无机凝胶在18 m长岩心内的传输运移能力*

Transport Capacity of Inorganic gel in 18 m Core

曹伟佳 卢祥国 田中原 刘文辉 于 萌 闫炳旭

CAO Weijia LU Xiangguo TIAN Zhongyuan LIU Wenhui YU Meng YAN Bingxu

为了实现海上高盐油田高效低成本开发，满足深部液流转向技术需求，本文开展了无机凝胶药剂浓度优选 及18 m超长岩心内传输运移能力实验研究。结果表明，目标储层注入水中Ca2+和Mg2+ 含量分别为0.569 g/L和 0.229 g/L，二者不足以与主剂Na2SiO3溶液反应生成大量无机凝胶，需选用外加CaCl2溶液作为助剂，选择主剂与 助剂浓度均为3.7 g/L。随“软化水+Na2SiO3溶液+软化水+CaCl2溶液”交替注入轮次增加，18 m长岩心上各个长 度区间压力梯度呈现逐渐升高趋势。多轮次交替注入结束后无机凝胶波及岩心区域达到总长度86.7%，岩心前 后相邻两个长度区间压力梯度比值分别为3.85、2.03、1.16、1.19和1.24，各个长度区间压力梯度比值差不大，无机 凝胶调剖剂具有良好传输运移和深部液流转向能力。后续水驱结束时，岩心各个长度区间封堵率在19.97%~ 72.26%，表明无机凝胶在孔隙内具有较强耐冲刷和持久液流转向能力。图3表5参17

In order to achieve high efficiency and low cost development of offshore oilfield with high salinity，and meet the needs of deep liquid diversion technology，the transport capacity of the inorganic gel in 18 m super-long core was studied in this paper. The results showed that the contents of Ca2+ and Mg2+ in the injected water of target reservoir are 0.569 g/L and 0.229 g/L， respectively，and the two are not enough to react with the main agent Na2SiO3 solution to produce a large amount of inorganic gels， hence，additional CaCl2 solution is needed as additives. The concentrations of main agent and auxiliary agent were 3.7 g/L， respectively. When the injection course of "softened water + sodium silicate solution + softened water + calcium chloride solution" increased，the pressure gradient in each length of the core increased gradually. After alternating injection courses of intra layer precipitate，the inorganic gel reached 86.7% of the total core length，the ratio of pressure gradient in two adjacent length intervals of the core was 3.85，2.03，1.16，1.19 and 1.24，respectively，the pressure gradient ratio difference in each length interval was not significant，which indicating that the profile control agent of inorganic gel had good transport capacity and deep liquid diversion ability. Moreover，at the end of the following water flooding，the plugging rate of cores in each length interval was about 19.97%— 72.26%，which indicated that inorganic gel in the layer had strong scour resistance and durable deep liquid diversion capability.

10.19346/j.cnki.1000-4092.2020.03.009