古地理学报2009，Vol.11Issue(5)：551-560,10.
济阳坳陷沾化凹陷古近系水化学场对湖盆演化的响应及其油气意义
Response of formation water chemical fields to evolution of lacustrine basin of the Paleogene in Zhanhua Sag of Jiyang Depression and its hydrocarbon significance
摘要
Abstract
On the basis of calculation and analyses of 1160 testing data including salinity, formation water types, content of ions and physical properties of crude oil, the Paleogene formation water chemical field in Zhanhua Sag was investigated.The results show that the formation water chemical field has a good response to the evolution of lacustrine basin, the average salinity and content of ions decreased with the lake level deepening and desalinating from the initial faulted stage to the peak stage of fault development(the Member 4 to Member 3 of Shahejie Formation);The average salinity and content of ions increased with lake level shoaling in lake basin withering period(the Member 2 of Shahejie Formation to the Dongying Formation).Typical characteristics of an opening faulted lacustrine basin were displayed by the low content of total salinity and ions(total salinity averaged by 10 g/L), NaHCO_3 formation water being the dominant type(with a proportion of 80%), and the high values of r_(Na+)/r_(Cl-)and[r_(HCO_(3~-)+r_(CO_3~2-)]/rCl-(the average values respectively higher than 1.0 and 50), which indicated the stronger metamorphic process and alternation of the formation water.Influenced by the opening formation water chemical fields, the viscous crude oil was widespread and the widespread secondary heavy crude oil was the result of water-flush, oxidization and biodegradation in the course of oil migration, accumulation and preservation in opening formation water chemical fields.The samples with NaHCO_3 type were mainly distributed in the formation water with a lower salinity(<15 g/L), which indicated the opening hydrogeology and unfavorable preservation conditions for hydrocarbon.The formation water of NaHCO_3 type with a higher salinity(>15 g/L)was mainly distributed in the Bonan subsag and the Yidong faulted zone.Its origin was relative with oil and gas fields and a high content of CO_2 from mantle by the connection of faults, and correspondingly the density of crude oil was lower than 0.9 g/mL generally, which indicated favorable conditions for hydrocarbon preservation.关键词
浏阳坳陷/沾化凹陷/古近系/湖盆演化/断陷湖盆/水化学场响应/矿化度与水型Key words
Jiyang Depression/Zhanhua Sag/Paleogene/evolution of lacustrine basin/ faulted lacustrine basin/ response of formation water chemical fields/ salinity and water types分类
天文与地球科学引用本文复制引用
陈中红,王黎,杨勇,查明..济阳坳陷沾化凹陷古近系水化学场对湖盆演化的响应及其油气意义[J].古地理学报,2009,11(5):551-560,10.基金项目
国家自然科学基金(编号:40802026)和山东省自然科学基金(编号:Q2007 E04)联合资助 （编号:40802026）
