低渗透砂岩储层分步溶离酸化改造及实施效果 ———以临南洼陷夏463 井为例

低渗透砂岩储层经工艺改造后,各井储层产能差异明显,关键在于没有根据储层本身特性制定有效的改造方案。利用岩石薄片、铸体薄片、X-衍射分析和矿物溶蚀实验等技术,对低渗透砂岩储层进行测试分析,准确把握储层岩石矿物特征,制定针对性强的分步溶离改造方案,形成了低渗透砂岩储层分步溶离酸化改造技术。以临南洼陷夏463井低渗透砂岩储层为例,阐述了酸化施工前低渗透储层所须进行的微观分析流程,在分析储层微观特征和溶离实验结果的基础上,制定了低渗透储层酸化施工方案,并且进行了现场跟踪。夏463井2918.1～2923.0m井段致密砂岩储层于2010年11月初酸化改造后,产油量为6.97m3/d,连续开采1a多,产油量仍达2～4t/d。现场施工证实,将岩石学基础研究与现场工艺成功对接,不但对提高低渗透砂岩储层的稳产能力具有重要的意义,而且对于控制后期含水率上升也具有极好的指导意义。

Acidification technology and implementation of substep elutriation for low permeability reservoir-case of Xia 463 well in Linnan depression

After stimulation,different well achieves different productivity for the low permeability sandstone reservoir.The key is that the stimulation scheme is not formulated based on the reservoir characteristics.Using the rock sections,cast sections,X diffraction analysis and mineral dissolution experiment techniques,we can accurately understand the characteristics of reservoir rock minerals,and then formulating the corresponding acidification techniques of sub-step elutriation.Using this technique for the low permeability reservoir of Xia 463 well herein,the microcosmic test content and methods for low permeability reservoir are discussed on how to correctly formulate process of acidification technique,as well as the field surveillance.Acidification scheme is proved successful by field operation.It is proved that this technique is not only important for production maintenance,but also for the control of water saturation in low permeability reservoir over a long period of time.