海上高含水油田就地封堵体系优化研究

Optimization of in-situ sealing system applied in offshore high water-cut oilfields

针对渤海油田部分区块高含水和作业空间受限的问题,从油井堵水方面提出就地封堵水窜层位技术。模拟渤海油田储层条件,对自生气体系、冻胶体系和泡沫体系进行性能评价和配伍性实验,优选就地封堵体系,并模拟非均质储层对封堵体系的堵水性能进行了研究。优选的就地封堵体系配方为:质量分数36% NaNO_2+28% NH_4Cl+0.3%海水速溶型HPAM+0.005%～0.01%有机铬交联剂+0.5%COSL-3起泡剂,优选体系与地层流体配伍性良好。就地封堵体系具有优良的选择性封堵性能,可以优先封堵水窜层位,调整高、低渗层分流率,降低注入水的无效循环,提高渤海油田高含水油藏的开发效果。

Aiming at the problem of high water cut in some blocks of Bohai oilfield,the paper puts forward the technology of in-situ blocking water channeling.The performance evaluation and compatibility experiments were carried out on the self-generating gas system,the gel system and the foam system in the Bohai oilfield reservoir conditions.The in-situ sealing system was optimized,and the water blocking performance of the optimized system was studied using heterogeneous sandpack models.The optimum in-situ sealing system is:36wt% sodium nitrite+28wt% ammonium chloride+0.3wt% seawater quick-dissolving HPAM+0.005wt%~0.01wt% organic chromium crosslinking agent+0.5wt% COSL-3 foaming agent.The optimized system is compatible with formation fluids.The in-situ sealing system has excellent selective plugging effect,which can block water channeling high-permeability layer,adjust the liquid flow rate of high and low permeability layer,reduce the inefficient circulation of injection water,and improve the development effect of high water cut oil reservoir in Bohai oilfield.