天环坳陷南北部盒8段地层水地化特征差异性分析
Analysis on Geochemical Characteristics and Difference of Formation Water in He 8th Member in Northern and Southern Tianhuan Depression
吴颖 1孙磊 2冯敏 2李爱荣 1卢达1
作者信息
- 1. 西安石油大学 地球科学与工程学院,陕西 西安 710065;西安石油大学 陕西省油气成藏地质学重点实验室,陕西 西安 710065
- 2. 长庆油田公司勘探开发研究院,陕西 西安 710018
- 折叠
摘要
通过对鄂尔多斯盆地天环坳陷中二叠统下石盒子组盒 8段地层水样品测试结果的统计分析,分别对区内南北部的地球化学特征进行研究,对比其差异性,分析天然气运聚和保存条件,为勘探部署提供支持.研究显示,天环坳陷中二叠统下石盒子组盒 8段为偏酸性、氯化钙型地层水,区内矿化度、Cl-含量和浓度都显示为北高南低,反映了北部铁克苏庙地区地层水封闭条件优于南部青石峁-李庄子区域,更有利于气藏的聚集和保存.南北部地层水地化特征参数与气藏形成条件有较好的对应性.北部地区为Ⅳ型、Ⅴ型原始地层水,地层水的钠氯系数低、脱硫系数低、钠钙系数低、变质系数高,具有油气伴生水的特征,地层封闭性较好,利于气藏的聚集和保存;而南部地区为Ⅱ型、Ⅲ型、Ⅳ型地层水,显示较差的封闭条件,地层水与外界有沟通,不利于气藏的运聚和保存.
Abstract
Based on the statistics and analysis of the test results of formation water samples of He 8th Member of Tianhuan depression,Ordos basin,the geochemical characteristics of the northern and southern parts of the area are studied,and the differences were compared.The results show that the formation water of He 8th mem-ber of Tianhuan Depression is acidic and CaCl2 water type,and the mineralization degree,Cl-content and con-centration in the area are higher in the north than in the south.It reflects that the sealing condition of formation water in the Tiekesumiao area in the north is better than that in Qingshimao-Lizhuangzi area in the south,which is more conducive to the accumulation and preservation of gas reservoirs.The Geo-chemical characteris-tic parameters of formation water in the north and south have good correspondence with the formation condi-tions of the gas reservoir.The formation water in the northern area is characterized by low sodium-chloride coef-ficient,low desulfurization coefficient,low sodium-calcium coefficient and high metamorphic coefficient.The formation water is of Ⅳ-type and Ⅴ-type original formation water,which is favorable for the accumulation and preservation of gas reservoirs.In the southern area,the formation water of Ⅱ-type,Ⅲ-type and Ⅳ-type shows poor sealing conditions,and the formation water communicates with the outside world,which is not conducive to the accumulation and preservation of gas reservoirs.
关键词
地层水/地化特征/差异性/盒8段/天环坳陷Key words
formation water/geochemical characteristics/difference/He 8th Member/Tianhuan depres-sion引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据