中高含水油藏聚驱后进一步提高采收率技术研究

Study on enhancing oil recovery technology of medium high water cut reservoir after polymer flooding

针对冀东油田南堡断块油藏聚驱后大孔道发育、前期常规调剖措施效果差等问题,研究一种利用残留聚合物的絮凝剂和冻胶复合体系新技术,其中絮凝体系配方:4%潍坊改性钠土(CX-1)+0.06%稳定剂Na_2CO_3;冻胶体系配方为:0.5%~0.6%聚合物YG100+0.6%~0.7%交联剂YJ-1+0.016%~0.017%交联剂TJ-1。长岩心驱替实验表明,注入复合体系后,高渗通道的渗透率降低93%,是因为复合体系中CX-1与岩心残留聚合物发生絮凝作用,形成粒径较大的絮凝体,封堵高渗通道,冻胶成冻后通过吸附和滞留方式封堵渗透层。纵向三层非均质岩心驱油实验表明,在不同高含水时期,均能大幅度提高原油采收率12.5%以上。

Aiming at the problems of big channel development,the poor effect of the early stage of the conventional profile control measures after polymer flooding in Nanpu fault block oil reservoir of Jidong oilfield,a novel complex system of flocculation and high-strength gel was developed to use the residual polymer and blocking. The new technology could achieve the purpose of increasing the benefits and cost reduction. The appropriate mass fraction in complex system of Weifang modified sodium soil( CX-1) was4%,the stabilizer was 0. 06%,the polymer YG100 was 0. 5% ~ 0. 6%,the crosslinking agent YJ-1 was0. 6% ~ 0. 7%,the crosslinking agent TJ-1 was 0. 016% ~ 0. 017%. Long core displacement experiment showed that the permeability of high permeable channels could dropped by 93% after the injection of complex system. The reason was that CX-1 reacted with the core residual polymer to form the flocculation to plugging high permeable channels and the whole gel could be gelation to block permeable zone by adsorption and retention. Three-layer-heterogeneity core displacement experiment results indicated that complex system could greatly enhance oil recovery efficiency reaching above 12. 5% in different water-cut period.