results in setting of the slurry at - 5℃ and using retarder RD adjusts the thickening time at 5℃ in range 4-8 hrs and easily at 35℃. Introducing 6-8% filtrate loss reducer JPO keeps the filtrate loss of the slurry 〈20 mL. With 5% reinforcer GCO added, the compression strength of a slurry of density 1.35 g/cm^3 is increased from 8.14 to 10.41 MPa. The density of the slurry is adjustable in range 0.8-1.5 g/cm^3 and reaches 1.48 g/cm^3 at 8 MPa pressure. The typical recept for the slurry system is as follows. T5＋90% sea water＋7% JPO＋ 1% FLY （dispersant） ＋0.8% ACL＋ 1.5% RD＋35% LGT （lightening material） ＋5% GCO＋ 1.% SB （foam dispersant） ＋2% INS＋l% 1NL.