东海表层沉积物间隙水、可溶铁和△C油气化探指标的初步研究

PRELIMINARY STUDY OF INTERSTITIAL WATER,DISSOIVED IRON AND △C IN SURFACE SEDIMENTS AS CRITERIA FOR OIL AND GAS GEOCHEMICAL PROSPECTATION IN THE EAST CHINA SEA

东海表层沉积物中能反映东海油气藏异常的气、液、固相物质成分和物理化学参数可作为东海油气化探指标。本文讨论了东海表层沉积物间隙水、可溶铁和△C的油气化探指标。表层沉积物间隙水可作为海洋油气化探液态烃的样品源。根据油气藏顶部氧化还原环境的异常,圈出东海陆架盆地古滨海砂可溶铁Fe^(3+)/Fe^(2+)<1分布区作为油气远景区,提出了东海陆架盆地找油的新领域。△C是用无机组分反映油气富集的一种化探方法。东海陆架沉积物与△C有关的碳酸盐矿物主要是菱铁矿。

Material components and physiochemical parameters in gas, liquid and solid phases of surface sediments, which reflect anomaly of oil and gas reservoirs can be considered as criteria for oil and gas prospectation in the East China Sea. The interstitial water in surface sediments is taken to be the sample source of liquid hydrocarbon for offshore oil and gas geochemical prospectation. According to the anomaly of oxidation-reduction enviro- nment on the top oil and gas reservoirs, the area of dissolved iron Fe^(3+)/ Fe^(2+)< 1 in ancient littoral sand of continental basin in the East China Sea is delimitated as prospect area for oil and gas reservoirs. △C is a geochemical prospecting method using inorganic constituents to reflect abundance of oil and gas. The main carbonate mineral related to △C in the sediment of the continental shelf in the East China Sea is siderite.