γ油田嫩二底套损成因及防控措施研究

Study on the Causes and Control Measures of Casing Damage in Nen II Bottom of γ Oilfield

摘要: 针对嫩二底套损井数多、区域集中、对开发影响大、治理难的实际问题，通过对嫩二底的岩心特征进行观察、电阻率峰值分析、井径测试分析及岩心水化试验，确定嫩二底套损的地质因素；通过对注入水浸入嫩二段几种方式的研究，确定了水侵源头；根据嫩二底成片套损取得的认识，制定对应防控对策。研究表明，成片套损位置大多发生在嫩二化石层中化石带的第三个峰值(最大峰值)的附近，富含生物碎屑，页理发育，为硬岩性薄弱面，易启开，是套损地质因素；固井质量差，注入水上窜到嫩二段、报废井附近注水井注水通过未报废井段窜流进入嫩二段、套损注水井发现不及时均导致注入水侵入，使套损区域不断扩大；提高防控能力、控制进水通道防止嫩二段进水和排出进入嫩二段注入水三项措施利于治理嫩二底套损，效果较好。嫩二底的套损成因研究和防控措施实施有利于降低油田套损危害，保障原油生产，降低修井投资。

Abstract: In view of the practical problems such as the number of casing damage Wells, concentrated area, great influence on development and difficulty in treatment in the Nen II bottom, the geological factors of casing damage in the Nen II bottom were determined by observing the core characteristics of the standard layer of the Nen II Bottom, analyzing the peak resistivity, well diameter testing and core hydration test. The source of water invasion was determined by studying several ways of injecting water into the II section of Nen. According to the understanding of the sleeve damage of Nen II bottom, the corresponding prevention and control measures are made. The results show that the locus of casings damage mostly occurs near the third peak (the largest peak) of fossil zone in the Nen 2 fossil layer, which is rich in bioclasts, developed in foliation, and is the weak surface of hard lithology, which is easy to open, and is the geological factor of casings damage. The poor cementing quality, injected water flowed through the Nen II section, the injection well near the abandoned well entered the Nen II section through the channeling flow of the unabandoned section, and the casing loss injection well was not found in time, which all led to the intrusion of injected water and the continuous expansion of the casing loss area. The three measures of improving the prevention and control ability, controlling the inlet passage and preventing the inflow of water and discharging into the II section of Nen are beneficial to the treatment of the bottom casing damage of the II section of Nen and the effect is good. The research on the cause of casing damage and the implementation of prevention and control measures in the standard layer of the II bottom of Nen Oilfield are beneficial to reduce the damage of casing damage, guarantee the production of crude oil and reduce the investment of workover.