一种新型二次交联凝胶体系的合成与应用

针对海上油田多轮次调剖后,调剖效果逐渐变差的问题,研制了一种成胶时间及强度可控的二次交联凝胶体系。通过改变交联剂合成过程中冰醋酸与已二酸的摩尔比,调控凝胶体系不同阶段的成胶时间与成胶强度,扩大凝胶体系注入过程中的波及范围,改善多轮次调剖后的调剖效果;并对所合成二次交联凝胶体系在渤海S油田条件下的性能进行评价,获得适合现场应用的体系配方。研究表明,二次交联凝胶体系浓度选用4 000 mg/L聚合物+3 000 mg/L交联剂,冰醋酸与已二酸摩尔比为1∶3时,分级交联凝胶体系与渤海S油田高渗条带具有最佳的匹配效果,体系兼具封堵性能与运移性能。平板模型驱油实验表明,调剖前后水驱采收率提高16.05%。研究结果应用于渤海S油田,2口井累计增油18 288方,平均含水降低8.4%,矿场试验效果良好。

Synthesis and application of a new type of secondary crosslinking gel system

According to the effect of profile control gradually become poor after multi-round profile control in offshore oilfield, a secondary crosslinking gel system was developed which gel time and strength were controllable. By changing the molar ratio of acetic acid to adipic acid, the gel time and gel strength can be control at different stages. Through enhancing the initial strength of the profile control system, expand sweep volume in the process of gel injection, and improve profile control effect after multi-round profile control. Performance of the secondary crosslinking gel system was evaluated in Bohai S Oilfield condition, and the formula was selected. Studies have shown that secondary crosslinking gel system has the best matching performance with highSpermeabilitySbelt when the system concentration is 3000mg/L polymer and 4000mg/L crosslinking agent, and molar ratio of acetic acid to adipic acid is 1:3. Displacement experiment with flat plate model show that water flooding recovery was enhanced 16.05% after injecting profile control system. The results are applied to the S oilfield which lead to a decrease of 8.4% in water cut and a increase of 18288 m3 of oil production.