延长油田深穿透大液量酸化案例分析研究

王鹏 高苗苗 高荣

摘 要：基质酸化被广泛应用于碳酸盐岩储层的解堵。2017年，在延长油田进行了70多次基质增产作业。然而，对于无严重伤害且受地层能量降低影响的低产能井，常规基质的作用有限。为此，开发了一种新的酸化技术，即大液量深穿透酸化。胶凝酸以其经济效益得到广泛应用，并对其流变性能进行了测试。在注入过程中，优化注入速度，选择大酸量，在地层中形成长效孔洞，降低油气渗流阻力，连通深层油气储层，提高产量。应用该技术对密山油田3口井进行了增产改造，取得了良好的效果。由于非压裂地层，大液量深穿透酸化仍属于基质酸化。这样就不需要钻机，节约了成本。介绍了延长油田首次应用低地层能量井和低污染井的增产新方法。

关键词：延长油;大液量;向酸系统;酸化

中图分类号：TQ127.1+3;TE357.2 文献标识码：A 文章编号：1001-5922（2021）06-0012-05

Abstract：Matrix acidification is widely used in the deblocking of carbonate reservoirs. In 2017， more than 70 substrate stimulation operations were carried out in Yanchang Oilfield. However， for low productivity wells that have no serious damage and are affected by the reduction of formation energy， the role of conventional matrix is limited. For this reason， a new acidification technology has been developed， namely deep penetration acidification with large liquid volume. Gelling acid has been widely used for its economic benefits， and its rheological properties have been tested. During the injection process， optimize the injection rate and select a large amount of acid to form long-lasting pores in the formation， reduce oil and gas seepage resistance， connect deep oil and gas reservoirs， and increase production. 3 wells in Mishan Oilfield were modified to increase production by applying this technology， and good results were achieved. Due to the non-fracturing formation， deep penetration acidification with large liquid volume still belongs to matrix acidification. This eliminates the need for drilling rigs and saves costs. This paper introduces the first application of low formation energy wells and new production stimulation methods for low pollution wells in Yanchang Oilfield.

Key words：Yanchang oil; large liquid volume; acidification system; acidification

0 引言

延長油田集团位于我国陕西省西安市。成立于1905年，它由子长、余家坪、 姚店、丰富川、川口、子北、志丹、蟠龙等油田组成。下辖延安炼油厂、永坪炼油厂、榆林炼油厂等多个大中型炼化厂，是我国西北地区重要的国有大型油气田勘探与开采企业。近年来，酸化和有机物驱油是密山油田增产的主要手段。随着油田开发的不断深入，含水率上升，油井产量相应下降。而常规酸化不能有效提高产量。

以川口油田为例，川口油田为石灰岩储层，埋深3800～4000m，储层温度112～117℃，酸化存在酸岩反应速度快、腐蚀严重、酸液漏失大等问题，限制了酸化的处理范围和有效的空洞，从而限制了酸化效果。……