二氧化碳对塔河油田裂缝性储层酸岩反应的影响研究

发布时间：2019-04-25 18:09

【摘要】：为提高塔河油田裂缝性油藏的酸压改造效果,研究了CO_2对裂缝性油藏酸岩反应影响的问题。利用自主研制的裂缝性储层酸岩反应仪,基于网状裂缝模型,对考虑CO_2影响的不同类型、不同黏度和不同浓度酸液的酸岩反应情况进行了试验评价。试验得出:随着回压增大,酸岩反应产生的CO_2转变为超临界态后大量溶于酸液中,酸液流动阻力大幅降低,酸蚀量增大;与胶凝酸及Ⅰ型地面交联酸相比,HCl质量分数为20%的Ⅱ型地面交联酸滤失量小、黏度高,受CO_2影响最大,酸岩反应最慢,有利于实现裂缝性储层深穿透酸压的目的。Ⅱ型地面交联酸在YJY井重复酸压中进行了现场试验,与该井应用胶凝酸的首次酸压效果相比,液体效率大幅提高,酸蚀缝缝长大幅增加,压裂后累计产油1.2×104 t,增油效果显著。研究表明,超临界CO_2有助于降低酸液流动阻力,提高酸液深穿透能力,提高塔河油田裂缝性储层酸压改造效果。
[Abstract]:In order to improve the acid fracturing effect of fractured reservoir in Tahe oilfield, the influence of CO_2 on acid rock reaction in fractured reservoir was studied. Based on the reticulated fracture model, the acid rock reaction of different types, different viscosity and different concentration of acid solution considering the influence of CO_2 has been evaluated by using a self-developed acid rock reaction instrument for fractured reservoirs. The results show that with the increase of backpressure, the CO_2 produced by acid-rock reaction is transformed into super-critical state and then dissolved in acid solution, the flow resistance of acid liquid decreases greatly, and the amount of acid corrosion increases. Compared with cementitious acid and ground cross-linked acid type 鈪，

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