杏南油田基于石油磺酸盐的降压增注体系配方研究

杏南油田太北区块为典型的低渗透砂岩储层,其具有低孔低渗、非均质严重、储层敏感性强等特性,在生产过程中出现了注水压力上升快、生产井压力和产量下降快等问题。为了缓解这些问题,进行表面活性剂降压增注技术研究,以石油磺酸盐为主剂,通过添加各种助剂,依据测定油水界面张力和岩心模拟降压实验,研究了降压增注表面活性剂体系配方,优化了注入参数,达到了降压增注的效果。结果表明,所研制的配方体系(质量分数)为0.7% XPS+0.9%椰子油二乙醇酰胺+1.2%Na₂CO₃ +0.5% NBA,与太北区块原油间的界面张力为8.61×10-3mN/m;在室内岩心驱替中,降压增注表面活性剂溶液的最佳注入质量分数为0.5%,最佳注入量为0.5PV,降压率为18.37%。

Research of Decreasing Injection Pressure and Increasing Injection Rate by Petroleum Sulfonate-Based Surfactant in Xingnan Oilfield

The Taibei block of Xingnan oilfield is a typical extra low-permeability and strong sensitivity reservoir, which has many characters, such as low porosity, low permeability and severe heterogeneity. During water flooding of the Taibei block of Xingnan oilfield, the rapidly-increasing pressure in injecting wells and the rapidly-decreasing pressure in producing wells occurred. In order to abate these problems, in this paper, technology of decreasing injection pressure and increasing injection rate by petroleum sulfonate-based surfactant was studied.The petroleum sulfonate was selected as the main chemical agent, assisted by various additives. By IFT measurement of oil and surfactant solution and core simulation displacement experiment, the chemical agent formula used for decreasing injection pressure and increasing injection rate was developed, and the injection parameters were optimized.The results showed that the formula system was 0.7%XPS+0.9%6501+1.2%Na₂CO₃+0.5%NBA, the IFT between the Taibei block oil and formula system was 8.61×10^-3mN/m, the best concentration of agent was 0.5%, the best injection volume was 0.5 PV, and the ratio of decreasing injecting pressure was 18.37%.