摘要
伊通盆地岔路河储层有效孔隙度8.4%~14.7%,渗透率0.3~8.9 m D,属于低孔低渗储层,压裂过程中易出现异常现象。分析认为储层存在砂泥交互特征,坚硬、致密及钻井过程中泥浆滤失等原因造成储层伤害,导致压裂出现异常压力高、压不开、加砂困难等问题。针对储层岩性及污染特征,优选高强度复合酸液体系及添加剂,酸液体系对储层岩样溶蚀率大于40%,钻井泥浆溶蚀率大于28%,通过酸化改造可以使砂岩微观孔隙结构发生改变,增加储层的渗透性,有效降低储层压裂压力。现场优选1口井开展先导性试验,酸化处理后压裂施工压力下降20%,顺利完成压裂施工,为后续区块开发提供技术保障。
Chaluhe reservoir of Yitong Basin is a low-porosity and-permeability one with effective porosity of 8.4% ~14.7% and permeability of 0.3 ~8.9 m D. Some abnormality often appears during its fracturing. The reservoir characteristics of sandstone interbedded with mudstone,hardness, and densification, combining with formation damage caused by slurry filtration, all can lead to some problems including abnormally high pressure, fracturing failure, and sand adding difficulty. So, according to lithology and pollution characteristics, a high-strength compound acid-fluid system and additives are optimized. The corrosion ratio of this acid-fluid system to both rock samples and drilling slurry is higher than 40% and 28%, respectively. Acidizing reconstruction can change micropore structure of sandstone, increase permeability, and reduce effectively fracturing pressure. A pilot test was carried out. As a result, fracturing pressure fell by 20% after acidification. This study provides technical guarantee for further development.
出处
《天然气勘探与开发》
2016年第1期60-62,14,共3页
Natural Gas Exploration and Development
关键词
压裂异常
破裂压力
酸化
现场应用
abnormal fracturing
fracture pressure
acidification
field application
