摘要
为了进一步认识污水回注对大牛地气田储层岩石性质的影响,明确影响回注液进入回注层岩石能力的主要因素,参照现行储层岩石敏感性评价实验行业标准,完成了大牛地气田两个回注层致密岩心的敏感性实验与固相损害实验。基于微观实验发现上石盒子组回注层岩心较为致密,表现出弱速敏、中等碱敏、无酸敏与弱水敏特性;而延长组回注层岩心发育溶蚀孔和粒间孔,表现出弱速敏、中等碱敏、强酸敏与中等水敏特性,原因在于胶结的黏土矿物不一样,前者以伊利石为主,而后者以伊/蒙混层为主。此外,两个回注层岩心都表现出较强的固相损害程度,这与环境扫描电镜下观察发现的岩心在污水作用过程中出现了微粒堵塞现象一致,建议实施污水回注时控制固相悬浮物。研究成果为大牛地气田矿场污水有效回注提供了重要的依据。
In order to further study the influence of wastewater reinjection on the rock properties,the sensitivity evaluation experiments and solid-phase damage experiment of tight sandstone samples,drilled from two rejection layer in Daniudi gas field,are carried out,which helps us have an insight into the main factors affecting the reinjection fluid to enter the reinjection layer rock.The results show that the sandstone samples in the Upper Shihezi formation behave week velocity sensitivity,medium Alkali sensitivity,no acid sensitivity and week water sensitivity,the sandstone samples in Yanchang formation indicate also week velocity sensitivity and medium Alkali sensitivity,but strong acid sensitivity and medium water sensitivity,the reason is that the cemented clay minerals in the two layers are different—mainly illite in the former and I/S mixed layer in latter.At the same time,the sandstone samples in the two rejection layers demonstrate strong solid-phase damage,which agrees with the observed results under SEM that the solid particles blocked the intercrystalline micro-pores and dissolved pores of the rock,indicating that the solid phase must be removed when the reinjection fluid is reinjected into our rock formations.This study provides a theoretical basis for reinjecting effectively wastewater in Daniudi gas field.
作者
刘绪钢
周涌沂
张骏强
肖文联
LIU Xugang;ZHOU Yongyi;ZHANG Junqiang;XIAO Wenlian(North China Oil and Gas Branch,Zhengzhou,Henan 450006,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China)
出处
《钻采工艺》
CAS
北大核心
2020年第6期100-102,127,I0007,共5页
Drilling & Production Technology
基金
国家自然科学基金“致密砂岩气藏岩石非线性有效应力耦合机制研究”(编号:5187042106)
西南石油大学非常规油气渗流物理青年科技创新团队(编号:2018CXTD10)。
关键词
致密砂岩
污水
回注
渗透率损害
tight sandstone
wastewater
reinjection
permeability damage
